Development of a rice glutelin-based nanoparticle delivery system: fabrication, characterization, and stability.

Background: Curcumin has been shown to regulate the expression of receptor complexes, growth factors, and other pathways, ultimately displaying biological functions such as anti-inflammatory, anticancer, and antidiabetic effects. However, it is precarious and susceptible to damage by complex environmental factors both inside and outside the body, making the development of biocompatible delivery systems critical.

Results: Rice glutelin-rhamnolipid-curcumin (RG-Rha-Cur) nanoparticles were constructed using a pH-driven method. The results indicate that the nanoparticle composites (CNPs) made with RG and Rha mass ratios of 5:1 had good encapsulation efficiency (EE) for curcumin (93.5 ± 0.17%). Scanning electron microscopy (SEM) findings demonstrated that curcumin was successfully incorporated. Fluorescence spectroscopy (FS) revealed that rice glutelin (RG) underwent fluorescence quenching upon interaction with curcumin and rhamnolipids, indicating that RG was combined with curcumin and rhamnolipids through hydrophobic interactions. Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) spectroscopy indicated that hydrogen bonding, hydrophobic interactions, and electrostatic attraction were the main forces driving complex formation. X-ray diffraction (XRD) data confirmed that the complexes' curcumin was amorphous. According to the results of the stability experiments, the suspensions of nanoparticles remained stable between pH 6.0 and 9.0. The nanoparticles aggregated at increasing electrolyte concentrations at neutral pH but remained stable at low ionic strengths (< 300 mM NaCl). Curcumin encapsulated in the CNPs also showed improved stability against ultraviolet light, heat, and storage conditions.

Conclusion: These results suggested that hydrophobic active ingredients might be encapsulated and protected by RG-Rha nanoparticles, which could constitute a viable and effective delivery method. © 2025 Society of Chemical Industry.