This study investigates new composite porous titanium nickelide-based materials, which have been obtained for the first time by functionalizing their surface with a promising macrocyclic compound-bambus[6]uril. Such functionalization aims to enhance the hemocompatibility and cytocompatibility of bone implants, addressing issues of uncontrolled drug release and poor implant integration. The surface modification was carried out by applying bambus[6]uril in the form of a dispersion using various physical methods such as immersion, vacuum treatment, and ultrasonic exposure. The obtained materials were characterized using IR spectroscopy, synchronous thermal analysis, and electron microscopy. The results of the study demonstrated that the highest cytocompatibility was observed in the samples obtained using vacuum and ultrasonic methods, while the samples modified using immersion exhibited cytocompatibility comparable to that of the control samples, which is attributed to the distribution pattern of bambus[6]uril molecules on the porous TiNi surface.

BackgroundDiaphragmatic plication is a standard treatment for symptomatic unilateral diaphragmatic paralysis, but the best minimally invasive technique and reinforcement material remain debated. We evaluated a two-port VATS plication technique using porous Nitinol pledgets.MethodsThis retrospective single-center study included 30 consecutive adults with symptomatic unilateral diaphragmatic paralysis who underwent two-port VATS plication between 2018 and 2024. All procedures were performed using porous NiTi pledgets (7 × 5 × 3 mm) and non-absorbable sutures. Perioperative outcomes included operative time, blood loss, extubation, ICU use, chest tube duration, pain scores, complications, and length of stay. Functional outcomes comprised spirometry (FVC, FEV1), MRC dyspnea scores, and radiographic hemidiaphragm elevation at 1, 6, and 12 months.ResultsMean age was 61.3 ± 10.3 years; 66.7% of patients were female. Mean operative time was 123.1 ± 29.0 min and blood loss 20.3 ± 20.8 mL. Immediate extubation occurred in 86.7%; 40% required brief ICU monitoring. Chest tube duration and hospital stay were 2.2 ± 1.3 and 5.5 ± 2.9 days. Complications occurred in 13.3%, all grade I-II. At 12 months, FVC increased from 60.2 ± 12.2% to 82.1 ± 10.6%, FEV1 from 60.2 ± 14.5% to 81.1 ± 11.8%, MRC score improved from 3.8 ± 0.4 to 0.5 ± 0.6, diaphragm elevation decreased by ∼34%, and 90% of patients reported symptomatic improvement.ConclusionsTwo-port VATS diaphragmatic plication reinforced with porous NiTi pledgets demonstrates feasibility, safety, and reproducibility with sustained functional and symptomatic improvement and low morbidity. The absence of a control group precludes claims of material superiority; observed benefits primarily reflect the mechanical restoration achieved by plication itself, with porous NiTi serving as a biocompatible alternative to standard PTFE pledgets.

This study explores how the time spent in plasma electrolyte oxidation (PEO) for a proprietary Mg-Ca-Zn alloy in a weak alkaline phosphate-borate solution affects the coating's structure, ability to resist corrosion, and potential to break down in vivo. The PEO procedure lasted 15, 25, and 35 min, respectively. The 15-min exposure ensures the formation of PEO-derived coatings with the lowest porosity. All the synthesized coatings exhibited a multilayer structure, including an inner dense sublayer composed of fluorine and a superficial sublayer consisted of oxygen, phosphorus, and magnesium. The outer layer appeared to be amorphous, as revealed using XRD and TEM instruments. The TEM study detected inclusions of the MgF2 phase next to the magnesium substrate. Electrochemical impedance spectroscopy and potentiodynamic linear polarization methods were employed to conduct corrosion tests in a 0.9 % NaCl solution. The data indicated the coatings deposited through the 15-min PEO treatment exhibited the highest corrosion-proof performance. In vivo tests for post-implantation behavior and morphological assessment of biological response using a rabbit model showed no inflammation and implantassociated serious side effects. In terms of bone remodeling and biodegradation rate, the M15 sample showed the most promising results.

The paper reports the results of the computer-aided analysis of the durability of porous cylindrical titanium nickelide prostheses intended for replace the intervertebral disk in the cervical spine segment and vertebral bone tissue of different density. Endoprostheses of different sizes were made of titanium nickelide obtained by self-propagating high-temperature synthesis. Experimental uniaxial compression load curves were obtained to assess the mechanical properties of the prostheses. The assessment of segment durability when the segment is tilted forward was carried out on the basis of stress state calculations of the segment with prostheses, as well as expressions approximating experimental data on porous samples cyclic loading made of titanium nickelide and bone tissue. The results of the study show the possibility of long-term operation of the implants in question and the absence of fatigue destruction of vertebral bone tissue throughout a person's life.

