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PL
Wysoka makroporowatość biomateriału, która sprzyja procesowi angiogenezy, ma największy wpływ na dobrą osseointegrację implantu z kością pacjenta. W niniejszej pracy porównano skuteczność trzech różnych metod wprowadzania porów do biomateriału polimerowo-ceramicznego w celu wykorzystania go do zastosowań w medycynie regeneracyjnej kości. W ramach badań modelowy biomateriał zbudowany z agarozy i bioceramiki w postaci nanoproszku hydroksyapatytowego został wyprodukowany przy pomocy trzech alternatywnych metod z wykorzystaniem: 1. porogenów stałych (ang. porogen leaching, P-L), 2. gazu CO2 jako porogenu (ang. gas-foaming, G-F) i 3. procesu liofilizacji (ang. freeze-drying, F-D). Następnie porównano mikrostrukturę oraz porowatość otrzymanych biomateriałów. Wyniki badań wykazały, że biomateriał wytworzony metodą F-D posiada największą porowatość otwartą i całkowitą oraz charakteryzuje się obecnością porów zespolonych, które w warunkach ustrojowych stymulują proces angiogenezy. Ponadto technika F-D jako jedyna umożliwia równomierną dystrybucję porów w obrębie całej próbki.
EN
High macroporosity of the biomaterial, which is crucial for the angiogenesis process, has a great impact on good osseointegration of the implant with patient bone. In this study, effectiveness of three various methods for pore introduction into polymer-ceramics biomaterial for potential bone regenerative medicine applications was compared. Within the research, a model biomaterial made of agarose and bioceramics in the form of nanohydroxyapatite powder was produced using: (i) a porogen leaching method (P-L), (ii) CO2 gas as a porogen (gas-foaming method, G-F), and (iii) the lyophilisation process (freeze-drying method, F-D). Then, the microstructure and porosity of fabricated biomaterials were compared. Obtained results demonstrated that the biomaterial produced by the F-D method possesses the highest open and total porosity as well as is characterized by the presence of network of interconnected pores, which in physiological conditions stimulates the angiogenesis process. Moreover, F-D technique is the only one that allows for uniform distribution of pores within whole volume of the sample.
EN
High purity, fine crystalline, degradation-free at low temperature powders have attracted special interest in CAD/CAM prosthetic dentistry full ceramic restorations. This study reports the preparation and characterisation of zirconia-ceria (0.9ZrO20.1CeO2) powders. Materials were obtained from zirconium-n-alkoxide and cerium nitrate hexahydrate in the pH 2–4 and 8–10. Methods: Zirconia-ceria powders were obtained with the sol-gel method in a humid-free environment. Thermal analysis (TGA/DTA) of the as-prepared materials was made for an assessment of its behaviour at elevated temperatures. Specimens were dried at 80°C and calcinated in two stages: at 300°C with soaking time 2.5 h and 850°C with holding time 2.5 h, in order to evaluate the phase transformations. Thermal analyses of the as-dried powders were made for an assessment of its thermal behaviour during heat treatment up to 1000 °C. By X-ray diffraction (XRD), polymorphs of ZrO2 were identified. Additionally, scanning electron microscopy (SEM) and laser particle size distribution (PSD) were involved for characterisation of morphology of the powders. Results: We found a correlation between the pH of the colloidal system and the morphology of the as-obtained powders. Based on analysis (SEM,PSD), structures were identified known as soft and hard agglomerates. Conclusions: In summary, it can be stated differences were found between powder morphology depending on the used pH, which can be crucial for powder densification during sintering and compacting green bodies which, as a consequence, may be crucial for the lifetime of zirconia prostheses. Correlations between phase composition and pH are difficult to grasp, and require further more sophisticated studies.
EN
The study presents an investigation of thermoregulatory processes of ceramic-containing textile materials used in cold environments. Bio-ceramic additives have a heat-retaining function caused by its far-infrared (FIR) radiation. Storing heat at a high temperature, bioceramics can radiate heat to the body when the temperature outside drops. In order to improve the thermal efficiency of fabrics primarily worn next to the skin, our intention was to increase the active surface area of the ceramic-containing textile material. For this purpose a combined knitted PET fibre textile material was used, which was treated with ceramic additives using different application methods. Tests were performed where specimens were kept in a constant temperature oven, then placed on a cold surface, and the temperature decrease of the specimens was periodically recorded in a given time period. The results revealed that the highest heat accumulation was determined in screen-printed fabric with continuous coating, and the lowest – in PET fabric knitted of bio-ceramic containing fibres.
