Co-Encapsulation of Curcumin and α-Tocopherol in Bicosome Systems: Physicochemical Properties and Biological Activity

Evaluation of Preclinical Efficacy of Curcumin-Loaded Bicosome Systems in Amelioration of Oral Mucositis

BACKGROUND/OBJECTIVES

Oral mucositis (OM) is a common and debilitating side effect of cancer therapy, characterized by ulceration or inflammation of the oral mucosa. This study evaluates the preclinical efficacy of curcumin-loaded bicosome systems (cur-BS) in mitigating chemotherapy-induced OM in mice.

METHODS

BS were prepared using a combination of 1,2-di-palmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), α-tocopherol, and curcumin, encapsulated within liposomal vesicles. Three formulations with different curcumin concentrations (180, 540, and 900 μM) were characterized by particle size, polydispersity index (PDI), encapsulation efficiency (EE), appearance, and morphology. The formulation with the highest concentration (cur-BS 5×) was selected for ex vivo permeability studies, release profile analysis, and in vitro anti-inflammatory efficacy. OM was induced in mice using 5-fluorouracil (5-FU) and acetic acid. Cur-BS 5× was compared to the commercial product Dentoxol®.

RESULTS

The results showed that cur-BS 5× provided sustained release through a mechanism involving both diffusion and matrix relaxation, enhancing curcumin retention in deeper skin layers. Treatment with cur-BS 5× downregulated the expression of inflammatory markers (IL-1β and TNF-α). Macroscopic assessments demonstrated that both cur-BS 5× and Dentoxol® reduced OM severity, with the greatest improvement observed between days 6 and 9. By day 24, OM scores were 1.25 ± 0.5 for cur-BS 5× and 1.0 ± 0.0 for Dentoxol®, indicating effectiveness in both treatments. However, histological analysis revealed superior tissue recovery with cur-BS 5×, showing better epithelial structure and reduced inflammation. Cur-BS 5×-treated mice also exhibited greater weight recovery and higher survival rates compared to the Dentoxol® group.

CONCLUSIONS

These findings suggest that cur-BS 5× may enhance OM treatment, offering outcomes comparable to or better than those of Dentoxol®.

Injectable Liposome-Loaded Hydrogel Formulations with Controlled Release of Curcumin and α-Tocopherol for Dental Tissue Engineering

An injectable hydrogel formulation is developed utilizing low- and high-molecular-weight chitosan (LCH and HCH) incorporated with curcumin and α-tocopherol-loaded liposomes (Lip/Cur+Toc). Cur and Toc releases are delayed within the hydrogels. The injectability of hydrogels is proved via rheological analyses. In vitro studies are conducted using human dental pulp stem cells (hDPSCs) and human gingival fibroblasts (hGFs) to examine the biological performance of the hydrogels toward endodontics and periodontics, respectively. The viability of hDPSCs treated with the hydrogels with Lip/Cur+Toc is the highest till day 14, compared to the neat hydrogels. During odontogenic differentiation tests, alkaline phosphatase (ALP) enzyme activity of hDPSCs is induced in the Cur-containing groups. Biomineralization is enhanced mostly with Lip/Cur+Toc incorporation. The viability of hGFs is the highest in HCH combined with Lip/Cur+Toc while wound healing occurs almost 100% in both (Lip/Cur+Toc@LCH and Lip/Cur+Toc@HCH) after 2 days. Antioxidant activity of Lip/Cur+Toc@LCH on hGFs is significantly the highest among the groups. Antimicrobial tests demonstrate that Lip/Cur+Toc@LCH is more effective against Escherichia coli whereas so is Lip/Cur+Toc@HCH against Staphylococcus aureus. The antimicrobial mechanism of the hydrogels is investigated for the first time through various computational models. LCH and HCH loaded with Lip/Cur+Toc are promising candidates with multi-functional features for endodontics and periodontics.

Fabrication, characterization and release behavior of α-tocopherol acetate-loaded pH-responsive polyhydroxybutyrate/cellulose acetate phthalate microbeads

Microbeads are used in personal care and cosmetic products (PCCPs) but are produced from nondegradable materials. Biodegradable polyhydroxybutyrate (PHB) has been recognized as a promising alternative material for use in PCCPs; however, utilizing PHB to encapsulate PCCPs is challenging because PCCPs need to be protected from the environment but their release needs to be permitted under specific physiological conditions. The aim of this work was to develop and evaluate pH-responsive cellulose acetate phthalate (CAP) to formulate lipophilic α-tocopherol acetate (α-TA)-loaded pH-responsive PHB/CAP microbeads. The influences of the PHB/CAP ratio and initial α-TA loading on the microbead size, surface morphology, encapsulation efficiency (%EE), loading capacity (%LC), and α-TA release profile were studied. The microbeads exhibited a spherical shape with a size of 328.7 ± 2.9 μm. The EE and LC were 86.7 ± 2.6 % and 13.5 ± 0.4 %, respectively. The release profile exhibited pH-responsive characteristics. These α-TA-loaded pH-responsive microbeads were stable with >50 % of the α-TA remaining after 90 days at 4, 25 and 45 °C in the dark. The results from the cytotoxicity assay with PSVK1 cells demonstrated that the microbeads were nontoxic. Hence, our developed formulation has the potential to be used to encapsulate oil-based drugs to formulate lipophilic substance-loaded pH-responsive microbeads.