Biocompatibility, structure, and properties of medical grade nickel-titanium (NiTi) alloys doped with tungsten were studied in this paper. The main phases are TiNi, Ti2Ni, and pure W, based on the x-ray diffraction analysis. W is present in the NiTi alloys in the form of separate particles with 1.5 µm average size. Starting at a W concentration of 0.4 at.

Numerical simulation of deformation in the surface layer of coated polycrystalline titanium nickelide is performed. The coating is synthesized from a layered Ti/Ni/Ti nanolaminate. The polycrystalline microstructure is studied by electron backscatter diffraction (EBSD) analysis. Based on the available experimental data, a model microstructure of the polycrystalline composite assuming the grain orientation is created. An anisotropic constitutive model of composite elastoplastic deformation is developed taking into account the cubic syngony, slip systems, and phase transition. The microstructure and model are integrated into ABAQUS/Explicit. Finite element calculations of tension and subsequent unloading of the microstructure are performed. The interrelated processes of nucleation and propagation of elastic phase transformation in titanium nickelide and elastoplastic flow in the coating layer are studied. It is found that the phase transition in the base material contributes to a more uniform distribution of strains, while the plastic flow in the coating leads to the formation of residual martensite in the titanium nickelide surface layer.

The development of advanced decontamination materials is crucial for mitigating biological threats, particularly in scenarios involving airborne bacterial contamination. Conventional energetic materials often fail to ensure complete bacterial inactivation due to limited biocidal efficiency. This study addresses the problem by investigating multicomponent nanothermites incorporating biocidal additives-crystalline iodine (I2), iodoform (CHI3), and zinc oxide (ZnO). These additives were integrated into nanoscale aluminum (nAl)-based thermites with copper(II) oxide (CuO) as the oxidizer, optimizing the balance between energy release and bactericidal effectiveness. Experimental results demonstrated that nanothermite systems containing 20 wt% biocide additives exhibited the highest inactivation efficiency, achieving up to 73 % bacterial reduction. Furthermore, bactericidal activity decreased with increasing distance from the explosion epicenter, with the highest effectiveness observed at 10 cm. Our findings establish biocide-containing nanothermites as promising materials for microbial inactivation.

In this work, the reasons for the difference between the deformation curves of TiNi wire and the metal knitted fabric made of it under uniaxial tension in the load-unload cycle have been investigated. Experimental stress-strain diagrams of NiTi wire under uniaxial tension to rupture and in the load-unload cycle have been obtained. The phase composition of the wire at each loading stage was investigated. The load curves of the NiTi wire under uniaxial tension has three linear sections corresponding to the following evolution of phase composition: up to 2% there is a section of elastic deformation of 91% austenite; in the strain range from 2% to 11% there is a plateau section associated with direct phase transformation from austenite to monoclinic martensite; the strain range from 11% to 18% is a linear hardening section associated with deformation of 69% monoclinic martensite. An accurate geometric model was developed and the stress-strain state of the metal weft-knitted fabric was evaluated to understand the mechanism of the transition from superelastic to hyperelastic deformation behavior. Direct phase transformation in metal weft-knitted web starts at a relative strain of 8% at a stress of 278 MPa. The stress reaches the ultimate strength of the wire of 684 MPa at a strain of 16.3%, and increasing the strain up to 20% causes the formation of new defect areas, mainly where the loops are in contact with each other. The calculated cyclic curve of the periodic unit cell of the metal weft knitted fabric is typical of hyperelastic materials and differs from the deformation curve of the titanium nickelide wire.

This paper presents a study of the inelastic behaviour of structurally inhomogeneous porous materials made of titanium nickelide with the addition of silver nanoparticles obtained by self-propagating high temperature synthesis. The inelastic behaviour of the porous samples was studied by compressive loading at room temperature until failure. Based on the results of the mechanical tests, an increase in the plastic properties, a decrease in the modulus and the elastic limit of the samples was observed with an increase in the amount of silver in the composition. The change in mechanical properties is related to the complex stress state of the inhomogeneous structure of the porous alloys. In order to explain the results obtained, studies of the structure and phase composition of the alloys obtained were carried out using X-ray diffraction analysis, scanning and transmission electron microscopy.

