Comparative Study of Chitosan-Pyrophosphate and Magnesium Hydroxide-Alginate Hybrid Nanoparticles: Physicochemical...

Vascular calcification (VC) is a progressive pathological process that contributes significantly to cardiovascular morbidity, particularly in patients with chronic kidney disease. In this study, we developed and compared two biocompatible nanoparticle formulations designed for biomedical applications in the context of vascular calcification: chitosan-sodium pyrophosphate (NPs-CS-PPi) and magnesium hydroxide-alginate (NPs-Mg-(OH)₂-Alg). The nanoparticles were synthesized via ionic gelation and hydrothermal precipitation methods, followed by surface functionalization. Comprehensive physicochemical characterization was performed using dynamic light scattering (DLS), Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy. Both formulations exhibited spherical morphology, hydrodynamic diameters under 200 nm, and a low polydispersity index (PDI < 0.2). Surface charge measurements indicated successful functionalization, with zeta potentials ranging from +22 mV (NPs-CS-PPi) to -15 mV (NPs-Mg-(OH)₂-Alg). In vitro cytotoxicity assays using L929 fibroblasts confirmed high biocompatibility, meeting ISO 10993-5 criteria, with cell viability exceeding 90% for NPs-Mg-(OH)₂-Alg and above 80% for NPs-CS-PPi across all tested concentrations. The magnesium-based system demonstrated a more favorable balance between physicochemical properties and cytocompatibility. Overall, this work establishes a robust physicochemical and cytocompatibility framework that supports future studies employing dedicated vascular calcification and biomaterial evaluation models.