Ophthalmic drug-loaded N,O-carboxymethyl chitosan hydrogels: synthesis, in vitro and in vivo evaluation

Abstract

Aim: To investigate the ability of drug-loaded N,O-carboxymethyl chitosan (CMCS) hydrogels to modulate wound healing after glaucoma filtration surgery. Methods: The drug-loaded CMCS hydrogels were in situ synthesized using genipin as the crosslinker in the presence of 5-fluorouracil (5Fu) or bevacizumab. Their structures were characterized by FTIR, ultraviolet-visible (uV-vis) spectroscopy and scanning electron microscopy (SeM). In-vitro drug release experiments and in vivo evaluation in rabbits were performed. Results: The results of FTIR, uV-vis spectroscopy and SeM analyses indicated that 5Fu was encapsulated into the CMCS hydrogels that were crosslinked by genipin. The in vitro drug release experiments showed that nearly 100% of 5Fu was released from the drug-loaded hydrogels within 8 h, but less than 20% bevacizumab was released after 53 h. The in vivo evaluation in rabbits indicated that the drugloaded CMCS hydrogels were nontoxic to the cornea and were gradually biodegraded in the eyes. Furthermore, the drug-loaded CMCS hydrogels effectively inhibited conjunctival scarring after glaucoma filtration surgery and controlled postoperative intraocular pressure (IoP). Conclusion: The drug-loaded CMCS hydrogels provide a great opportunity to increase the therapeutic efficacy of glaucoma filtration surgery.

Synthesis and characterization of polysialic acid/carboxymethyl chitosan hydrogel with potential for drug delivery

“…When PSA was combined with CMCS, the resulting hydro gel showed apparent pH sensitivity, similar to the property of chitosan and its derivatives. In contrast to other hydrogel systems [22][23][24], the PSA-CMCS hydrogel achieved a large swelling ratio under acidic conditions but not under neutral conditions. In addi tion, the physiochemical properties of the drugs to be loaded showed significant influences on the drug loading and release rates of the hydrogel.…”

Genipin-crosslinked electrospun chitosan nanofibers: Determination of crosslinking conditions and evaluation of cytocompatibility

“…The characteristic peaks of GP didn't turn out from the spectrum of the GP-crosslinked CTS nanofibers as well. These features suggest that the carboxymethyl group of GP reacted with the amino group of CTS to form a secondary amide (Mi et al, 2005;Mi, Sung, & Shyu, 2000;Yang et al, 2010). In terms of crosslinking with GTA as the crosslinker, it has been well-documented that a Schiff base reaction occurs between the CHO group of GTA and the NH 2 group of CTS, which can be often observed from 1620 to 1660 cm −1 (Knaul, Hudson, & Creber, 1999;Schiffman & Schauer, 2007a, 2007b.…”

Mollusk Glue Inspired Mucoadhesives for Biomedical Applications

“…NOCC exhibited greater biodegradability and higher mucoadhesion and increased the bioavailability of drugs for ophthalmic preparations. 20,21 Adhesion in wet conditions is challenging, but several marine organisms have evolved to excel in this. Marine and fresh water mussels secrete proteinaceous material that mediate firm attachment of the organisms to inorganic and organic objects, such as rocks, metal ship hulls, and wood structures.…”