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We developed a method for differential staining of human platelets preserving their functional activity based on vital fl uorochrome stains trypafl avin and acridine orange. Platelets stained with trypafl avin and acridine orange exhibited under a fl uorescent microscope green fl uorescence of the cytoplasm and red-orange fl uorescence of the granules. Morphofunctional analysis of platelets was carried out on the cells from donor blood, donor concentrated platelets, and cells from hematological patients and patients with thromboembolic complications. Populations with low (16 %) and high (2 %) morphofunctional activities of platelets were detected among donors. The morphofunctional parameters of platelets were sharply reduced in hematological patients with the hemorrhagic syndrome and elevated signifi cantly in patients with thromboembolic complications in comparison with donors. The method seemed to be effective for evaluating the platelet quality in donor and patients' blood components.

Serum concentration of platelet-derived growth factor was measured in patients with trophic ulcers and proliferative activity of human fibroblasts was measured in wells with different content of added serum platelet-derived growth factor. In parallel, morphofunctional analysis of platelets from the whole blood of these patients was performed. A close correlation was found between morphofunctional parameters of blood platelets and serum concentration of platelet-derived growth factor. Platelet-derived growth factor in concentrations below 150 pg per well stimulated fibroblast proliferation and preserved their viability. Platelet-derived growth factor in concentrations >200 pg per well suppressed fibroblast proliferation and impaired their viability.

This article is dedicated to the realistic, present-day problem in treating patients with a damaged cornea. It contains a general summary of the practical experience of treatments in various spheres of medicine and in ophthalmology in particular, concerning the new developing method of restoring tissue with the aid of platelet rich plasma. This is a branch of regenerative medicine. In ophthalmology an effective method has long been sought for treating patients with a damaged cornea. It is well-known that platelet rich plasma contains a high quantity of elements which contribute to growth: thrombocyte, transformation, insulin-like, epidermal etc. And although the mechanism of the parts their role has not been sufficiently studied, the positive results of the PRP use in various fields of surgical medicine and in particular in the treatment of burns and ulcers of the tissue, speak of the key role being played in the growth factor and the process of tissue restoration. Despite the fact that this method has not been fully studied by ophthalmologists, it is of great interest to practising doctors, considering its potential value due to it being therapeutically effective and both simple and economic to produce. Our aim here is to give a short overview of the literature which contains descriptions of the morphological qualities of thrombocytes, to note and describe the characteristics of PRP and its role in the regeneration of tissue, to make special note of the history of the discovery of the growth factor in medico-biological science and to analyze the publications which give details of the PRP use.

The aim of the investigation was to study the possibilities of evaluating the biological properties of various tissue grafts analyzing autofluorescence level of their collagen fibers.Materials and Methods. The study involved various types of standard-produced tissue grafts, some of them being exposed to additional treatment to stimulate changes in collagen fiber structure. Analysis of preparations was made using light, fluorescent and confocal microscopy. To evaluate human cell adhesion on tissue grafts with different autofluorescence levels, M-22 human fibroblasts and human blood platelets were used.Results. Collagen autofluorescence has been registered in both fixed and non-fixed tissue graft samples, autofluorescence level of single fibers reflecting the extent of their compaction. Damage to the initial collagen structure leads to changes in tissue graft composition due to formation of picrinophilic fibers with very high autofluorescence levels, which do not appear in normal tissues or after collagen decondensation in conditions of hypotonia. Grafts with collagen fiber autofluorescence intensity 30 foot-candles are highly adhesive for M-22 human fibroblasts and donor platelets, whereas grafts with autofluorescence levels of more than 40 foot-candles exhibit significantly lower adhesive properties.Conclusion. Collagen autofluorescence analysis provides important data about connective tissue topography, intercellular matrix integrity and allows collagen defects to be revealed, even in non-fixed tissue slices and grafts.