Synthesis and characterization of biodegradable interpenetrating polymer networks based on gelatin and divinyl ester synthesized from poly(caprolactone diol)

Abstract

This article describes the synthesis and characterization of interpenetrating polymer networks (IPNs) from hydrophilic and hydrophobic polymers using emulsification technique. Tween 20 (0.001 wt % of gelatin) was employed as emulsifier for the preparation of semi and full IPNs. Gelatin (G), a hydrophilic component was crosslinked by glutaraldehyde (Glu) and divinyl ester (DVE), a hydrophobic component was polymerized/crosslinked using 3 mol % of AIBN as an initiator. Structural characterization was done using FTIR (doublet at 1620 and 1636 cm À1 ) and NMR (signals in the range of d ¼ 5-7 ppm), which confirmed the formation of DVE. Several samples were prepared by varying the ratio of gelatin : DVE (w/w) and the Glu concentration. The swelling characteristics (as a function of varying pH maintained using buffers) and degradation behavior (in phosphate buffer saline pH 7.4) of hydrogels was studied to investigate the effect of composition and crosslinker concentration. Percent water uptake decreased from 496 to 181 at pH 7.4 and pH 6.5 in IPNs as the concentration of DVE increased from 0.3 g to 0.7 g per g of gelatin. Semi-IPNs, where DVE was not polymerized, demonstrated higher swelling at pH 7.4 in contrast to pH 6.5 irrespective of Glu concentration. Gelatin hydrogels degraded within 180 h and IPNs degraded within 290 h whereas DVE did not degrade till the study period of 20 days. The formation of IPN was confirmed by thermal characterization (DSC, TGA) and scanning electron microscopy (SEM). Observation of cross-sectional microstructure of disrupted honeycomb of Gx into closely packed fiber-like structure upon interpenetration by SEM clearly suggests the formation of IPN.

Evaluation of the chondrogenic differentiation of mesenchymal stem cells on hybrid biomimetic scaffolds

“…On the other hand, in crosslinked scaffolds, cleavage of the chemical crosslinkers (degradation) and then dissolution led to erosion. Because degradation is slower than dissolution, the erosion of the scaffolds decreased after crosslinking …”

Assessment of multicomponent hydrogel scaffolds of poly(acrylic acid-2-hydroxy ethyl methacrylate)/gelatin for tissue engineering applications

“…In-vitro weight loss profile of the hydrogels was studied by measuring the change in weight as a function of time. 7,13 Dry hydrogel discs (approximately 10 mg) were dipped into 5 mL of PBS (pH 6.5, 0.2 M, sodium azide 0.04% w/v) at 37°C. The media was changed every day.…”

“…These factors ultimately affect swelling, degradation, compression, and other important properties of the matrices. 7,11–13 In spite of many favorable properties, hydrogels are devoid of mechanical strength, which limits their biomedical and pharmaceutical applications. Various research schools improved the mechanical strength and elasticity by formulating interpenetrating polymeric network (IPNs) matrices and by incorporating nanocomposite materials.…”

Cell adhesion and proliferation studies on semi‐interpenetrating polymeric networks (semi‐IPNs) of polyacrylamide and gelatin

“…18,21 Semi-IPNs of PAm/G using PCL-DAr as a cross-linker were prepared by thermal initiated redox polymerization technique using APS and TEMED as reaction accelerators.…”