Study of structural features of porous TiNi-based materials produced by SHS and sintering

Structural properties of porous TiNi-based materials produced by SHS method and sintering have been investigated. The material having different pore wall surface topography, porosity and pore size distribution was shown to be produced depending on the powder metallurgy method for porous TiNi-based alloy. All the materials having porosity of 55-70%, mean pore size 90-150 μm, as well as normal pore size distribution are most preferable. Ultimate strength and breaking point were determined to depend on porosity, pore size distribution, pore intersections and phase chemical composition of the material. Strength properties of the sintered alloy are twice as much compared to the SHS-produced ones due to homogeneity of its macrostructure, low chemical heterogeneity and TiNi3 precipitations strengthening the TiNi matrix.</jats:p

Effects of infrared and ultraviolet radiation on the viability of cells immobilized in porous TiNi-based alloy scaffold

Сell responses to electromagnetic radiation are due to many factors including the cellular microenvironment. The aim of the present study was to explore the effects of ultraviolet (UV) and infrared (IR) irradiation of low intensity on cultured cells derived from different biological tissues (spleen, bone marrow, and Ehrlich's adenocarcinoma), which were immobilized in a porous TiNi-based alloy scaffold. Accordingly, the following objectives were set: i) to evaluate the impact of low-intensity radiation on cell suspensions, and ii) to carry out a comparative analysis of the viability of cells immobilized in porous TiNibased alloy and IR- and UV-irradiated. The data show that the extracellular environment of bone marrow, tumor and spleen cel

Strength and Plastic Properties of TiNiMoFeCu Alloys

В работе исследованы пористые сплавы TiNi49,9-xMo0,1Fe0,1Cux(где x = 0, 1, 3, 6, 10 ат.%), полученные методом (СВС). Показано, что существенное влияние на формирование поверхностей разрушения оказывает сформированная структура сплавов. Установлено, что многообразие проявления свойств сплавов с увеличением легирующей добавки от 1 до 10 ат.% Cu определяется как составом материала, так и температурой деформации.In this work, porous alloys TiNi49,9-xMo0.1Fe0.1Cux (where x = 0, 1, 3, 6, 10 at.%) Obtained by the (SHS) method are investigated. It is shown that the formed structure of the alloys has a significant effect on the formation of fracture surfaces. It was found that, the variety of properties of properties of alloys with the alloying additive formula from 1 to 10 at.% Cu is determined by both the composition of the material and the temperature of deformation.Исследование выполнено за счет гранта Российского научного фонда (проект № 19-79-10045).The research was carried out at the expense of a grant from the Russian science foundation (project No. 19-79-10045)

P17

The most effective method in treatment of inoperable cancer is currently miniallogeneic transplantation. This type of treatment focuses on reaction of “graft-versus-tumor”. According to preliminary data, such treatment leads to long-term remission in patients with metastatic cancer, who did not respond to previous therapy. Anti-tumor immune response after transplant may be extended or enhanced by additional infusion of donor lymphocytes. Research has shown that introduction of donor lymphocytes achieves complete remission of the tumor, even in case of relapse after allogeneic transplantation from the same donor, but these effects are unstable and not so long because of rapid elimination of donor lymphocytes [1]. The main problem is the preservation of cell transplantation viability and functional activity of the cells in patient’s body, and protecting them from recipient’s immune system. In recent years, most suitable for this purpose are the three-dimensional porous biomaterials (3D-scaffold). Specific pore space does not allow immunity effectors quickly destroy the cells in scaffold [2,3]. Research Institute of medical materials and implants with shape memory at the Tomsk State University created a porous-permeable incubators (scaffold) of TiNi-based shape memory alloy (TiNi). The material has unique properties: permeable porous structure by open interconnected pores, characterized by high degree of wettability with tissue media and nanoporous inner surface of the pore walls, exhibits high adhesion to various cell types, so all mentioned meet requirements of the bio-chemical and bio-mechanical compatibility. Porous TiNi-based scaffolds allow continually to keep the functionality cells and prolong their action [4,5]. The purpose of this study was to investigate possibility of modulation of antitumor response in allogeneic bone marrow transplantation in porous-permeable incubator of TiNi. Intraperitoneal injection of allogeneic bone marrow (BM) reduces metastasis by 30% and has easy 10%-antitumor effect. At the same time, the implantation of bone marrow cells on incubator of TiNi (BM + TiNi) leads to more pronounced antitumor (25%) and significant antimetastatic effects (45%). Life span of animals with tumors and implanted bone marrow cells on incubator TiNi is increased by 60% Since bone marrow cells do not have direct antiproliferative effect on tumor target cells in vitro, it is assumed that one of the mechanisms effecting the bone marrow transplantation on neoplastic process is the stimulation of endogenous effectors of antitumor immunity. The study of morphological parameters immunocompetent organs showed that administration of allogeneic bone marrow cells can reduce thymic regression, decrease splenomegaly at animals with transplanted tumors. Conclusion: Allogeneic transplantation of bone marrow cells on porous incubator was shown to prolong and enhance antitumor and antimetastatic action compared to injecting the cells. This effect is directly due to the stimulation of antitumor immunity, that is described by the study of immunity factors. The results show perspectives of porous TiNi-based scaffolds in complex treatment of neoplastic diseases

Investigation of the Effect of Copper Addition on Physical and Mechanical Properties of TiNi-Cu Porous Alloy

This work is devoted to the physical and mechanical properties of porous alloys based on TiNi alloyed with different amounts of Cu additive. We show that by doping a porous TiNi alloy with copper instead of nickel, it is possible to obtain characteristics acceptable for use in implantology and superior to those of known porous TiNi alloys. Cu addition in the range from 1 to 10 at.% is shown to optimize the properties of tested alloys. There is a decrease in the minimal martensitic transformation stress &tau;Msmin from 37 to 17 MPa when compared to initial unalloyed TiNi. Alloys with 3 and 6 at.% of Cu are found to be optimal for use in medical practice. Along with a wide temperature range of reversible deformations that cover the range of operating temperatures (273&ndash;313 K), such alloys demonstrate their martensitic transformation stress values below 28 MPs. This permits to model implantable structures of complex configuration from such materials under a certain temperature regime

Effects of infrared and ultraviolet radiation on the viability of cells immobilized in porous TiNi-based alloy scaffold

Сell responses to electromagnetic radiation are due to many factors including the cellular microenvironment. The aim of the present study was to explore the effects of ultraviolet (UV) and infrared (IR) irradiation of low intensity on cultured cells derived from different biological tissues (spleen, bone marrow, and Ehrlich's adenocarcinoma), which were immobilized in a porous TiNi-based alloy scaffold. Accordingly, the following objectives were set: i) to evaluate the impact of low-intensity radiation on cell suspensions, and ii) to carry out a comparative analysis of the viability of cells immobilized in porous TiNibased alloy and IR- and UV-irradiated. The data show that the extracellular environment of bone marrow, tumor and spleen cel