Silicon-Enriched Poly(vinyl alcohol)/Gelatin Hydrogels\nfor 3D Printed Inks

Biomaterials have\nemerged as a promising approach for tissue engineering\nbecause they can mimic various physicochemical properties of tissues\nand support cell growth and proliferation. Recently, research in this\nfield has focused on developing systems that promote tissue regeneration\nrather than replacing all damaged tissues. This study compares the\nsynthesis and production of silicon bioceramic nanoparticles through\nchemical methods with naturally occurring silicon-rich particles known\nas diatoms. These nanoparticles were incorporated into poly(vinyl\nalcohol)/gelatin (PVA/Gel) hydrogels to enhance their bioactivity\nand mechanical behavior. The study began with characterizing ceramic\nparticles using X-ray diffraction, scanning electron microscopy, Fourier-transform\ninfrared spectroscopy, and energy-dispersive X-ray analyses. Viability\nassays determined the optimum amount of CaSiO<sub>3</sub> and diatom\nto promote cell proliferation in fibroblasts (NIH) and osteoblasts\n(HFOB). Intriguingly, silica-rich particles improved viability by\npromoting cell proliferation, which was increased by at least 20%\nin both cell lines. This suggests that silica-rich particles may mitigate\nthe adverse effect of the hydrogel on cell viability. Finally, a new\nnoncommercial printing system for the preparation of freeze–thaw\ncross-linked hydrogels was developed, and the possibility of 3D printing\nof the generated PVA/Gel formulation was verified.