Specific Features of the Functional Activity of Human Adipose Stromal Cells in the Structure of a Partial Skin-Equivalent.

Mesenchymal adipose stromal cells (ASCs) are considered the most promising and accessible material for translational medicine. ASCs can be used independently or within the structure of scaffold-based constructs, as these not only ensure mechanical support, but can also optimize conditions for cell activity, as specific features of the scaffold structure have an impact on the vital activity of the cells. This manuscript presents a study of the secretion and accumulation that occur in a conditioned medium during the cultivation of human ASCs within the structure of such a partial skin-equivalent that is in contact with it.

Specifics of Porous Polymer and Xenogeneic Matrices and of Bone Tissue Regeneration Related to Their Implantation into an Experimental Rabbit Defect.

This paper provides a study of two bone substitutes: a hybrid porous polymer and an osteoplastic matrix based on a bovine-derived xenograft. Both materials are porous, but their pore characteristics are different. The osteoplastic matrix has pores of 300-600 µm and the hybrid polymer has smaller pores, generally of 6-20 µm, but with some pores up to 100 µm across.

Functionalization of Osteoplastic Material with Human Placental Growth Factor and Assessment of Biocompatibility of the Resulting Material In Vitro.

This article provides the results of a study of the interaction of placental growth factor with adipose-derived stem cells (ASCs) of various origins, as well as the possibility of generating osteoplastic material based on xenogeneic matrix functionalization with human placental growth factor (PLGF). It is demonstrated that the greatest release of this factor from the functionalized material into the medium occurs during the first 3 h of contact with the model medium, but then the levels of the factor being released fall sharply, although release did continue throughout the 7 days of observation. The modified material was not cytotoxic, and its surface provided good cell adhesion.

Effectiveness and Safety of Transplantation of the Stromal Vascular Fraction of Autologous Adipose Tissue for Wound Healing in the Donor Site in Patients with Third-Degree Skin Burns: A Randomized Trial.

Background: The quality of the wound healing at the donor site significantly determines the overall condition of the burn patient, the extent of wound fluid and protein losses, the severity of any systemic in-flammatory reaction, and the intensity of the pain syndrome. It is known that the stromal vas-cular fraction (SVF) has a beneficial effect on the healing of wound defects. This study is aimed at assessing the safety and effectiveness of the application of the SVF of autologous adipose tis-sue to stimulate wound healing of the donor site in patients with burns.

Pore Structure Tuning of Poly-EGDMA Biomedical Material by Varying the O-Quinone Photoinitiator.

Porous polymer monoliths with thicknesses of 2 and 4 mm were obtained via polymerization of ethylene glycol dimethacrylate (EGDMA) under the influence visible-light irradiation in the presence of a 70 wt% 1-butanol porogenic agent and o-quinone photoinitiators. The o-quinones used were: 3,5-di-tret-butyl-benzoquinone-1,2 (35Q), 3,6-di-tret-butyl-benzoquinone-1,2 (36Q), camphorquinone (CQ), and 9,10-phenanthrenequinone (PQ). Porous monoliths were also synthesized from the same mixture but using 2,2'-azo-bis(iso-butyronitrile) (AIBN) at 100 °C instead o-quinones.

Application of hydrogel wound dressings in cell therapy-approaches to assessment in vitro.

Cell therapy is actively used to treat skin defects, particularly burn lesions. The effectiveness of its application may depend on the appropriate choice of wound dressings used together with any cellular material. The aim of the study was to investigate the interaction of 4 hydrogel dressings used in clinical practice with human cells in an in vitro model to determine if their use in combination with cell therapy is possible.

Biological Characteristics of Polyurethane-Based Bone-Replacement Materials.

A study is presented on four polymers of the polyurethane family, obtained using a two-stage process. The first composition is the basic polymer; the others differ from it by the presence of a variety of fillers, introduced to provide radiopacity. The fillers used were 15% bismuth oxide (Composition 2), 15% tantalum pentoxide (Composition 3), or 15% zirconium oxide (Composition 4).

Crystal-chemical and morphological interpretation of the biocompatibility of compounds in a Ca-Na-Bi-fluorapatite system.

