Covalently crosslinked hyaluronic acid‐chitosan hydrogel containing dexamethasone as an injectable scaffold for soft tissue engineering

Abstract

Injectable hybrid hydrogels were produced by mixing crosslinked aldehyde hyaluronic acid with dexamethasone grafted water soluble chitosan, without the addition of a chemical crosslinking agent. The gelation is attributed to the Schiff‐base reaction between amino and aldehyde groups of hydrogel precursors. In this article, the water soluble chitosan, N‐succinyl‐chitosan, grafted with dexamethasone via water soluble carbodiimide chemistry has been characterized. In vitro gelation time, morphologies, swelling, weight loss, and compressive modulus of hybrid hydrogels in phosphate buffered saline were studied. The dexamethasone grafted hydrogel showed a slightly lower gelation time, higher water uptake and faster weight loss compared to the hydrogel without dexamethasone. Human adipose‐derived stem cells were encapsulated into the dexamethasone grafted hydrogel in vitro to assess the biological performance and applicability of the hydrogel as cell carrier. Results demonstrated that the dexamethasone grafted hydrogel resulted in enhanced cell adhesion and proliferation as compared to the hydrogel without dexamethasone. These characteristics provide a potential opportunity for the dexamethasone grafted hybrid hydrogel as an injectable scaffold in adipose tissue engineering applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

N-succinyl chitosan–dialdehyde starch hybrid hydrogels for biomedical applications

“…As seen, FTIR spectrum of N-succinyl chitosan (SCS) exhibited stretching vibration peaks of —OH and —NH 2 at 3416 cm −1 , the weak band of —CH 2 stretching at 2918 cm −1 , and the C O stretching of amide groups at 1585 cm −1 . The peak at 1402 cm −1 belongs to —COOH symmetric stretching vibration, and the peak at 1057 cm −1 for —OH groups of characteristic peak of —CH 2 OH of alcohol and C—O stretching [17] , [18] , [19] . FTIR spectrum of dialdehyde starch (DAS) exhibited dialdehyde stretching peaks at 2924 cm −1 and 1384 cm −1 , while the peak at 3435 cm −1 is due to —OH groups of unconverted soluble starch and the peak at 1055 cm −1 belongs to —OH groups (characteristic peak of —CH 2 OH in primary alcohol of glucose ring).…”

“…The degradation behavior or weight loss rate of in situ hybrid hydrogel scaffold has a critical influence on the biological long-term performance e.g. cell-adhesion construct of the injected polymer [4] , [19] . This interest stems from the importance of understanding the in vitro weight loss profile of the synthesized hybrid hydrogels.…”

“…This is owing to its appealing and intrinsic properties such as, simple solubility in different pHs without specific acidified medium need, high hydrophilicity, biocompatibility, and its antibacterial activity as existing in the pristine chitosan. SCS was previously synthesized and crosslinked with other polymers such as, hyaluronic acid, alginate [17] , [18] , [19] , lactosaminate [20] , and low-density lipoprotein for biomedical applications. Similarly, SCS was incorporated previously and covalently crosslinked with hyaluronic acid as scaffolds for soft and cartilage tissue engineering and repair [17] , [19] .…”

“…SCS was previously synthesized and crosslinked with other polymers such as, hyaluronic acid, alginate [17] , [18] , [19] , lactosaminate [20] , and low-density lipoprotein for biomedical applications. Similarly, SCS was incorporated previously and covalently crosslinked with hyaluronic acid as scaffolds for soft and cartilage tissue engineering and repair [17] , [19] . Dialdehyde starch (DAS) is a starch derivative, which is derived from the oxidation of raw starch using periodic acid or sodium periodate as oxidants to oxidize 2,3- o -dihydroxy starch into dialdehyde starch.…”

Magnetic hyaluronic acid nanospheres via aqueous Diels–Alder chemistry to deliver dexamethasone for adipose tissue engineering

“…The establishment of vectoring delivery systems is necessary for ensuring Dex target the defect sites in the use of nanospheres. Although some microspheres and nanospheres have been served as delivery systems, conventional delivery methods are limited by the intrinsic inability to translate Dex into soft tissue engineering due to the un-controlled release [16][17][18]. Dex that is covalently immobilized into carriers can be more efficiently transported to a localized site and be released in a sustained-dosage form.…”