Purpose of the study: to experimentally study the morphological features of the reaction of diaphragm tissue to porous titanium nickelide in comparison with medical felt.Materials and methods. A series of experiments was carried out on 20 rats. The animals were divided into two comparison groups: in the main group (n = 10), the reaction of diaphragm tissue to an implant made of titanium nickelide was studied; in the control group (n = 10), an implant made of medical felt (fluoroplastic-4) was used. Animals were removed from the experiment 14, 30, 60 and 90 days after surgery. A histological study of the reaction of the diaphragm tissue to the implant was carried out, as well as the structural behavior of the material under study.Results. Macroscopically, after 14 days in the main group, a local adhesive process was noted. In the long term, the implant was covered with a thin connective tissue film without signs of inflammation. In the control group, after 14 days, phenomena of inflammatory infiltration with organ involvement were observed. After 30 days, the inflammatory infiltrate persisted with the formation of a connective tissue capsule. The implant increased in size with deformation, swelling, and in the long term, disintegration of the structure. Histologically, on the 14th day in both groups, granulation tissue formed between the implant and the diaphragm. By the 30th day in the main group, the number and thickness of collagen fibers increased, they filled the porous structure of the material. In the control group, the appearance of giant multinucleated cells was noted between the felt fibers, which are indicators of the body's tissue reaction to foreign material. On the 60th day in the main group, a regenerate of mature connective tissue formed around the implant, filling the pores of the material and spreading to the muscle fibers of the diaphragm. In the control group, a picture of productive granulomatous inflammation with phenomena of biodegradation of the material was observed.Conclusion. The results of the experiment demonstrated the absolute advantage of titanium nickelide in reconstructive surgery of the diaphragm. At the same time, the disadvantages of using medical felt associated with the body’s reaction to the material as a foreign body and the tendency to resorption are noted.

NiTi alloys are actively used in medicine as implants because of their mechanical properties. At the same time, however, the NiTi surface is not biologically active, which has a negative effect on osteogenesis. In addition, Ni is capable of causing various toxic reactions in the human body. It is therefore necessary to create a composite coating that is both bioactive and prevents the release of Ni ions. It has been shown that by changing the modes of plasma assisted RF sputtering of a calcium phosphate target, it is possible to obtain coatings with different contents of the amorphous phase. The coatings formed consist of hydroxyapatite and amorphous calcium phosphate. On the surface of a sample not treated with argon plasma, there are no phases containing calcium or phosphorus, although these elements are present on the surface. The different ways in which the CaP coatings were applied also affected their structure. It was found that the CaP coatings of samples M2 and M3 have mediocre corrosion resistance, dissolving quickly. This has a positive effect on the ability to osteogenesis, which was discovered as a result of in vitro tests. These tests have shown that the sample obtained at Idischarge = 30 A and Ubias = 30 V has the highest bioactivity and produces the lowest percentage of dead cells.

In this work, the characteristics of the deformation behaviour of metal meshes knitted from thin NiTi wires have been studied and an experimental evaluation of their biological compatibility has been carried out. The experimental stress-strain diagrams obtained fully correspond to the typical tensile diagrams of superelastic NiTi alloys with marten-sitic transformation. The nonlinear dependencies of the stress of the metal mesh knitted from NiTi wire are rheologically similar to hyperelastic materials and differ from the ob-tained stress diagrams of the wire. It was found that the tensegrity structure of the knit-ted fabric limits the manifestation of the superelasticity effect characteristic of the wire. The tensile strength of the knitted fabric was found to be significantly lower than that of the wire. Using numerical modelling methods, it has been shown that the complex stress state of the metal mesh during deformation leads to inhomogeneity of the stress distribution in the structure and localisation of its maximum values in the contact area of the loops, confirming the hypothesis of suppression of superelasticity due to design features. An analysis of the stress distribution in the loops showed that stretching in the range of physiological loads does not lead to local destruction of the NiTi metal mesh. The results of an experimental macroscopic evaluation of the implantation area showed that there were no hernia defects in the endoprosthesis area and the adhesive process was recorded in only 3 (15 %) cases. The replacement area of the endoprosthesis was elastic and easily deformable. The porous surface structure of the NiTi wire, as well as the biomechanical and biochemical properties of the bilayer metal mesh, ensure optimal integration of the endoprosthesis into the body tissues and contribute to the formation of an elastic frame close to the natural one. Bilayer NiTi knitted mesh has shown promis-ing results in the replacement of complex anatomical structures, opening up prospects for further clinical research.

NiTi wires used for biological implants demonstrated ductile fracture. NiTi 40, 60, and 90 mu m thick wires were tested in uniaxial tension to fracture and loading-unloading. Uniaxial stress-strain curves demonstrate superelastic behavior. The inelastic martensite transformation strain is completely recovered upon unloading, forming thermo-mechanical hysteresis. A mathematical model was developed to describe superelasticity effects in NiTi wires. Modeling results are qualitatively and quantitatively similar to experimental data, and capture elastic deformation of austenite, forward martensite phase transformation stress plateau before the onset of martensite elastic deformation and the entire unloading range. The elastic limit and strength increase with the wire thickness.

