Lectin-Fortified Cationic Copper Sulfide Nanoparticles Gain Dual Targeting Capabilities to Treat Carbapenem-Resistant Acinetobacter baumannii Infection

Antimicrobial peptides grafted onto the surface of N-acetylcysteine-chitosan nanoparticles can revitalize drugs against clinical isolates of Mycobacterium tuberculosis

Tuberculosis is caused by Mycobacterium tuberculosis (MTB) and is the leading cause of death from infectious diseases in the World. The search for new antituberculosis drugs is a high priority, since several drug-resistant TB-strains have emerged. Many nanotechnology strategies are being explored to repurpose or revive drugs. An interesting approach is to graft antimicrobial peptides (AMPs) to antibiotic-loaded nanoparticles. The objective of the present work was to determine the anti-MTB activity of rifampicin-loaded N-acetylcysteine-chitosan-based nanoparticles (NPs), conjugated with the AMP Ctx(Ile21)-Ha; against clinical isolates (multi- and extensively-drug resistant) and the H37Rv strain. The modified chitosan and drug-loaded NPs were characterized with respect to their physicochemical stability and their antimycobacterial profile, which showed potent inhibition (MIC values <0.977 μg/mL) by the latter. Furthermore, their accumulation within macrophages and cytotoxicity were determined. To understand the possible mechanisms of action, an in silico study of the peptide against MTB membrane receptors was performed. The results presented herein demonstrate that antibiotic-loaded NPs grafted with an AMP can be a powerful tool for revitalizing drugs against multidrug-resistant M. tuberculosis strains, by launching multiple attacks against MTB. This approach could potentially serve as a novel treatment strategy for various long-term diseases requiring extended treatment periods.

Moringa oleifera seed based green synthesis of copper nanoparticles: Characterization, environmental remediation and antimicrobial activity

Textile dyes and heavy metals like hexavalent chromium [Cr(VI)] are considered major water pollutants. In addition, microbial contamination also seriously threatens potable water availability. The present study used Moringa oleifera seed aqueous extract to synthesize copper nanoparticles (MOS-CuNPs). MOS-CuNPs were characterized by various spectroscopy and microscopic techniques. MOS-CuNPs were shown to be effectual at removal of Cr(VI). The initial concentration of Cr(VI), contact time, pH, and temperature all impacted the removal of Cr(VI) by different concentrations of MOS-CuNPs. At low concentrations of MOS-CuNPs (0.3 mg/ml) pseudo-first order and high concentrations of MOS-CuNPs (0.4 and 0.5 mg/ml), pseudo-second order kinetics were obeyed. Thermodynamic analysis revealed that Cr(VI) was removed spontaneously, and the reaction was exothermic. In adsorption isotherm, equilibrium data followed Langmuir equation for Cr(VI) adsorption by MOS-CuNPs and maximum uptake capacity calculated was 38.6 mg/g. MOS-CuNPs efficiently removed cationic (rhodamine B, malachite green and methylene blue and) and anionic (congo red, titan yellow and methyl orange) dyes within 10 min of contact time. Further MOS-CuNPs showed antimicrobial activity against human pathogenic bacteria and fungi. Altogether, MOS-CuNPs could be used for environmental (water treatment) and biological applications.

Evaluation of citrus pectin capped copper sulfide nanoparticles against Candidiasis causing Candida biofilms

The incidence of candidiasis has significantly increased globally in recent decades, and it is a significant source of morbidity and mortality, particularly in critically ill patients. Candida sp. ability to generate biofilms is one of its primary pathogenic traits. Drug-resistant strains have led to clinical failures of traditional antifungals, necessitating the development of a more modern therapy that can inhibit biofilm formation and enhance Candida sp. sensitivity to the immune system. The present study reports the anticandidal potential of pectin-capped copper sulfide nanoparticles (pCuS NPs) against Candida albicans. The pCuS NPs inhibit C. albicans growth at a minimum inhibitory concentration (MIC) of 31.25 μM and exhibit antifungal action by compromising membrane integrity and overproducing reactive oxygen species. The pCuS NPs, at their biofilm inhibitory concentration (BIC) of 15.63 μM, effectively inhibited C. albicans cells adhering to the glass slides, confirmed by light microscopy and scanning electron microscopy. Phase contrast microscopy pictures revealed that NPs controlled the morphological transitions between the yeast and hyphal forms by limiting conditions that led to filamentation and reducing hyphal extension. In addition, C. albicans showed reduced exopolysaccharide (EPS) production and exhibited less cell surface hydrophobicity (CSH) after pCuS NPs treatment. The findings suggest that pCuS NPs may be able to inhibit the emergence of virulence traits that lead to the formation of biofilms, such as EPS, CSH, and hyphal morphogenesis. The results raise the possibility of developing NPs-based therapies for C. albicans infections associated with biofilms.

A Review Unveiling Various Machine Learning Algorithms Adopted for Biohydrogen Productions from Microalgae

Biohydrogen production from microalgae is a potential alternative energy source that is now intensively being researched. The complex natures of the biological processes involved have afflicted the accuracy of traditional modelling and optimization, besides being costly. Accordingly, machine learning algorithms have been employed to overcome setbacks, as these approaches have the capability to predict nonlinear interactions and handle multivariate data from microalgal biohydrogen studies. Thus, the review focuses on revealing the recent applications of machine learning techniques in microalgal biohydrogen production. The working principles of random forests, artificial neural networks, support vector machines, and regression algorithms are covered. The applications of these techniques are analyzed and compared for their effectiveness, advantages and disadvantages in the relationship studies, classification of results, and prediction of microalgal hydrogen production. These techniques have shown great performance despite limited data sets that are complex and nonlinear. However, the current techniques are still susceptible to overfitting, which could potentially reduce prediction performance. These could be potentially resolved or mitigated by comparing the methods, should the input data be limited.

Recent Advances in Nanotechnology for the Management of Klebsiella pneumoniae-Related Infections

Klebsiella pneumoniae is an important human pathogen that causes diseases such as urinary tract infections, pneumonia, bloodstream infections, bacteremia, and sepsis. The rise of multidrug-resistant strains has severely limited the available treatments for K. pneumoniae infections. On the other hand, K. pneumoniae activity (and related infections) urgently requires improved management strategies. A growing number of medical applications are using nanotechnology, which uses materials with atomic or molecular dimensions, to diagnose, eliminate, or reduce the activity of different infections. In this review, we start with the traditional treatment and detection method for K. pneumoniae and then concentrate on selected studies (2015-2022) that investigated the application of nanoparticles separately and in combination with other techniques against K. pneumoniae.