Antitumor and antibiofilm effect of a hydrogel loaded with octenidine hydrochloride (OCTH) for topical treatment of cancer.

OBJECTIVE

To determine and characterize the antitumor activity of a hydrogel loaded with octenidine hydrochloride (OCTH) and its action mechanism on human tumor cells.

MATERIAL AND

METHODS

The antibiofilm property of OCTH against a clinical methicillin-resistant Staphylococcus aureus isolate (MRSA-CI) was evaluated by disk diffusion assays and a human bone-biofilm model in combination with the BacLight™ staining. The antitumor activity of soluble OCTH and OCTH-loaded biodegradable hydrogels was assessed in human tumor cell lines (MCF-7, CAL-27, FaDu, and A549) under different experimental conditions. Cell viability was measured with the MTT assay, and membrane permeability after OCTH-loaded hydrogel exposure was evaluated with the Calcein AM assay. Genotoxicity was evaluated with comet assay and fluorescence microscopy.

RESULTS

A stable, transparent, and biodegradable OCTH hydrogel with a pH of 7.2 was successfully developed. Biofilms exposed to 50 μm OCTH for 24 h exhibited only dead bacteria (red fluorescence), comparable to the effect of 100 μm vancomycin. Soluble OCTH demonstrated dose-dependent inhibition of tumor cell growth in all tested cell lines, with significant effects observed from 1 μm. The LD50 values for soluble OCTH across the tumor cell lines ranged from 2.32 to 5.1 µm. Notably, hydrogel loaded with 50 μm OCTH significantly reduced cell growth by 44% after a 15-min exposure and by 97% after 120 min. The Calcein AM assay revealed that OCTH's antitumor mechanism involves the disruption of tumor cell plasma membrane permeability.

CONCLUSION

This study is the first that describes the antitumor activity of octenidine hydrochloride on different human tumor cell lines. A biodegradable hydrogel loaded with octenidine hydrochloride constitutes an innovative, low-cost alternative for the topical treatment of cancer.