Chalcone ((E)-1-(3-hydroxyphenyl)-3-(4-methoxyphenyl) prop-2-en-1-one) and ZnO flower-like nanorods were prepared and coated on cotton cloth with acacia as binder. The surface was characterized by FT-IR, AFM, goniometer and SEM-EDAX. The antibacterial activity of the coated cotton was tested against three organisms namely Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa in terms of live bacterial load, as measured by the colony forming units (CFU), adhered on the cotton surface. More than 99% reduction in bacterial load was observed against all three organisms. Viability of the bacterial cells was tested using a dual staining BacLight Kit. Majority of the cells adhered on the coated cotton surface were dead and on uncoated were live. S. aureus was found to be most hydrophobic organism. The chalcone showed 48%, 45% and 35% reduction in slime produced by S. aureus, E. coli and P. aeruginosa, respectively. © 2009 Elsevier Ltd. All rights reserved.

Mukesh Doble

Department Of Biotechnology

Ponnurengan Malliappan Sivakumar

Veluchamy Prabhawathi

Periyakaruppan Thangiah Manoharan

ADHESIVE COATINGS

Anti-bacterial activity

Bacterial cells

BACTERIAL LOAD

chalcone

Chalcones

COLONY FORMING UNITS

E. coli

FLOWER-LIKE

HYDROPHOBIC ORGANISMS

P.AERUGINOSA

Pseudomonas aeruginosa

S. aureus

SEM-EDAX

Staphylococcus aureus

ZnO nanorod

Bacteriology

Escherichia coli

nanorods

Semiconducting zinc compounds

Zinc oxide

Cotton

ACACIA

Bacteria (microorganisms)

Gossypium hirsutum

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Carbohydrate Polymers

Preparation of the gold core and silver shell NP (AuAgNP) is challenging because of the facile oxidation of silver. Here such a NP is carefully synthesized and conjugated with subtilisin to arrive at a stable spherical material of 120–130 nm in diameter (AuAgSNP). A biomaterial prepared by immobilizing AuAgSNP on polycaprolactam (PCL) exhibits antibiofilm properties against S. aureus and E. coli, but with lesser potency than the one prepared with bare AuAgNP. Subtilisin degrades the adhesive surface proteins of the bacteria thereby preventing the biofilm formation. Subtilisin conjugated AuAgSNP is not cytotoxic to 3T3 cells at its MIC, in contrast to AuAgNP. The presence of subtilisin promotes the fibroblast proliferation. This study indicates that AuAgSNP has antibacterial/antibiofilm activities as well as biocompatibility unlike NPs which are very cytotoxic to cells. Hence AuAgSNP can be used in medical implants and devices. © 2018

Materials Science and Engineering C

Design of antimicrobial polycaprolactam nanocomposite by immobilizing subtilisin conjugated Au/Ag core-shell nanoparticles for biomedical applications

Polydimethyl siloxane (PDMS), in spite of possessing excellent foul-release properties, is prone to microbial fouling caused by organisms such as bacteria and diatoms. In the present study, we incorporated metal oxide nanoparticles in PDMS matrix to create composites with enhanced antifouling properties. The nanocomposites were prepared by incorporating small amounts (0.1wt per cent) of CuO, CTAB-capped CuO and ZnO nanoparticles in PDMS. Their antibiofilm properties were tested invitro against a marine bacterium and a diatom and also in the field. ZnO nanocomposite, exhibiting highest hydrophobicity, surface roughness and good antimicrobial activity, prevented biofouling in the sea for 45 days. PDMS with CTAB-capped CuO showed minimum roughness and hydrophobicity and performed well against the bacterium Bacillus flexus and the diatom Navicula sp. Metal leaching rates from the nanocomposites were quite low when compared to reported data, indicating that environmental effects of the nanocomposites would be minimal. The study indicates that the antifouling property of a foul-release polymer such as PDMS can be further increased by incorporation of nanoparticles, so that the formulation remains fouling-free even without extra shear forces. © 2015 Elsevier Ltd.

