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Preparation of thermo-responsive and injectable hydrogels based on hyaluronic acid and poly( N -isopropylacrylamide) and their drug release behaviors

Preparation of thermo-responsive and injectable hydrogels based on hyaluronic acid and poly( N... Abstract Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30∼33°C. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA (M w =6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA (M w = 13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35°C, thus allowing the gels to maintain their shape for 24 h afterin vivo administration. From thein vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png "Macromolecular Research" Springer Journals

Preparation of thermo-responsive and injectable hydrogels based on hyaluronic acid and poly( N -isopropylacrylamide) and their drug release behaviors

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References (33)

Publisher
Springer Journals
Copyright
2006 The Polymer Society of Korea and Springer
ISSN
1598-5032
eISSN
2092-7673
DOI
10.1007/BF03219073
Publisher site
See Article on Publisher Site

Abstract

Abstract Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30∼33°C. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA (M w =6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA (M w = 13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35°C, thus allowing the gels to maintain their shape for 24 h afterin vivo administration. From thein vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h.

Journal

"Macromolecular Research" – Springer Journals

Published: Feb 1, 2006

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