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Investigation of the Surface Topography of Titanium Alloys Applied to Friction Components

Gawłowski Grzegorz, Niemczewska-Wójcik Magdalena

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 2

150--158

EN

The subject of this study and analysis was titanium alloy, applied among others to the friction components of orthopaedic (artificial hip joint) implants. This material was subjected to abrasive finishing using a synthetic diamond as a tool. The properties of the studied titanium alloy were characterised. The processing technology and the research methods are discussed. The surfaces, after being subjected to abrasive machining, were studied using three research instruments – an interference microscope, a scanning electron microscope, and an atomic force microscope. Advanced metrology software was used to analyse the measurement data. The aim of the research was to present the changes taking place in the forming of the surface of the studied titanium alloy, in particular those occurring in the final sequential processing. A characterisation of the machined surfaces was prepared based on parametric (surface topography – parameters and functions) and non-parametric (surface morphology – images) analysis. The significant influence of the sequence and the tool (diamond grain and micro-grain) on the surface topography shaped during the technological process is presented. Improvement in the surface quality and features was observed. Parametric analysis showed no significant differences between TA-III and TA-IV surfaces, while these differences were visualised by non-parametric analysis. Moreover, the hereditary features of the surface topography (isotropy and pits/valleys) and their influence on the potential functional properties (place/area for accumulation/retaining of the lubricant in the friction zone) of the titanium alloy were analysed.

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May metallic biomaterials used for orthopaedic implants promote carcinogenesis? Preliminary transcriptomic research on human chondrocytes

Walkowiak-Przybyło Magdalena

Engineering of Biomaterials

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2020

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Vol. 23, no. 157

15--19

EN

The aim of this research was to assess the risk of carcinogenesis induced by the metallic materials intended for orthopaedic implants. The report is an analytical summary of changes in the expression of cancer-related genes in human chondrocytes of normal and neoplastic phenotype. Cq values (quantification cycle values) obtained from qRT-PCR reactions (quantitative real-time polymerase chain reactions) were used to count Fc values (fold change values) for each gene. Differences in Fc values obtained for primary and cancer cells grown on the surface of medical steel AISI316L and titanium-aluminum-vanadium alloy Ti6Al4V were then analyzed by t-Student test. The results indicate that for cancer cells grown on the surfaces of both examined materials the fold change greater than 2, usually considered essential, was found for LUM gene involved in sarcoma induction. For FOS gene, also involved in sarcoma induction, the Fc value was also very close to 2 in the primary cells exposed to Ti6Al4V alloy. The remaining observed changes were rather subtle, although they cannot be omitted from further studies because differences in gene expression in primary and tumor cells grown on the same biomaterial were statistically significant in several cases. The compilation of qRT-PCR experiments carried out on primary and cancer cells in parallel allowed to identify possible future contraindications for patients with a genetic predisposition to cancer or with cancer history.

3

Impact of a pulsed magnetic field on selected polymer implant materials

Szponder Tomasz, Stodolak-Zych Ewa, Polkowska Izabela, Sobczyńska-Rak Aleksandra

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 1

87--96

EN

Physiotherapy with the use of pulsed magnetic fields is one of the methods of activating the processes of bone healing and regeneration. Exposing materials serving as membranes in guided bone regeneration (GBR) or guided tissue regeneration (GTR) to magnetic fields is an effective model that allows to monitor changes in the material under the influence of the magnetic field. Methods: Materials engineering methods were used to verify the extent of material degradation resulting from magnetic field exposure in an aqueous environment. Changes in surface morphology were observed under an optical microscope and a scanning electron microscope (SEM). Changes in surface wettability were analysed in relation to the direct contact angle. Chemical structural changes were verified with the use of infrared spectroscopy (FTIR-ATR). Results: The PCL-based membrane materials underwent relatively moderate surface degradation (altered contact angle, changes in surface morphology), but the absence of observable FTIR-ATR spectral shifts evidenced material stability under the influence of magnetic field. More extensive degradation processes were observed in the case of PLDLA-based materials, whose surface character changed from hydrophilic to hydrophobic. The spectra revealed enhanced intensity of the chain terminal groups, provided that modifiers (nanometric SiO2 and TCP (water reservoir)) were present in the polymer matrix. Conclusions: The extent degradation in the polymer membrane was primarily dependent on the presence of aqueous environment, while the influence of the magnetic field on the analysed membrane materials was negligible. Therefore, GBR/GTR membrane implants can be considered to remain stable during rehabilitation with the use of alternating magnetic field.

