Nitrocinnamate-Functionalized Gelatin:  Synthesis and “Smart” Hydrogel Formation via Photo-Cross-Linking

Abstract

Gelatin having p-nitrocinnamate pendant groups (Gel-NC) was prepared via an efficient one-pot synthesis, yield >87%. (1)H NMR data indicated that 1 mol of gelatin was modified with 18 +/- 6 mol of the photosensitive group. Upon exposure to low-intensity 365 nm UV light and in the absence of photoinitiators or catalysts, Gel-NC cross-linked within minutes into a gelatin-based hydrogel as monitored by UV-vis spectroscopy. The degree of swelling of this biodegradable hydrogel in aqueous solutions responded to changes in Gel-NC concentration levels, the ionic strength of the aqueous solutions, and photo-cross-linking time. Topography changes associated with phase transition resulting from "photocleavage" of the hydrogel network with 254 nm UV light were studied with AFM. Both Gel-NC and its hydrogel expressed low toxicity to human neonatal fibroblast cells. In addition, gelatin-based microgels were prepared via the photo-cross-linking of Gel-NC within inverse micelles.

Preparation and characterization of poly(ethylene glycol) crosslinked chitosan films

“…31 PEG has been widely incorporated with hydrolysable polyrotaxane, proteins, poly(a-hydroxy acids), or gelatin to form hydrogels. [32][33][34][35][36] Bhattarai et al has investigated the sol-gel transition property of PEG-grafted chitosan synthesized via an aldehyde-amine reaction. 37 Chitosan is expected to be used in various medical applications because of the biocompatibility.…”

Extended interaction of β1 integrin subunit-deficient cells (GD25) with surfaces modified with fibronectin-derived peptides: Culture optimization, adhesion and cytokine panel studies

“…1 H-NMR comparisons between the various peptides and peptide-modified gelatins demonstrated differing characteristic chemical shifts gelatin modification with PEGylated-peptides. Gelatin exhibited a broad doublet peak at 7.250 ppm, a sharp peak at 8.411 ppm, and broad, asymmetrical peaks from 0.885 to 4.803 ppm [43]. Prominent PEG peaks were present in all modified-gelatin samples at approximately 3.64 ppm [44].…”

Green chemistry for the cross-linking of photo-sensitive furan modified gelatin

“…The [π2 þπ2] cycloaddition of grafted conjugated furanic chromophores has been used in photochemistry [3] for the photopolymerization of 5-[2-(5-Methyl furylene vinylene)] furancarboxyaldehyde (MFVF) [4] and was successfully used for the design of photosensitive polymer electrolytes [5,6]. Moreover, the [π2þ π2] cycloaddition has been reported to be reversible when higher energy UV light is applied [7].…”