Antibacterial and anticancer activity of loaded quinazolinone polypyrrole/chitosan silver chloride nanocomposite

Polypyrrole/chitosan-silver chloride core shell nanocomposite (AgCl@PPC) was prepared by in situ oxidative polymerization of pyrrole (Py) using ferric chloride in the presence of chitosan (CS) and silver nitrate to develop a carrier and controlled release system for 3-amino-2-phenyl-4(3H)-quinazolinone (I). For sake of comparison, polypyrrole chitosan core shell nanoparticles (PPC) were prepared and loaded by (I). Fourier transform infrared spectroscopy, X-ray diffraction and thermal gravimetric analysis confirm that I was loaded into PPC and AgCl@PPC core shell nanocomposites respectively, through physical interaction. Results revealed that loaded AgCl@PPC and PPC exhibited excellent antibacterial and anticancer efficacy against Ehrlich ascites carcinoma cells.     

Vegetable oil based highly branched polyester/clay silver nanocomposites as antimicrobial surface coating materials

The unison of nanotechnology and polymer science enables the development of novel silver-based polyester nanocomposite as an antimicrobial coating material. Highly branched polyester/clay silver nanocomposites based on vegetable oil with different loadings of silver were prepared via reduction of silver salt by employing dimethylformamide as solvent as well as reducing agent at room temperature. Organically modified montmorillonite clay of 2.5 wt% was used as the nanofiller for the property improvement of the pristine polymer. The highly branched polyester resin was synthesized by condensation of 2,2-bis(hydroxymethyl) propionic acid with Mesua ferrea L. seed oil based carboxyl terminated pre-polymer, as reported earlier. FTIR, UV–vis, XRD, SEM and TEM studies substantiate the formation of well-dispersed silver nanoparticles within the clay gallery with an average size of 15 nm. The thermostability of the silver nanocomposites obtained by thermogravimetric analysis was enhanced by 20 °C. The mechanical properties such as tensile strength and scratch hardness were improved 4.5 and 2.6 units respectively and impact resistance improved a little by nanocomposites formation. The antimicrobial efficacy of the as-prepared silver nanocomposites was also premeditated and highly antibacterial activity against Gram negative bacteria (Escherichia coli and Psuedomonas aeruginosa) was observed. Excellent chemical resistance in various chemical media except in alkali has also been noticed. The study reveals that the polyester/clay silver nanocomposites based on vegetable oil show the potential to be applicable as antibacterial surface coating materials.     

Preparation and characterization of Polyethylene/Clay/Silver nanocomposites using functionalized polyethylenes as an adhesion promoter

The performance of Polyethylene (PE)/Clay/Silver nanocomposites is dependent to a great extent on the properties of filler–matrix interface. To improve the interfacial properties in PE/Clay/Silver composites, different types of compatibilizers or adhesion promoters were introduced. The compatibilization provided by maleic anhydride (MA), itaconic acid (IA) and 2-[2-(dimethylamine)-ethoxy] ethanol (DMAE) functionalized PEs for forming PE-based nanocomposites was studied and compared. IA was grafted into PE by melt mixing to obtain PEgIA (compatibilizer 1), thereafter, PEgIA and PEgMA (compatibilizer 2) were reacted with DMAE also by melt mixing to obtain PEgI-DMAE (compatibilizer 3) and PEgM-DMAE (compatibilizer 4). These compatibilizers were reacted using ultrasound with a solution of AgNO₃ 0.04 M and ethylene glycol. Ammonium hydroxide was added in a ratio of 2:1 M with respect to silver nitrate. These silver coated compatibilizers were mixed with PE and with a quaternary ammonium modified montmorillonite clay (Nanomer I28E), thus forming the different hybrid PE/Clay/Silver nanocomposites. FTIR confirmed the formation of these compatibilizers. All the DMAE compatibilized nanocomposites had better filler (clay and silver) dispersion and exfoliation. XRD, oxygen and water transmission rate as well as antimicrobial properties attained showed that the PEgI-DMAE produced the better dispersed PE, clay and silver nanocomposites. The obtained nanocomposites showed enhanced barrier properties and outstanding antimicrobial properties against bacteria, E. coli. PEgI-DMAE offers an outstanding capability for preparing nanocomposites with highly exfoliated and dispersed filler into the PE matrix that offers a new option for obtaining hybrid nanocomposites with enhanced properties to be used in packaging applications.     

