Biodegradable and Photopolymerizable Hydrogels for Tissue Engineering Application Based on Poly(Ethylene Glycol) and Diacid Monomers
Jinku Kim1, Kee-Won Lee2, Bradford L. Currier1, Lichun Lu1, and Michael J. Yaszemski1. (1) Orthopedic Surgery and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, (2) Biomedical Engineering, Mayo Clinic, Rochester, MN 55905
We have developed a new family of photopolymerizable and biodegradable hydrogels based on poly (ethylene glycol) (PEG) and various diacid monomers. Their synthesis and post synthesis processing are straightforward. By introducing different hydrophobic segments (dicarboxylic acids) into the hydrogel main chain, these macromers degrade by hydrolysis of ester linkage into PEG, dicarboxylic acids and oligo(arylic acid) which are known to be biocompatible. These hydrogels also exhibited substantially higher mechanical strength and relatively low swelling ratios compared to conventional PEG based hydrogels such as PEG diacrylates. In addition, these materials can take advantage of such photopolymerization properties like spatial and temporal control of polymerization. In vitro cell viability study with bone marrow stromal cells (BMSC) shows that these macromers are non-cytotoxic compared to tissue culture polystyrene. Furthermore, the hydrogels modified with cell adhesion peptides, Arg-Gly-Asp (RGD) significantly enhance the cell attachment after 24 h and can induce cell proliferation and differentiation. We also fabricated 3D porous structure with these hydrogels by using solid free form (SFF) techniques such as 3D printing. Overall, these novel biomaterials are expected to be useful for drug delivery systems and/or tissue engineering applications.