A Novel Method for Synthesizing Hydrogels

UCLA researchers in the Department of Chemistry and Biochemistry have developed a novel and efficient method for synthesizing biocompatible hydrogels as scaffolding for tissue engineering and a vehicle for drug delivery.

Hydrogels – networks of crosslinked polymers – have received great commercial interest as materials for tissue engineering and drug delivery. The 3-D architecture of hydrogels allows for loading of therapeutic molecules or encapsulation of cells for tissue scaffolding purposes. The properties of hydrogels are largely determined by their crosslinking chemistry. For biomedical applications it is essential that the gelling reaction is biocompatible and can be formed in complex solutions near neutral pH. Methods utilized for chemically crosslinking hydrogels are fraught with limitations. Current methods require reagents which react with the encapsulated biomaterials, compromising their activity. In addition, crosslinking often involves toxic catalysts and/or byproducts that trigger immune responses and are toxic to target tissues. Thus, improved hydrogels may lead to better efficacy and safety of drug delivery and implant scaffold technology.

UCLA researchers have developed a simple and efficient method for forming biocompatible hydrogels. This novel method utilizes oxime click chemistry and provides the ability to fine tune the desired hydrogel for specific applications thereby improving the biocompatibility, safety, and specificity for therapeutic application. This technology utilizes a simple reaction that occurs quickly under mild conditions around physiological pH. Furthermore, the reaction exhibits high yield in both organic solvents and biological fluids. The reaction is inert to the cargo and uses nontoxic reagents with water as the only byproduct. These properties result in biocompatible materials that are suitable for biomedical applications.

Researchers have synthesized hydrogel material with aminooxy poly(ethylene glycol) and glutaraldehyde. The hydrogel contained mesenchymal stem cells and a cell adhesive peptide. High cell viability and proliferation of the encapsulated cells demonstrated the biocompatibility of the material. Thus, the concept has been verified.