Improved cell activity on biodegradable photopolymer scaffolds using titanate nanotube coatings.

The development of bioactive materials is in the premise of tissue engineering. For several years, surface functionalization of scaffolds has been one of the most promising approaches to stimulate cellular activity and finally improve implant success. Herein, we describe the development of a bioactive composite scaffold composed of a biodegradable photopolymer scaffold and titanate nanotubes (TNTs). The biodegradable photopolymer scaffolds were fabricated by applying mask-projection excimer laser photocuring at 308 nm. TNTs were synthesized and then spin-coated on the porous scaffolds. Upon culturing fibroblast cells on scaffolds, we found that nanotubes coating affects cell viability and proliferation demonstrating that TNT coatings enhance cell growth on the scaffolds by further improving their surface topography.

Titanate nanotube coatings on biodegradable photopolymer scaffolds.

Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion.

Safety and efficacy of Mycoplasma gallisepticum TS-11 vaccine for the protection of layer pullets against challenge with virulent M. gallisepticum R-strain.

Mycoplasma gallisepticum TS-11 vaccine was studied for its safety and protective ability in 49-day-old M. gallisepticum-free and Mycoplasma synoviae-free commercial Tetra SL layer chickens. Sixty birds were distributed into four groups: 15 were unvaccinated but were challenged with M. gallisepticum R-strain, 15 were vaccinated by eye drop and then challenged with virulent M. gallisepticum R-strain 4 weeks post vaccination, 15 were designated as controls without vaccination and challenge, and 15 received TS-11 vaccine but no challenge. Based on the post-challenge clinical signs, body weight gain, gross pathological examination of air sacs and peritoneum, histological examination of the trachea, lung, spleen and liver, and reisolation of mycoplasmas from inner organs, the TS-11 vaccine is safe and does not produce clinical signs, a major decrease of body weight gain or pathological lesions. Vaccination induced a slight serological response to M. gallisepticum antigen in serum plate agglutination and blocking enzyme-linked immunosorbent assay tests and prevented development clinical signs of airsacculitis, peribronchitis and interstitial pneumonia on M. gallisepticum challenge.

[Evaluation of a complex trace element composition and bioutilization using isotope technics and total body measurement]. / Komplex nyomelem készítmény biológiai hasznosulásának tanulmányozása izotópos nyomjelzéstechnika és egésztest-mérés alkalmazásával.

Modified mineral and trace element solutions were prepared containing Zn-65, Co-57, Mn-54, Fe-59, Mo-99 and Ni-63 isotopes which were physico-chemically identical to the original solution. Bioutilization examinations were carried out on animals receiving their normal feeding, after p. os application of complex trace element composition (CTEC) namely whole-body retention studies, bioassays, scintigraphic and excretion examinations in altogether 180 Wistar rats, 6 Beagle and 2 mongrel dogs using whole body counter, gamma and beta counters, gamma camera and metabolic cages. Extremely high whole body retention was measured in case of iron (8-30%), high utilizations in case of zinc (4-5%), cobalt (4-6%), molybdenum (3-4%) and manganese (2-4%) and a lower value in case of nickel. Bioassay and scintigraphic evaluations showed marked liver-, kidney-, and muscle and moderated blood uptakes. The way of excretion was mainly (more than 90%) via the faeces in case of zinc, manganese, iron and nickel, although cobalt excreted in 8% and molybdenum in 52% via the urinary tract. Our results show, that isotope technique combined with whole body counting and excretion studies in an available method for trace element bioutilization studies.

The use of electroimmunoassay for the determination of the in vivo stability of labelled proteins.

The in vivo stability of 125I, 99Tcm and 67Ga labelled HSA was measured by electroimmunoassay (EIA). Radiolabelled HSA compounds were intravenously injected into rabbits, and blood samples were taken 2, 5, 10, 30 and 60 min after injection. The activity and HSA content of rabbit sera were measured simultaneously. The results showed that HSA had been eliminated from the bloodstream at the same rate in all three cases (95-97% of HSA were in the circulation). Significant differences in the activity of serum samples are unequivocally due to differences in labelling and type of binding. Metal isotope detachment values were: 99Tcm-HSA, 47.3%; 67Ga-DF-HSA, 20.8% and 125I-HSA, 11.4% The data demonstrate that EIA may be a suitable method for the determination of the serum stability of protein-based radiopharmaceuticals.

Inhibition of protein synthesis in developing mouse brain after fission neutron irradiation in utero.

Previous investigations showed that when pregnant mice were exposed to a single whole-body dose of 0.5 Gy fission neutrons on Day 17 +/- 2 of gestation [H. H. Vogel, Jr. and S. Antal, Radiat. Res. 98, 52-64 (1984)] about 40% of the newborn mice died and the body and brain weights of surviving animals decreased by 30-35%. Decreases of body and brain weights were most prominent by the third week after birth, but the content of nucleic acids related to wet weight did not change in liver and brain upon irradiation [S. Antal, A. Fónagy, Z. Fülöp, E. J. Hidvégi, and H. H. Vogel, Jr. Int. J. Radiat. Biol. 46, 425-433 (1984)]. Studies presented in this paper show that after a single whole-body dose of 0.5 Gy neutron irradiation on Day 18 of pregnancy protein synthesis decreased in liver and brain of 3-week-old mice irradiated in utero. Incorporation of labeled amino acids in vivo into acid soluble nuclear proteins decreased by 15% in liver and by 40% in brain. It was significantly reduced into brain histones and certain brain nonhistone proteins (separated by two-dimensional electrophoresis). The amount of H1 and H4 brain histones decreased as well. Investigations with isolated protein synthesizing systems proved that the peptide bond formation was not impaired by irradiation. The aminoacylation of transfer-RNA, however, decreased in both liver and brain by 26-34 and 34-41%, respectively. Comparing the aminoacylation capacities in the two unirradiated organs, a much lower (about one-third) capacity was found in brain than in liver. Moreover, this low aminoacylation capacity of brain decreased further by about 40% after neutron irradiation. These results suggest that in the developing irradiated brain the reduced capacity of aminoacylation of transfer-RNA might be rate limiting for the efficiency of protein synthesis.