Development of an anti-infective coating on the surface of intraosseous implants responsive to enzymes and bacteria

Background Bacterial proliferation on the endosseous implants surface presents a new threat to the using of the bone implants. Unfortunately, there is no effective constructed antibacterial coating which is bacterial anti-adhesion substrate-independent or have long-term biofilm inhibition functions. Methods Drug release effect was tested in Chymotrypsin (CMS) solution and S. aureus. We used bacterial inhibition rate assays and protein leakage experiment to analyze the in vitro antibacterial effect of (Montmorillonite/Poly-l-lysine-Chlorhexidine)10 [(MMT/PLL-CHX)10] multilayer film. We used the CCK-8 assay to analyze the effect of (MMT/PLL-CHX)10 multilayer films on the growth and proliferation of rat osteoblasts. Rat orthopaedic implant-related infections model was constructed to test the antimicrobial activity effect of (MMT/PLL-CHX)10 multilayer films in vivo. Results In this study, the (MMT/PLL-CHX)10 multilayer films structure were progressively degraded and showed well concentration-dependent degradation characteristics following incubation with Staphylococcus aureus and CMS solution. Bacterial inhibition rate assays and protein leakage experiment showed high levels of bactericidal activity. While the CCK-8 analysis proved that the (MMT/PLL-CHX)10 multilayer films possess perfect biocompatibility. It is somewhat encouraging that in the in vivo antibacterial tests, the K-wires coated with (MMT/PLL-CHX)10 multilayer films showed lower infections incidence and inflammation than the unmodified group, and all parameters are close to SHAM group. Conclusion (MMT/PLL-CHX)10 multilayer films provides a potential therapeutic method for orthopaedic implant-related infections.

Antibacterial activity of lactic acid bacteria isolated from Dengke Naniura of Carp (Cyprinus carpio) against diarrhea-causing pathogenic bacteria

Nasri, Harahap U, Silalahi J, Satria D. 2021. Antibacterial activity of lactic acid bacteria isolated from Dengke Naniura of Carp (Cyprinus carpio) against diarrhea-causing pathogenic bacteria. Biodiversitas 22: 3098-3104. Diarrhea is the discharge of liquid or watery stools 3 to 4 times a day caused by a bacterial infection. Treatments for diarrhea are probiotics, which have a beneficial effect on the health of the host such as antibacterial. Traditional Batak Toba fermented food, Dengke Naniura, is a source of probiotics. This study aimed to determine the minimum inhibitory concentration, minimum bactericidal concentration, and leakage of DNA and protein from lactic acid bacteria against pathogens. Isolation of LAB was obtained from Dengke Naniura by pour plate method on deMann Rogosa and Sharpe Agar + CaCO3 1%. In this study, Characterization and analysis of bacterial sequencing used Polymerase Chain Reaction. Determination of MIC used the agar diffusion method. The MBC test used the streaking method which was a stroke from the inhibition zone formed. DNA and protein leakage was measured using spectrophotometry UV-VIS (260nm and 280nm). The isolation results obtained were Lactobacillus fermentum, the characterization showed that the bacteria were Gram-positive, bacilli, non-sporing, catalase-negative, and able to ferment sugar. The MIC determination was obtained at a concentration of 10%v/v with a clear zone diameter. Determination of MBC against pathogens was obtained at different concentrations. The results of DNA and protein leakage showed an increased absorption (260nm and 280nm).

Neurovascular Unit Alterations In The Growth Restricted Newborn Are Improved Following Ibuprofen Treatment

The developing brain is particularly vulnerable to fetal growth restriction (FGR) and abnormal neurodevelopment is common in the FGR infant ranging from behavioural and learning disorders through to cerebral palsy. No treatment exists to protect the FGR newborn brain. Recent evidence suggests inflammation may play a key role in the mechanism responsible for the progression of brain impairment in the FGR newborn, including disruption to the neurovascular unit (NVU). We explored whether ibuprofen, an anti-inflammatory drug, could reduce NVU disruption and brain impairment in the FGR newborn. Using a preclinical FGR piglet model, ibuprofen was administered for three days from birth. FGR brains demonstrated an inflammatory state, with changes to glial morphology (astrocytes and microglia), and blood brain barrier disruption, assessed by IgG and albumin leakage into the brain parenchyma and a decrease in blood vessel density. Loss of interaction between astrocytic end-feet and blood vessels was evident where plasma protein leakage was present, suggestive of structural deficits to the NVU. A significant increase in peripheral infiltrates were also evident in the parenchyma of FGR piglet brains. Ibuprofen treatment reduced the pro-inflammatory response in FGR piglets, reducing levels of pro-inflammatory cytokines and number of activated microglia and astrocytes associated with blood vessels. Ibuprofen also attenuated plasma protein leakage, regained astrocytic end-feet interaction around vessels, and decreased T-cell infiltration into the FGR brain. These findings suggest postnatal administration of ibuprofen modulates the inflammatory state, allowing for stronger interaction between vasculature and astrocytic end-feet to restore NVU integrity. These changes to the FGR brain microenvironment may be key to neuroprotection.

