Preparação, otimização e caracterização de nanocristais do derivado 2-Amino-Tiofeno, 6CN10, e avaliação de sua atividade antifúngica sobre Candida spp. E Cryptococcus spp

Abstract

Fungal infections, such as candidiasis and cryptococcosis, represent a growing challenge to public health, especially among immunocompromised individuals. The limited diversity of available antifungals and the emergence of drug resistance increase the need for new therapies. The compound 6CN10, a 2-amino-thiophene derivative with promising antifungal activity, exhibits low water solubility, limiting its clinical application. In the present study, the development, optimization, and characterization of 6CN10 nanocrystals using X-ray Diffraction, Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and Nuclear Magnetic Resonance (NMR) aimed to evaluate the increase in solubility in aqueous medium of the developed nanoparticle, assess its antifungal activity through the analysis of Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) via the CLSI m27-a3 protocol against 9 strains of C. neoformans and 3 of Candida spp., and evaluate potential target proteins of 6CN10 through molecular docking. The nanocrystals were obtained using the anti-solvent nanoprecipitation technique and exhibited an average particle size of 252.1 ± 14.2 nm with a polydispersity index (PDI) of 0.04 ± 0.03. The optimized experimental design demonstrated with p>0.05 that the studied variables—solvent volume, stabilizer concentration, and the interaction between factors such as solvent volume and stabilizer type, solvent volume and stabilizer concentration, and stabilizer type and stabilizer concentration—influence the response variable particle size. The 6CN10 nanocrystals showed a 7-fold increase in water solubility compared to the pure drug. The lyophilized nanocrystals remained stable after 90 days, with a particle size of 256.42 ± 3.25 nm and a PDI of 0.17 ± 0.2. XRD studies indicated the amorphization of lyophilized nanocrystals. Raman spectroscopy, NMR, and FTIR studies demonstrated that there were no changes in the molecular bonds during the formulation of the nanocrystals. In the MIC evaluation, the strains C. neoformans 6895, C. neoformans 6901, C. neoformans 6907, and C. neoformans 6909 were susceptible to treatment, showing equal MIC values ranging from 250 to 125 μg/mL for both free 6CN10 and 6CN10 nanocrystals. The C. auris 01132023 strain was susceptible to the nanocrystals, exhibiting an MIC of 125 μg/mL. The 6CN10 nanocrystals did not show fungicidal activity, while the free drug exhibited fungicidal activity. Based on these results, we conclude that 6CN10 and 6CN10 nanocrystals demonstrate promise in antifungal therapy and have potential against C. auris and C. neoformans strains.