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At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F7","text":"The shares are held for LS, the child of the reporting person, through a custodial account established pursuant to the Uniform Transfer to Minors Act (\"UTMA\") for which the reporting person serves as custodian."}],"balance_after":0,"derivative":{"underlying":"Common  Stock","underlying_shares":94568},"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":13,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543723,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":false,"shares":436.066,"ownership":{"direct":false,"nature":"by spouse"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). 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At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. 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At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person's spouse is a trustee of this trust."}],"balance_after":0,"derivative":{"underlying":"Common  Stock","underlying_shares":7005},"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":11,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543721,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":false,"shares":1672.389,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person is a trustee of this trust."}],"balance_after":0,"derivative":{"underlying":"Common  Stock","underlying_shares":55746},"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":10,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543720,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":false,"shares":11316.263,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Shares are held in a trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of this trust."}],"balance_after":0,"derivative":{"underlying":"Common  Stock","underlying_shares":377208},"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":9,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543719,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":false,"shares":3304.559,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"derivative.underlying_shares","element":"underlyingSecurityShares","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."}],"balance_after":0,"derivative":{"underlying":"Common  Stock","underlying_shares":110151},"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543718,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":94568,"ownership":{"direct":false,"nature":"as custodian"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F8","text":"The shares are held for SS, the child of the reporting person, through a custodial account established pursuant to the UTMA for which the reporting person serves as custodian."}],"balance_after":96219,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543717,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":94568,"ownership":{"direct":false,"nature":"as custodian"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F7","text":"The shares are held for LS, the child of the reporting person, through a custodial account established pursuant to the Uniform Transfer to Minors Act (\"UTMA\") for which the reporting person serves as custodian."}],"balance_after":96219,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543716,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":14535,"ownership":{"direct":false,"nature":"by spouse"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F6","text":"Shares are held by the reporting person's spouse."}],"balance_after":14788,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543715,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":7005,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person's spouse is a trustee of this trust."}],"balance_after":7127,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543714,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":55746,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person is a trustee of this trust."}],"balance_after":56719,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543713,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":377208,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Shares are held in a trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of this trust."}],"balance_after":383796,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1543712,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common  Stock","published_at":"2024-04-11T01:47:15.000Z","date":"2024-04-08","kind":"exercise","planned":false,"acquired":true,"shares":110151,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On March 27, 2024, the issuer held a special meeting of stockholders (the \"Special Meeting\"). At the Special Meeting, the stockholders of the issuer approved a 1-for-30 reverse stock split (the \"Reverse Stock Split\") of the issuer's common stock (\"Common Stock\") and the conversion of the issuer's Series A Non-Voting Convertible Preferred Stock (\"Series A Preferred Stock\") into shares of Common Stock. On April 8, 2024, the conversion of the majority of the shares of Series A Preferred Stock occurred automatically (the \"Automatic Conversion\"). The remaining shares of Series A Preferred Stock remain subject to certain beneficial ownership limitations described in the issuer's filings with the Securities and Exchange Commission. At the time of the Automatic Conversion, all of the reporting person's shares of Series A Preferred Stock converted into shares of Common Stock."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"On April 4, 2024, the issuer effected the Reverse Stock Split. The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split."}],"balance_after":119754,"source":{"system":"sec-edgar","filing":"0001453687-24-000067","document":"wk-form4_1712800025.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000067/wk-form4_1712800025.xml","form_type":"4"}},{"id":1687680,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Convertible Preferred 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effect to such conversion."},{"field":"kind","element":"transactionCoding","label":"F10","text":"Bona fide gift to Yale University."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F9","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series A Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F9","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series A Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."