Melanin nanoparticles (MNPs) have attracted growing attention in biomedical fields due to their wide bioavailability, high biocompatibility, biodegradability, and multifunctionality. Key features of MNPs are broad-spectrum light absorption, high drug-loading capacity, near-infrared light-triggered drug release and reactive oxygen species generation, efficient hepatobiliary, renal clearance, and superior binding affinity towards metal ions that enhance MNPs’ traceability in magnetic resonance imaging (MRI). Despite challenges such as agglomeration in time, lack of extraction standardization, and a limited number of animal and clinical studies, the strong photothermal conversion and reactive species production abilities of MNPs make them effective photosensitizers and photothermal agents, while their dual capability for molecular binding and metal chelation positions them as promising agents for theranostic applications. This review provides a comprehensive overview of MNPs, covering their structural features, manufacturing methods and associated limitations, and recent advances in their physicochemical characterization. Special focus is given to MRI-guided biomedical applications, including drug delivery, photothermal therapy, and photodynamic therapy, along with critical challenges related to the clinical translation and commercialization of MNP-based platforms. By consolidating recent advances, this review highlights key structure–function relationships that underpin emerging melanin-based nano-systems.

This study aimed at preparing chitosan nanoparticles (C.N.P.s) from fungal Chitosan for the purpose of producing nano-drug delivery systems for antifungal drugs. Chitosan was extracted from mycelia of Aspergillus niger using modified methods of George et al., (2011) and (Naghdi et al., 2014). For confirmation, the FTIR spectrum of the isolated Chitosan was compared with standard. A nanoformulation for Voriconazole antifungal drug was synthesized via ionic gelation method and characterized for their particle size, polydispersity index, surface charge, functional group composition using and Malvern Zeta Sizer ZS-90, P.C.S., FTIR, S.E.M. The prepared nanoformulation was also checked for its antifungal activity using Aspergillus niger and Aspergillus fumigatus as an indicator organism. Voriconazole showed maximum growth with no mycelial growth while CNPS showed minimum growth of about 70 percent, and Voriconazole loaded CNPS showed inhibitory growth effects on the mycelial growth of A. niger and A. fumigatus. Our results indicated that Chitosan Nanoparticles have huge potential against fungal diseases caused by Aspergillus species.