PL
W pracy przedstawiono badania procesów termoregulacji materiałów włókienniczych, modyfikowanych ceramiką, stosowanych w niskich temperaturach. Bioceramiczne dodatki charakteryzują się zdolnością zatrzymywania ciepła, dzięki promieniowaniu w dalekiej podczerwieni (FIR). Po zmagazynowaniu ciepła w wysokiej temperaturze, bioceramiczne materiały emitują ciepło do ciała ludzkiego, gdy temperatura zewnętrzna spada. W celu zwiększenia wydajności termicznej materiałów tekstylnych noszonych blisko skóry przy projektowaniu starano się żeby aktywna powierzchnia była jak największa. Dla tego celu zastosowano kombinację dzianiny z włókien PET modyfikowanych materiałami ceramicznymi za pośrednictwem różnych metod. Testy prowadzono w ten sposób, że próbki były przechowywane w piecu o stałej temperaturze, a następnie umieszczane na zimnej powierzchni i rejestrowano spadek temperatury próbki w określonych odstępach czasu. Badania wykazały, że najwyższą akumulację ciepła stwierdzono w próbkach z nadrukowanymi materiałami ceramicznymi i zachowaniu ciągłości powierzchni, przy czym najniższą w dzianinach z włókien PET modyfikowanych bioceramiką.
EN
Mechanical and corrosion properties of magnesivm-bioceramic nanocomposites Magnesium alloys have recently attracted much attention as a new generation of biodegradable metallic materials. In this work, MglMnlZn0.3Zr-bioceramic nanocomposites and their scaffolds were synthesized using a combination of mechanical alloying and a space-holder sintering process. The phase and microstructure analysis was carried out using X-ray diffraction, scanning electron microscopy and the properties were measured using hardness and corrosion testing equipment. Nanostructured Mg-bioceramic composites with a grain sizes below 73 run were synthesized. The Vickers hardnesses for the bulk nanostructured Mg-based composites are two times greater than that of pure rnicrocrystalline Mg metal (50 HV0.3). Produced Mg-based bionanomaterials can be applied in medicine.
EN
The present article is dedicated to an investigation of a production method of hydroxyapatite (HA) disks with a study of an influence of compression speed (5, 10 and 15 mm/min) and sintering temperature (900˚C and 1200˚C) on structure and properties of those disks. Measurements of density, mass loss and shrinkage as well as scanning electron microscopy (SEM) and light optical microscopy (LM) observations were performed. The aim of this study is to define optimal process parameters, which are applicable for using as a substrate for in vitro experiments.
PL
Niniejszy artykuł poświęcony analizie sposobu krążków hydroksyapatytowych (HA) poprzez ocenę wpływu szybkości ściskania (5, 10 i 15 mm/min) i temperatury spiekania (900˚C i 1200˚C) na strukturę i właściwości krążków. Plan badań zawierał pomiary gęstości, utraty masy i kurczliwości oraz obserwację struktury krążków przy użyciu skaningowej mikroskopii elektronowej (SEM) i mikroskopii optycznej (MO). Celem badań jest określenie optymalnych parametrów procesu do produkcji krążków HA, stosowanych jako podłoże dla eksperymentów in vitro.
10
Content available Materiały porowate do zastosowań medycznych
PL
W artykule poruszono zagadnienia związane z zastosowaniem materiałów porowatych w medycynie wraz technologią ich wytwarzania oraz właściwościami. Zaprezentowano przegląd literaturowy dotyczący materiałów ceramicznych oraz metalicznych, a także część wyników własnych badań naukowych porowatych stopów z pamięcią kształtu.
EN
The paper addresses the issues associated with the application of porous materials in medicine, properties and technology for their preparation. The review of literature of ceramic and metallic materials and also some results of my own research porous shape memory alloys has been presented.
