To overcome the disadvantages generated by the lack of interfacial bonding between hydroxyapatite nanocrystals (HAPN) and agglomeration of particles in the development of biodegradable nanocomposites a chemical grafting method was applied to modify the surface of HAPN through grafting of the three-arms star-shaped poly(ε-caprolactone) (SPCL) onto the nanoparticles. The chemical grafting of SPCL onto HAPN (SPCL-g-HAPN) has been investigated using Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM), photoelectron spectroscopy, X-ray diffraction, zeta potential (ZP) and contact angle (CA). TEM micrographs of the SPCL-g-HAPN revealed the existence of hybrid organic/inorganic (O/I) nanoscale domains.
View Article and Find Full Text PDFElectrospinning is a suitable method to produce scaffolds composed of nanoscale to microscale fibers, which are comparable to the extracellular matrix (ECM). Hyperbranched polyglycerol (HPGL) is a highly biocompatible polyether polyol potentially useful for the design of fibrous scaffolds mimicking the ECM architecture. However, scaffolds developed from HPGL have poor mechanical properties and morphological stability in the aqueous environments required for tissue engineering applications.
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December 2016
Micronucleus (MN) assay constitutes a valuable surrogate to the chromosome aberration technique for in vitro testing of the genotoxicity of substances. As test substances, two peptidic compounds (DOTATATE and Ubiquicidin) used in nuclear medicine, were tested for in vitro cytotoxicity and genotoxicity in CHO-K1 cells. None of the compounds showed detectable cytotoxicity (0.
View Article and Find Full Text PDFThe corrosion stability of a W-DLC coated surgical AISI 316L stainless steel in Hanks' solution has been evaluated. Particle induced X-ray emission (PIXE) measurements were performed to evaluate the incorporation of potentially bioactive elements from the physiological solution. The film structure was analyzed by X-ray diffractometry and micro-Raman spectroscopy.
View Article and Find Full Text PDFA polyglycerol with dendritic structure (PGLD) was synthesized by ring-opening polymerization of deprotonated glycidol using a polyglycerol as core functionality in a step-growth process. Then, PGLD reacted with O-carboxymethylated chitosan to obtain PGLD-chitosan dendrimer (PGLD-Ch). After the reaction of PGLD-Ch with boric acid, there was a marked increase in the bulk viscosity evidencing physically that boron can initiate a charge transfer complex formation, (PGLD-Ch)B.
View Article and Find Full Text PDFThe effect of gamma-radiation doses of 12.5-380 kGy on the infrared spectra, gel content, mechanical properties, and the release of oxobutyl-5-fluoro-2'-deoxyuridine (OfdUrd, an antitumor agent) from poly(ethylene-co-vinyl acetate) (EVA) films was studied. The results showed that the application of radiation doses produced a crosslinking reaction leading to a maximum gel content of about 85% in the case of 150 kGy.
View Article and Find Full Text PDFThe most serious problem usually encountered in the field of implanted biomedical devices is infectious morbidity as a primary source of mortality. In this work, the synthesis and characterization of a macroporous iodine-based sanitizer (iodophor), poly(caprolactone)-iodine (PCL-I(2)), are presented. Characterization methods include nuclear magnetic resonance spectroscopy, gel permeation chromatography, nitrogen adsorption-desorption, and scanning electron microscopy.
View Article and Find Full Text PDFThe use of computer vision coupled with scanning electron microscopy (SEM) was used to monitor the platelet adhesion and activation onto blood-contacting materials. The interaction of blood platelets with polyethylene (PE), poly(ethylene terephthalate) (PET), and poly(vinylchloride) (PVC) after contact of the polymeric surfaces with whole blood was studied. The SEM images (SEM Phillips XL 30) were captured using HLImage++ computer vision systems.
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