Biomimetic Porous Inorganic Materials for Bone Engineering Using a Natural Yam Stalk Template

This study explores biomimicry as a widely recognized and promising approach for developing sustainable structural materials that embody the principles of the circular economy. In this context, the study explores using yam stalks (Dioscorea) as a biotemplate. This natural material, composed of biopolymers such as cellulose and lignin and typically discarded as tuber waste, is characterized by a highly porous morphology with a large volume of interconnected pores. Such a structure can be used as a template to create a bone-mimicking scaffold with potential applications in tissue engineering. Through the sol-gel process and the combination of the Dioscorea biotemplate with tetraethyl orthosilicate (TEOS) or titanium bis-(ammonium lactate) dihydroxide (TiBALDH) precursors, silica and titania inorganic porous materials were obtained. After sol-gel deposition of inorganic oxides and removal of the Dioscorea biotemplate by calcination at 700 °C, scanning electron microscopy (SEM) revealed a scaffold with a homogeneous network of interconnected macropores evenly distributed throughout the material. At higher magnification, hexagonal patterns (honeycomb-like structures) were observed, highlighting the natural structural optimization that offers advantages in permeability and cellular growth. Micro CT analysis revealed total volumes of 768.61 mm³ for the silica-based porous scaffold and 853.00 mm³ for the titania-based sample, along with macropores of 203-395 and 176-286 μm per gram, respectively. This pore range is particularly suitable for cell proliferation and nutrient transport in applications like tissue engineering. Moreover, in vitro cytotoxicity and osteogenic assays showed that SD/Ti and SD/Si demonstrated promising osteogenic potential, with good cell viability, ALP activity, and collagen production in both culture media. This pore range is particularly suitable for cell proliferation and nutrient transport in applications like Tissue Engineering. Therefore, this is a promising scaffold alternative, suggesting the use of porous biomimetic materials in tissue engineering, especially synthetic bone. Furthermore, these materials offer multifunctional applications, are environmentally friendly, and are economically viable.