Green synthesis and antibacterial activity of silver nanoparticles from the aqueous extracts of Cassia alata

The current study involves the synthesis of silver nanoparticles from the aqueous extracts of Cassia alata. The synthesized silver nanoparticles were characterized by UV-Vis, FT-IR, SEM-EDX and XRD. The in vitro bioactivity studies were examined against a Gram-positive and Gram-negative micro-organism by performing antibacterial activity, minimum inhibition assay, swarming motility and protein leakage assay. The characteristic study on the nanoparticles using spectrometric and microscopic analysis, revealed them to be sized between 25 nm and 60 nm. The nanoparticles on evaluating the antibacterial activity against Pseudomonas aeruginosa and Bacillus subtilis interacted well with the microorganisms producing a significant inhibitory effect at a minimum concentration of 0.5 µg/mL. The permeability of the particles was also studied through protein leakage assay.

Effect of Silver Nanoparticles on Biofilm Formation and EPS Production of Multidrug-Resistant Klebsiella pneumoniae

Antibiotic resistance against present antibiotics is rising at an alarming rate with need for discovery of advanced methods to treat infections caused by resistant pathogens. Silver nanoparticles are known to exhibit satisfactory antibacterial and antibiofilm activity against different pathogens. In the present study, the AgNPs were synthesized chemically and characterized by UV-Visible spectroscopy, scanning electron microscopy, and X-ray diffraction. Antibacterial activity against MDR K. pneumoniae strains was evaluated by agar diffusion and broth microdilution assay. Cellular protein leakage was determined by the Bradford assay. The effect of AgNPs on production on extracellular polymeric substances was evaluated. Biofilm formation was assessed by tube method qualitatively and quantitatively by the microtiter plate assay. The cytotoxic potential of AgNPs on HeLa cell lines was also determined. AgNPs exhibited an MIC of 62.5 and 125 μg/ml, while their MBC is 250 and 500 μg/ml. The production of extracellular polymeric substance decreased after AgNP treatment while cellular protein leakage increased due to higher rates of cellular membrane disruption by AgNPs. The percentage biofilm inhibition was evaluated to be 64% for K. pneumoniae strain MF953600 and 86% for MF953599 at AgNP concentration of 100 μg/ml. AgNPs were evaluated to be minimally cytotoxic and safe at concentrations of 15-120 μg/ml. The data evaluated by this study provided evidence of AgNPs being safe antibacterial and antibiofilm compounds against MDR K. pneumoniae.

Synthesis, Characterization, Comparative Antidandruff Efficacy and Cytotoxicity Studies of Biosynthesized Silver Nanoparticles by Using Glycyrrhiza glabra Root

In the present study silver nanoparticles (AgNPs) were synthesized using Glycyrrhiza glabra root extract and evaluated their antimicrobial potential against dandruff causing pathogens. Dandruff is an inflammatory of scalp expression that impacts approximately half of the world's population. The development of new class of antidandruff agents based on sustainable means is essential. Characterization of AgNPs were done by UV-Visible spectroscopy, transmission electron microscopy (TEM) and fourier transform infrared (FTIR) spectroscopy. Bradford assay was performed for protein leakage analysis. Cytotoxicity was checked by 3-(4,5-dimethyl-2-yl)-2,5-diphynyl tetrazolium bromide (MTT) assay on human embryonic kidney (HEK)-293 cell lines. The zone of inhibition for Glycyrrhiza glabra extracts and AgNPs was measured from 9–42 mm while minimum inhibitory concentration (MIC) was in the range of 25–380 μg/ml. AgNPs showed lowest MIC against P. acne at concentration of 25 μg/ml. Protein leakage analysis revealed that AgNPs may disturb the solidity of pathogens membrane. Cytotoxicity evaluation on cell lines showed that both Glycyrrhiza glabra root extract and AgNPs are nontoxic on HEK-293 cell lines. Therefore, it can be concluded from the studies that utilization of Glycyrrhiza glabra based synthesis of AgNPs could be explored to manage dandruff.