International Biodeterioration and Biodegradation

Polydimethyl siloxane nanocomposites: Their antifouling efficacy invitro and in marine conditions

Porous biomaterial is the preferred implant due to the interconnectivity of the pores. Chances of infection due to biofilm are also high in these biomaterials because of the presence of pores. Although biofilm in implants contributes to 80% of human infections [1], there are no commercially available natural therapeutics against it. In the current study, glutaraldehyde cross linked lipase was transferred onto a activated porous polycaprolactam surface using Langmuir-Blodgett deposition technique, and its thermostability, slimicidal, antibacterial, biocompatibility and surface properties were studied. There was a 20% increase in the activity of the covalently crosslinked lipase when compared to its free form. This immobilized surface was thermostable and retained activity and stability until 100°C. There was a 2 and 7 times reduction in carbohydrate and 9 and 5 times reduction in biofilm protein of Staphylococcus aureus and Escherichia coli respectively on lipase immobilized polycaprolactam (LIP) when compared to uncoated polycaprolactam (UP). The number of live bacterial colonies on LIP was four times less than on UP. Lipase acted on the cell wall of the bacteria leading to its death, which was confirmed from AFM, fluorescence microscopic images and amount of lactate dehydrogenase released. LIP allowed proliferation of more than 90% of 3T3 cells indicating that it was biocompatible. The fact that LIP exhibits antimicrobial property at the air-water interface to hydrophobic as well as hydrophilic bacteria along with lack of cytotoxicity makes it an ideal biomaterial for biofilm prevention in implants. © 2014 Prabhawathi et al.

Fulltext

PLoS ONE

Antibiofilm properties of interfacially active lipase immobilized porous polycaprolactam prepared by LB technique

Drug resistant bacteria are a major threat to humans, especially those which mediate nosocomial infections. In this paper, three different 4-sulfonylmethyl chalcones are coated onto cotton cloths with acacia as the binder using a padding mangle to make them antibacterial. A 99% reduction in the adhesion of three slime producing organisms, namely Staphylococcus aureus NCIM5021, Escherichia coli NCIM2931 and Pseudomonas aeruginosa NCIM2901, on these surfaces was observed. The coated surfaces are more hydrophobic than the original one. The attachment of the bacteria (CFU ml-1) to the cloth is directly proportional (correlation coefficient, R = 0.58) to the hydrophobicity of the surface of the microorganism. The extent of bacterial attachment on the cloths (CFU ml-1) is not correlated with the minimum inhibitory concentration (MIC) of the chalcones (R = -0.1), but on the other hand it is negatively correlated with the hydrophilicity of the coated cloth (R = -0.52). This indicates that hydrophilic surfaces prevent bacterial attachment and hydrophobic organisms have a greater propensity to attach to hydrophobic surfaces than hydrophilic ones. A simple multi-linear regression model with the surface hydrophobicity of the organism and the hydrophilicity of the cloth is able to predict the extent of bacterial attachment. This study suggests that the coated cloths could find applications in hospital environments. © 2014 the Partner Organisations.

Biomaterials Science

Chalcone coating on cotton cloth-an approach to reduce attachment of live microbes

Silver and gold nanoparticles (of average size ∼20-27 nm) were incorporated in PU (Polyurethane), PCLm (Polycaprolactam), PC (polycarbonate) and PMMA (Polymethylmethaacrylate) by swelling and casting methods under ambient conditions. In the latter method the nanoparticle would be present not only on the surface, but also inside the polymer. These nanoparticles were prepared initially by using a cosolvent, THF. PU and PCLm were dissolved and swollen with THF. PC and PMMA were dissolved in CHCl3 and here the cosolvent, THF, acted as an intermediate between water and CHCl3. FTIR indicated that the interaction between the polymer and the nanoparticle was through the functional group in the polymer. The formation of E.coli biofilm on these nanocomposites under low (in a Drip flow biofilm reactor) and high shear (in a Shaker) conditions indicated that the biofilm growth was higher (twice) in the former than in the latter (ratio of shear force = 15). A positive correlation between the contact angle (of the virgin surface) and the number of colonies, carbohydrate and protein attached on it were observed. Ag nanocomposites exhibited better antibiofilm properties than Au. Bacterial attachment was highest on PC and least on PU nanocomposite. Casting method appeared to be better than swelling method in reducing the attachment (by a factor of 2). Composites reduced growth of organisms by six orders of magnitude, and protein and carbohydrate by 2-5 times. This study indicates that these nanocomposites may be suitable for implant applications. © 2013 Sawant et al.

