Agradecimentos: The authors would like to thank Prof. Benedicto de Campos Vidal from University of Campinas for providing collagen type II, and Tereza Salles and Paulo Latuf Filho for their valuable technical assistance. We also thank Raquel Foglio for English review and Michel Moraes for figure formatting and design. This work was supported by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq/MCT), Fundavao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) and Fundacao de Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) Ver menos

Abstract: Objective. Articular cartilage is an avascular tissue with limited ability of self-regeneration and the current clinical treatments have restricted capacity to restore damages induced by trauma or diseases. Therefore, new techniques are being tested for cartilage repair, using scaffolds and/or stem cells. Although type II collagen hydrogel, fibrin sealant, and adipose-derived stem cells (ASCs) represent suitable alternatives for cartilage formation, their combination has not yet been investigated in vivo for focal articular cartilage defects. We performed a simple experimental procedure using the combination of these 3 compounds on cartilage lesions of rabbit knees. Design. The hydrogel was developed in house and was first tested in vitro for chondrogenic differentiation. Next, implants were performed in chondral defects with or without ASCs and the degree of regeneration was macroscopically and microscopically evaluated. Results. Production of proteoglycans and the increased expression of collagen type II (COL2 alpha 1), aggrecan (ACAN), and sex-determining region Y-box 9 (SOX9) confirmed the chondrogenic character of ASCs in the hydrogel in vitro. Importantly, the addition of ASC induced a higher overall repair of the chondral lesions and a better cellular organization and collagen fiber alignment compared with the same treatment without ASCs. This regenerating tissue also presented the expression of cartilage glycosaminoglycan and type II collagen. Conclusions. Our results indicate that the combination of the 3 compounds is effective for articular cartilage repair and may be of future clinical interest Ver menos