Denial Mahata

Purification, biochemical characterization and self-assembled structure of a fengycin-like antifungal peptide from Bacillus thuringiensis strain SM1

An antifungal lipopeptide fengycin, producing strain SM1 was isolated from farm land soil sample and identified as Bacillus thuringiensis strain SM1 by using 16S rDNA analysis. Fengycin detected in the culture extract was further purified using HPLC and showed a molecular mass of 1492.8 Da by MALDI-TOF-MS analysis. Purified fengycin was allowed to construct their self-assembled structure onto a hydrophobic surface showing a clear improvement of antibacterial activity. In self-assembly, fengycin adapts a spherical micelle core shell like structure. Self-assembled fengycin may be a successful antimicrobial compound modifying its action from confined antifungal function. Besides it can open up a new area of research in supramolecular lipopeptide based compound making. This can revealed the mode of action of this unique self-assembled structure to fully evaluate its potential for use as an antimicrobial drug to control the emergence of bacterial infection.

Self-assembled cardanol azo derivatives as antifungal agent with chitin-binding ability

Cardanol is a non-isoprenoic phenolic lipid-mixture of distilled cashew nut shell liquid obtained from Anacardium occidentale. Herein, cardanol is purified from cashew nut shell liquid (CNSL) and synthesized to new compounds with different azo amphiphiles. These synthesized compounds are allowed to self-assembled in hydrophobic environment and checked antifungal activity against Candida albicans. Self-assembled structure of CABA showed higher antifungal activity (16μg/mL) and chitin-binding ability in comparison to CAP and CANB. Furthermore, the self-assembled azo amphiphiles are immobilized with silver ions to prepare hydrogel which showed eight folds enhanced antifungal activity. Toxicity is reduced by several folds of self-assembled or hydrogel structure in comparison to pure compounds. Thus, the self-assembled structure of amphiphiles and their hydrogels have been found to be new macromolecules of interest with potential use as antifungal drugs.

Functional and structural insights on self-assembled nanofiber-based novel antibacterial ointment from antimicrobial peptides, bacitracin and gramicidin S

A novel antibacterial ointment using bacitracin, specific for Gram-positive bacteria, and gramicidin S, a highly toxic antibacterial peptide, was here developed showing broad-spectrum antibacterial activities against pathogenic strains with less toxicity after self-assembly into nanofiber structures. Such structures were confirmed with scanning electron microscopy and CD analyses. In addition, in silico studies using docking associated with molecular dynamics were carried out to obtain information about fiber structural oligomerization. Thus, the bacitracin and gramicidin S-based self-assembled nanopeptide ribbon may be a successful ointment formulation for bacterial infection control.

Glucose Directly Promotes Antifungal Resistance in the Fungal Pathogen, Candida spp.

Background: Glucose level alters susceptibility of antifungal agents during chemotherapy in diabetes patients. Results: Glucose selectively interacts with antifungal agents, strongly affects azole drugs, and forms complexes by hydrogen bonding. Conclusion: It is important for researchers and pharmaceuticals to make new antibiograms for diabetes patients. Significance: Drug selection is important for controlling fungal infections in diabetes patients. Effects of glucose on the susceptibility of antifungal agents were investigated against Candida spp. Increasing the concentration of glucose decreased the activity of antifungal agents; voriconazole was the most affected drugs followed by amphotericin B. No significant change has been observed for anidulafungin. Biophysical interactions between antifungal agents with glucose molecules were investigated using isothermal titration calorimetry, Fourier transform infrared, and 1H NMR. Glucose has a higher affinity to bind with voriconazole by hydrogen bonding and decrease the susceptibility of antifungal agents during chemotherapy. In addition to confirming the results observed in vitro, theoretical docking studies demonstrated that voriconazole presented three important hydrogen bonds and amphotericin B presented two hydrogen bonds that stabilized the glucose. In vivo results also suggest that the physiologically relevant higher glucose level in the bloodstream of diabetes mellitus mice might interact with the available selective agents during antifungal therapy, thus decreasing glucose activity by complex formation. Thus, proper selection of drugs for diabetes mellitus patients is important to control infectious diseases.

Lignin- graft -Polyoxazoline Conjugated Triazole a Novel Anti-Infective Ointment to Control Persistent Inflammation

Lignin, one of the most abundant renewable feedstock, is used to develop a biocompatible hydrogel as anti-infective ointment. A hydrophilic polyoxazoline chain is grafted through ring opening polymerization, possess homogeneous spherical nanoparticles of 10–15 nm. The copolymer was covalently modified with triazole moiety to fortify the antimicrobial and antibiofilm activities. The hydrogel was capable of down regulating the expression level of IL-1β in LPS induced macrophage cells, and to cause significant reduction of iNOS production. It supported cellular anti-inflammatory activity which was confirmed with luciferase assay, western blot, and NF-κB analysis. This novel lignin-based hydrogel tested in-vivo has shown the abilities to prevent infection of burn wound, aid healing, and an anti-inflammatory dressing material. The hydrogel reported here provides a new material platform to introduce a cost-effective and efficient ointment option after undertaking further work to look at its use in the area of clinical practice.