EN
Purpose: Calcium phosphate cements (CPCs) are extensively used as synthetic bone grafts due to their excellent bioactivity, moldability and ability to set in vivo. Although there are some commercial CPCs in the market, there are many ongoing research directed mainly to improve some of their properties, such as mechanical strength, cohesion or resorbability. The purpose of the study was to develop a more systematic approach for the formulations of CPCs and to obtain complex composite that will be gradually resorbed in vivo. Design/methodology/approach: In the present studies cements composed of different ratios of α-TCP, Mg2+/CO32- co-substituted hydroxyapatite (MgCHA) and calcium sulphate were developed. The obtained materials were characterized in terms of setting time, compressive strength and open porosity. XRD technique was employed to determine the phase composition of the initial powders and the final materials. Chemical stability of the studied materials was checked. Bioactive potential of the bone cements was evaluated in accordance to Kokubo’s protocol. Findings: The investigated materials possess excellent handling properties, appropriate setting times (initial: 6-8 min, final-17-21 min) and compressive strength comparable to cancellous bone (6-12 MPa). The expected gradual resorption of composites (resorbability: CSD >> α-TCP > MgCHA) is believed to facilitate a healing process and stimulate bone regeneration. Research limitations/implications: Further in vitro and in vivo experiments need to be done to confirm cytocompatibility of these biomaterials. Originality/value: The new chemically bonded bioceramics with addition of calcium sulphate was developed. A systematic approach for the formulations of CPCs on the basis of α-TCP, MgCHA and calcium sulphate was performed. The obtained chemically bonded bioceramics may have a chance to be apply as bone substitutes in low load bearing places.
EN
Biological performance of bioceramics such as calcium phosphate has been proved to be improved by substitution of different ions like Mg, Sr and Si. In this study, different amounts of Zn ions in nitrate form were incorporated into b-tricalcium phosphate in which various molar ratios of Ca:Zn were achieved: 3:0, 2.8:0.2, 2.6:0.4, 2.4:0.6, and 2.2:0.8. The mixtures were heated at different temperatures ranging from 800 – 1100 °C. The phase composition, amount of each phase and lattice parameters of b-tricalcium phosphate were determined by means of X-ray diffractometry and coupled software. Also, solubility of the heated mixtures was investigated by determining the amount of Ca and Zn released into a simulated body fluid during 120 h. The results revealed that only limited amount of Zn ions could be incorporated into b-tricalcium phosphate lattice and ZnO phase was formed when high content of zinc nitrate was introduced in initial mixture. Both a and c lattice parameters of b-tricalcium phosphate were reduced by adding Zn. The release rate of calcium ions into the simulated body fluid was approximately constant during 120 h while for Zn minor release was observed.
EN
The paper presents research on degree of bioactivity of nanometric ceramic particles used as a nanofiller in nanocomposite materials based on polymers. The nanoperticles used in our examination were: different bioceramics powders such as: hydroxyapatite (HAp), β-phosphate (V) calcium (βTCP), silica (SiO2) and bioglass (BG). Based on ζ-potential measurements dynamics of processes occurring on the surface of nanoparticles in stimulated body fluid (SBF) was determined and it confirmed possibility of apatite formation. This study showed predominance of bioglass over other bioceramic materials, Bioglass nanoparticles were the most bioactive ones. In the end of the experiment the bioacermic particles were used as a nanofiller of poli-L/DL-lactide (PLDLA) matrix composites. The composite materials were prepared by casting from solution. Bioactivity tests were performed in simulated body fluid (artificial plasma of various ions concentration, and SBF 2SBF). Based on surface microstructure observed in the SEM (EDS) analysis were confirmed the degree of bioactivity of various materials depending on the type nanofiller.
