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The aim is to study the basic physico-mechanical properties of hydroxyapatite (HA) composites (up to 25–50 wt%) with polylactide (PLA-HA) and poly(e-caprolactone) (PCL-HA) prepared by melt compounding, as well as the osteogenic potential of PLA-HA in vivo.Materials and methods. All biodegradable polymer composites were prepared by hot melt compounding and studied by dielectric spectroscopy in frequency domain, optical microscopy, X-ray diffraction analysis and tensile tests. An ability of PLA-5 wt% HA composites prepared by 3D-printing to induce bone tissue growth in vivo was detected with the help of ectopic subcutaneous test in inbred mice.Results. Values of the real part of complex permittivity of PLA-HA and PCL-HA composites are increased by 15–30% compared to those for initial PLA and PCL, while tand loss factor does not exceed 0.02 for PLA-based composites and 0.2 for PCL-based composites. The crystallinity degree of PLA-HA composites is increased by 3 and 6 times with an increase of HA content from 25 to 50 wt% respectively compared to the indicator for PLA. The crystallinity degree of PCL-HA composites with 25 wt% HA is increased by 2 times compared to the value for PCL. It is due to the fact that HA powder particles play the role of additional nucleation centers. For all this, mechanical strength of composites diminished statistically. Even lowest HA content (5 wt%) in PLA-HA composites prepared by 3D-printing increased the incidence of ectopic osteogenesis by 40%.Conclusion. Designed biodegradable composites have a potential of practical use for bone tissue engineering.

Aim: to review current scientific literature concerning the main advances and problems of magnesium (Mg) alloys for traumatology and orthopedics. Methodology of the study. Analytical review based the comprehensive investigation of public scientific and technological sources. Results of the study. Modern knowledge about classification, in vitro and in vivo biodegradation, biomechanics, local and general biocompatibilities, clinical efficacy, and hazards of infectious complications in conditions of osteosynthesis with implants made of Mg alloys with or without protective (anticorrosion and antimicrobial) coatings is presented. Conclusion. Fast degradation and a risk of periprosthetic infection strongly limit clinical application of implants made of Mg and its alloys. Development of novel Mg alloys and their modification by incorporating antimicrobial elements into their body or protective coating is a promising direction to control biomedical characteristics of Mg alloys.

Antibodies are indispensable tools for basic research as well as diagnostic and therapeutic applications. Consequently, the development of alternative manufacturing strategies which circumvent the hurdles connected to conventional antibody production technologies is of enormous interest. To address this issue, we demonstrate the synthesis of complex antibody formats, in particular immunoglobulin G (IgG) and single-chain variable fragment Fc fusion (scFv-Fc), in a microsome-containing cell-free system based on translationally active chinese hamster ovary (CHO) cell lysates. To mimic the environment for antibody folding and assembly present in living cells, antibody genes were fused to an endoplasmic reticulum (ER)-specific signal sequence. Signal-peptide induced translocation of antibody polypeptide chains into the lumen of ER microsomes was found to be the prerequisite for antibody chain assembly and functionality. In this context, we show the rapid synthesis of antibody molecules in different reaction formats, including batch and continuous-exchange cell-free (CECF) reactions, depending on the amount of protein needed for further analysis. In addition, we demonstrate site-specific and residue-specific labeling of antibodies with fluorescent non-canonical amino acids. In summary, our study describes a novel antibody production platform which combines the highly efficient mammalian protein folding machinery of CHO cells with the benefits of cell-free protein synthesis.

There is a forthcoming link between chronic alcohol consumption and proteins covalently modified by ethanol metabolites and their antibodies. To identify sensitive probes of protein-ethanol conjugates, we screened for the ethanol-altered protein domains with a phage-display combinatorial peptide library. In principle, recognition of the epitopes by the library peptides occurs through protein-protein interactions. A general screening, M13-based library with 10(9) random sequences of linear heptameric peptides was used. The peptides were displayed in five copies each, as fusion proteins with phage's minor coat protein III. They were located on one end of the surface of the phage particles. The targets were a model protein, streptavidin, and protein-ethanol conjugates (hydroxyethyl radical- or acetaldehyde-modified bovine serum albumin). They were either immobilized on a surface by direct coating or affinity captured on floating beads. An enriched library of phages with the tightest peptide binders for each target was selected and amplified in a multiple-cycle biopanning in vitro procedure. Binders were characterized by DNA sequencing of the corresponding phages and by counter-screening with positive and negative targets in either an enzyme-linked immunosorbent assay or plaque assay. We obtained the HPQ motif for streptavidin and two unique subsets of peptides that recognized each ethanol target with a selectivity of two orders of magnitude above the carrier protein and controls. The application of biopanning processes, coupled with phage-display peptide libraries on biological fluids and tissues, could provide a systematic mapping of protein--ethanol conjugates and supply a means for early diagnosis and prognosis of chronic alcohol consumption in human beings.

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Raj Lakshman and Mikihiro Tsutsumi. The presentations were (1) Sialic acid index of apolipoprotein J: A new marker for chronic alcohol consumption, by P. Ghosh and M. R. Lakshman; (2) Microheterogeneity of serum glycoproteins in alcoholics, by M. Tsutsumi and S. Takase; (3) Probing protein-ethanol adducts with combinatorial peptide libraries displayed by filamentous phage, by H. Anni, O. Nikolaeva, and Y. Israel Y; (4) Carbohydrate-deficient transferrin as a marker for heavy alcohol use: What have we learned; Where do we go from here, by R. F. Anton; (5) Sensitivity and specificity of carbohydrate-deficient transferrin in drinking experiments and different patient groups, by O. M. Lesch; (6), Transferrin variants interfere with the measurement of carbohydrate-deficient transferrin, by A. Helender, G. Eriksson, and J-O. Jeppson; and (7) Chronic ethanol on protein trafficking in liver, by P. Marmillot, M. N. Rao, and M. R. Lakshman.