Influence of maleated elastomer on filler dispersion,mechanical and antimicrobial properties of hybrid HDPE/clay/silver nanocomposites

This work analyses the effect of using ethylene-propylene-diene-monomer-grafted maleic anhydride (EPDM-g-MA) as compatibilizer to improve the interfacial properties and toughness of high-density polyethylene–organoclay–silver (HDPE/clay/silver) nanocomposites. EPDM-g-MA was reacted using ultrasound with a solution of AgNO₃ 0.04 M and ethylene glycol using ammonium hydroxide to obtain the silver ammonium complex. This silver-coated maleated EPDM was then melt mixed with HDPE and organoclay (Nanomer I28E) using a twin-screw extruder. Transmission electron microscopy (STEM) and X-ray diffraction (XRD) results confirmed the filler dispersion of both organoclay and silver nanoparticles into HDPE matrix when maleated EPDM was used. Both fillers were better dispersed and exfoliated by using this compatibilizer. The thermal stability enhancement of nanocomposites was confirmed using thermogravimetric analysis. Mechanical and antimicrobial properties demonstrated that better dispersed filler obtained with maleated EPDM enhanced the toughness and antimicrobial behaviour of HDPE/clay/silver hybrid nanocomposites. This confirmed that maleated EPDM was an efficient compatibilizer to obtain hybrid nanocomposites with enhanced properties to be used for several HDPE applications.     

Synergistic antimicrobial effects of polyaniline combined with silver nanoparticles

Silver/polyaniline nanocomposites (Ag NPs/PANI) containing PANI nanofiber and Ag nanoparticles were synthesized by one-step approach without using any extra reducing agent or surfactant and applied to new antimicrobial agents. Morphologies and crystallinity of the nanocomposites were characterized with SEM and XRD. The results showed that the average diameter of the PANI nanofibers is around 50–150 nm, and the average particle size of Ag NPs is around 100 nm. The crystallinity of PANI gets better with increasing silver nitride concentration. UV–vis absorption spectroscopy analysis indicated that the Ag NPs have some effect on the microstructure of PANI. The antimicrobial properties of Ag NPs/PANI against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and fungous Yeast were evaluated using viable cell counts. The test results demonstrated that Ag NPs/PANI have enhanced antimicrobial efficacy compared to that of pure Ag NPs or pure PANI under the same test condition. The mechanism of the synergistic antimicrobial effect of Ag NPs with PANI was also proposed. In addition, thermal gravity analysis indicated that pure PANI and Ag NPs/PANI exhibit better thermal stability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

新型高效抗菌粉末涂料的研究

针对抗菌涂料在不同使用环境和高效抗菌性能的要求,从抗菌粉末涂料机理出发,研究了不同抗菌剂在不同工艺下制备的抗菌粉末涂层抗菌效果,并研究了不同抗菌剂在耐水洗涤、耐水煮、耐高温、耐紫外光照试验下对粉末涂层抗菌效果、光泽、色差的影响;同时研究了抗菌剂及其用量对涂层性能的影响。结果表明：添加带玻璃网状结构的银离子与锌离子复配的抗菌剂抗菌效果最佳;内挤搭配外混加入方式的粉末涂层的抗菌性能优异;得到的涂层在高温处理、水洗处理等条件下也具有良好的抗菌性能。选择含有玻璃网状结构的银离子的抗菌剂,涂层中的玻璃网状结构载体能缓慢地释放银离子,保证涂层的长效抗菌性能。     

Fabrication of Au and Ag Bi-metallic nanocomposite for antimicrobial applications

