Avaliação da viabilidade, adesão e proliferação de células tronco da medula óssea e fibroblastos NIH3T3 cultivadas em matriz de PLGA com rhGH

• Ano de defesa: 2016
• Autor(a) principal: Gerzson, Alexandre da SIlveira
• Orientador(a): Pagnoncelli, Rogério Miranda
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul
• Programa de Pós-Graduação: Programa de Pós-Graduação em Odontologia
• Departamento: Faculdade de Odontologia
• País: Brasil
• Palavras-chave em Português: MATERIAIS BIOCOMPATÍVEIS; HORMÔNIO DO CRESCIMENTO; POLÍMEROS; ODONTOLOGIA
• Área do conhecimento CNPq: CIENCIAS DA SAUDE::ODONTOLOGIA
• Link de acesso: http://tede2.pucrs.br/tede2/handle/tede/6678

Biomaterials, as an alternative to autogenous bone and other biological 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 (rhGH) 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 rhGH. PLGA and PLGA/PCL (at a 70/30 ratio of PLGA to PCL) matrices were prepared by the solvent evaporation method, combined or not with GH. The biomaterials were tested for toxicity and cell viability using an MTT assay with NIH3T3 mouse cells (ATCC). Cell toxicity was assessed at 24, 48, 72 hours, and 7 days of biomaterial exposure to culture medium. After were tested”for cell adhesion and proliferation by culture in mesenchymal stem cells derived from Wistar rat bone marrow, 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. All polymers had high cell viability rates. However, from 48 hours onwards, the groups with rhGH-polymer combinations had better results than the polymer groups without association with GH when compared to the control group. At 7 days of culture, only the pure PLGA matrix showed a significant difference from the control group. These results may suggest a preference of cells for the presence of rhGH in the biomaterial in culture medium” especially in the PLGA matrix. GH appeared to contribute to the increase in cell viability observed at some assessment time points, especially when combined with PLGA as compared to pure PLGA. All tested polymers exhibited cell adhesion and proliferation. However, PLGA-based biomaterials, especially when combined with rhGH, showed greater cell proliferation when the difference in growth from 24 to 72 hours was evaluated. rhGH appeared to modify the polymer surface, with increased roughness and microporosity. This feature was more evident in the PLGA+rhGH combination. Further studies are required to clarify this potential for development of new biomaterials.