Effect of Collagen and GelMA on Preservation of the Costal Chondrocytes' Phenotype in a Scaffold in vivo.

The aim of the study was to compare type I collagen-based and methacryloyl gelatin-based (GelMA) hydrogels by their ability to form hyaline cartilage in animals after subcutaneous implantation of scaffolds. Materials and Methods: Chondrocytes were isolated from the costal cartilage of newborn rats using 0.15% collagenase solution in DMEM. The cells was characterized by glycosaminoglycan staining with alcian blue. Chondrocyte scaffolds were obtained from 4% type I porcine atelocollagen and 10% GelMA by micromolding and then implanted subcutaneously into the withers of two groups of Wistar rats. Histological and immunohistochemical studies were performed on days 12 and 26 after implantation. Tissue samples were stained with hematoxylin and eosin, alcian blue; type I and type II collagens were identified by the corresponding antibodies. Results: The implanted scaffolds induced a moderate inflammatory response in both groups when implanted in animals. By day 26 after implantation, both collagen and GelMA had almost completely resorbed. Cartilage tissue formation was observed in both animal groups. The newly formed tissue was stained intensively with alcian blue, and the cells were positive for both types of collagen. Cartilage tissue was formed among muscle fibers. Conclusion: The ability of collagen type I and GelMA hydrogels to form hyaline cartilage in animals after subcutaneous implantation of scaffolds was studied. Both collagen and GelMA contributed to formation of hyaline-like cartilage tissue type in animals, but the chondrocyte phenotype is characterized as mixed. Additional detailed studies of possible mechanisms of chondrogenesis under the influence of each of the hydrogels are needed.

[Study of photodynamic treatment for P-388 lympho-leukemia in mice].

Data are presented on the results of photodynamic treatment (PDT) of mice DBA2 with transplantable lympho-leukemia P-388. Different regimens of photosensitizer Dimegin and emission were used. Both intravenous PDT and in combination with local PDT should be recommended.

[Biological effects of Lamipharen photodynamic therapy].

Biological effects of Lamipharen treatment of sarcoma M-1 was studied in newborn rats and photodynamic therapy in combination with radiation was evaluated.

[Use of photosense treatment to enhance photodynamic effect on solid sarcoma-1 in Wistar rats].

Interaction between such components of photodynamic therapy as tumor, intact tissues, lighting and photosensitizers has been investigated. The efficacy of Photosense treatment was demonstrated in the experiments using transplantable tumors in Wistar rats. The photodynamic procedure both inhibited tumor process and stimulated immune system.

[The optimization of a plan for the photodynamic therapy of sarcoma M1 using photosens]. / Optimizatsiia skhemy fotodinamicheskoi terapii sarkomy M1 s primeneniem fotosensa.

The study established the importance of optimal dosage, concentration and mode of administration of the drug Fotosens for the effectiveness of photodynamic therapy of tumor. Of similar importance is the interval between administration and irradiation to potentiate the drug's action. Failure to consider the latter factor may lower the effect dramatically or even reverse it. Experimental findings point to high antitumor potency of the drug. Preference should be given to injecting relatively low concentrations along the periphery of tumor, thus avoiding the undesirable cytostimulating effect and toxicity of Fotosens and saving on the drug. The potential of the treatment as a component of "white light" photodynamic therapy is discussed.

[Biological effects of the low-intensive laser of the near infra-red spectrum]. / Biologicheskie éffekty nizkointensivnogo lazernogo izlucheniia blizhnefrakrasnogo diapazona.

The immediate and the remote effects of the total one-time uniform irradiation with arsenid-hallium laser (wavelength 0.89 mu, pulse power 450 W, pulsed mode 80-3000 Hz) on the new-born Wistar rats have been examined. The complex of tests illustrated the biotropical effects of used laser regimes. The stimulating or braking of the animal's growth was observed in accodanse with the laser regime.

[Effect of the gaseous hypoxic mixture GHM-10 on the radiosensitivity of the fetus and the development of offspring]. / Vliianie gazovoi gipoksicheskoi smesi GGS-10 na radiochuvstvitel'nost' ploda i razvitie potomstva.

A gas hypoxic mixture containing 10 percent of O2 and 90 percent of N2 was shown to exert a radioprotective action on pregnant rats and young rats of the first generation if animals were exposed to ionizing radiation during the periods of preimplantation, organogenesis and fetus development. The effect depended on the radiation dose and the period of the intrauterine development of fetus.

[Effect of whole-body irradiation of females on pregnancy and postnatal development of the offspring]. / Vliianie obshchego gamma-oblucheniia samok na beremennost' i postnatal'noe razvitie potomstva.

In 218 primigravida rats of Wistar strain with body mass 200-250 g radiosensitivity during the whole period of pregnancy has been studied after a single total gamma-radiation with 60Co given in LD50 2.0 Gy. The multifactor analysis includes: dynamics of the body mass of the pregnant rats, ability to implantation and pregnancy, duration of pregnancy, number of births that failed, body mass loss during delivery, death of the embryos during the antenatal period, number of viable offsprings, dynamics of body mass in the offsprings and their viability during 30 days after birth, time for covering with fur and eyes opening, developmental anomalies etc. Quantitative and qualitative postradiative disorders of the intrauterine and postnatal development of the offsprings are described. The most sensitive days of pregnancy are revealed (the 1st--3d and the 9th--11th days).