4

Deposition of various gradient multilayer coatings on Ti-6Al-4V alloy using MW CVD methods for orthopaedic implants

Kyzioł K., Oczkowska J., Klich M., Kaczmarek Ł., Kyzioł A.

Engineering of Biomaterials

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2017

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Vol. 20, no. 143 spec. iss.

26

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Badanie działania antybakteryjnego kompozytów na bazie poli(L-laktydu) przeznaczonych na biodegradowalne gwoździe śródszpikowe

Domalik-Pyzik P., Morawska-Chochół A., Rzewuska M., Szaraniec B., Chłopek J.

Engineering of Biomaterials

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2015

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Vol. 18, no. 133

7--13

PL

Implantacja gwoździ śródszpikowych wiąże się z ryzykiem wystąpienia poważnej infekcji kości spowodowanej zakażeniem bakteryjnym. Tradycyjna antybiotykoterapia w tym przypadku ma wiele ograniczeń. Rozwiązaniem tego problemu może być lokalne dostarczanie leku bezpośrednio do miejsca implantacji. Jednym ze sposobów na realizację takiego rozwiązania jest stosowanie pokryć tradycyjnych gwoździ metalowych pokrytych degradowalnym materiałem polimerowym pozwalającym na kontrolowane uwalnianie substancji leczniczej. Autorzy poszli o krok dalej proponując wytworzenie nowatorskich gwoździ śródszpikowych z materiału degradowalnego, któremu nadano właściwości antybakteryjne poprzez wprowadzenie do resorbowalnej matrycy polimerowej antybiotyku w postaci siarczanu gentamycyny (GS). Dodatkowo osnowę z poli(L-laktydu) (PLA) zmodyfikowano wprowadzając druty ze stopów magnezu (MG), włókna węglowe (CF), włókna alginianowe (ALG) oraz nanocząstki fosforanu trójwapnia (TCP) w różnych układach. Test aktywności antybakteryjnej przeprowadzono z użyciem szczepu metycilino-wrażliwego Staphylococcus pseudintermedius. Dokonano analizy ilościowej i jakościowej stref zahamowania wzrostu bakterii utworzonych wokół badanych fragmentów gwoździ. Wykazano, że wszystkie zaproponowane materiały kompozytowe z dodatkiem gentamycyny wykazują działanie hamujące wzrost i namnażanie bakterii, najsilniejsze w przypadku układów PLA/CF/ ALG/GS oraz PLA/CF/ALG/TCP/GS. Działanie to utrzymuje się nawet po 12 dniach od pierwszego wysiewu. Ponadto badania wykazały, że gwóźdź PLA/MG również wykazuje słabe oddziaływanie antybakteryjne pomimo braku dodatku w postaci antybiotyku, jednak działanie to zostaje zablokowane po wprowadzeniu TCP do matrycy polimerowej.

EN

Intramedullary nails implantation carries a risk of a serious bone infection caused by bacteria. In this case traditional antibiotic therapy has many limitations. A good solution to the problem can be local drug delivery directly to the implantation site. One of the ways to implement such solution is to use, on the surface of traditional metallic nails, degradable polymer coatings that enable controlled drug release. Authors went a step further by proposing to fabricate novel intramedullary nails entirely from degradable material that has been endowed with antibacterial properties. Antibacterial protection was provided by the introduction of an antibiotic - gentamicin sulphate (GS) to the poly(L-lactide) (PLA) matrix. Into the resorbable matrix the following modifying phases were also introduced: magnesium alloy wires (MG), carbon fibers (CF), alginate fibers (ALG) and tricalcium phosphate nanoparticles (TCP), in various systems. Antibacterial activity test was carried out using methicillin-sensitive strain Staphylococcus pseudintermedius. Qualitative and quantitative analysis of bacteria growth inhibition zones formed around studied nails’ samples were performed. It has been proven that all of the proposed composite materials with gentamicin addition showed inhibitory effect on growth and proliferation of bacteria, with the strongest in the case of PLA/CF/ALG/GS and PLA/CF/ALG/TCP/GS systems. The inhibitory effect was maintained even after 12 days since the first inoculation. Moreover, the study proved that PLA/MG nails also showed some antibacterial activity, despite lack of the antibiotic addition. However, after introduction of TCP to the matrix, this action has been blocked.

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Badania potencjodynamiczne drutów ze stali nierdzewnych w środowisku płynów ustrojowych

Przondziono J., Walke W., Kulak K.

Engineering of Biomaterials

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2008

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Vol. 11, no. 77-80

104--106