PL
W niniejszym artykule omówiono stan wiedzy dotyczącej biomateriałów opartych na fosforanach wapnia. Przedstawiono dane na temat rozwoju bioceramiki CaPs na przestrzeni lat, z uwzględnieniem prac wykonanych i nadal realizowanych w tym zakresie na Wydziale Inżynierii Materiałowej i Ceramiki AGH, we współpracy z licznymi ośrodkami medycznymi w kraju. Nakreślono przyszłościowe kierunki badań nad preparatami zawierającymi fosforany wapnia obejmujące: kompozyty, cementy kostne, ceramiczne nośniki leków oraz skafoldy dla inżynierii tkankowej i medycyny regeneracyjnej. Obecnie wysiłki badaczy koncentrują się na poprawie wytrzymałości mechanicznej, funkcjonalności, parametrów biologicznych i poręczności chirurgicznej nowej generacji preparatów implantacyjnych CaPs przeznaczonych do substytucji kości.
EN
In the present paper a current state of the art of calcium phosphate based biomaterials was discussed. Date regarding the development of CaPs bioceramics over the years were presented, taking into consideration the already done as well as the ongoing researches, conducted in this field, in the Faculty of Materials Science and Ceramics UST-AGH, in the cooperation with many domestic medical centers. Future research directions including: composites, bone cements, ceramic drug carriers and scaffolds for the tissue engineering and regenerative medicine consisting of calcium phosphates were presented. Nowadays, the efforts of researches are focused on the improvement of mechanical strength, functionality, biological properties and surgical handiness of the new generation of CaPs implant materials for bone substitution.
PL
Z powodu znakomitej biokompatybilności i bioaktywności fosforany wapnia takie jak hydroksyapatyt (Ca10(PO4)6(OH)2) oraz ß-TCP (Ca3(PO4)2) są z powodzeniem stosowane jako substytuty kostne w ortopedii, chirurgii twarzoczaszki i stomatologii. Jednak, zastosowanie tych materiałów w medycynie ogranicza się do miejsc nie przenoszących znacznych obciążeń ze względu na ich kruchość i niską wytrzymałość mechaniczną. Ich niedostatkiem jest także niezadowalająca poręczność chirurgiczna utrudniająca założenie do ubytków kostnych. Praca dotyczy opracowania i oceny kompozytu złożonego z hydroksyapatytu (HA), cementu magnezowo–fosforanowego (MPC) oraz półwodnego siarczanu(VI) wapnia (CSH) o parametrach optymalnych dla zastosowań medycznych.
EN
Because of excellent biocompatibility and bioactivity, calcium phosphates such as hydroxyapatite (Ca10(PO4)6(OH)2) and ß-TCP (Ca3(PO4)2) are successfully used as bone substitutes in orthopaedics, maxillofacial surgery and dentistry. However, due to low mechanical strength and brittleness, the application of these biomaterials in medicine is limited to places not loaded significantly. Limited surgical handiness is also a disadvantage of calcium phosphates, what makes diffi cult to place the material into bone voids. This study is focused on development of composites containing hydroxyapatite (HA), magnesium–phosphate cement (MPC) and calcium sulphate hemihydrate (CSH), and showing the optimum parameters for medical applications.
20
Content available remote Titanium-ceramic nanocomposites fabricated by the mechanical alloying process
EN
Wide use of titanium and its alloys as biomaterials stems from their low elastic moduli, good fatigue strength and better corrosion resistance compared to other metals and alloys used in medicine. However, they have poor tribological properties and a release of titanium alloy elements into surrounding tissues can cause eventual inflammation, failure and removal of an implant. For this reason, there is a great need for creating composite materials using ceramic particles to reinforce titanium which would give the possibility of optimizing mechanical and biological properties. In the present work Ti hydroxyapatite (HA, 3, 10 vol. %) and Ti-SiO2 (3, 10 vol. %) nanocomposites were fabricated by a combination of mechanical alloying (MA) and sintering processes. Mechanical properties and corrosion resistance of these composites were investigated by the Vicker hardness measurement and in vitro studies. The experimental results show that Ti-10 vol. % HA and Ti-10 vol. % SiO2 nanocomposites have good corrosion resistance (Ic = 1.1×10-6, Ec = -0.48; Ic = 9.23×10-7, Ec = -0.45, respectively) in comparison with microcrystalline titanium (Ic = 2.7×10-5, Ec = -0.47). Vickers' microhardness of the prepared nanocomposites is a few times higher than that of microcrystalline titanium. In conclusion, titanium ceramic nanocomposite is a suitable material for hard tissue replacement from the point of view of both mechanical and corrosion properties.
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