Efficacy of CG 3 R 6 TAT Nanoparticles Self-Assembled from a Novel Antimicrobial Peptide for theTreatment of Candida albicans Meningitis in Rabbits

Background: Candidal meningitis is a common clinical manifestation of invasive candidiasis in neonates. The aim of this study was to evaluate the in vivo antifungal efficacy of CG3R6TAT nanoparticles, novel core-shell structures self-assembled from cationic antimicrobial peptides, in a rabbit model of candidal meningitis. Methods: In vitro activity of CG3R6TAT nanoparticles against Candida albicans was assessed by determining the minimum inhibitory concentration and kill-time curves. In vivo, intravenous treatment with CG3R6TAT nanoparticles (n = 6; 0.25 mg/kg/day) or fluconazole (n = 6; 100 mg/kg/day) began 3 days after infection and continued for 11 consecutive days; the efficacy was assessed following 11 days of treatment by yeast counting in cerebrospinal fluid (CSF), the leukocyte concentrations in CSF and the histopathology of brain parenchyma. Results: At a concentration three times higher than the minimum inhibitory concentration (8.1 µmol/l), the nanoparticles completely sterilized C. albicans after 5 h of incubation. In addition, there was a significant reduction in fungal counts and leukocyte concentrations in the CSF from rabbits treated with CG3R6TAT nanoparticles or fluconazole versus those from untreated control rabbits (p 0.05, vs. control). The histopathologic severity of rabbits was significantly attenuated after CG3R6TAT treatment (p = 0.001, vs. control). Conclusion: This study suggests that CG3R6TAT nanoparticles may be a promising therapeutic agent for candidal meningitis