Among natural sources, guava leaf oil (GLO) has emerged as a potential anticancer agent. However, its limited water solubility poses a significant challenge for its use. Oil-in-water nanoemulsions are used to address the limitation of water solubility of GLO prior to its incorporation into orodipersible films. Nanoemulsions containing GLO:virgin coconut oil (VCO) at a ratio of 50:50 to 70:30 presented a small droplet size of approximately 50 nm and a relatively low zeta potential. GLO:VCO at a ratio of 70:30 was selected for incorporation into sodium alginate film at various concentrations ranging from 1% to 30% w/w. Tensile strength and elongation at break relied on the concentration of nanoemulsions as well as the internal structure of films. Fourier transform infrared spectroscopy revealed that GLO was compatible with sodium alginate. Film containing 2% w/w of nanoemulsions (2G_ODF) exhibited effective in vitro antioral cancer activity, with an IC₅₀ of 62.49 ± 6.22 mg/mL; furthermore, its anticancer activity showed no significant difference after storage at 25 °C for 1 year. Moreover, 2G_ODF at IC₆₀ arrested colony formation and cell invasion. There is also evidence that cell death occurred via apoptosis, as indicated by nuclear fragmentation and positive Annexin-V staining. These findings highlight the potential of orodispersible films containing GLO nanoemulsions as a prospective oral anticancer agent.

The aim of this study was to investigate the effect of Ostwald ripening inhibitors on D-limonene (D-LMN) nanoemulsions and to elucidate their impact on oral cancer cells. Various inhibitors, including olive oil, soybean oil, and perilla oil, were incorporated into D-LMN nanoemulsions at different ratios (25:75–75:25, D-LMN to inhibitor). The resulting nanoemulsions were evaluated for droplet size, size distribution, zeta potential, stability, droplet morphology, cytotoxicity, antimetastatic and anti-invasive activities, apoptosis induction, and cell cycle arrest. Results showed that the 75:25 D-LMN to inhibitor ratio produced the smallest droplet size and exhibited great stability, particularly with perilla oil. Notably, D-LMN nanoemulsions displayed strong anti-oral cancer effects by reducing cell viability, metastasis, and invasion. Apoptosis was induced, as evidenced by nuclear fragmentation, Annexin V binding, and altered expression of BAX, BCL-XL, Cytochrome c, and Caspase-9. Additionally, the nanoemulsions caused cell cycle arrest via downregulation of Cyclin D1, CDK2, CDK4, and CDK6. These findings highlight the potential of D-LMN nanoemulsions as a promising alternative therapeutic strategy for oral cancer treatment.

Solvent removal-induced in situ matrices (ISMs) have garnered attention for periodontitis treatment because of their capability to localize antibiotic drug release within the periodontal pocket over an extended duration, effectively targeting and eliminating infecting microbes. In this study, various concentrations of borneol—10%–70%—were used as a matrix agent in ISMs, with a 40% w/w borneol-based ISM selected to load 1% vancomycin HCl. The injectability and mechanical properties of drug-free and vancomycin HCl-loaded borneol ISMs were evaluated with a texture analyzer. Both maximum injection force and energy increased proportionally with borneol concentrations and slightly further with vancomycin HCl. Nevertheless, the injection energy required for borneol-loaded ISMs at 10%–50% was low, from 12.22–25.00 mJ. Consequently, these formulations were considered appropriate and feasible as injectable drug delivery systems, providing ease of administration while promoting patient comfort and compliance. Additionally, a more compact borneol matrix was formed after complete solvent removal; it exhibited plastic deformation, enabling close adaptation to the periodontal pocket geometry.

The innate immune system serves as the body’s first line of defense, with macrophages playing a central role in pathogen recognition and elimination.

In this study, a hyaluronic acid (HA)-coated glabridin nanoemulsion was developed for enhanced macrophage uptake using the phase inversion temperature (PIT) method. The optimized cationic nanoemulsion consisted of a 10% w/w 60:40 peppermint oil:virgin coconut oil ratio, 10% w/w Cremophor RH40, 1% w/w cetyltrimethylammonium bromide, and 1% w/w ethanol. It exhibited a small droplet size, narrow size distribution, and positive zeta potential. Molecular dynamics simulations supported the experimental results, showing that systems containing a cosurfactant formed smaller droplets than those without a cosurfactant, particularly when ethanol was used as the cosurfactant. A concentration of 0.15% w/w HA solution at a 1:10 nanoemulsion–HA ratio yielded favorable characteristics, including a small droplet size (69.98 ± 0.48 nm), narrow size distribution (0.30 ± 0.00), and negative zeta potential (−23.00 ± 2.08 mV). Transmission electron microscopy image confirmed the presence of HA coating at 0.15% w/w. The incorporation of glabridin stabilized the droplet size (67.63 ± 0.33 nm) and polydispersity index (0.36 ± 0.01) but slightly decreased the absolute zeta potential (−10.83 ± 1.91 mV), whereas the entrapment efficiency was 91.65% ± 1.52% w/w. The nanoemulsion exhibited good physicochemical stability after storage at 40 °C for 6 months. HA coating enhanced the cellular uptake of the nanoemulsion into macrophage cells. The HA-coated glabridin nanoemulsion significantly inhibited the production of reactive oxygen species and nitric oxide and it also demonstrated low cytotoxicity. These findings indicated the potential of the PIT method to produce HA-coated glabridin nanoemulsion as a receptor-mediated delivery system for treating inflammation.