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Biomedical subjects

M Bohdanecký

Publications and source records attributed to M Bohdanecký.

4 recordsLinked to original sources
PubMed1997

Phase transition parameters of potential thermosensitive drug release systems based on polymers of N-alkylmethacrylamides.

The phase separation and its thermohysteresis in dilute aqueous solutions of polymeric components of potential drug release systems (homopolymers and copolymers of N-isopropylacrylamide, N-isopropylmethacrylamide, N-propylmethacrylamide, N-sec-butylmethacrylamide, and N-(2-hydroxypropyl)methacrylamide) was studied, both on heating and cooling. Plots of light transmittance vs temperature were constructed and the parameters characterizing them were correlated with polymer structures. Qualitative information was obtained on the rate of formation of the concentrated phase on heating and its disappearance on cooling. Attention has been drawn to the improper identification of the cloud-point temperature, measured at an arbitrary concentration, with the lower critical solution temperature (LCST) as is frequently found in papers dealing with biomedical applications of thermosensitive polymers.

Acrylamides↗
PubMed1991

Analysis of hydrodynamic data for denatured globular proteins in terms of the wormlike cylinder model.

Hydrodynamic data, i.e. intrinsic viscosity and sedimentation coefficient, for denatured globular proteins in 6 M guanidinium chloride have been re-analysed in terms of the Yamakawa-Fujii theory of the wormlike cylinder model. Molecular parameters thus obtained ((mean value of R2 0/M) infinity, the Kuhn statistical segment length and the molecular weight per unit contour length) are in better agreement with the values obtained theoretically or by other methods than those evaluated on the basis of the model of non-draining random coil.

Mathematics↗
PubMed1989

Conformational transitions of leucine-containing isomeric sequential basic polytripeptides.

Conformational transitions of basic sequential polytripeptides (Lys-Ala-Leu)n, (Arg-Ala-Ala)n, (Arg-Leu-Ala)n, and (Arg-Ala-Leu)n, induced by elevated salt concentrations and/or temperatures in aqueous solutions, were investigated by CD, sedimentation equilibrium, and viscometry. The behavior of (Lys-Ala-Leu)n was compared with that of the sequential isomer (Lys-Leu-Ala)n, studied previously. It was found that both polypeptides are highly helical with a tendency to aggregate in high salt solutions. Although the hydrophobic interactions between Lys and Leu residues play an important role in both cases, the final effect on helix stabilization and aggregation is different. The Arg-containing polypeptides were found to assume the alpha-helical conformation. Compared to the Lys-containing polypeptides (Lys-Ala-Leu)n and (Lys-Leu-Ala)n, a very low tendency to aggregate was observed.

Isomerism↗