Synthesis and evaluation of poly(cyclotriphosphazene-co-phloridzin) microspheres for controlled drug delivery application

Abstract

Polyphosphazene-derived microspheres have gained attention due to their versatilesurface,biocompatibility, and potential in drug delivery applications. They are widely used as adsorbents, biomaterials, and controlled release systems. This study presents the efficient synthesis of Poly(cyclotriphosphazene-co-phloridzin) P(CPPhz) microspheres using a simple precipitation polymerization method. Comprehensive characterization confirmed the successful polymerization, as evident from FT-IR and EPR spectroscopy, which detailed the functional groups and molecular dynamics of the microspheres. The P(CPPhz)-3 microspheres demonstrated notable biological properties, including excellent hydrolytic degradation, biocompatibility, and low cytotoxicity, validated through hemolysis and CCK-8 assays. These microspheres exhibited significant antibacterial activity attributed to the hydroxyl groups on the polymer network. As drug carriers, the microspheres achieved a high drug loading capacity (73.6 mg/g) of Dexamethasone (DEX) and displayed controlled, pH-dependent drug release behavior. Specifically, 45.2 % of DEX was released at pH 4.0 over 240 hours, compared to lower release rates in neutral and alkaline conditions. These findings underscore the potential of P(CPPhz) microspheres in long-term, controlled drug delivery applications. The study concludes with a promising outlook for P(CPPhz) microspheres in biomedical applications, particularly in drug delivery, while emphasizing avenues for future research, such as in vivo studies to explore their clinical applicability.