ABSTRACT
The performance of polymeric nanomaterials relies greatly upon their properties which are intimately related to the methods of fabrication of their materials. Among various synthetic polymers the polymers of 2-hydroxyethyl methacrylate (PHEMA) maintains a prime position in the biomedical field due to their useful physicochemical properties and suitability for controlled drug delivery applications. Furthermore, the addition of iron oxide to PHEMA nanoparticles imparts superparamagnetism to the nanoparticles and expands the range of their uses to include magnetic drug targeting applications. Here we focus on three methods for preparation of PHEMA nanoparticles, one by suspension polymerization, a second by emulsion polymerization without the use of any surfactants, and the final one with the incorporation of iron oxide into PHEMA nanoparticles.
Subject(s)
Drug Compounding/methods , Magnetic Iron Oxide Nanoparticles/chemistry , Polyhydroxyethyl Methacrylate/chemical synthesis , Drug Delivery Systems , Emulsions , Particle Size , Polyhydroxyethyl Methacrylate/chemistry , Polymerization , SuspensionsABSTRACT
In this investigation cryogels composed of poly (vinyl alcohol) (PVA) were prepared by repeated freeze thaw method followed by in situ precipitation of zinc oxide nanoparticles within the cryogel networks. Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX) were used to characterize the nanocomposites. The morphologies of native PVA cryogels and PVA cryogel-ZnO nanocomposites were observed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) techniques. The SEM analysis suggested that cryogels show a well-defined porous morphology whereas TEM micrographs revealed the presence of nearly spherical and well separated zinc oxide nanoparticles with diameter<100nm. XRD results showed all relevant Bragg's reflections for crystal structure of zinc oxide nanoparticles. Thermo gravimetric-differential thermal analysis (TG-DTA) was conducted to evaluate thermal stability of the nanocomposites. Mechanical properties of nanocomposites were determined in terms of tensile strength and percent elongation. Biocompatible nature was ascertained by anti-haemolytic activity, bovine serum albumin (blood protein) adsorption and in vitro cytotoxicity tests. The prepared nanocomposites were also investigated for swelling and deswelling behaviours. The results revealed that both the swelling and deswelling process depend on the chemical composition of the nanocomposites, number of freeze-thaw cycles, pH and temperature of the swelling medium. The developed biocompatible PVA cryogel-ZnO nanocomposites were also tested for antibacterial activities against both Gram-negative and Gram-positive bacteria.
Subject(s)
Anti-Bacterial Agents/chemistry , Cryogels/chemistry , Nanocomposites/chemistry , Polyvinyl Chloride/chemistry , Zinc Oxide/chemistry , Adsorption , Animals , Anti-Bacterial Agents/pharmacology , Bandages , Cattle , Cryogels/chemical synthesis , Erythrocytes/cytology , Erythrocytes/drug effects , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Hemolysis/drug effects , Humans , Hydrogen-Ion Concentration , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nanocomposites/toxicity , Serum Albumin, Bovine/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature , Thermogravimetry , Wound HealingABSTRACT
The performance of polymeric nanomaterials relies greatly upon their properties which are intimately related to the methods of fabrication of the materials. Among various synthetic polymers, the polymers of 2-hydroxyetyhyl methacrylate (PHEMA) maintain a prime position in biomedical field due to their useful physicochemical properties and suitability for controlled drug delivery applications. Here we focus on three methods of preparation of PHEMA nanoparticles, by suspension polymerization, emulsion polymerization and dispersion polymerization without the use of any surfactants.
Subject(s)
Nanoparticles/chemistry , Polyhydroxyethyl Methacrylate/chemistry , Drug Delivery Systems , Emulsions/chemistry , Methacrylates/chemistry , Methacrylates/isolation & purification , Polyhydroxyethyl Methacrylate/chemical synthesis , PolymerizationABSTRACT
Swellable polymeric nanosystems have emerged as promising materials in drug release technologies. Such systems have shown potential in releasing antibiotic drugs and to do so controllably. In the present investigation poly(2-hydroxyethyl methacrylate) nanoparticles were synthesized by suspension polymerization of 2-hydroxyethyl methacrylate and characterized by various techniques such as Fourier transform-infrared spectrometry, scanning electron microscopy, particle size analysis, and surface charge measurements. The synthesized nanoparticles were swellable in water and showed promise to function as a swelling controlled-release system. The release kinetics of drug-loaded particles was studied in phosphate-buffered saline (PBS) using ciprofloxacin as a model antibacterial drug. The chemical stability of the pure and released drug was also assessed in PBS (pH 7.4), acidic (pH 1.8), and alkaline (pH 8.6) solutions. The in vitro blood compatibility of nanoparticles was also investigated in terms of hemolysis tests. The drug-loaded nanoparticles were also examined for their antibacterial and blood-compatible behaviors. FROM THE CLINICAL EDITOR: Swellable polymeric nanosystems have emerged as promising materials in drug release technologies. In this paper, the release kinetics, antimicrobial properties and in vitro "blood compatibility" is reported for a specific swellable polymeric nanosystem.
