Gelatin Based Hydrogels for Tissue Engineering and Drug Delivery Applications

Abstract

Gelatin is one of the most popular natural polymers which is widely used in food, pharmaceutical, biomedical and cosmetic industries. The gelatin has been prepared from different sources such as porcine skin, cattle bone, and fish, etc. Depending on the type of acidic and alkali extraction processes the type of gelatin A and B were obtained. This chapter provides a comprehensive overview of preparation of gelatin base hydrogel. Furthermore, we evaluate their method of crosslinking through Schift-base, Mischeal-addition-based, light, UV, chemical, and physical crosslinking. Moreover, due to the unique properties of gelatin they have the ability to immobilize cells and can be applied for stem cell and drug delivery in biomedical applications.

Versatile Potential of Photo-Cross-Linkable Silk Fibroin: Roadmap from Chemical Processing Toward Regenerative Medicine and Biofabrication Applications

“…MA and GMA are both proposed to react with the primary amines of SF that constitute around 0.2% of its total amino acid content. , Among typical reactive amino acids, the primary amino acid groups are lysine 0.2%, arginine 0.3%, asparagine 0.4%, and glutamine 0.2%, with lysine being the predominant amino acid participating in MA and GMA reactions. GMA is also capable of reacting with carboxyl and hydroxyl groups which are present in SF. ,,, Based on a recent report, GMA can react with carboxyl and hydroxyl groups either via transesterification or opening of the epoxide ring. , The SF heavy chain contains a higher molar ratio of hydroxyl and carboxyl groups, approximately 19.4%, and a lower molar ratio of primary amine groups (lysine 0.2%). As a result, methacryloyl substitution on the carboxyl and hydroxyl groups may lead to an increase in cross-linkable sites in SF, meaning an increase in photo-cross-linking density, which can be reflected in the final mechanical properties of the formed hydrogels.…”

“…Another substance that has recently received a lot of attention for the functionalization of SF is GMA. ,, In this method SFMA is synthesized by reacting SF with GMA in lithium bromide with a concentration of 9.3 M at 60–65 °C for 1–4 h under vigorous stirring conditions (Figure A). ,− The degree of methacrylation will be dependent on the primary amine on lysine and will occur through the ring-opening of epoxy at GMA . However, based on the recent report, GMA can also react with other groups, such as carboxyl and hydroxyl, either via transesterification or the opening of the epoxide ring.…”

“…In recent years various types of hydrogels based on natural and synthetic polymers were employing multiple different cross-linking mechanisms. − It has been shown that the appropriate choice of chemical cross-linking approach leads to the generation of hydrogel networks with properties tailored to the desired clinical or tissue engineering application. − Among all types of hydrogels, peptide- and protein-based hydrogels have been widely studied as biocompatible matrices for numerous biomedical applications. ,− These molecules typically form safe and effective biomaterials due to their ability to form stable networks under mild conditions, their excellent intrinsic biocompatibility, as well as tunable biochemical and biophysical properties. ,,,− Their physical and biochemical properties depend on the composition, the polymerization method, and the type and degree of cross-linking . The utilization of cross-linking approaches has led to the development of many applications for these hydrogels in biomedical science, especially in designing injectable cell and drug cargo vehicles. ,, Moreover, they have become an integral part of 3D culture research to investigate the cellular proliferation and migration as well as interactions between encapsulated cells (cell–cell) and cells with the matrix (cell–material). , Since they mimic the structure and characteristics of extracellular matrix (ECM), they appear as ideal mimicking biomaterials for many biomedical applications. ,,,, …”

“… 4 − 6 Among all types of hydrogels, peptide- and protein-based hydrogels have been widely studied as biocompatible matrices for numerous biomedical applications. 2 , 7 − 12 These molecules typically form safe and effective biomaterials due to their ability to form stable networks under mild conditions, their excellent intrinsic biocompatibility, as well as tunable biochemical and biophysical properties. 1 , 2 , 5 , 8 − 12 Their physical and biochemical properties depend on the composition, the polymerization method, and the type and degree of cross-linking.…”

“… 2 , 7 − 12 These molecules typically form safe and effective biomaterials due to their ability to form stable networks under mild conditions, their excellent intrinsic biocompatibility, as well as tunable biochemical and biophysical properties. 1 , 2 , 5 , 8 − 12 Their physical and biochemical properties depend on the composition, the polymerization method, and the type and degree of cross-linking. 5 The utilization of cross-linking approaches has led to the development of many applications for these hydrogels in biomedical science, especially in designing injectable cell and drug cargo vehicles.…”