Hydrogel silver nanocomposites have shown immense potential in many biomedical applications, specifically wound healing. The combination of bi-metallic (Ag, Au) hydrogel nanocomposites are developed to enhance their antimicrobial activity. This paper presents the fabrication of bi-metallic nanocomposites obtained from the synthesis of acrylamide (AM) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) based hydrogels for antimicrobial applications. The nanocomposite formation was confirmed by scanning electron microscopy (SEM), thermal analysis (TGA/DSC), as well as X-ray diffraction (XRD) methods. The bi-metallic nanocomposite hydrogel has shown significant antibacterial activity on bacillus. Therefore, these bi-metallic antibacterial materials are promising candidates for a wide range of biomedical applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Layer by Layer Deposition of Polyethylene Glycol Capped Silver Nanoparticles/Chitosan on Polyethylene Substrate

Multilayers of silver nanoparticles and chitosan were deposited on polyethylene film by a layer-by-layer (LBL) self-assembly technique. Silver nanoparticles with a size of about 5 nm were prepared by chemical reduction and then fabricated onto a polyethylene (PE) substrate, which led to the formation of a colored film with the thicknesses of 2, 4, 8, 12, and 20 layers. Silver nanocomposites were characterized by atomic force microscopy (AFM) and UV-visible spectroscopy, X-ray diffraction (XRD), and infrared spectroscopy (FTIR). Results showed that nanoparticles deposited homogenously on the surface of the polyethylene film. LBL silver nanocomposites showed considerable antimicrobial activity by agar diffusion test.     

Radiation synthesis, characterisation and antimicrobial application of novel copolymeric silver/poly(2-hydroxyethyl methacrylate/itaconic acid) nanocomposite hydrogels

Silver nanoparticles were fabricated via in situ reduction of silver nitrate embedded in swollen P(HEMA/IA) hydrogel, using gamma radiolysis method. Copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA), previously synthesised by gamma radiation for wound dressing application, were used as a carrier and a stabilising agent, while ethyl alcohol was used as a free radical scavenger. The influence of different P(HEMA/IA) hydrogels and silver salt concentrations on the size and distribution of nanoparticles was investigated. The Ag/P(HEMA/IA) nanocomposites were characterised by high resolution scanning electron microscopy, energy dispersive spectroscopy, wide-angle X-ray diffraction, UV-Vis spectroscopy and swelling measurements. Escherichia coli (Gram-negative bacterium), Staphylococcus aureus (Gram-positive bacterium) and Candida albicans (fungus) were used to prove the antimicrobial properties of Ag/P(HEMA/IA) nanocomposites. The inhibition kinetics of bacteria growth was investigated by measuring the colony-forming unit. The antimicrobial effectiveness of the Ag/P(HEMA/IA) hydrogel nanocomposite was demonstrated even at small silver concentrations. P(HEMA/IA) hydrogels containing nanosilver particles was found suitable to be used as wound dressing.     

A novel method for preparing silver/poly(siloxane‐b‐methyl methacrylate) nanocomposites with multiple properties in the DMF‐toluene mixture solvent

A novel method for preparing silver/poly(siloxane‐b‐methyl methacrylate) (Ag/(PDMS‐b‐PMMA)) hybrid nanocomposites was proposed by using the siloxane‐containing block copolymers as stabilizer. The reduction of silver nitrate (AgNO₃) was performed in the mixture solvent of dimethyl formamide (DMF) and toluene, which was used to dissolve double‐hydrophobic copolymer, as well as served as the powerful reductant. The presence of the PMMA block in the copolymer indeed exerted as capping ligands for nanoparticles. The resultant nanocomposites exhibited super hydrophobicity with water contact angle of 123.3^° and the thermogravimetry analysis (TGA) revealed that the resultant nanocomposites with more PDMS were more heat‐resisting. Besides, the antimicrobial efficiency of the most desirable nanocomposite (Ag/PDMS₆₅‐b‐PMMA₃₀ loaded with 7.3% silver nanoparticle) could reach up to 99.4% when contacting with escherichia coli within 120 min. As a whole, the resultant nanocomposites by the integration of excellent properties of silver nanoparticles as well as siloxane‐block copolymers can be a promising for the development of materials with hydrophobic, heat‐resisting and outstanding antibacterial properties from the chemical product engineering viewpoint. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4780–4793, 2013     

