Biomedical subjects

Jirí Michálek

Publications and source records attributed to Jirí Michálek.

4 recordsLinked to original sources

PubMed2006

New perfluoroalkylated amphiphilic methacrylates bearing sulfinyl group as monomers for biomedical applications: water content and oxygen permeability of their copolymers with DEGMA.

Perfluoroalkylated methacrylates 7a-c bearing sulfinyl group within a straight-chain ester group, i.e. CH(2)=C(CH(3))CO(2)CH(2)CH(2)S(O)-CH(2)CH(2)CF(2)(CF(2)CF(2))(n)CF(3) (n=1-3) were prepared by two alternative synthetic sequences from 2-[(polyfluoroalkyl)sulfanyl]ethanols HOCH(2)CH(2)SCH(2)CH(2)CF(2)(CF(2)CF(2))(n)CF(3) (n=1-3) in overall yields of 88-91%. Copolymers of 7a-c with diethylene glycol methacrylate (DEGMA) prepared in bulk under radical conditions display high transparency, increased water content and good oxygen permeability properties, which are advantageous for their application in ophthalmology and as prosthetic materials.

Biocompatible Materials↗

PubMed2006

Macroporous hydrogels based on 2-hydroxyethyl methacrylate. Part 5: hydrolytically degradable materials.

Macroporous hydrogels based on 2-hydroxyethyl methacrylate, 2-ethoxyethyl methacrylate and N-(2-hydroxypropyl)methacrylamide, methacrylic acid and [2-(methacryloyloxy)ethyl]trimethylammonium chloride crosslinked with N,O-dimethacryloylhydroxylamine were prepared. Hydrogels were degraded in a buffer of pH 7.4. Completely water-soluble polymers were obtained over time periods ranging from 2 to 40 days. The process of degradation was followed gravimetrically and by optical and electron microscopy. In vivo biological tests with hydrogels based on copolymers of 2-ethoxyethyl methacrylate/N-(2-hydroxypropyl)methacrylamide were performed.

Absorbable Implants↗

PubMed2004

Topographical properties of polymer films deposited in capillaries for electrophoretic separations of large organic molecules.

Topography and thickness of hydrophilic polymer coatings of fused-silica capillaries for capillary electrophoresis (CE) were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and profilometry. Three hydrogels, poly(2-hydroxyethyl methacrylate) [poly(HEMA)], poly(diethylene glycol monomethacrylate) [poly(DEGMA)], and poly(triethylene glycol monomethacrylate) [poly(TEGMA)], were deposited using two procedures, either by simple physical sorption of the polymers, or by derivatization of the capillary wall surface with glycidyl methacrylate (EPMA) followed by polymerization of the appropriate monomers. The performance of the modified capillaries was tested under CE conditions (decrease in the electroosmotic flow, EOF dependence on pH, separation of milk and standard proteins). It has been found that the most important property of the polymer coating is its thickness, whereas its topography and the degree of its hydrophobicity are less significant. Film deposition by physical adsorption is preferable to polymerization on the derivatized surface.

Adsorption↗

PubMed2003

Reconstruction of epidermis by grafting of keratinocytes cultured on polymer support--clinical study.

BACKGROUND: Extensive wound coverage still represents a challenge for contemporary medicine. We demonstrate the results of a clinical trial of the grafting of cultured keratinocytes directly on a polymer cultivation support in the treatment of skin defects in seriously burned patients and in patients with trophic ulcers. METHODS: Wound closure was evaluated clinically. The morphology and phenotypic pattern of the reconstructed epidermis, including the basal lamina, as well as the presence of Langerhans cells, were evaluated immunocytochemically using a panel of monoclonal antibodies. RESULTS: All layers of the reconstructed epidermis were normally differentiated (cytokeratin immunocytochemistry). The basal lamina contained collagen type IV and laminin. The reconstructed epidermis was extensively colonized by Langerhans cells. CONCLUSIONS: The results of the described technology are encouraging, especially in patients after a burn injury. The described procedure is suitable for the treatment of skin defects in clinical practice.

Adult↗