Formation and properties of bioactive surface layers on titanium

Gnedenkov, Sergey V.; Scharkeev, Yu. P.; Sinebryukhov, Sergey L.; Khrisanfova, O. A.; Легостаева, Е. В.; Zavidnaya, A. G.; Puz, A. V.; Хлусов, И. А.

doi:10.1134/s2075113311050133

Cited by 39 publications

(17 citation statements)

References 11 publications

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“…It can be seen that, in the second case, the system has a substantially higher electrical resistance. This occurs because higher voltage drops are reached at the same current densities, which leads od from oxide-forming electrolytes via formation of a gas-vapor interlayer enveloping the samples and its electric breakdowns in potentiodynamic, rather than galvanostatic modes, with the voltage across the electrodes raised at a certain rate dU/dt [24,27,28]. In this case, considerable currents fl ow through the anode at the initial instants of time.…”

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confidence: 97%

“…have been under development. No passive oxide layers with a valve (diode) effect are formed in anodic polarization on the surface of metals of this kind [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].The already developed, or being discussed in the literature, approaches to coating formation by PEO on metals and alloys of the nonvalve group can be conditionally divided into three groups. In the fi rst of these, a layer of a valve metal, commonly aluminum or its alloys, with a certain thickness is preliminarily deposited on the surface and then processes into an oxide RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol.…”

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Combination of plasma-electrolytic oxidation and extraction-pyrolytic method for formation of metal oxide layers

et al. 2012

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Elemental composition and morphology of oxide coatings formed on stainless steel, nickel alloy (nonvalve metals), and titanium (valve metal) by plasma-electrolytic method combined with the extraction-pyrolytic technique are reported. It is shown that combination of these methods is promising for obtaining oxide coatings with a complex chemical composition and various physicochemical properties.One of modern ways to form functional oxide layers on metals and alloys is by plasma-electrolytic oxidation (PEO), i.e., anodic or anodic-cathodic oxidation of the surface of metals and alloys in aqueous electrolytes at spark or arc electric-discharge voltages [1,2]. This method is employed to form wear-and corrosionresistant oxide layers on products made of aluminum, titanium, magnesium, and their alloys. These are metals and alloys of the valve group, on whose surface a barrier oxide fi lm is formed at the initial instants of time before the spark (conventional) anodization. This fi lm has high electrical resistance and leads to development of spark breakdowns upon an increase in voltage.In electrolytes of certain composition, commonly of aqueous type, electric discharges initiate high-rate growth of an anodic oxide layer on the surface of valve metals, with this layer containing high-temperature oxide phases, e.g., γ-and α-Al 2 O 3 on aluminum [3,4]. This circumstance is widely used in practice to form wear-resistant layers on articles made of aluminum and its alloys [1,2].At the same time, processes caused by electric discharges can produce coatings containing electrolyte components [5], including solid dispersed particles [6]. These specifi c features of PEO are used, e.g., to develop ways to cover valve metals with biocompatible oxide layers with calcium phosphates [7], Zr-containing light-refl ecting layers [8], protective antifriction oxidepolymeric structures [9], Fe-containing layers with ferromagnetic properties [10,11], and layers with transition metal oxides and noble metals exhibiting a catalytic activity [12,13]. Since the beginning of systematic studies in the fi eld of PEO, ways to form functional oxide layers on metals and alloys of nonvalve type (iron, steel, cast iron, nickel, lead, zinc, copper, etc.) have been under development. No passive oxide layers with a valve (diode) effect are formed in anodic polarization on the surface of metals of this kind [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].The already developed, or being discussed in the literature, approaches to coating formation by PEO on metals and alloys of the nonvalve group can be conditionally divided into three groups. In the fi rst of these, a layer of a valve metal, commonly aluminum or its alloys, with a certain thickness is preliminarily deposited on the surface and then processes into an oxide RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 85 No. 4 2012 622 RUDNEV et al.coating by PEO. An aluminum layer is deposited, e.g., by electric arc metallization [20,21] in aluminum-plating baths [23]. In the second group, high curre...

