Growth-Stimulating Effect of Platelet Preparations Obtained by Different Methods on Human Fibroblast Culture.

We studied the growth-stimulating effect of platelet-based preparations obtained by different methods on cultured human fibroblasts M-22. Platelet lysates prepared from platelet-rich plasma, platelet-poor plasma, concentrated suspension of platelets washed from plasma, and platelet-rich plasma activated with calcium chloride (ActPRP) were used. The volume of the platelet preparations was 10-500 µl per 104 cells. The most effective dose of platelet-rich and platelet-poor plasma in cell culture was 20 µl, whereas for ActPRP, the most effective dose was 500 µl. Lysates of platelet-rich and platelet-poor plasma in doses of 100-500 µl inhibited fibroblast growth and disturbed their structural integrity. At the same time, lysates of washed platelets in doses of 10-500 µl stimulated cell growth and preserved their viability. An inverse correlation was found between the number of cells in culture and the level of proinflammatory cytokines in the platelet preparations.

Experimental Study of the Effect of Biological Matrixes with Stabilized and Non-Stabilized Platelets on Reparative Process in the Wound Equivalent to Deep Burn.

We studied reparative effect of platelet-filled biological matrixes in the treatment of mice with wounds equivalent to deep burn. The wound coatings were based on decellularized dermal matrix without platelets (control), with native platelets, and with platelets stabilized with 2.5 µM nanosilver. In 3 days, the epithelial layer and derma were absent in all groups and extensive scab was formed. Dermal matrix with platelets simulated intensive migration of macrophages and fibroblasts to the wound bottom; in the control group, this migration was absent. In 14 days, granulation tissue appeared in the wound bottom in animals of all groups; in the experimental groups, the number of vessels was 2-4-fold higher than in the control, though the number of inflammatory cells in experimental groups remained high. On day 21, the scab on the most of the wound area was absent in all animals of the experimental groups and epithelialization and hair growth were pronounced, comparing to control. Nevertheless, in experiment dermal layer was not already completed, inflammation reaction remained.

Interaction of Magnesium-Based Materials with Human Blood Cells and Culture of Human Diploid Cells In Vitro.

We studied morphofunctional properties of human blood cells and diploid culture cells exposed to different types of magnesium materials: pure magnesium (Mg), magnesium-yttrium-neodymium-zirconium alloy (Mg-Y-Nd-Zr) and magnesium-zinc-calcium alloy (Mg-Zn-Ca). The materials were incubated with donor blood and mesenchymal multipotent stromal cells over 3 days. The studied materials did not induce massive lysis of human erythrocytes and leukocytes in vitro, but gradually impaired their structural integrity. In all cases, spontaneous platelet aggregation was observed in 6 h. In the presence of pure Mg and Mg-Zn-Ca alloy, this was accompanied by a decrease in the number of platelets with granules. In 24 h, substantial platelet degranulation occurred in all cases and in 72 h, the platelets did not contain granules. In parallel, the formation of large aggregates (60 µ) was observed. In the culture of stromal cells, all Mg-based materials reduced structural integrity of cells in 24 h, but did not significantly inhibit cell proliferation. Structural integrity of stromal cells partially recovered by day 3 in culture. The studied materials (Mg, Mg-Y-Nd-Zr, and Mg-Zn-Ca) seemed to be low-toxic for human cells during short-term contact, but could stimulate platelet aggregation and spontaneous degranulation and reduced the viability of diploid cells in vitro.

Growth-Stimulating Effect of Human Platelets Stabilized with Silver Nanoparticles.

We studied proliferative activity of multipotent mesenchymal stromal cells on collagen matrices containing platelets stabilized with silver nanoparticles. Dose-dependent stimulation of the growth of stromal cells without their structural damage was observed in the presence of stabilized platelets in proportion of 20-120 mln per 105 multipotent mesenchymal stromal cells. The same doses of non-stabilized platelets produced less pronounced stimulation effect. In higher doses (≥180 mln) stabilized platelets inhibited cell proliferation and induced their damage. Stabilized platelets enhanced migration of multipotent mesenchymal stromal cells; after formation of the monolayer, they actively colonized deep layer of the collagen matrix. The formed monolayer of multipotent mesenchymal stromal cells survived over 14 days without appreciable cell damage.

[The cellular sensitivity of the primary tumor and its metastases in breast cancer patients to cytostatics, interferon and tumor necrosis factor]. / Issledovanie chuvstvitel'nosti kletok pervichnoi opukholi i metastazov u bol'nykh rakom molochnoi zhelezy k tsitostatikam, interferonu i faktoru nekroza opukholei.

Samples of tumor tissue obtained from 47 patients with primary and metastatic breast cancer were implanted under the renal capsule of mice (SRCA-test) to assess individual sensitivity of these malignancies to cytostatics, recombinant interferon (rIFN) and--in some cases--to tumor necrosis factor (TNF). Primary tumor was shown to respond to cytostatics and rIFN in as few as 33.3 and 26.7% of cases, respectively. Xenografts of metastases displayed higher rates of response to all the drugs studied, viz. 64.2, 86.7 and 90% for cytostatics, rIFN and TNF, respectively.