Hyaluronic Acid Hydrogel Films

1. Hyaluronic Acid Hydrogel Films October 21, 2008 Supervising Professor Christine E. Schmidt Department of Chemical Engineering University of Texas at Austin Post-doctoral and Graduate Student Researchers Scott Zawko Department of Chemical Engineering Nathalie Guimard Department of Chemistry and Biochemistry

2. Triethylamine Water/Acetone (50/50) Synthesis of GMHA + Glycidyl Methacrylate (GM) Hyaluronic Acid (HA) GMHA The average degree of substitution of GMHA is 0.32 (i.e., 32 out of every 100 disaccharides bears a methacrylate group).

3. Photocrosslinked GMHA Hydrogels photocrosslink 365 nm UV Irgacure 2959 GMHA Hydrogel Film GMHA Bulk Hydrogels

4. Schmidt Lab Publications with GMHA Hydrogels GMHA Bulk Hydrogels 1. Chemistry and material characterization Leach, J.B. et al. 2003 Biotechnol. Bioeng. 2. Peptide functionalization Leach, J.B. et al. 2004 J. Biomed. Mater. Res. 3. Protein release Leach, J.B. et al. 2005 Biomaterials 4. Drug release Zawko, S.A. et al. (In press) J. Biomed. Mater. Res. 5. Patterned swelling Zawko, S.A. et al. (In press) Acta Biomaterialia GMHA Hydrogel Films 1. Synthesis and characterization Zawko, S.A. Dissertation, UT Austin

5. GMHA Bulk Hydrogel Biocompatibility EXPERIMENTAL: Hydrogels were subcutaneously implanted in rat and explanted at 2 weeks. The implanted hydrogels had been placed in plastic devices that allowed them to be easily located for explantation. RESULTS: Inflammation was minimal; hydrogels were partially degraded; endothelial cell infiltration into GMHA hydrogels was not statistically different from fibrin gels. Leach, J.B. et al. 2003 Biotechnol. Bioeng.

6. GMHA Bulk Hydrogel Degradation (in vitro) EXPERIMENTAL: Hydrogels were incubated in buffer with hyaluronidase. Weight loss was measured at each time point and plotted as degradation rate. RESULTS: GMHA bulk hydrogels can be solubilized by hyaluronidase. Leach, J.B. et al. 2003 Biotechnol. Bioeng.

7. GMHA Hydrogel Films are Optically Transparent

8. Triangles – left axis Squares – right axis GMHA Hydrogel Film Swelling (as a function of UV exposure and photoinitiator concentration) Zawko, S.A. Dissertation, UT Austin

9. GMHA Hydrogel Films are non-cell adhesive 500 mm EXPERIMENTAL: GMHA Hydrogel films were incubated in DMEM with 10% fetal bovine serum for 24 hours. Then primary human dermal fibroblasts were seeded on the films. Films were treated with calcein and examined for cell adhesion after 24 hour culture. RESULTS: Almost no cells adhered to the GMHA hydrogel film. The few cells that adhered were not spread. In contrast, many spread cells were found adhered to the positive control, tissue culture polystyrene. Zawko, S.A. Dissertation, UT Austin