}],"balance_after":3304.559,"derivative":{"underlying":"Common  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installments, so that it shall be fully vested on the third anniversary of the date of grant."}],"balance_after":228000,"derivative":{"exercise_price":0.6552,"expiration_date":"2034-01-01","underlying":"Common  Stock","underlying_shares":228000},"source":{"system":"sec-edgar","filing":"0001453687-24-000028","document":"wk-form4_1704406322.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000145368724000028/wk-form4_1704406322.xml","form_type":"4"}},{"id":1687678,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common  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Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. (the \"Company\") acquired Cartesian Therapeutics, Inc. (\"Cartesian\") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F7","text":"Shares are held by the reporting person's spouse."}],"balance_after":436.066,"derivative":{"underlying":"Common Stock","underlying_shares":436066},"source":{"system":"sec-edgar","filing":"0001062993-23-020922","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":14,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000106299323020922/form4.xml","form_type":"4"}},{"id":1740585,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2023-11-15T21:41:44.000Z","date":"2023-11-13","kind":"other","planned":false,"acquired":true,"shares":2837.052,"ownership":{"direct":false,"nature":"as custodian"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. (the \"Company\") acquired Cartesian Therapeutics, Inc. (\"Cartesian\") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F6","text":"The shares are held for SS, the child of the reporting person, through a custodial account established pursuant to the UTMA for which the reporting person serves as custodian."}],"balance_after":2837.052,"derivative":{"underlying":"Common Stock","underlying_shares":2837052},"source":{"system":"sec-edgar","filing":"0001062993-23-020922","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":13,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000106299323020922/form4.xml","form_type":"4"}},{"id":1740584,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2023-11-15T21:41:44.000Z","date":"2023-11-13","kind":"other","planned":false,"acquired":true,"shares":2837.052,"ownership":{"direct":false,"nature":"as custodian"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. (the \"Company\") acquired Cartesian Therapeutics, Inc. (\"Cartesian\") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"The shares are held for LS, the child of the reporting person, through a custodial account established pursuant to the Uniform Transfer to Minors Act (\"UTMA\") for which the reporting person serves as custodian."}],"balance_after":2837.052,"derivative":{"underlying":"Common Stock","underlying_shares":2837052},"source":{"system":"sec-edgar","filing":"0001062993-23-020922","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":12,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000106299323020922/form4.xml","form_type":"4"}},{"id":1740583,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2023-11-15T21:41:44.000Z","date":"2023-11-13","kind":"other","planned":false,"acquired":true,"shares":210.152,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. (the \"Company\") acquired Cartesian Therapeutics, Inc. (\"Cartesian\") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person's spouse is a trustee of the trust."}],"balance_after":210.152,"derivative":{"underlying":"Common Stock","underlying_shares":210152},"source":{"system":"sec-edgar","filing":"0001062993-23-020922","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":11,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000106299323020922/form4.xml","form_type":"4"}},{"id":1740582,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2023-11-15T21:41:44.000Z","date":"2023-11-13","kind":"other","planned":false,"acquired":true,"shares":1672.389,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. (the \"Company\") acquired Cartesian Therapeutics, Inc. (\"Cartesian\") in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. These securities represent merger consideration payable as a result of the closing of the merger."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Shares are held in a trust for which the reporting person is a beneficiary. The reporting person is a trustee of the trust."}],"balance_after":1672.389,"derivative":{"underlying":"Common Stock","underlying_shares":1672389},"source":{"system":"sec-edgar","filing":"0001062993-23-020922","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":10,"url":"https://www.sec.gov/Archives/edgar/data/1453687/000106299323020922/form4.xml","form_type":"4"}},{"id":1740581,"issuer":{"id":6015,"kind":"organization","name":"Cartesian Therapeutics, Inc."},"owners":[{"id":60971,"kind":"person","name":"Singer Michael","position":1,"cik":"0002000122","reported_name":"Singer Michael","relationship":{"director":true,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Series A Non-Voting Convertible Preferred Stock","published_at":"2023-11-15T21:41:44.000Z","date":"2023-11-13","kind":"other","planned":false,"acquired":true,"shares":11316.263,"ownership":{"direct":false,"nature":"by trust"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F8","text":"Following the approval by the Stockholders of the conversion of the Series A Non-Voting Convertible Preferred Stock of the Company (\"Series A Preferred Stock\") into shares of common stock of the Company (\"Common Stock\"), each share of Series A Preferred Stock will be convertible into 1,000 shares of Common Stock, subject to certain limitations, including that a holder of Series A Preferred Stock is prohibited from converting shares of Series Preferred Stock into shares of Common Stock if, as a result of such conversion, such holder, together with its affiliates, would beneficially own more than 19.9% of the total number of shares of Common Stock issued and outstanding immediately after giving effect to such conversion."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"On November 13, 2023, Selecta Biosciences, Inc. 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