RESUMO
The use of three-dimensional (3D) cultures may induce cardiac progenitor cells to synthesize their own extracellular matrix (ECM) and sarcomeric proteins to initiate cardiac differentiation. 3D cultures grown on synthetic scaffolds may favour the implantation and survival of stem cells for cell therapy when pharmacological therapies are not efficient in curing cardiovascular diseases and when organ transplantation remains the only treatment able to rescue the patient's life. Silk fibroin-based scaffolds may be used to increase cell affinity to biomaterials and may be chemically modified to improve cell adhesion. In the present study, porous, partially orientated and electrospun nanometric nets were used. Cardiac progenitor cells isolated from adult rats were seeded by capillarity in the 3D structures and cultured inside inserts for 21 days. Under this condition, the cells expressed a high level of sarcomeric and cardiac proteins and synthesized a great quantity of ECM. In particular, partially orientated scaffolds induced the synthesis of titin, which is a fundamental protein in sarcomere assembly.
Assuntos
Fibroínas/química , Miocárdio/metabolismo , Células-Tronco/citologia , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/química , Bombyx , Adesão Celular , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular , Colágeno/química , Conectina/química , Eletroquímica , Matriz Extracelular/metabolismo , Citometria de Fluxo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Porosidade , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Sarcômeros/metabolismo , Engenharia Tecidual/métodos , Água/químicaRESUMO
The main goal in the last few years in cardiac research has been to isolate cardiac potential stem cells from adult myocardium and to demonstrate their differentiation potential. We have previously demonstrated that c-Kit positive cardiac stem cells are able to organize themselves into a tissue-like cell mass. In this 3D mass, they can produce a high concentration of natural extracellular matrix, can create vessels, a capsule and, with the help of an Open-pore Polylactic Acid scaffold, many cells can organize an elementary myocardium. Drawing from this background, we decided to design and use poly-lactic scaffolds and the model of the athymic Nude-Foxn1(nu) mouse to evaluate the extent of the myogenic vs endothelial differentiation in vivo, and to evaluate the presence or the absence of a foreign body reaction.