The Impact of Graphite Oxide Nanocomposites on the Antibacterial Activity of Serum

Nanoparticles can interact with the complement system and modulate the inflammatory response. The effect of these interactions on the complement activity strongly depends on physicochemical properties of nanoparticles. The interactions of silver nanoparticles with serum proteins (particularly with the complement system components) have the potential to significantly affect the antibacterial activity of serum, with serious implications for human health. The aim of the study was to assess the influence of graphite oxide (GO) nanocomposites (GO, GO-PcZr(Lys)₂-Ag, GO-Ag, GO-PcZr(Lys)₂) on the antibacterial activity of normal human serum (NHS), serum activity against bacteria isolated from alveoli treated with nanocomposites, and nanocomposite sensitivity of bacteria exposed to serum in vitro (using normal human serum). Additionally, the in vivo cytotoxic effect of the GO compounds was determined with application of a Galleria mellonella larvae model. GO-PcZr(Lys)₂, without IR irradiation enhance the antimicrobial efficacy of the human serum. IR irradiation enhances bactericidal activity of serum in the case of the GO-PcZr(Lys)₂-Ag sample. Bacteria exposed to nanocomposites become more sensitive to the action of serum. Bacteria exposed to serum become more sensitive to the GO-Ag sample. None of the tested GO nanocomposites displayed a cytotoxicity towards larvae.     

Polyamide/silver antimicrobials: effect of crystallinity on the silver ion release

Polyamide/silver (PA/Ag) composite materials are regarded as potential antimicrobials by virtue of their efficacy to release the Ag⁺ ions in an aqueous medium. The effects of the matrix crystallinity on the Ag⁺ ion release characteristics of PA/Ag composites are discussed. It is found that matrix crystallinity is very decisive for the silver ion releasing properties and hence the antimicrobial efficacy of silver‐based antimicrobial polyamides. The crystallinities of the composites were evaluated using differential scanning calorimetry. The silver ion release characteristics of these composites were measured by anode stripping voltammetry. Silver ion release was higher in systems possessing lower degrees of crystallinity. Water‐diffusion characteristics of the composites control the silver ion release. The effect of crystallinity on silver ion release rate depends on the time of soaking of the specimens in water. Copyright © 2005 Society of Chemical Industry     

Synthesis and characterization of hydrogel‐silver nanoparticle‐curcumin composites for wound dressing and antibacterial application

Hydrogel silver nanocomposites are found to be excellent materials for antibacterial applications. To enhance their applicability novel hydrogel‐silver nanoparticle‐curcumin composites have been developed. For developing, these composites, the hydrogel matrices are synthesized first by polymerizing acrylamide in the presence of poly(vinyl sulfonic acid sodium salt) and a trifunctional crosslinker (2,4,6‐triallyloxy 1,3,5‐triazine, TA) using redox initiating system (ammonium persulphate/TMEDA). Silver nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating the silver ions and subsequent reduction with sodium borohydride. Curcumin loading into hydrogel‐silver nanoparticles composite is achieved by diffusion mechanism. A series of hydrogel‐silver nanoparticle‐curcumin composites are developed and are characterized by using Fourier transform infrared (FTIR) and UV–visible (UV–vis) spectroscopy, X‐ray diffraction, thermal analyses, as well as scanning and transmission electron microscopic (SEM/TEM) methods. An interesting arrangement of silver nanoparticles i.e., a shining sun shape (ball) (～ 5 nm) with apparent smaller grown nanoparticles (～ 1 nm) is observed by TEM. The curcumin loading and release characteristics are performed for various hydrogel composite systems. A comparative antimicrobial study is performed for hydrogel‐silver nanocomposites and hydrogel‐silver nanoparticle‐curcumin composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Chitosan–silver nanocomposites: New functional biomaterial for health-care applications

