In this paper, the release of proteins from a novel self-gelling hydrogel based on biodegradable dextran microspheres is investigated. The protein-loaded macroscopic gels are obtained by hydration of mixtures of oppositely charged hydroxyethyl methacrylate-derivatized dextran microspheres with a protein solution. In media of low ionic strength (100 mM Hepes pH 7.0) it was found that the release...

This paper reports the synthesis of highly cross-linked polymers in supercritical CO2 (scCO2), both with and without the addition of a CO2-soluble diblock copolymer stabilizer. It was demonstrated that, under certain specific conditions, relatively uniform, nonporous poly(divinylbenzene) (PDVB) microspheres (1-5 μm diameter) can be generated in the absence of added stabilizers. The effects of c...

Chitosan microspheres of a small particle size and with good sphericity were prepared by a spraydrying method followed by treatment with a cross-linking agent. Owing to restrictions on the use of crosslinked chitosan microspheres in the pharmaceutical field, d,l-glyceraldehyde, a biocompatible reatant was used. The parameters studied affecting extent of cross-linking were cross-linking time and...

Imunomicrospheres consist of hydrophilic cross-linked particles with antibodies bound to their surface. These particles find specific receptors on living or fixed cells and therefore can label cell sub-populations and the labelled cells can be observed by means of a scanning electron or light-microscope. To label . cells with polymeric particles, biocompatible microspheres are neded preferably ...

Injectable dermal filler materials consist of either fluids, biological fragments, or suspensions of particles or microspheres. Particles and microspheres are said to "migrate," but migration can occur only when they are injected into blood vessels. To evaluate biocompatibility and transport, five nonresorbable polymethylmethacrylate microspheres of various sizes, suspended in different carrier...

Preparation of cross-linked pH/thermoresponsive microspheres from preformed polymers is still lacking in literature since copolymers possessing both temperature- and pH-sensitive units together with a cross-linkable moiety in appropriate ratios are required. Moreover, choosing of the appropriate drugs able to be loaded and then released in a pulsatile manner is randomly performed. Here, we repo...

during last two decades, polysaccharides such as alginate (alg) alone and in combination with other biopolymers are widely used in vaccine and drug delivery systems. the aim of the present work was to investigate the potential utility of microparticles made of alginate (alg) as new vehicles for improving nasal vaccine delivery. for this purpose, diphtheria toxoid (dt) was chosen as a model anti...

In this study suitable, smooth, spherical, cross-linked egg albumin microspheres in the size range of 15-40 um loaded with norethisterone were prepared by multiple emulsion (o/w/o) method by the glutarldehyde cross-linking and thermal denaturation technique. Microspheres were prepared by using different drug/polymer ratios. Egg albumin was used as a mucoadhesive polymer in the formulation to in...