Synthesis, neutralization and blocking procedures of organic/inorganic hybrid scaffolds for bone tissue engineering applications

Abstract

Bioactive glasses (BaG) can bind to human bone tissues and have been used in many biomedical applications for the last 30 years. However they usually are weak and brittle. On the other hand, composites that combine polymers and BaG are of particular interest, since they often show an excellent balance between stiffness and toughness. Bioactive glass-poly(vinyl alcohol) foams to be used in tissue engineering applications were previously developed by our group, using the sol-gel route. Since bioactive glass-polymer composite derived from the sol-gel process cannot be submitted to thermal treatments at high temperatures (above 400 degrees C), they usually have unreacted species that can cause cytotoxicity. This work reports a technique for stabilizing the sol-gel derived bioactive glass/poly(vinyl alcohol) hybrids by using glutaraldehyde (GA), NH(4)OH solutions and a blocking solution containing bovine serum albumin. PVA/BaG/GA hybrids were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM/EDX) analyses. Moreover, MTT (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) biocompatibility and cytotoxicity assays were also conducted. The hybrids exhibited pore size varying from 80 to 820 mum. After treatments, no major changes in the pore structure were observed and high levels of cell viability were obtained.

Hybrid Matrix Grafts to Favor Tissue Regeneration in Rabbit Femur Bone Lesions

“…Considering that, in a lesion, bone regeneration has the intention of restituting the tissue ad integrum, thus generating a tissue with biomechanical and functional characteristics similar to the original bone area, the biotechnological developments aimed at optimizing these implant models in depth. Other authors have recently presented encouraging results when considering other types of similar sol-gel type structures, based on bioactive glass intertwined with type II collagen [17-18]. The present work provides evidence that the implants studied showed no rejection, and presented incipient integration, thus indicating that the studied matrixes represent a promising system concerning problems involving bone repair.…”

“…Hybrid scaffolds in the Polyvinyl alcohol/bioactive glass (PVA/BaG) system have been developed and extensively studied as regards their structure and mechanical behavior [17]. These materials posses both osteoconductive ability and good mechanical properties; however, emerging cytotoxicity problems can arise from the synthesis method itself [18]. …”

Engineered Hybrid Scaffolds of Poly(vinyl alcohol)/Bioactive Glass for Potential Bone Engineering Applications: Synthesis, Characterization, Cytocompatibility, and Degradation

“…Recently, hybrid organic-inorganic scaffolds in the poly(vinyl alcohol)/bioactive glass (PVA/BaG) system have been prepared through the sol-gel process [30,[35][36][37][38], by hydrolysis of tetraethyl orthosilicate in the presence of an acid solution and a subsequent addition of calcium chloride. A solution of PVA, surfactant, and hydrofluoric acid were added to the sol, and the mixture vigorously agitated until the foam had formed.…”

Mechanical Behavior of Nanostructured Hybrids Based on Poly(Vinyl Alcohol)/Bioactive Glass Reinforced with Functionalized Carbon Nanotubes

“…Our group has been active on researching the synthesis and characterization of organic-inorganic hybrids in the system poly(vinyl alcohol)/bioactive glass (PVA/BaG) [12][13][14][15] to be used as scaffolds in tissue engineering applications. PVA/BaG have been prepared by the sol-gel process and the effect of PVA content, degree of hydrolysis, and synthesis conditions on properties of the porous scaffolds, and on degradation kinetics have been reported [16][17][18][19]. The results have clearly shown that it is possible to tailor the hybrids mechanical properties and degradation behavior by engineering the structure of the materials.…”