Green Synthesis of PVA-Stabilized Gold Nanoparticles from Aloe vera: Physicochemical Characterization and Biocompatibility Under Mild UV Exposure.

BACKGROUND

Aloe vera is widely used for dermatological applications due to its bioactive phenolic compounds, including aloin, aloesin, aloe-emodin, and tannins. Gold nanoparticles (AuNPs) have pharmacological properties such as antioxidant and antibacterial activities and may enhance skin elasticity.

OBJECTIVE

This study developed polyvinyl alcohol (PVA) stabilized gold nanoparticles from Aloe vera extract and evaluated their physicochemical properties, preliminary stability, and in vitro biocompatibility under mild UV exposure.

METHODS

Gold nanoparticles were biosynthesized by reacting Aloe vera extract with 1 mM chloroauric acid (HAuCl4) in the presence of PVA. The formulations were characterized by UV-Vis spectroscopy, particle size and polydispersity index (PDI), TEM, SEM-EDS, and FTIR. The optimized formulation was further evaluated in a preliminary accelerated stability study and tested for cytotoxicity in B16F10 melanoma cells using the MTT assay under mild UVA and UVB exposure.

RESULTS

Formula 4 was selected as the optimized formulation after preliminary screening, showing stable dispersion without visible aggregation, a particle size of 101.40 ± 1.51 nm, and a PDI of 0.24 ± 0.06. After optimization, this formulation was subjected to accelerated stability testing, with Day-1 particle size and PDI values of 107.00 ± 1.11 nm and 0.25 ± 0.04, respectively. During accelerated storage, the particle size remained within the nanoscale range. Cytotoxicity testing showed that NGA was non-cytotoxic toward B16F10 melanoma cells, with an IC50 value of 2873.20 μg/mL. Under the mild UVA and UVB conditions used in this study, treated cells also maintained high viability.

CONCLUSION

PVA-stabilized gold nanoparticles synthesized from Aloe vera showed favorable physicochemical properties, preliminary storage stability, and low in vitro cytotoxicity. Under the mild UV exposure conditions applied in this study, NGA remained biocompatible; however, the present findings do not yet establish a definitive photoprotective effect. Further studies using stronger irradiation settings and appropriate positive controls are required.