Innovative strategy for chitosan nanoparticles biosynthesis using Gelidium amansii, statistical optimization,...

The demand for biosynthesized chitosan nanoparticles (chitosan-NPs) increases owing to their biocompatibility, versatile functional groups, mucoadhesive capabilities, antimicrobial activity, controlled drug release, and anticancer efficacy. The current study presents an innovative green-synthesis strategy for chitosan-NPs using Gelidium amansii hot-water extract as a crosslinking and stabilizing agent. The UV-vis spectrum shows a strong absorption peak at 243 nm. The transmission electron microscopy analysis revealed that the biosynthesized chitosan-NPs were spherical and their sizes varied from 5.1 to 13.57 nm. Fourier-transform infra-red analysis proved the presence of multiple functional groups, confirming the existence of capping agents on chitosan-NPs surface. The ζ-potential value on chitosan-NPs surface was +32.4 mV. To maximize chitosan-NPs yield, face-centered central composite design was used. The highest yield of 14.3 mg/mL was obtained using an initial pH of 7.42, a 23.42-h incubation time, and 1.49 % chitosan. Doxorubicin (DOX) was successfully loaded into chitosan-NPs with encapsulation efficiency and drug loading of 65.42 ± 0.03 and 11.89 ± 0.01 %. The IC₅₀ values for DOX, chitosan-NPs, and chitosan-NPs + DOX for HePG-2 cells were 7.32 ± 0.5, 21.17 ± 1.4, and 5.90 ± 0.3 μg/mL; respectively. Chitosan-NPs have a strong capacity to interact with the receptor proteins through numerous hydrogen bond interactions. These findings highlight the significance of chitosan-NPs in biological and pharmacological applications that require protein-ligand interactions.