Antibiofilm Properties of Silver and Gold Incorporated PU, PCLm, PC and PMMA Nanocomposites under Two Shear Conditions

Forty-eight chalcone analogs were synthesized and their in vitro antibacterial activity against Staphylococcus aureus NCIM 5021, Bacillus subtilis NCIM 2718, Phaseolus vulgaris NCIM 2813, Escherichia coli NCIM 2931, Salmonella typhi 2501 and Enterobacter aerogenes NCIM 5139 were evaluated by microdilution broth assay. Quantitative structure-activity relationships were developed for all the cases (r2 = 0.68-0.79; = 0.58-0.78; q 2 = 0.51-0.68; F = 13.02-61.51). Size, polarizability, electron-donating/withdrawing and hydrophilic nature of the molecule determine the activity against these Gram-positive and Gram-negative bacteria. Staphylococcus aureus was the most and S. typhi was the least hydrophobic of these organisms. These chalcones act better against more hydrophobic organisms. The more active chalcones have log P between 1.5 and 3. Compound 24, one of the most active compounds, was found to act by damaging the cell wall of S. aureus. Slimicidal activity of five of the most active compounds (24, 31, 32, 34 and 37) was found to be in the range of 48-60% against S. aureus and 40-54% against E. coli. A correlation was observed among the hydrophobicity of the compounds, hydrophobicity of the bacterial cell surface and the antibacterial activity of the compound. © 2009 Blackwell Munksgaard.

Chemical Biology and Drug Design

Synthesis, biological evaluation, mechanism of action and quantitative structure-activity relationship studies of chalcones as antibacterial agents

Several polymeric materials find application in biomedical implants and devices due to their superior physicochemical properties. The main requirement for these polymers is that they should be biocompatible, which means they prevent bacterial adhesion and are blood compatible. Many parameters contribute to the degree of biocompatibility. This paper discusses the mechanism of the formation of biofilms and lists the factors that influence the bacterial adhesion and haemocompatibility. Polymer surfaces are also modified to enhance adsorption of host cells. The physical, chemical and biological techniques are meant to modify the surface of the biomaterial but at the same time retain the key properties. The various polymer treatment processes have advantages and disadvantages and a few techniques have been proved to be both highly effective at treatment and found suitable for various in vivo environments. The current research focus pertaining to smart materials, biodegradable polymers, combinatorial chemistry, computational modelling and newer analytical techniques to understand polymer-cell interaction holds promise in designing better, cost effective and biocompatible polymers. © 2008 IOP Publishing Ltd.

Biomedical Materials

Biofilm formation, bacterial adhesion and host response on polymeric implants - Issues and prevention

Journal of Materials Science: Materials in Medicine

Role of size scale of ZnO nanoparticles and microparticles on toxicity toward bacteria and osteoblast cancer cells

American Journal of Infection Control

Decontamination of laundry at low temperature with CuWB50, a novel copper-based biocidal compound

Advanced Functional Materials

Enhanced Antibacterial Activity of Nanocrystalline ZnO Due to Increased ROS-Mediated Cell Injury

Effective antibacterial adhesive coating on cotton fabric using ZnO nanorods and chalcone

Journal	Carbohydrate Polymers
ISSN	01448617
Open Access	No