Propolis-Based Nanostructured Lipid Carrier of α-Mangostin for Promoting Diabetic Wound Healing in Alloxan-Induced Mice

Abstract

Introduction: Diabetic wounds present a significant challenge due to delayed healing and susceptibility to infection. Conventional therapies often fall short of achieving complete and timely wound repair. This study investigates the potential of α-mangostin (αM) and its propolis-based nanostructured lipid carrier (NLC-P-αM) formulation as novel therapeutic agents for diabetic wound healing.

Purpose: To evaluate the release profile, safety, and efficacy of NLC-P-αM in promoting wound repair in an in vitro and in vivo diabetic wound model.

Methods: The NLC-P-αM formulation was prepared using a melt-emulsification technique with ultrasonication. In vitro release studies were conducted using a dialysis bag method and analyzed using kinetic models. Cytotoxicity was assessed using the WST-8 assay on NIH-3T3 fibroblast cells. In vivo diabetic wound healing was evaluated using alloxan-induced diabetic Swiss Webster mice. The treatments were applied topically for 14 days, and wound closure was monitored quantitatively. Histological analysis was performed to assess the inflammatory cell infiltration, epidermal thickness, and tissue regeneration.

Results: NLC-P-αM demonstrated a significantly enhanced release profile, with 85.55 ± 4.25% of αM released at 360 min compared to 19.82 ± 6.78% for free αM, following a non-Fickian diffusion mechanism. Both formulations exhibited excellent safety, with cell viabilities of 94.76 ± 4.95% for NLC-P-αM and 102.16 ± 7.98% for αM in NIH-3T3 cells. In vivo, NLC-P-αM achieved the highest wound closure rate (85.83 ± 3.33%) by day 14, outperforming αM and the controls. Histological analysis confirmed reduced inflammation, a thinner epidermis, and advanced tissue regeneration in the NLC-P-αM group, highlighting its superior therapeutic efficacy.

Conclusion: NLC-P-αM demonstrated enhanced release, excellent safety, and superior efficacy in promoting diabetic wound healing compared to free αM and other controls. This nanoformulation offers a promising therapeutic strategy for accelerating wound repair in diabetic patients.

Keywords: (NLC); diabetic wound; nanostructured lipid carrier; propolis; wound healing; α-Mangostin.

Graphical abstract

Figure 1

Physical appearance of NLC-P and NLC-P-αM preparation.

Figure 2

In vitro release profile of NLC-P-αM compared to unloaded α-mangostin. Data are presented as mean ± standard deviation (n=3).

Figure 3

Viability of NIH-3T3 fibroblast cells after 24-hour exposure to NLC-P-αM and unloaded α-mangostin. Data are presented as mean ± standard deviation (n=3).

Figure 4

Representative images of wound closure at days 0, 4, 7, and 14 post-treatment, showing the progression of healing over time.

Figure 5

Wound closure rate (%) over days 0, 4, 7, and 14 post-treatment, showing the healing progression in different treatment groups. Data are presented as mean ± standard deviation (n=5); * significance level of P < 0.05; ** significance level of P < 0.01; and # insignificance level of P > 0.05.

Figure 6

Histological evaluation of skin tissue on day 14 post-treatment with PBS (A), αM (B), NLC-P (C), and NLC-P-αM (D), stained with H&E. The images highlight sebaceous gland formation (black arrow), hair follicle growth (blue arrow), and inflammatory cell infiltration (red arrow).

Figure 7

Epidermal thickness (μm) of skin tissue on day 14 post-treatment, measured from H&E-stained sections. Data are presented as mean ± standard deviation (n=5); ** significance level of P < 0.01; and # insignificance level of P > 0.05.