Catechol-Functionalized Alginate Nanoparticles as Mucoadhesive Carriers for Intravesical Chemotherapy

This research aimed to synthesize and evaluate mucoadhesive catechol-functionalized alginate (Cat-Alg) nanoparticles (NPs) for bladder cancer. Cat-Alg was synthesized using coupling chemistry, and the structure was verified using NMR and FT-IR. Cat-Alg NPs were generated by ionic gelation between the synthesized Cat-Alg and calcium chloride. Garcinia mangostana L. extract (GM extract) was entrapped into the NPs during particle formation. The physical characteristics, mucoadhesive properties, drug loading and release, cellular uptake, and anticancer activity of the GM extract-loaded NPs were investigated. The Cat-Alg NPs were spherical with sizes in the range of 155-186 nm. The slightly negative surface charge of the NPs provided them with excellent stability. The Cat-Alg NPs could be retained on a porcine bladder mucosa to a greater extent compared with unmodified Alg NPs. High loading efficiency (71.6%) and loading capacity (292 μg/mg) of GM extract in the NPs were achieved, and a constant release of GM extract was obtained for up to 8 h with zero-order kinetics. Moreover, the GM extract-loaded NPs were deposited in bladder tissue and accumulated in MB49 cells at a higher rate compared with GM extract suspension. In addition, the NPs could kill a mouse urothelial carcinoma cell line with low IC₅₀. Therefore, these NPs have the potential to be a mucoadhesive drug delivery system for bladder cancer treatment. However, additional in vivo investigations are needed for clinical application in cancer treatment. Graphical abstract.