Сплавы на основе никелида титана активно используются в медицине в качестве имплантатов. Особую популярность получила проволока из никелида, которую применяют для изготовления сетчатых имплантатов, использующихся в рабочих элементах для ортодонтических аппаратов, искусственных связках при разрывах сухожилий и др. Однако, перед производством изделий из проволоки никелида титана последнюю подвергают термообработке для придания нужной формы в процессе обжатия. Многие работы посвящены исследованию отжига проволок толщиной более 1 мм, поэтому целью данной работы будет представление результатов изучения структуры и механических свойств никелидтитановых проволок диаметром 100 мкм, отожженных при 300, 400, 500, 600 °C. Деформационное поведение проволоки исследовалось после испытаний на прочность при растяжении. Полученные кривые растяжения описывают его механические свойства и сверхэластичность. Поверхность излома проволоки исследовалась на сканирующем электронном микроскопе с энергодисперсионным рентгеновским анализатором. Также проводился фрактографический анализ основных характеристик излома. Установлено, что прочность на разрыв и мартенситное напряжение сдвига уменьшаются с увеличением температуры отжига. Условия отжига, определенные полученными результатами, не подавляют сверхэластичность проволоки, а придают ей прочность и пластичность, необходимые для медицинских целей. Образцы проволоки, отожженные при 300 и 400°С, демонстрируют схожее сверхэластичное поведение при циклических испытаниях, характеризующихся механическим гистерезисом и 1 % остаточной деформации. Отжиг проволоки толщиной 100 мкм при 500 и 600 °C спровоцировал большую остаточную деформацию после циклических испытаний.

In order to reduce infections, porous NiTi alloys with 62% porosity were obtained by self-propagating high-temperature synthesis with the addition of 0.2 and 0.5 at. % silver nanoparticles. Silver significantly improved the alloys' antibacterial activity without compromising cytocompatibility. An alloy with 0.5 at. % Ag showed the best antibacterial ability against Staphylococcus epidermidis. All alloys exhibited good biocompatibility with no cellular toxicity against embryonic fibroblast 3T3 cells. Clinical evaluation of the results after implantation showed a complete absence of purulent-inflammatory complications in all animals. Even distribution of silver nanoparticles in the surface layer of the porous NiTi alloy provides a uniform antibacterial effect.

The cyclic stability of the elastocaloric effect and the operating parameters (adiabatic cooling value Delta T-ad, coefficient of performance, operating temperature range) in Ni50.8Ti49.2 and Ni51.5Ti48.5 single crystals oriented along the < 001 >-direction and containing dispersed Ti3Ni4 particles of different sizes were investigated, and the mechanisms of cyclic degradation of the elastocaloric effect were determined. Aged Ni50.8Ti49.2 single crystals containing nanosized Ti3Ni4 particles were shown to possess the optimal combination of operational properties for solid-state cooling. These crystals are characterized by high adiabatic temperature change Delta T-ad of 16.8-21.4 K over a wide temperature range above 160 K, the highest elastocaloric effect cyclic stability, and high coefficient of performance values up to 27.8. Ni50.8Ti49.2 single crystals with semi-coherent particles (400 nm in size) demonstrate maximum values of Delta T-ad = 25.3 K; but, they are not feasible for practical applications because of cyclic degradation caused by the formation of residual martensite and dislocations near large particles as well as low coefficient of performance up to 12.7. The use of Ni-rich Ni51.5Ti48.5 crystals can improve the operating characteristics of crystals with semi-coherent Ti3Ni4 particles and achieve high cyclic stability of the elastocaloric effect by strengthening the crystals through an increase in the volume fraction of particles and a decrease in the distance between them.

The paper addresses the study of the thermodynamic compatibility of carbon-chain polymer compositions of offset rubber blankets with low-molecular-weight liquids, paint solvents and care agents for rubber damping machine parts used in transport, mechanical engineering and printing industries. The Flory-Huggins parameters chi were determined by inverted gas chromatography and calculation performed using the mathematical model of sorption, and the correlation between chi obtained by these two independent methods was found. The excess thermodynamic characteristics of the studied systems G E, H E and S E were calculated to predict the compatibility of components in these systems. The relationship was found between chi that characterizes the thermodynamic quality of the solvent and the equilibrium swelling index of polymer networks.