Synthesis and characterization of photocrosslinkable gelatin and silk fibroin interpenetrating polymer network hydrogels

Abstract

To effectively repair or replace damaged tissues, it is necessary to design scaffolds with tunable structural and biomechanical properties that closely mimic the host tissue. In this paper, we describe a newly synthesized photocrosslinkable interpenetrating polymer network (IPN) hydrogel based on gelatin methacrylate (GelMA) and silk fibroin (SF) formed by sequential polymerization, which possesses tunable structural and biological properties. Experimental results revealed that IPNs, where both the GelMA and SF were independently crosslinked in interpenetrating networks, demonstrated a lower swelling ratio, higher compressive modulus and lower degradation rate as compared to the GelMA and semi-IPN hydrogels, where only GelMA was crosslinked. These differences were likely caused by a higher degree of overall crosslinking due to the presence of crystallized SF in the IPN hydrogels. NIH-3T3 fibroblasts readily attached to, spread, and proliferated on the surface of IPN hydrogels as demonstrated by F-actin staining and analysis of mitochondrial activity (MTT). In addition, photolithography combined with lyophilization techniques was used to fabricate 3D micropatterned and porous micro-scaffolds from GelMA-SF IPN hydrogels, furthering their versatility for use in various microscale tissue engineering applications. Overall, this study introduces a class of photocrosslinkable, mechanically robust and tunable IPN hydrogels that could be useful for various tissue engineering and regenerative medicine applications.

Photochemical Production of Interpenetrating Polymer Networks; Simultaneous Initiation of Radical and Cationic Polymerization Reactions

“…Hydrogels have received a considerable attention for use in tissue engineering scaffolds (with gelatin methacrylamide/PEG [72], silk fibroin/poly(vinyl alcohol) [73], silk fibroin/gelatin [74] or others [75]), cartilage tissue engineering (with poly (ethylene glycol)/agarose [76]), vascular tissue engineering (dextran/gelatin [77]). Mechanically enhanced properties (e.g., Young's moduli) rivaling those of natural load-bearing tissues was found in a poly (acrylic acid)/end-linked poly (ethylene glycol) crosslinked material [78].…”

Comparison of Gelation Time and Polyalcohol Effect on Hydrogels from Domestic and Wild Silk Fibroins

“…Through reviewing research articles about B. mori SF hydrogels, we found that the gelation time of SF hydrogels is excessively long unless nonphysiological treatments (such as low pH, high temperature, or additives) are considered [6,[13][14][15][16][17]. The question we want to answer is do the A. pernyi SF hydrogels have a similar problem?…”

Smart hydrogels for 3D bioprinting

“…These GelMA-SF IPN hydrogels have higher Young's modulus and are resistant to collagenase digestion. In addition, by varying GelMa and SF ratio, the IPN hydrogels' structural and biophysical properties can be tuned [81] .…”