Development of microbial resistant thermosensitive Ag nanocomposite (gelatin) hydrogels via green process.

In this investigation, an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) using biodegradable gelatin as a stabilizing agent is reported. Here, we prepared thermosensitive silver nanocomposite hydrogels composed of gelatin and N-isopropylacrylamide. In this green process AgNPs were formed from Ag(+) ions and reduced with leaf [Azadirachta indica (neem leaf)] extracts, resulting in a hydrogel network. The Ag(0) nanoparticles affect the hydrogel strength and improved the biological activity (inactivation effect of bacteria) of the biodegradable hydrogels. The resulted hydrogel structure, morphology, thermal, swelling behavior, degradation, and antibacterial properties were systematically investigated. The biodegradable thermosensitive silver nanocomposite hydrogels developed were tested for antibacterial activities. The results indicate that these biodegradable silver nanocomposite hydrogels are suitable potential candidates for antibacterial applications.

Development of microbial resistant Carbopol nanocomposite hydrogels via a green process.

The present scientific research resulted in the development of novel microbial resistant inorganic nanocomposite hydrogels, which can be used as antibacterial agents. They are promising candidates for advanced antimicrobial applications in the field of biomedical science. Novel inorganic nanocomposite hydrogels were developed from Carbopol® 980 NF and acrylamide. Dual-metallic (Ag0-Au0) nanoparticles were prepared (via a green process) by the nucleation of silver and gold salts with mint leaf extract to form a hydrogel network. The Carbopol nanocomposite hydrogels contain (Ag0-Au0) nanoparticles ∼5 ± 3 nm in size, which was confirmed by transmission electron microscopy. The developed hydrogels were characterized using Fourier transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The pure and inorganic nanocomposite hydrogels developed were tested against Bacillus and E. coli, for their antibacterial properties. The results indicate that the inorganic nanocomposites show significantly greater antimicrobial activity than the pure hydrogels. Therefore, novel microbial resistant Carbopol nanocomposite hydrogels can be used as potential candidates for antibacterial applications.

Development of novel protein-Ag nanocomposite for drug delivery and inactivation of bacterial applications.

The potential applications, in the biomedical fields, of curcumin loaded silver nanocomposite were studied by using bovine serum albumin (protein) and acrylamide. The design and development of silver nanoparticles with small size and adequate stability are very important, in addition to their applicability, particularly in bio-medicine. In this study, silver nanoparticles were prepared by chemical reduction method, employing sodium borohydride as the reducing agent for silver nanoparticles. The properties of the protein hydrogels formed were characterized via Fourier transform infrared spectroscopy and X-ray diffraction analyses. The size and its distribution, and formation of metal nanoparticles were confirmed by transmission electron microscopy indicating the diameter of the silver nanoparticles in the range of 3-8 nm. The thermal study of curcumin-silver nanocomposite hydrogels was determined by thermo-gravimetric analysis. In order to increase the antibacterial activity of theses inorganic nanomaterials, natural biological curcumin was incorporated into the protein hydrogel. The main emphasis in this investigation is to increase the antibacterial activity of the hydrogels by loading curcumin, for advanced medical application and as a model drug.

ZnSe/ZnSe:Ag nanoparticles: synthesis, characterizations, optical and raman studies.

Nanoparticles (NPs), grown in liquid media, stand out over other classes of inorganic nanomaterials due to the high degree of control with which their crystal structure, size, shape, and surface functionalities can be engineered in the synthesis stage and to the versatility with which they can be processed and implemented into a large spectrum of devices and processes. In present work pure and Ag-doped ZnSe NPs were successfully synthesized from the solution phase chemistry and investigated with respect to their structural and optical properties. The resulting powder consists of nanocrystalline particles were characterized by X-ray diffraction (XRD), UV-Visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) techniques and Raman spectroscopy. A UV emission peak was observed from the excitons transition at 380 nm in the room temperature photo luminescent (PL) spectra. The blue emission band was assigned to the Zn interstitial and vacancy level transition. Even though Ag ions known to act as an efficient non-radiative loss center for near band gap emission (NBE), a decreased NBE is obtained at room temperature even for a nominal Ag concentration. XRD data analysis shows that the Ag dopant atoms are incorporated into the cubic ZnSe host lattice.

Iota-Carrageenan-based biodegradable Ag0 nanocomposite hydrogels for the inactivation of bacteria.

In this paper, we report the synthesis and characterization of Iota-Carrageenan based on a novel biodegradable silver nanocomposite hydrogels. The aim of study was to investigate whether these hydrogels have the potential to be used in bacterial inactivation applications. Biodegradable silver nanocomposite hydrogels were prepared by a green process using acrylamide (AM) with I-Carrageenan (IC). The silver nanoparticles were prepared as silver colloid by reducing AgNO3 with leaf extracts of Azadirachta indica (neem leaf) that (Ag(0)) formed the hydrogel network. The formation of biodegradable silver nanoparticles in the hydrogels was characterized using UV-vis spectroscopy, thermo gravimetrical analysis, X-ray diffractometry studies, scanning electron microscopy and transmission electron microscopy studies. In addition, swelling behavior and degradation properties were systematically investigated. Furthermore, the biodegradable silver nanoparticle composite hydrogels developed were tested for antibacterial activities. The antibacterial activity of the biodegradable silver nanocomposite hydrogels was studied by inhibition zone method against Bacillus and Escherichia coli, which suggested that the silver nanocomposite hydrogels developed were effective as potential candidates for antimicrobial applications. Therefore, the inorganic biodegradable hydrogels developed can be used effectively for biomedical application.

Synthesis and magnetic studies of Co-Ni-Zn ferrite nano crystals.

This paper reports the investigation on synthesis and magnetic characterization of Ni substituted Co0.8Zn0.2Fe2O4 nano-particles. The nano-particles of Co(0.8-x)Ni(x)Zn(0.2)Fe2)O4 (x = 0.15, 0.20, 0.35, 0.50, 0.65) were prepared by co-precipitation method. The X-ray diffraction analysis confirmed the formation of single-phase face centered cubic (fcc) spinal structure. The lattice parameter decreased as Ni concentration increased from x = 0 (a = 8.388 A) to x = 0.65 (a = 8.3612 A). The morphology of the particles examined through high-resolution TEM showed a well-isolated and less agglomerated homogeneous distribution of nano-particles which suggests that co-precipitation method is beneficial for magnetic nano-materials synthesis and their characterization. The influence of Ni on magnetic behavior (saturation magnetization and 4piMs) of Co(0.8-x)Ni(x)Zn(0.2)Fe2O4 nano-materials have been evaluated and discussed.