Regenerated cellulose sponge as sacrificial template for the synthesis of three-dimensional porous alumina-silica scaffold for tissue engineering

Tissue engineering has emerged as a multidisciplinary field that aims to improve health and quality of life by restoring functions of tissues and organs. Cells and scaffolds are the two major components of tissue engineering. Scaffolds act as a support for cells, thus facilitating cell adhesion, proliferation, morphogenesis, differentiation, and extracellular matrix production. Since three-dimensional (3D) porous scaffolds can better simulate the native 3D architecture of in vivo systems than conventional 2D cultures, they are more appropriate to support tissue regeneration. This study aimed to use regenerated cellulose sponge (RCS) as sacrificial template for the synthesis of three-dimensional porous alumina-silica scaffold (ASS). RCS was coated with boehmite-GPTS (3-glycidoxypropyltrimethoxysilane) solution and dried at 60 °C for 12 h. The coated RCS was converted into porous alumina-silica scaffold via thermal treatment at 500 °C for 4 h in air. The materials were characterized by Fourier transform‐infrared (FT‐IR), X-Ray diffraction (XRD), thermogravimetric analysis (TGA) aluminum-27 and silicon-29 nuclear magnetic resonance (NMR), scanning electron microscopy, and energy dispersive X-ray spectroscopy (SEM-EDS). The MTT metabolism assays were used to evaluate indirectly cytocompatibility and cell proliferation using MCT3T3-E1, HDFa and HaCaT cells. The biological in vitro assays demonstrated that only RCS exhibited toxicity toward HDFa cells, although this behavior has been shown questionable once other studies have reported the non-cytotoxic, mutagenic and genotoxic potential of RCS. We believe that tests including clonogenic and mutagenic assays should be performed using HDFa cells in contact with RCS-derived extract in order to further investigate this behavior. The sponge materials have demonstrated different growth rate and adhesion to three different cell lines evaluated. Therefore, the employed sacrificial template approach presents as a viable alternative to produce 3D scaffolds for tissue engineering. Graphical abstract Schematic illustration of the synthesis of alumina-silica scaffold using regenerated cellulose sponge as sacrificial template.