Assessment of Adhesion and Proliferation of Bone Marrow Mesenchymal Stem Cells in Polymer Matrices with rhGH

Purpose: Biomaterials, as an alternative to autogenous bone and other biologic tissues, have been widely used in oral and maxillofacial surgery. In this context, a biomaterial that functions as a scaffold (osteoconductor), combined with a growth factor (osteoinductor), would be of great interest for clinical application. Biodegradable polymers used for slow drug release have been investigated, demonstrating good results and interesting potential. Growth hormone (GH) may be released by incorporating it into these polymers. This study aimed to evaluate cell adhesion and proliferation of a polymeric biomaterial for slow release of recombinant human GH (rhGH). Materials and Methods: Poly(lactic-co-glycolic acid) (PLGA) and PLGA/polycaprolactone (PCL) (at a 70/30 ratio of PLGA to PCL) matrices were prepared by the solvent evaporation method, combined or not with GH. Biomaterials were tested for cell adhesion and proliferation by culture in mesenchymal stem cells derived from Wistar rat bone marrow, 4',6-diamidino-2-phenylindole (DAPI) staining, and subsequent cell counting, in addition to scanning electron microscopy. Cell adhesion and proliferation was assessed at 24 and 72 hours of biomaterial exposure to culture medium. Results: All tested polymers exhibited cell adhesion and proliferation. However, PLGA-based biomaterials, especially when combined with GH, showed greater cell proliferation when the difference in growth from 24 to 72 hours was evaluated. GH appeared to modify the polymer surface, with increased roughness and microporosity. This feature was more evident in the PLGA + GH combination. Conclusion: The biomaterials tested showed pronounced cell adhesion in all test groups, and GH appeared to contribute to the increase in cell proliferation, especially when combined with PLGA as compared with pure PLGA. Further studies are required to clarify this potential for development of new biomaterials. Keywords: biocompatible materials, growth hormone, polymers