In Vitro Modulation of Spontaneous Activity in Embryonic Cardiomyocytes Cultured on Poly(vinyl alcohol)/Bioglass Type 58S Electrospun Scaffolds.

Because of the physiological and cardiac changes associated with cardiovascular disease, tissue engineering can potentially restore the biological functions of cardiac tissue through the fabrication of scaffolds. In the present study, hybrid nanofiber scaffolds of poly (vinyl alcohol) (PVA) and bioglass type 58S (58SiO2-33CaO-9P2O5, Bg) were fabricated, and their effect on the spontaneous activity of chick embryonic cardiomyocytes in vitro was determined. PVA/Bg nanofibers were produced by electrospinning and stabilized by chemical crosslinking with glutaraldehyde. The electrospun scaffolds were analyzed to determine their chemical structure, morphology, and thermal transitions. The crosslinked scaffolds were more stable to degradation in water. A Bg concentration of 25% in the hybrid scaffolds improved thermal stability and decreased degradation in water after PVA crosslinking. Cardiomyocytes showed increased adhesion and contractility in cells seeded on hybrid scaffolds with higher Bg concentrations. In addition, the effect of Ca2+ ions released from the bioglass on the contraction patterns of cultured cardiomyocytes was investigated. The results suggest that the scaffolds with 25% Bg led to a uniform beating frequency that resulted in synchronous contraction patterns.

Fast cyclical-decellularized trachea as a natural 3D scaffold for organ engineering.

Commonly reported decellularization protocols for trachea may take up from several weeks to months in order to remove the cellular materials. Two years ago, we significantly reduced the time of decellularization trachea process using trypsin. Despite the positive outcome, the protocol was useful to produce 5 cm graft length, an unsuitable length graft for most patients with tracheal disorders. In this work we improved the decellularization procedure for longer sections up to 10 cm without considerable extension in the necessary time process (2 weeks). Herein, for the first time, we completely describe and characterize the process for pig tracheal bioactive scaffolds. Histological and molecular biology analysis demonstrated effective removal of cellular components and nuclear material, which was also confirmed by the Immunohistochemical (IHC) analysis of the major histocompatibility complexes (MHCs) and DNA stain by 4'-6-diamidino-2-phenylindole (DAPI). The images and data obtained from scanning electron microscopy (SEM) and thermal analysis showed conservation of the hierarchical structures of the tracheal extracellular matrix (ECM), the biomechanical tests showed that decellularization approach did not lead to a significant alteration on the mechanical properties. In this paper, we demonstrate that the proposed cyclical-decellularization protocol allowed us to obtain a non-immunological 10 cm natural tracheal scaffold according to the in vivo immunological assessment. Furthermore, the recellularization of the matrix was successfully achieved by demonstrating first-stage cellular differentiation from stem cells to chondrocytes expressed by the SOX9 transcription factor; this organ-engineered tracheal matrix has the potential to act as a suitable template for organ regeneration.