Chitosan–silver nanocomposites (CS-HDA-AgNCs) was prepared using chitosan, biogenic silver nanocomposites, and crosslinker, hexamethylene 1,6-di(amino carboxysulfonate) (HDA). The film is flexible and transparent. Its physical, mechanical, thermal, hydrophilicity, and swelling properties were improved by HDA (2.5%). The antimicrobial activity of CS-HDA-AgNCs were not displayed any remarkable zone of inhibition but showed toxic effect in the presence of normal 3T3 fibroblasts and cancer HeLa cells. It decreases to ca. 5–7% for both cell lines. In conclusion, it can be mentioned that the CS-HDA-AgNCs, a kind of new functional biomaterial, could be useful for health-care applications.     

Preparation and characterization of cellulose/Ag nanocomposites

A simple, green, and efficient microwave‐assisted heating method was developed to synthesize the cellulose/Ag nanocomposites by reducing silver nitrate in aqueous solution. The structure of nanocomposites was analyzed with X‐ray diffraction and Fourier transform infrared, the results showed that nanosilver particles were synthesized successfully on the surface of cellulose and did not change the structure of cellulose obviously. The shape and average size of silver nanoparticles and its distribution on cellulose fiber surface were observed by scanning electron microscopy, and the results demonstrated that the silver nanoparticles had a good distribution on the surface of cellulose fiber and high dosage of polyvinyl pyrrolidone decreased the size of nanosilver particles. Atomic absorption spectroscopy was used to measure the silver content in the composites, it was found that the silver content was higher in composites obtained by microwave heating compared with oil bath heating. The effect of silver nanoparticles on the thermal stability of cellulose fiber was studied by thermogravimetric analysis and differential scanning calorimetry, and it revealed that the silver nanoparticles had no obvious influence on the thermal stability of cellulose. The excellent antimicrobial activity against both Escherichia coli (gram‐negative bacteria) and Staphylococcus aureus (gram‐positive bacteria) showed a potential application in medical and health care field. POLYM. COMPOS., 36:2220–2229, 2015. © 2014 Society of Plastics Engineers     

A Novel Approach to Prepare Poly(Vinyl Acetate)/Ag Nanocomposite for Effective Antimicrobial Coating Applications

Polyvinyl acetate nanocomposites were successfully prepared based on silver nanoparticles. First, silver nanoparticles were directly prepared during the in situ emulsion polymerization of vinyl acetate monomer using AgNO₃ as a source of Ag⁺ ions and poly(vinyl alcohol) was used for dual functions as emulsifier for emulsion polymerization and as a stabilizing agent, trisodium citrate (C₆H₅O₇Na₃) was used as reducing agent for Ag⁺ ions during the polymerization process. The prepared polyvinyl acetate/Ag nanocomposites were assessed using X-ray diffraction, scanning electron microscopy, Fourier transform infrared, transmission electron microscopy, and ultraviolet spectra. The antibacterial properties of the prepared polyvinyl acetate/Ag nanocomposites were investigated as antimicrobial activity against pathogenic bacteria, i.e., Staphylococcus aureus (G^+ve bacteria) and Escherichia coli (G^?ve bacteria). These polyvinyl acetate nanocomposites could be used as a promising material for enhanced and continuous antibacterial applications as coating and packaging materials.     

Anisotropy investigation of cobalt ferrite nanoparticles embedded in polyvinyl alcohol matrix: A Monte Carlo study

The magnetic properties of the cobalt ferrite/polyvinyl alcohol nanocomposites have been studied experimentally and theoretically. For investigation the impact of polymeric matrix on magnetic properties of magnetic nanoparticles, four different processes have been considered for synthesizing the polymer based nanocomposites by co-precipitation method. The effective magnetic anisotropy obtained by Monte Carlo simulation and law of approach to the saturation magnetization showed a significant decrease relative to the bulk and bare cobalt ferrite nanoparticles. The polymeric matrix interacted with the surface of particles by different strength and made them approximately non-interacting. The as synthesized samples characterized by X-Ray diffractions (XRD) and Fourier transform infrared spectroscopy (FT-IR). Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM).     

