Simvastatin-Release Photocurable Hydrogel With Microsphere Delivery System for Improved Dental Applications

Abstract

The development of multifunctional injectable biomaterials that serve as frameworks for tissue neo-deposition and promote dentin regeneration through resident dental pulp cells represents an innovative approach in regenerative dentistry. This study presents an injectable system based on a photocrosslinkable hydrogel, functionalized with a drug release system to deliver bioactive doses of the biomineralizing drug simvastatin. Chitosan microspheres (MSCH) loaded with 2%, 5%, or 10% simvastatin (MSCHSV) were prepared and incorporated into gelatin methacryloyl (GelMA) to create a hybrid hydrogel activated by LED light. Characterizations, including Fourier transform infrared (FTIR), scanning electron microscopy (SEM), pore size, porosity, and swelling capacity, confirmed the inclusion of particles and creation of a 3D biomaterial. The inclusion of microspheres did not alter the hydrogel's degradability under enzymatic action. Biostimulation of human dental pulp cells (HDPCs) on the hydrogel was evaluated through cell viability and mineralized matrix assays. Results showed no cytotoxic effects, with significant cell proliferation over time. HDPCs displayed an increase in mineralization nodules when cultured with GelMA functionalized with MSCH containing 2%, 5%, and 10% simvastatin. However, only the 10% concentration resulted in a significant increase. Thus, incorporating chitosan microspheres with 10% simvastatin into GelMA creates a controlled release system with high potential for direct pulp capping.