Biopolymer-Based Nanocomposite Scaffolds: Methyl Cellulose and Hydroxyethyl Cellulose Matrix Enhanced with Osteotropic Metal Carbonate Nanoparticles (Ca, Zn, Mg, Cu, Mn) for Potential Bone Regeneration

Bone fractures are a serious health problem worldwide, and up to 10% of emergency department visits are related to such injuries. The development of effective materials for bone repair remains an urgent need of modern medicine. The aim of this study was to develop new scaffolds based on biopolymers (methyl cellulose and hydroxyethyl cellulose) modified with carbonate nanoparticles (CaCO3, MgCO3, ZnCO3, MnCO3, CuCO3) for potential applications in bone tissue engineering. FTIR spectroscopy confirmed the successful formation of stable composite structures: characteristic absorption bands of the functional groups of the molecules that make up the scaffold, as well as specific fluctuations in metal-oxygen bonds (Ca–O, Zn–O, Cu–O), were revealed. Stability tests revealed the most stable samples when changing the pH and the ionic strength of the solution. The developed scaffold matrices had a high porosity in the range from 93.3% to 98.0%, and their moisture absorption capacity ranged from 858% to 1402%. Specific gravity measurements ranged from 0.050 g/cm3 to 0.067 g/cm3, indicating optimal material density for potential biomedical applications. Biological evaluation demonstrated different cytotoxic effects depending on the type of nanoparticles. Thus, matrices with minimal toxicity and promising biocompatibility (modified CaCO3), as well as with significant toxic effects (modified ZnCO3 and CuCO3) were found. As a result, it was found that CaCO3-modified scaffolds have the most favorable combination of structural, physical, and biological properties for potential applications in bone tissue engineering. The developed innovative materials are porous scaffolds in which nanoparticles of carbonates of osteotropic elements are embedded, which presumably contribute to the acceleration of bone tissue regeneration. However, this study provides encouraging preliminary data, and further in-depth biological and functional studies are needed to fully confirm the osteogenic potential and regenerative efficacy of the scaffolds.