On-demand storage and release of antimicrobial peptides using Pandora's box-like nanotubes gated with a bacterial infection-responsive polymer

Background: Localized delivery of antimicrobial agents such as antimicrobial peptides (AMPs) by a biomaterial should be on-demand. Namely, AMPs should be latent and biocompatible in the absence of bacterial infection, but released in an amount enough to kill bacteria immediately in response to bacterial infection.Methods: To achieve the unmet goal of such on-demand delivery, here we turned a titanium implant with titania nanotubes (Ti-NTs) into a Pandora's box. The box was loaded with AMPs (HHC36 peptides, with a sequence of KRWWKWWRR) inside the nanotubes and “closed” (surface-modified) with a pH-responsive molecular gate, poly(methacrylic acid) (PMAA), which swelled under normal physiological conditions (pH 7.4) but collapsed under bacterial infection (pH ≤ 6.0). Thus, the PMAA-gated Ti-NTs behaved just like a Pandora's box. The box retarded the burst release of AMPs under physiological conditions because the gate swelled to block the nanotubes opening. However, it was opened to release AMPs to kill bacteria immediately when bacterial infection occurred to lowering the pH (and thus made the gate collapse).Results: We demonstrated such smart excellent bactericidal activity against a panel of four clinically important bacteria, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus. In addition, this box was biocompatible and could promote the osteogenic differentiation of human mesenchymal stem ce...
Source: Theranostics - Category: Molecular Biology Authors: Tags: Research Paper Source Type: research

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Conclusions: The study showed that Micromeria fruticosa serpyllifolia volatile oil samples from different regions in Palestine possess different potential antioxidant and antimicrobial activities that were in line with traditional uses of the plant extracts. PMID: 32733942 [PubMed - in process]
Source: Biomed Res - Category: Research Authors: Tags: Biomed Res Int Source Type: research
There is grave necessity to counter the menace of drug-resistant biofilms of pathogens using nanomaterials. Moreover, we need to produce nanoparticles (NPs) using inexpensive clean biological approaches that demonstrate broad-spectrum inhibition of microbial biofilms and cytotoxicity against HepG2 cell lines. In the current research work, titanium dioxide (TiO2) NPs were fabricated through an environmentally friendly green process using the root extract of Withania somnifera as the stabilizing and reducing agent to examine its antibiofilm and anticancer potential. Further, X-ray diffraction (XRD), Fourier transform infrare...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Microbial Drug Resistance, Ahead of Print.
Source: Microbial Drug Resistance - Category: Microbiology Authors: Source Type: research
Conclusions: L. iteodaphne crude leaf extracts showed promising antibacterial activity against Gram-positive and Gram-negative bacteria and clinical isolates of MRSA. Further investigations toward fractionation and the identification of an active compound will enhance the antimicrobial potential of L. iteodaphne. PMID: 32695731 [PubMed]
Source: Biomed Res - Category: Research Authors: Tags: Adv Biomed Res Source Type: research
This study evaluated the chemical compounds present in Eucalyptus citriodora essential oil (EOEc) cultivated in northeastern Brazil and its properties as an antibacterial agent and resistance modifier against methicillin-resistant Staphylococcus aureus (MRSA) and β-lactamase-producing strains. The EOEc was obtained using the hydrodistillation method, later analyzed by GC/MS, presenting a total of twelve compounds, with citronellal (65.45%); citronellol (14.87%); isopulegol (11.80%) and citronellyl acetate (2.51%) as its main constituents. The microdilution test was used to determine the minimum inhibitory concentratio...
Source: Cellular and Molecular Biology - Category: Molecular Biology Tags: Cell Mol Biol (Noisy-le-grand) Source Type: research
Authors: Phuyal N, Jha PK, Raturi PP, Rajbhandary S Abstract Crude methanol extracts of fruits, seeds, and bark of Zanthoxylum armatum were investigated in vitro for antimicrobial activities against 9 different bacterial strains: Bacillus subtilis, Enterococcus faecalis, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus epidermidis using agar well diffusion method, and the MBC values were determined. Only 5 bacteria, i.e., Bacillus subtilis, Enterococcus faecalis, MRSA, Staphylococcus aureus...
Source: Journal of Tropical Medicine - Category: Tropical Medicine Tags: J Trop Med Source Type: research
ConclusionA high rate of Taiwanese adults in the community carried 3GC-R Enterobacteriaceae, while no CRE or VRE colonization was noted. Compared with non-carriers, an expansion of Enterobacteriaceae in gut microbiota was found among 3GC-R Enterobacteriaceae carriers.
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
This study presents trends in organism isolation and antimicrobial resistance in routine microbiology test results from acute-care hospital microbiology laboratories in Vermont. METHODS: Organism identifications and antimicrobial susceptibility test results were captured from acute-care hospital laboratories to monitor geographic and temporal trends in resistance and emerging microbial threats with the free WHONET software. RESULTS: Data were provided from 12 acute care hospital laboratories from 2011 through 2018 for 318,833 isolates from 148,994 patients (70% female, 74% outpatient, and 63% urine). Significant differences (p 
Source: Expert Review of Anti-Infective Therapy - Category: Infectious Diseases Tags: Expert Rev Anti Infect Ther Source Type: research
The objective of this study was to identify and isolate lactic acid bacterial (LAB) strains from the intestinal tracts of pigs and feces of dogs and then characterize them as potential probiotics with antimicrobial activity against multidrug-resistant pathogenic bacteria. In a preliminary isolation screening, 45 of 1167 isolated LAB strains were found to have anti-S. aureus ATCC 27,735 activity. Using 16S rDNA and 16S-23S rDNA intergenic spacer region (ISR) sequences, five of these isolates were further identified as Lactobacillus animalis 30a-2, Lactobacillus reuteri 4-12E, Weissella cibaria C34, Lactococcus lactis 5-12H,...
Source: Archives of Microbiology - Category: Microbiology Authors: Tags: Arch Microbiol Source Type: research
Conclusion: Staphylococcus sp. was the most common pathogen found in hip infections. However, the high incidence of Gram-negative infection requires that prophylactic antibiotics cover these organisms as well. The high resistance to first-line antibiotics should be taken into consideration while making protocols. The knowledge of the microbial profile is especially important when considering arthroplasty for arthritis secondary to hip infections.
Source: Indian Journal of Medical Microbiology - Category: Microbiology Authors: Source Type: research
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