Hydrogel Nanocomposites with Silver Nanoparticles

Copolymer hydrogels based on acrylic monomers (primarily acrylamide and acrylonitrile) are synthesized and their physicochemical properties are investigated. Methods of incorporation of nanoparticles of gold and silver into hydrogel pores and methods of their stabilization using reagents of different nature are developed. Our studies showed pronounced bactericidal properties of the nanocomposites regarding gram-positive and gram-negative bacteria and, at the same time, their biocompatibility to stem cells

Thermal effects of carbonated hydroxyapatite modified by glycine and albumin

In this work calcium phosphate powders were obtained by precipitation method from simulated solutions of synovial fluid containing glycine and albumin. X-ray diffraction and IR spectroscopy determined that all samples are single-phase and are presented by carbonate containing hydroxyapatite (CHA). The thermograms of solid phases of CHA were obtained and analyzed; five stages of transformation in the temperature range of 25-1000°C were marked. It is shown that in this temperature range dehydration, decarboxylation and thermal degradation of amino acid and protein connected to the surface of solid phase occur. The tendency of temperature lowering of the decomposition of powders synthesized from a medium containing organic substances was determined. Results demonstrate a direct dependence between the concentration of the amino acid in a model solution and its content in the solid phase

Separation of nonreacted acrylamide from polyacrylamide gel for endoprothesing

The separation of toxic acrylic monomers (mainly acrylamide) from some polymeric hydrogels of medical application was studied. It was found that “clean hydrogel” can be obtained after 4-6 days of washing with nonpyrogenic water. The quantity of monomeric acrylamide remained in the samples was controlled by a liquid chromatography method

Using Optical Tweezers for the Characterization of Polyelectrolyte Solutions with Very Low Viscoelasticity

Recently, optical tweezing has been used to provide a method for microrheology addressed to measure the rheological properties of small volumes of samples. In this work, we corroborate this emerging field of microrheology by using these optical methods for the characterization of polyelectrolyte solutions with very low viscoelasticity. The influence of polyelectrolyte (i.e., polyacrylamide, PAM) concentration, specifically its aging, of the salt concentration is shown. The close agreement of the technique with classical bulk rheological measurements is demonstrated, illustrating the advantages of the technique