Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Abstract

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC’s clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of −46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

Graphical Abstract

Keywords:

• Tetrahydrocurcumin nanocrystals
• kappa-carrageenan
• nanocomposite sponge
• oral precancerous lesion
• oral cancer

Acknowledgements

The authors express deep gratitude to the Center of Excellence for Research in Regenerative Medicine and Applications (CERRMA), Faculty of Medicine, Alexandria University (STDF-Funded) for providing technical assistance and facilitation of the microscopic imaging unit.

Ethical approval

The Syrian male hamsters were used for induction of oral precancerous condition, as anatomically hamsters have sac-like structures known as buccal pouch. The cheek pouches have been called immunologically privileged sites, where precancerous and tumors can be induced without being rejected by the hamster immune system. Additionally, molecular and cellular changes in the multistep process of oral carcinogenesis in hamsters are thought to represent similar changes to human oral cancer.

All institutional and national guidelines for the care and use of laboratory animals were followed. All procedures were conducted according to the established principles of animal experiments in the UK Directive of 1986; 86/609/EEC. The experimental protocols were approved by the Alexandria University Ethics Committee (IRBNO:00010556-IORG0008839).

Hamsters at 5 weeks of age (80–120 g) were obtained from VACSERA, Cairo, Egypt. They were housed in show box cages (Technoplast, Italy), one per cage, at the Animal House Unit in the Medical Research Institute, Alexandria University. They were allowed to acclimatize for 2 weeks before starting the experiment. The hamsters were housed at a room temperature of 23 ± 1 °C, a relative humidity of 50% ± 5, and a 12-h light/dark cycle. Hamsters received standard diet and water throughout the experimental period, with close monitoring of their normal behavior throughout the duration of the experiment. During therapeutic application, animals were lightly sedated by IP injection of a low-dosed combination of 0.1 mL/100 g ketamine hydrochloride and 0.05 mL/100 g xylazine hydrochloride. At the end of experimental duration, hamsters were euthanized by an overdose of ketamine hydrochloride (>30 mg/kg), given IP. Cautious assessment of animal was then performed to confirm death and the remains of animals’ bodies were handled by special authorities. All animal experiments were performed following the ARRIVE guidelines.

Authors’ contributions

All authors contributed to the design of the article. The initial idea of the article was developed by Ossama Y. Abdallah who conceived and designed the analysis, contributed to study design, interpretation of data, supervision, and manuscript review. Shimaa A. Elbanna performed the literature search, data collection/analysis, wrote the original draft and contributed to publication process. Hebatallah S. Barakat contributed to study design, interpretation of data, supervision, and manuscript review. Heba MK. Ebada contributed to study design, interpretation of data, supervision, and manuscript review. Marwa M. Essawy and Hend M. Abdelhamid carried out the in vivo experiment involving study design, clinical assessment, histopathological analysis, immunohistochemical/morphometric analysis, and manuscript review. All authors read and approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.