Fabrication of size-tunable polydopamine nanoparticles: toxicity evaluation in cellular and animal models

Nanotechnologically synthesized polymeric nanoparticles are now utilized as promising drug carriers. The size of the nanoparticles is crucial for the effective development of a drug delivery regime since it significantly affects drug loading, in vivo drug pharmacokinetics, bio-distribution, and cellular uptake. We demonstrate the fabrication of polydopamine nanoparticles (PDA NPs) in different molar concentrations of ammonia to dopamine hydrochloride to tune a suitable size for their effective efficacy. Dynamic light scattering (DLS) and SEM characterizations revealed their size and morphology. The stability of the nanoparticles was improved upon lyophilization and storage at 4 °C. FTIR, ¹H NMR, and UV-Vis measurements validated the successful synthesis of PDA NPs. In vitro antioxidant examinations exhibited potential DPPH scavenging, hydroxyl radical scavenging, and reducing ability of small-sized PDA NPs. The cytotoxicity was scrutinized through MTT assay, oxidative stress, and mitochondrial membrane study in breast and colon cancer cells. In vivo toxicity profiling was examined by acute and subacute toxicity studies of PDA NPs through biochemical and histoarchitectural analysis in Swiss albino mice. The findings may contribute to the possible utilization of PDA NPs as a safe nanocarrier for therapeutic purposes.