Engineering PLGA nanocomposites with magnesium hydroxide and oxide nanoparticles: Synthesis, characterization, and prospective biomedical applications

The limited mechanical strength and surface stability of poly(lactic-co-glycolic acid) (PLGA) restrict its use in load-bearing and long-term biomedical devices. In this study, magnesium hydroxide (Mg(OH) 2 ) and magnesium oxide (MgO) nanoparticles were synthesized using conventional sol–gel and continuous recirculation nanoprecipitation methods to address these limitations. Transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy confirmed the formation of crystalline nanoparticles with the recirculation method producing narrower size distributions and improved homogeneity. Nanoparticles were incorporated into PLGA (85:15) matrices at 1–5% (w/w) to form nanocomposites. Mechanical evaluation by atomic force microscopy (AFM) and Oliver–Pharr nanoindentation revealed significant reinforcement: 1%Mg(OH) 2 increased Young’s modulus by 37.8%, while 5% MgO achieved a maximum increase of 55.8% relative to pristine PLGA. Cytotoxicity assays (MTT) showed LC 50 values of 6.79 mg/mL for MgO and 4.19 mg/mL for Mg(OH) 2 , indicating acceptable biocompatibility. These results support the potential application of PLGA–Mg nanocomposites in temporary implants, bone regeneration scaffolds, and tissue engineering.