Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy
One-pot free-radical polymerization of <i>N</i>-acryloyl glycinamide in the presence of hyaluronic acid as transfer-termination agent led to new copolymers in high yields without any chemical activation of hyaluronic acid before. All the copolymers formed thermoresponsive hydrogels of th...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Gels |
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| Online Access: | https://www.mdpi.com/2310-2861/6/4/42 |
| _version_ | 1827701669466472448 |
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| author | Mahfoud Boustta Michel Vert |
| author_facet | Mahfoud Boustta Michel Vert |
| author_sort | Mahfoud Boustta |
| collection | DOAJ |
| description | One-pot free-radical polymerization of <i>N</i>-acryloyl glycinamide in the presence of hyaluronic acid as transfer-termination agent led to new copolymers in high yields without any chemical activation of hyaluronic acid before. All the copolymers formed thermoresponsive hydrogels of the Upper Critical Solution Temperature-type in aqueous media. Gel properties and the temperature of the reversible gel ↔ sol transition depended on feed composition and copolymer concentration. Comparison with mixtures of hyaluronic acid-poly(<i>N</i>-acryloyl glycinamide) failed in showing the expected formation of graft copolymers conclusively because poly(<i>N-</i>acryloyl glycinamide) homopolymers are also thermoresponsive. Grafting and formation of comb-like copolymers were proved after degradation of inter-graft hyaluronic acid segments by hyaluronidase. Enzymatic degradation yielded poly(<i>N-</i>acryloyl glycinamide) with sugar residues end groups as shown by NMR. In agreement with the radical transfer mechanism, the molar mass of these released poly(<i>N-</i>acryloyl glycinamide) grafts depended on the feed composition. The higher the proportion of hyaluronic acid in the feed, the lower the molar mass of poly(<i>N-</i>acryloyl glycinamide) grafts was. Whether molar mass can be made low enough to allow kidney filtration remains to be proved in vivo. Last but not least, Prednisolone was used as model drug to show the ability of the new enzymatically degradable hydrogels to sustain progressive delivery for rather long periods of time in vitro. |
| first_indexed | 2024-03-10T14:38:38Z |
| format | Article |
| id | doaj.art-25b2d7570e8d40c1a1b38fa743106b75 |
| institution | Directory Open Access Journal |
| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-10T14:38:38Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Gels |
| spelling | doaj.art-25b2d7570e8d40c1a1b38fa743106b752023-11-20T21:55:44ZengMDPI AGGels2310-28612020-11-01644210.3390/gels6040042Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for TherapyMahfoud Boustta0Michel Vert1Institute for Biomolecules Max Mousseron, UMR CNRS 5247, Faculty of Pharmacy, University of Montpellier-CNRS-ENSCM, 15 Avenue Charles Flahault, BP 14491, CEDEX 5, 34093 Montpellier, FranceInstitute for Biomolecules Max Mousseron, UMR CNRS 5247, Faculty of Pharmacy, University of Montpellier-CNRS-ENSCM, 15 Avenue Charles Flahault, BP 14491, CEDEX 5, 34093 Montpellier, FranceOne-pot free-radical polymerization of <i>N</i>-acryloyl glycinamide in the presence of hyaluronic acid as transfer-termination agent led to new copolymers in high yields without any chemical activation of hyaluronic acid before. All the copolymers formed thermoresponsive hydrogels of the Upper Critical Solution Temperature-type in aqueous media. Gel properties and the temperature of the reversible gel ↔ sol transition depended on feed composition and copolymer concentration. Comparison with mixtures of hyaluronic acid-poly(<i>N</i>-acryloyl glycinamide) failed in showing the expected formation of graft copolymers conclusively because poly(<i>N-</i>acryloyl glycinamide) homopolymers are also thermoresponsive. Grafting and formation of comb-like copolymers were proved after degradation of inter-graft hyaluronic acid segments by hyaluronidase. Enzymatic degradation yielded poly(<i>N-</i>acryloyl glycinamide) with sugar residues end groups as shown by NMR. In agreement with the radical transfer mechanism, the molar mass of these released poly(<i>N-</i>acryloyl glycinamide) grafts depended on the feed composition. The higher the proportion of hyaluronic acid in the feed, the lower the molar mass of poly(<i>N-</i>acryloyl glycinamide) grafts was. Whether molar mass can be made low enough to allow kidney filtration remains to be proved in vivo. Last but not least, Prednisolone was used as model drug to show the ability of the new enzymatically degradable hydrogels to sustain progressive delivery for rather long periods of time in vitro.https://www.mdpi.com/2310-2861/6/4/42thermoresponsive hydrogelUCST-type thermal transitionhyaluronic acidpoly(<i>N-</i>acryloyl glycinamide)hyaluronidaseenzymatic degradation |
| spellingShingle | Mahfoud Boustta Michel Vert Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy Gels thermoresponsive hydrogel UCST-type thermal transition hyaluronic acid poly(<i>N-</i>acryloyl glycinamide) hyaluronidase enzymatic degradation |
| title | Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy |
| title_full | Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy |
| title_fullStr | Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy |
| title_full_unstemmed | Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy |
| title_short | Hyaluronic Acid-Poly(<i>N</i>-acryloyl glycinamide) Copolymers as Sources of Degradable Thermoresponsive Hydrogels for Therapy |
| title_sort | hyaluronic acid poly i n i acryloyl glycinamide copolymers as sources of degradable thermoresponsive hydrogels for therapy |
| topic | thermoresponsive hydrogel UCST-type thermal transition hyaluronic acid poly(<i>N-</i>acryloyl glycinamide) hyaluronidase enzymatic degradation |
| url | https://www.mdpi.com/2310-2861/6/4/42 |
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