Exploiting chitosan and gold nanoparticles for antimycobacterial activity of in silico identified antimicrobial motif of human neutrophil peptide-1

Abstract

The upsurge of drug resistant tuberculosis is major health threat globally. To counteract, antimicrobial peptides are being explored as possible alternatives. However, certain limitations of peptide-based drugs such as potential toxicity, high cost and relatively low stability need to be addressed to enhance their clinical applicability. Use of computer predicted short active motifs of AMPs along with nanotechnology could not only overcome the limitations of AMPs but also potentiate their antimicrobial activity. Therefore, present study was proposed to in silico identify short antimicrobial motif (Pep-H) of human neutrophil peptide-1 (HNP-1) and explore its antimycobacterial activity in free form and using nanoparticles-based delivery systems. Based on colony forming unit analysis, motif Pep-H led to killing of more than 90% M. tb in vitro at 10 μg/ml, whereas, similar activity against intracellularly growing M. tb was observed at 5 μg/ml only. Thereafter, chitosan (244 nm) and gold nanoparticles (20 nm) were prepared for Pep-H with both the formulations showing minimal effects on the viability of human monocyte derived macrophages (MDMs) and RBC integrity. The antimycobacterial activity of Pep-H against intracellular mycobacteria was enhanced in both the nanoformulations as evident by significant reduction in CFU (>90%) at 5–10 times lower concentrations than that observed for free Pep-H. Thus, Pep-H is an effective antimycobacterial motif of HNP-1 and its activity is further enhanced by chitosan and gold nanoformulations.

Current Advances in Lipid and Polymeric Antimicrobial Peptide Delivery Systems and Coatings for the Prevention and Treatment of Bacterial Infections

“…Utilizing chitosan as the nanogel matrix often provides a positive surface charge, which may increase macrophage uptake, making it a suitable delivery system for treatment of intracellular infections, such as M. tuberculosis. Sharma et al showed that encapsulation of the peptide pep-H in chitosan nanogels resulted in the formation of nanoparticles with a cationic surface charge, which then allowed an 80% reduction of intracellular bacterial load in comparison to equivalent concentrations of peptide in solution, which only showed a 12% reduction in intracellular M. tuberculosis load [125]. Chitosan-based nanogels have also demonstrated an increased residence and a close contact with mucosa due to their mucoadhesive property, making them a desirable system for topical mucosal administration [126].…”

Antimicrobial Peptides as Potential Anti-Tubercular Leads: A Concise Review

“…Recently, a 15-amino acid long fragment of HNP1, Pep-H, was tested in vitro against Mtb H37Rv, displaying an inhibitory activity of 60% and 92% at 5 μg/mL and 10 μg/mL, respectively, the latter being taken as its MIC ( Table 1 ). The peptide was also tested against intramacrophagic Mtb , demonstrating a 91% reduction of intracellular mycobacterial growth at 5 μg/mL [ 75 ]. Moreover, Pep-H not only led to a significant increase in the levels of RNOS and IFN-γ but also decreases pro-inflammatory cytokines such as TNF-α, IL-6 and MCP-1, highlighting immunomodulatory properties in addition to direct antimicrobial activity against Mtb [ 75 ].…”

Application of “Magnetic Anchors” to Align Collagen Fibres for Axonal Guidance

“…The fabrication process of GMNPs used a "one pot" polyol synthesis method, which is a modified version of the high temperature hydrolysis process that was developed previously [34,35]. Basically, four different solutions were prepared before the GMNP synthesis process.…”