Investigation of Anti-Cancer Properties of Nano-Encapsulated Ciprofloxacin Using 3D Cancer Cell Spheroids as Tumour Models.

Bladder cancer remains a significant global health challenge, necessitating innovative therapeutic strategies to enhance treatment efficacy. This study investigates the potential of chitosan nanoparticles as a drug delivery system, using ciprofloxacin as a model compound and utilizing a 3D spheroid model of bladder cancer that better reflects in vivo tumour conditions. The encapsulation efficiency of ciprofloxacin was optimized on the appropriate mass ratio of chitosan to cross-linking tripolyphosphate (TPP) polyanion. The resulting spherical chitosan nanocapsules loaded with ciprofloxacin demonstrated improved stability and controlled drug release, addressing the limitations of non-encapsulated ciprofloxacin. In 3D T24 bladder cancer spheroids, encapsulated ciprofloxacin exhibited enhanced cytotoxicity compared to free-drug formulations, with significant effects observed at ciprofloxacin concentrations of 500 and 1000 μM after 48 and 72 h of exposure. The 3D spheroid model, which better mimics the tumour microenvironment than 2D cultures, enabled a more accurate drug efficacy evaluation. The results demonstrate that chitosan nanocapsules can improve the delivery and cytotoxic profile of ciprofloxacin in vitro, indicating their potential for further development as carriers in localized bladder cancer treatment.