Narrow spectrum nano-antibiotic for selective removal of ARB from contaminated water: New insights into stimuli response based on cellular attachment, lysis, and excretion.

Narrow spectrum nano-antibiotics are supposedly the future trouble-shooters to improve the efficacy of conventional antimicrobials for treatment of severe bacterial infections, remove contamination from water and diminish the development of antibiotic resistance. In this study, antimicrobial peptide functionalized boron-carbon-nitride nanosheets ((Ant)pep@BCN NSs) are developed that are a promising wastewater disinfector and antibiotic resistant bactericide agent. These nanosheets are developed for selective removal and effective inactivation of antibiotic resistant bacteria (ARB) from water in presence of two virulent bacteria. The (Ant)pep@BCN NSs provide reactive surface receptors specific to the ARB. They mimic muralytic enzymes to damage the cell membrane of ARB. These NSs demonstrate 3-fold higher antimicrobial efficiency against the targeted ARB compared to pristine BCN even at lower concentrations. To the best of our knowledge, this is the first time that functionalized BCN has been developed to remove ARB selectively from wastewater. Furthermore, the (Ant)pep@BCN selectively reduced the microbiological load and led to morphological changes in Gram negative ARB in a mixed bacterial inoculum. These ARBs excreted outer-inner membrane vesicles (OIMVs) of triangular shape as a stimuli response to (Ant)pep@BCN NSs. These novel antimicrobial peptide-NSs have potential to improve treatment efficacy against ARB infections and water contamination.

Polymer-Coated and Nanofiber-Reinforced Functionally Graded Bioactive Glass Scaffolds Fabricated Using Additive Manufacturing.

In this study, carbon nanotube (CNT) reinforced functionally graded bioactive glass scaffolds have been fabricated using additive manufacturing technique. Sol-gel method was used for the synthesis of the bioactive glass. For ink preparation, Pluronic F-127 was used as an ink carrier. The CNT-reinforced scaffolds were coated with the polymer polycaprolactone (PCL) using dip-coating method to improve their properties further by sealing the micro-cracks. The CNT- reinforcement and polymer coating resulted in an improvement in the compressive strength of the additively manufactured scaffolds by 98% in comparison to pure bioactive glass scaffolds. Further, the morphological analysis revealed interconnected pores and their size appropriate for osteogenesis and angiogenesis. Evaluation of the in vitro bioactivity of the scaffolds after immersion in simulated body fluid (SBF) confirmed the formation of hydroxyapatite (HA). Further, the cellular studies showed good cell viability and initiation of osteogensis. These results demonstrate the potential of these scaffolds for bone tissue engineering applications.