Self-assembled amphoterecin B loaded into a self- assembled cardanol derivative as a soft green carrier for delivery and enhanced antifungal activity†

Self-assembly strategies are used for soft green carrier (SGC) preparation from cardanol after modification with benzenediazonium functional moieties (PHPDB). A spherical core-shell like self-assembled structure of Amphotericin B (AmpB) was loaded into PHPDB and released in aqueous medium. AmpB and PHPDB show ergosterol and chitin binding affinity, respectively, and sustain enhanced activity with proficient biofilm eradication.

Antibacterial coating on in-line suction respiratory catheter to inhibit the bacterial biofilm formation using renewable cardanyl methacrylate copolymer

Abstract Health-care materials associated with infections are very common in hospital admitted patients. There are generally infected by contact with the catheter or other multipurpose devices which are contacted with microbes. The respiratory infections associated with the pathogens having strong biofilm forming ability on catheter surface, causes life-threatening in every year. Therefore, a catheter coating material is of great interest which inhibits the biofilm formation of pathogens on a catheter to prevent respiratory infections. In this study, we synthesized cardanol containing copolymers as antimicrobial healthcare material via radical polymerization of cardanyl methacrylate (CMA) with styrene (St) monomer in presence of free radical initiator. The rate of polymerization was drastically reduced with the increase of feeding CMA monomer in copolymer. The thermal and mechanical properties were found to increase with incorporation of cardanol moiety in brittle and hard polystyrene. This soft copolymer was grafted onto polyvinyl chloride respiratory catheter which showed high antibacterial activity, inhibit the biofilm formation and also prevent bacterial adhesion. Therefore, the developed coating material on respiratory catheter surface is effective way to control the respiratory catheter-associated nosocomial infections.

Self-Assembled Tea Tannin Graft Copolymer as Nanocarriers for Antimicrobial Drug Delivery and Wound Healing Activity

Green chemistry polymers from renewable resources have recently received much more attention from pharmaceutical researchers. However, the appropriate application of a polymer depends on its chemical nature, biocompatibility and microstructure. Here, tannin polyphenols from the common beverage, tea, are used to develop a novel self-assembled porous capsule as a microstructure of hydrogel for versatile biological applications, such as drug delivery, antioxidant and wound healing activity. Hydrogel has been successfully used for the delivery of both anticancer and antimicrobial drugs. The developed material shows excellent biocompatibility and antioxidant activity in vitro. The scratch assay for in vitro wound healing activity reveals their higher potential to repair the damaged cells in comparison to control.

Molecular Self-Assembly of Copolymer from Renewable Phenols: New Class of Antimicrobial Ointment Base

Abstract Ointments are highly viscous forms intended for external applications either medicated or non-medicated means. Formulation of ointment depends upon the base ingredients to measure the viscosity difference. Several limitations of ointment bases has been encountered timely as agglomeration, oil phase ingredients can form lumps, poor dispersion, poor drug delivery efficiency, make stained, immiscible, and difficult to wash off. Therefore, it is necessary to make a new type of ointment bases that can overcome those limitations. This review summarizes a new type of ointment base preparation from the copolymer of renewable phenolic derivatives. The nanohydrogel preparation from these copolymers are especially effortless and highly efficient in drug delivery, exhibited versatile biological activities such as antioxidant, anti-inflammatory and wound healing in addition to antimicrobial property. Molecular self-assembly mechanisms have been addressed for nanogel formulation. The strategy makes a significant value in health-care application and be supposed to come marketed soon.

Phosphorylated cardanol prepolymer grafted guayule natural rubber: an advantageous green natural rubber

Natural rubber (HNR), produced from Hevea Brasiliensis, is being considered as the major source of 99.9% 1,4-cis-polyisoprene. Till date, this grade of natural rubber is not manufactured synthetically even using sophisticated solution polymerization techniques and utilizing the most advanced catalyst systems. Rubber industries have been continuously thriving for an alternative as well as an additional source of natural rubber to compensate for the reduction in production of Hevea natural rubber and to reduce the consumption of petroleum-based rubbers. The present study deals with chemical grafting of phosphorylated cardanol prepolymer (PCP) onto the main chain of guayule natural rubber (GNR), which could impart inherent multifunctional characteristics to the rubber. The grafting of PCP onto GNR was carried out successively using benzoyl peroxide as a free radical initiator in the solution stage and the grafting parameters have been optimized through the Taguchi method using grafting efficiency and percent grafting. Grafting of PCP onto GNR (PCP-g-GNR) was confirmed through UV–Visible, FTIR, NMR and GPC analysis. Thermal behavior of PCP-g-GNR indicates a significant increase in thermo-oxidative stability and it also displays a slight depression of glass transition temperature as compared to GNR. The viscoelastic characteristics of GNR also alter and cure characteristic improves drastically in giving rise to improved processability after grafting of the PCP. The unfilled PCP-g-GNR vulcanizates show approximately similar physico-mechanical properties with 5 phr processing oil as plasticized GNR vulcanizates. Therefore, PCP-g-GNR can be used in rubber industries as gum rubber materials as it reduces the usage of processing aids significantly.