(600g) Controlled Release of Growth Factors for Bone Regeneration from Two-Phase Hydrogel Systems
AIChE Annual Meeting
Thursday, November 17, 2022 - 9:30am to 9:45am
Copolymeric nanoparticles containing methacrylic acid and methyl methacrylate and crosslinked with varying densities of tertraethylene glycol dimethacrylate were synthesized using an aqueous, one-pot UV-initiated emulsion polymerization. Nanoparticle composition was confirmed using Fourier-transform infrared spectroscopy and methacrylic acid incorporation was confirmed using potentiometric titration. Nanoparticle swelling studies was performed using dynamic light scattering and particle zeta potential was analyzed using electrophoretic light scattering. Bioactive agent delivery capacity was studied using a-chymotrypsin as a model protein for bone morphogenetic protein-2, a widely studied growth factor for bone regeneration. Nanoparticles with increased methacrylic acid content were able to achieve higher loading efficiencies up to 90%. After loading the nanoparticles with model proteins by equilibrium partitioning, nanoparticles were covalently attached to 2 wt% chitosan hydrogels via carbodiimide chemistry. Protein loading and release was quantified using microBCA assay. By increasing crosslinking density and methacrylic acid content in the nanoparticles, the burst release of model protein was reduced from 60% to 5% in the first 24 hours. In addition, covalent binding of nanoparticles to chitosan scaffolds improved protein retention within the scaffold over 4 weeks. The results of this work suggest that growth factor delivery can be tuned through nanoparticle properties and that the synthesized dual network system shows promise for sustained growth factor delivery by reducing burst release effects
Acknowledgements: The work was supported in part by National Institutes of Health Grant R01-EB022025 and the Cockrell Family Regents Chair in Engineering. M.S. was supported by an NSF GRFP.