Cinnamaldehyde-Loaded Chitosan Nanoparticles Prepared by Ionic Gelation: In Vitro Activity Against Candida Isolates from HIV-Associated Oral Candidiasis

Oral candidiasis is a common opportunistic infection in Human Immunodeficiency Virus (HIV) patients, significantly affecting their quality of life. This study examined the in vitro efficacy of nanoencapsulated cinnamaldehyde-chitosan as an innovative treatment for oral candidiasis in HIV patients in Yogyakarta, Indonesia. Cinnamaldehyde, a natural antifungal agent, was encapsulated in chitosan nanoparticles to enhance its bioavailability and activity. This study used a combination of in vitro antifungal assays to evaluate the efficacy of the nanoencapsulated formulation against Candida species isolated from HIV-infected patients. The cinnamaldehyde-loaded chitosan nanoparticles demonstrated promising in vitro antifungal activity against C. albicans isolates associated with HIV-related oral candidiasis, with minimum inhibitory concentration (MIC) values ranging from 0.195 to 1.56. The formulation demonstrated improved antifungal performance compared with chitosan nanoparticles (6.25), along with enhanced stability and controlled-release properties. In addition, the nanoformulation exhibited favorable stability and sustained release characteristics, supporting its potential for further antifungal formulation development. Cinnamaldehyde-loaded chitosan nanoparticles with a size of 261.99 ±21.06 nm, with a polydispersity index (PdI) of 0.252 and a zeta potential of +19.34 ±0.71 mV, showed a relatively uniform and stable distribution and little aggregation. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed the presence of organic molecules and aromatic amine groups, and UV-Vis spectrophotometer measurements at a wavelength of 225 nm with an absorbance of 2.882 indicated a high and stable concentration of cinnamaldehyde chromophore in the nanoencapsulation. Transmission Electron Microscopy (TEM) analysis showed spherical particles at the nanoscale morphology with a smooth and irregular surface; whereas Scanning Electron Microscopy (SEM) mainly showed dried aggregates surface morphology, demonstrating the typical core-shell architecture of the nanoencapsulation system. This study underscores the potential use of nanotechnology as a stable, prolonged-release antifungal formulation for oral candidiasis, which presents a promising approach to improve health outcomes for HIV patients. ©2026 The authors.