Abstract
Regenerative medicine has increased the expectations for the treatment of numerous degenerative diseases of the human being. For this reason, studies have as a key point the development of biomaterials with similar body tissue properties. Among these, we highlight the injectable hydrogels that can be used in less invasive surgeries and have the potential of regenerate and repair spinal cord injuries, cartilage and others. Therefore, characteristics as being biocompatible, moldable, adhesives, biodegradable, allowing cell growth and with adequate mechanical properties (elastic and with high compressive strength and tensile strength) are of paramount importance in medical applications. A strategic polymer for this application is the poly (N-vinyl caprolactam) (PNVCL), which is biocompatible and thermosensitive. It combined with poly (vinyl alcohol) (PVA) hydrogels can form biodegradable materials with cell adherence. In this sense, the nanocomposites are highly promising candidates in the field of biomaterials, because they exhibit excellent combination of the physicochemical properties of polymers with the mechanical strength of bioactive ceramics. As examples, mesoporous silica nanofibers and ytterbium trifluoride (YbF3) can improve the compressive strength, adhesion and cell growth, as well as the investigation of in vivo implant by the YbF3 radiopaque effect. Thus, in this research project, nanocomposites are being prepared by the in situ polymerization of the copolymer PNVCL-PVA in the presence of mesoporous SiO2 fibers decorated with YbF3 nanoparticles, with the goal of obtaining biocompatible hydrogels that act as scaffolds for tissue engineering. The copolymers are being synthesized by free radical polymerization and SiO2 and YbF3 nanoparticles will be prepared by the sol-gel route and hydrothermal method, respectively. The techniques used to estimate the morphology and structure of hydrogels, nanoparticles and nanocomposites are: transmission and scanning electron microscopies, X-ray diffraction, dynamic light scattering, small-angle X-ray scattering, nuclear magnetic resonance spectroscopy, ultraviolet-visible spectrophotometry and dynamic mechanical analysis (DMA). Furthermore, the in vitro evaluation of these materials as scaffolds in the repair and reconstruction of articular cartilage will be held through the growth, proliferation and adhesion of mesenchymal stem cells, the chondrogenic differentiation and biomechanical testing in the University of Pennsylvania under the supervision of Prof. Dr. Jason Burdick. (AU)
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