[Tissue equivalent for the closure of extended urethral defects].

The aim of the present work was to develop a method for culturing epidermal keratinocytes to be used in a tissue equivalent for the closure of extended urethral defects. The experiment was carried out using 15 rabbits. Skin biopsies were obtained from the inner surface of the ear. The tissue equivalent consisted of collagen gel with embedded fibroblasts and epidermal keratinocytes grown on its surface; lavsan-mesh endoprosthesis served as the framework. Prefabrication of the neourethral plate was performed on the superficial fascia of m. rectus abdominis. The neourethral tube was formed after engraftment which was complete in all 15 animals. A histological study revealed morphological similarity of the neourethral tube thus engineered and the normal urethra.

[Contractile capacity of fibroblasts from different sources in the model of living skin equivalent].

Human fibroblasts contract collagen gel in vitro and produce a connective tissue-like structure termed the living skin equivalent. In this study, the contractile capacity of postnatal dermal fibroblasts, bone marrow mesenchymal cells and mesenchymal cells derived from the fat tissue has been compared to that of fetal dermal fibroblasts in the model of living skin equivalent. The results show that fetal fibroblasts contract the collagen gel approximately six times stronger than do all other fibroblast cell types, with the numbers of all these cells being equal. A deeper insight into the behavior of fibroblasts differing in their origin will help to develop new approaches to the treatment and regulation of wound healing and fibrosis formation.

[Application of cell technologies to tissue defect closure in oncology].

In vivo and in vitro experiments on the application of cell technologies to tissue defect closure were conducted; autologic mesenchymal stem cells on 3-demensional matrices were used. The authors analyze the results of the application of bioengineering tissue equivalents for the closure of soft tissue and upper airway defects after extensive resections performed in 52 oncological patients. Tissue equivalents with stem cells provide engraftment and long-term graft functioning; they also modify wound surface, thus stimulating wound epithelization. In this study the application of tissue equivalents led to wound healing and functional recovery in 87% of patients.

[Immunomorphological study of time course of repair of corneal deep burn defects after stromal equivalent transplantation].

Early defects due to the afflux of monocytic phagocytes into the inflammatory focus, rapid resorption of detritis and normalisation of correlation between contents of matrix proteinases and their inhibitors, stimulation of stromal cornea keratinocytes migration and their proliferation characterize repair of postburn defects in transplantation of the stromal equivalent. Repair against the background of stromal equivalent transplantation is of a histotypical character: collagen gel organizes and serves the basis for migration of the cornea fibroblasts and temporary matrix for growing new epithelium, while restored basal membrane is a derivative of cornea epithelium.

[Repair of corneal defects using tissue engineering].

We propose to treat deep corneal burns by grafting a living stromal equivalent, since keratocyte death and stromal destruction are the main factors of ulceration and destruction of the eye. A technique was developed for isolation and grafting a living stromal equivalent. Twenty one patients with deep corneal defects were treated. A stable therapeutic effect was observed in 95% of cases. The advantage of the developed method is partial recovery of affected corneal transparency.

[The use of human fibroblasts grown on microcarriers for the formation of the connective tissue equivalent]. / Ispol'zovanie fibroblastov cheloveka, vyrashchennykh na mikronositeliakh, dlia formirovaniia ékvivalenta soedinitel'noi tkani.

Live equivalents of tissues, specifically those produced on the basis of fibroblasts and collagen gel, are widely used for repair of organ and tissues defects. In clinical practice, it is more convenient to use the fibroblasts grown on microcarriers or such a connective tissue equivalent when the fibroblasts on microcarriers are embedded in collagen gel. We studied the properties of a connective tissue equivalent produced by embedding the fibroblasts grown on microcarriers in collagen gel for its prospective use in clinical practice. According to our results, the optimal time of use of the live tissue equivalent amounts to three--four days after embedding of fibroblasts on microcarriers in gel. At that time, contraction only begins, which facilitates manipulations with the gel.