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Combination of plasma-electrolytic oxidation and extraction-pyrolytic method for formation of metal oxide layers

et al. 2012

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“…They appear as a result of the plasma arc and electrolyte interaction accompanied by the inclusion of the decomposition products of the electrolyte components into the coating structure [33].…”

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confidence: 99%

Flexible intramedullary nails for limb lengthening: a comprehensive comparative study of three nails types

et al. 2019

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A comparative study of flexible intramedullary nails (FIN) used for lengthening of long tubular bones in children is presented. It has been found that the presence of calcium phosphate coating obtained by micro-arc oxidation or a composite coating based on a copolymer of vinylidene fluoride with tetrafluoroethylene and hydroxyapatite on the surface of FIN significantly enhances the formation of bone regenerate in the area of osteotomy during limb lengthening by combined osteosynthesis. The investigation of physico-chemical properties of FIN with calcium phosphate coating obtained by micro-arc oxidation demonstrated that improved bone tissue formation is due to favourable conditions for adhesion, proliferation, and differentiation of MMSCs into osteoblasts on the coating surface. Composite coatings stimulated the formation of bone tissue only in vivo, mainly due to the piezoelectric properties of the copolymer of vinylidene fluoride with tetrafluoroethylene. Keywords: flexible intramedullary nails, calcium phosphate coating, vinylidene fluoride -tetrafluoroethylene, piezoelectric, combined limb lengthening 1. Introduction Deterioration of the environmental situation, primarily in industrialized countries, and rising frequency of genetic diseases provoke an increase in the number of patients and the severity of orthopaedic pathologies associated with congenital shortening and deformities of the limbs. The limb shortening, progressing as a person develops, leads to pathological changes in the entire biomechanical system. For example, overloading a healthy limb and skewing of the pelvis cause the development of pathologies associated with deformations and dislocation of the healthy hip, leading to a decrease in the quality of life. Thus, the restoration of the limb length allows solving not only the problems of orthopaedic and biomechanical recovery, but also the problem of social rehabilitation and patient's integration into society. For congenital limb length discrepancy the correction of pathology in the affected segment and functionally related elements of the biomechanical system could be done only through surgical interventions. A major contribution for solving this problem was made by outstanding orthopaedic surgeon G.A. Ilizarov, who developed the methods of surgical treatment based on distraction osteogenesis [1,2]. The recent development of G.A Ilizarov method resulted in development of combined osteosynthesis. In this approach, the external fixation devices and thin (up to 2.5 mm) flexible intramedullary nails (FIN) implanted into medullary canal of the tubular bone are used [3,4]. The circular external fixator allows to achieve the high stability of the bone fragments positioning. FIN located in the anatomical zone with multipotent cells depot and a good blood supply, allows to control the histogenesis aimed at bone tissue production. The unique anatomical location of FIN makes it one of the key elements of the combined osteosynthesis. FIN properties largely determine the clinical success of the limb leng...

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“…Nevertheless, the use of fixatives from bioinert metals in osteosynthesis requires repeated surgical interventions aimed at removing the metal implants that have performed their role, and this is often no less traumatic, than osteosynthesis itself. Therefore, it remains relevant to search for bioresorbable materials that are suitable for creating implants used in osteosynthesis, that could be completely metabolized by the organism without exerting a pathological effect on surrounding tissues and the organism as a whole [23,24]. Such materials include magnesium alloys, which, due to the strength properties, are suitable for the production of various types of implants.…”

Section: Introductionmentioning

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The Role of Dendritic Cells in Bone Loss and Repair

Плехова¹,

Lyapun²,

Gnedenkov³

et al. 2018

Dendritic Cells

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The cells of innate immunity, such as neutrophils, macrophages, and dendritic cells (DCs), stuck to the bone implant walls release reactive radicals, enzymes, and chemokines, which induced subsequent bone loss. DCs do not play a big role in bone homeostasis in steady-state conditions, but could act as osteoclasts precursors in inflammation foci of bone. The potent antigen-presenting cells responsible for activation of native T cells and modulation of T cell activity through RANK/RANKL pathway and other cytokines associated with osteoclastogenesis determine critically situated at the osteoimmune interface. The titanium (Ti) and magnesium (Mg), the metallic candidate in implant, including calcium-phosphate coating formation on them by method plasma electrolytic oxidation were used to evaluate the immune-modulatory effects of DCs. The calcium-phosphate coating on metals induced mature DC (mDC) phenotype, while Ti and Mg promoted a noninflammatory environment by supporting an immature DC (iDC) phenotype based on surface marker expression, cytokine production profiles, and cell morphology. These findings have numerous therapeutic implications in addition to DC's important role in regulating innate and adaptive immunity. A direct contribution of these cells to inflammation-induced bone loss establishes DC as a promising therapeutic target, not only for controlling inflammation but also for modulating bone destruction.

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Formation and properties of bioactive surface layers on titanium

Cited by 39 publications

References 11 publications

Combination of plasma-electrolytic oxidation and extraction-pyrolytic method for formation of metal oxide layers

Combination of plasma-electrolytic oxidation and extraction-pyrolytic method for formation of metal oxide layers

Flexible intramedullary nails for limb lengthening: a comprehensive comparative study of three nails types

The Role of Dendritic Cells in Bone Loss and Repair

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