Isolation and characterization of dental pulp stem cells from permanent third molars

Objective: To characterize pulp stem cells and evaluate their capacity for expansion and differentiation in vitro.Methods: Pulp tissue was collected from permanent third molars and digested and then the cells were seeded onto plates containing HDMEM medium. Expansion of the cells was performed and then differentiation tests were conducted with osteogenic, chondrogenic and adipogenic induction media; followed by determination of immunophenotypical profiles using specific antibodies with assessment by flow cytometry.Results: It was observed that the pulp stem cells exhibited the capacity to adhere to plastic and a high rate of expansion and, after detection with specific stains, it was shown that the cells were capable of differentiation into osteoblasts and chondroblasts, but not into adipocytes. Analysis of the cellular phenotype showed that the cells were negative for CD45, CD69, CD117 and HLA-DR, and positive for CD13, CD44, CD73, CD90 and CD105.Conclusions: The cells isolated from dental pulp exhibited characteristics compatible with those expected for mesenchymal stem cells (MSCs) and are good candidates for cell therapy applications and tissue bioengineering

Repair of bone defects using adipose-derived stem cells combined with alpha-tricalcium phosphate and gelatin sponge scaffolds in a rat model

Objectives This study aimed to evaluate the potential of adipose-derived stem cells (ASCs) combined with a modified α-tricalcium phosphate (α-TCP) or gelatin sponge (GS) scaffolds for bone healing in a rat model. Material and Methods Bone defects were surgically created in the femur of adult SHR rats and filled with the scaffolds, empty or combined with ASCs. The results were analyzed by histology and histomorphometry on days seven, 14, 30, and 60. Results Significantly increased bone repair was observed on days seven and 60 in animals treated with α-TCP/ASCs, and on day 14 in the group treated with GS/ASCs, when compared with the groups treated with the biomaterials alone. Intense fibroplasia was observed in the group treated with GS alone, on days 14 and 30. Conclusions Our results showed that the use of ASCs combined with α-TCP or GS scaffolds resulted in increased bone repair. The higher efficacy of the α-TCP scaffold suggests osteoconductive property that results in a biological support to the cells, whereas the GS scaffold functions just as a carrier. These results confirm the potential of ASCs in accelerating bone repair in in vivo experimental rat models. These results suggest a new alternative for treating bone defects

Padronização do isolamento das células-tronco de polpa dentária para aplicação em engenharia de tecido ósseo

O tecido pulpar dentário tem sido descrito como fonte de células multipotentes, apresentam capacidade de autorrenovação e diferenciação em diferentes tipos celulares. Na terapia de tecidos essas células são promissoras. O objetivo do estudo foi isolar células-tronco mesenquimais de polpa dentária (CTMPD). O estudo foi composto por doadores entre 12 e 26 anos. As células foram isoladas a partir da polpa dentária obtida dos terceiros molares inclusos superiores. No isolamento, expansão e caracterização das CTMPDs o tecido foi acondicionado em placas de cultura, com meio específico completo e suplementado e mantidas em temperatura adequada até aderirem e atingirem a confluência de 80 %. Após, as células foram mantidas nas condições do início do isolamento e apresentaram 2 % da capacidade de formação de colônias. É possível concluir que as células-tronco da polpa dentária adulta são capazes de formar colônias e proliferar in vitro

An. Acad. Bras. Ciênc.

Abstract Mesenchymal stem cells present clinical potential to recover and regenerate injured tissues in diverse pathologies. The in vitro expansion and characterization of these cells contribute to elucidation of the mechanisms of senescence and strategies involving cell therapies. This study aimed to compare specific characteristics between initial and advanced passages of mesenchymal stem cells derived from adipose tissue and bone marrow. Both cell types were characterized according to immunophenotype, osteogenic differentiation, genomic instability, migration assay, doubling population time and colony forming ability. Our results demonstrated that both cell types were able to maintain an immunophenotypic profile typical of mesenchymal stem cells during increasing passages. Adipose stem cells at initial passage presented greater migration capacity compared to advanced passage cells, and advanced passage cells proliferated faster than initial passage cells. Bone marrow stem cells at early passages presented higher osteogenic potential than advanced. At advanced passages they presented higher colony forming capacity and genetic damage than those at initial passage. These results suggest that mesenchymal stem cells maintained in culture presented characteristics of senescence that should be monitored prior the use in regenerative medicine and cells derived from bone marrow at initial passage have better potential for therapeutic use in bone tissue engineering