New routes to the preparation of silver-soft liner nanocomposites as an antibacterial agent

This study evaluated the antimicrobial and physical properties of silver-soft liner nanocomposites (Ag-SLN). Polymerized acrylic soft denture liner disk specimens containing 0 (control), 1500, 3000, or 6000 mg/L of silver nanoparticles were placed on the flat bottom of the separate 12-well cell culture plate dish and 100 μL samples of microbial suspensions of Escherichia coli strain were inoculated on each specimen and incubated at 37 °C, for 24 and or 72 h. The antimicrobial effects were determined according to the number of viable cells in the retrieved suspension. Characterization of silver nanoparticles was carried out based on UV–vis spectroscopy and transmission electron microscopy (TEM) analysis. The specimens were characterized by thermal gravimetric analysis (TGA), field emission scanning electron microscope and energy dispersive X-ray analysis (FE-SEM/EDAX), and atomic absorption spectroscopy (AAS). We successfully prepared Ag-SLN and identified the great excellent antimicrobial activity for E coli.     

In situ polymerization of polyurethane‐silver nanocomposite foams with intact thermal stability,improved mechanical performance,and induced antimicrobial properties

Silver nanoparticle‐reinforced thermoplastic polyurethane (PU/AgNP) nanocomposite foams were prepared using in situ polymerization techniques in accordance with DOW chemicals’ industrial standards. The foams exhibited improved mechanical performance, induced antimicrobial properties, and intact stability when subjected to a thermal degradation treatment. Scanning electron microscopy (SEM) indicated a homogeneous dispersion of the silver nanoparticle (AgNP) within the polymeric matrix at low filler loadings and a cluster formation at higher loadings. SEM also indicated the agglomeration of the silver nanofiller particles as a result of the thermal degradation treatment, which caused them to lose their nanoscopic characteristics and act as ordinary silver metal. Molecular modeling techniques were used to explain these observations and confirmed the higher repulsive interactions between the polymer chains and the silver nanoparticles with the increase in the nanofiller content. Stress relaxation of the nanocomposites showed optimum mechanical performance and lowest hysteresis for the 0.1% AgNP nanocomposites due to the confinement of the PU chains between the large number of the nanoparticles. Incubation with 0.1% foam inhibited the growth of Klebseilla spp. and Escherichia coli and to some extent Staphylococcus spp. This is very interesting as the same nanocomposite loaded with 0.1% AgNp has also shown the best mechanical performance highlighting the strong action of this “unclustered” low concentration on both the material and biomedical sides. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43125.     

Effects of silver nanoparticles on thermal properties of DBSA-doped polyaniline/PVC blends

Dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PAND) has been synthesized by redoping (PANDR) and aqueous polymerization (PANDA) methods. Silver nanoparticles were incorporated into the PANDR/tetrahydrofuran solution (PANDS) and then mixed with poly (vinyl chloride) (PVC) solution to prepare PANDS/PVC nanocomposites. In the present study, effects of silver nanoparticles on thermal properties of PAND/PVC blends have been investigated by employing thermal gravimetric analysis and heat flow microcalorimetry techniques. From these results it has been observed that the thermal stability of blends have increased by increasing the concentration of PAND in blends and nanocomposites. Addition of silver nanoparticles has suppressed the dehydrochlorination process and evolution/degradation of DBSA in PANDS/PVC nanocomposites. Presence of silver nanoparticles in PAND/PVC nanocomposites has reduced the mobility of PANI chains which in turn inhibited the transfer of free radicals formed during degradation of PAND and PVC through inter-chain reactions; hence, degradation process has been slowed down and thermal stability has been improved. Embedment of silver nanoparticles has reduced thermal weight loss corresponding to polymer degradation step and attains lower heat flow level in inert atmosphere for nanocomposites in contrast to those with no nanoparticles, thereby further improving thermal stability of nanocomposites. The heats of oxidation measured for blends and nanocomposites were independent of PAND/PVC blends composition.