This work is devoted to the study of the features of isomorphism in compounds of a Ca-Na-Bi-P-O-F system with a crystalline structure of the mineral apatite, as well as its effect on the biocompatibility of substances in relation to human cells in an model. A CaBiNa(PO)F system ( = 0, 1, 2, 3, 4, and 5) is characterized by continuous isomorphism, which follows from the minimum deviations of the unit cell parameters from the Vegard and Rötgers rules. The refinement of the crystal structure showed that the cations are unevenly distributed between the 4 and 6 positions of the crystal structure of apatite: the bismuth ions are predominantly localized in the 6 position, while the sodium ions are concentrated in the 4 position.

Aspects of In Vitro Biodegradation of Hybrid Fibrin-Collagen Scaffolds.

The success of the regenerative process resulting from the implantation of a scaffold or a tissue-engineered structure into damaged tissues depends on a series of factors, including, crucially, the biodegradability of the implanted materials. The selection of a scaffold with appropriate biodegradation characteristics allows for synchronization of the degradation of the construct with the processes involved in new tissue formation. Thus, it is extremely important to characterize the biodegradation properties of potential scaffold materials at the stage of in vitro studies.

Changes in the Molecular Characteristics of Bovine and Marine Collagen in the Presence of Proteolytic Enzymes as a Stage Used in Scaffold Formation.

Biopolymers, in particular collagen and fibrinogen, are the leading materials for use in tissue engineering. When developing technology for scaffold formation, it is important to understand the properties of the source materials as well as the mechanisms that determine the formation of the scaffold structures. Both factors influence the properties of scaffolds to a great extent.

Porous Polymer Scaffolds based on Cross-Linked Poly-EGDMA and PLA: Manufacture, Antibiotics Encapsulation, and In Vitro Study.

Porous polymer materials derived from poly(ethylene glycol dimethacrylate) (poly-EGDMA) and antibiotic containing polylactide (PLA) are obtained for the first time. Porous poly-EGDMA monoliths with a system of open interconnected pores are synthesized by a visible light-induced radical polymerization of EGDMA in the presence of 70 wt% of porogenic agent, e.g.

Quantitative analysis of cells encapsulated in a scaffold.

One of the urgent problems arising while carrying out research in the field of scaffold technology is achieving an objective, direct, quantitative analysis of cells cultivated within a scaffold; one which allows characterization of the density distribution of the cells, their viability and their proliferative activity when encapsulated within the scaffold. This problem is associated with the peculiarities of cell cultivation in the three-dimensional structure of scaffolds, including limitations imposed on the possibility of direct cell counting using light microscopy. Also, most scaffolds are opaque, so this generally excludes methods of quantitative analysis using light microscopy.

Long-Term Cryostorage of Mesenchymal Stem Cell-Containing Hybrid Hydrogel Scaffolds Based on Fibrin and Collagen.

The most difficult issue when using tissue engineering products is enabling the ability to store them without losing their restorative capacity. The numbers and viability of mesenchymal stem cells encapsulated in a hydrogel scaffold after cryostorage at -80 °C (by using, individually, two kinds of cryoprotectors-Bambanker and 10% DMSO (Dimethyl sulfoxide) solution) for 3, 6, 9, and 12 months were determined, with subsequent assessment of cell proliferation after 96 h. The analysis of the cellular component was performed using fluorescence microscopy and the two fluorochromes-Hoechst 3334 and NucGreenTM Dead 488.

Biopolymer Hydrogel Scaffold as an Artificial Cell Niche for Mesenchymal Stem Cells.

The activity of stem cell processes is regulated by internal and external signals of the cell "niche". In general, the niche of stem cells can be represented as the microenvironment of the cells, providing a signal complex, determining the properties of the cells. At the same time, the "niche" concept implies feedback.

Hydrogel scaffolds based on blood plasma cryoprecipitate and collagen derived from various sources: Structural, mechanical and biological characteristics.

At present there is a growing need for tissue engineering products, including the products of scaffold-technologies. Biopolymer hydrogel scaffolds have a number of advantages and are increasingly being used to provide means of cell transfer for therapeutic treatments and for inducing tissue regeneration. This work presents original hydrogel biopolymer scaffolds based on a blood plasma cryoprecipitate and collagen and formed under conditions of enzymatic hydrolysis.