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The eradication of several pathogenic drug resistant "Superbug" such as Escherichia coli became difficult especially in chronic infections using existing antibiotics due to the emergence of antibiotic resistance. Owing to their unique antibacterial properties, host defense peptides (HDP) have gained significant attention to combat colonization of bacteria. This study aims designing delivery systems for HHC10 peptide to target bacteria inside the cells might be a promising approach by protecting from degradation, controlling the release, enhancing the susceptibility of target microbes and improving bioavailability. Nano-formulated HHC10 was evaluated for its efficacy (CFU assay) and possible mechanism of action (membrane interaction and apoptosis) against E. coli. Dose-dependent inhibition of E. coli growth is observed for nano-encapsulated and bare HHC10 and encapsulated form remain non-toxic to macrophage mouse cells (RAW264.6) up to 20 μM. Mechanistic analyses using transmission electron microscopy and flow cytometry techniques revealed that bactericidal activity of HHC10-NP progresses via a multimodal mechanism of bacterial cell death by cell-membrane lysis on direct interaction with bacteria while through induction of the apoptotic death pathway inside the host cells. These results offer an insight on future strategies for the development and application of antimicrobial peptides as antibacterial alternatives. Controlled delivery of HHC10 peptide from PLGA-NP kills bacteria by two different mechanism: (i) direct killing: HHC10 disintegrate the cell membrane of bacteria by electrostatic interactions and (ii) indirect killing: induction of apoptosis in bacteria infect cells. [ABSTRACT FROM AUTHOR]

Lysosomes are of particular interest for the design and delivery of pH-dependent pro-drugs, enhancing selectivity and developing strategies to inhibit drug degradation inside the cells. There is great potential to bring intracellular drug delivery and distribution using nanotherapeutic approaches to target lysosomes for therapeutic interventions. Lysosomal targeting strategies involve two contrasting facets. One aspect is to directly target therapeutics to the lysosome through receptor-mediated endocytosis and the other facet involves strategies, which ensure escape from the lysosome in order to prevent their degradation, so that therapeutics may remain intact and available in the cytosol for their further action. It provides a unique opportunity to explore novel treatment strategies and design future drugs for the effective treatment of lysosome-related diseases especially lysosomal storage disorders (LSD), cancer, inflammatory, neurodegenerative conditions (Parkinson's, Alzheimer's and Huntington's diseases) and autoimmune diseases. In this review, we illustrate the fundamentals of membrane trafficking, subcellular organisation, strategies to target lysosomes and its implications for the advance design of efficient drug delivery vectors for safe and effective therapies. [ABSTRACT FROM PUBLISHER]