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Wyszukujesz frazę "Materials" wg kryterium: Temat


Tytuł:
Initial biocompatibility assessment of ceramic material intended for application in implantable heart assist device
Autorzy:
Janiczak, K.
Zawidlak-Węgrzyńska, B.
Gawlikowski, M.
Gonsior, M.
Kustosz, R.
Powiązania:
https://bibliotekanauki.pl/articles/284808.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomaterials
ceramic materials
implantation
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 67
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Results for modern bandaging materials application in alveolitis treatment
Autorzy:
Shevela, T. L.
Pohodenko-Chudakova, I. O.
Groshev, E. Y.
Powiązania:
https://bibliotekanauki.pl/articles/285401.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomaterials
bandaging materials
alveolitis
Źródło:
Engineering of Biomaterials; 2011, 14, no. 109-111 spec. iss.; 13-14
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan based drug delivery systems
Autorzy:
Piegat, A
Goszczyńska, A.
Niemczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/285591.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
drugs
polymeric materials
chitosan
Opis:
One of the research area in which polymeric materials are intensively explored, deals with the controlled drug delivery systems (DDSs), allowing for drugs distribution directly to the desired site of biological activity. The morphology of polymeric colloidal drug carriers can be described as a construction of a core-shell type. Depending on the chemical or physical bonds providing stability of those systems and the type of interactions between the drug and the polymer, among polymeric DDSs the following morphological structures can be distinguished: micelles, dendrimers, liposomes, niosomes, polymerosomes and micro- and nanocapsules [1]. The main advantages of those systems are the preparation of particles with desired size (diameter from nano to micrometers) during their synthesis / formation and high specific surface area, which can be modified by the appropriate chemical composition of the surface improving the efficiency of a drug delivery. Chitosan is biopolymer derived from chitin, that is characterised by biodegradability, biocompatibility, mucoadhesion and antimicrobial activity [2,3]. Taking into account the overall advantages of this polymer and the possibility of modification due to the accessible functional groups i.e. hydroxyl and amine, chemically modified chitosan is one of the most promising biomaterials for DDS. In order to obtain micelle structures by selfassemby in aqueous environment several hydrophobically modified chitosan derivatives, such as – stearic acid-modified chitosan [4], palmitic anhydridemodified chitosan [5], linolenic acid-modified chitosan [6], have been synthesized. The micelles prepared by these derivatives in the aqueous medium contain internal hydrophobic moieties as drug reservoir and external hydrophilic chitosan chains as surrounding shell. The above mentioned micellar systems allow encapsulation of hydrophobic antitumor drugs e.g. doxorubicin or paclitaxel due to the compatibility between the hydrophobic core and hydrophobic drug affecting the drug loading and regulate drug release. Another important group of chitosan based micro- and nanoparticles are those dedicated for gastric infection treatment. The use of chitosan in this specific application is mainly related with the mucoadhesive properties of chitosan resulted from the electrostatic interactions between its positively charged free amine groups and the negatively charged gastric mucins at the acidic stomach pH. Several problems such as high solubility of chitosan under stomach acidic conditions, low retention time and difficulty in crossing the mucus barrier have been observed in those systems [7]. Therefore various crosslinking methods e.g. with glutaraldehyde [8], genipin [9] or sodium triphosphate pentabasic (TPP) solution [10] were investigated in order to minimize these problems. The nanotechnological production of the polymeric drug carriers, as well as the disadvantages of already developed chitosan based drug delivery systems induce the NANOENCAP project concept on the development and characterization of new dendrimeric micelles polymeric systems, with rigidly defined chemical structure, allowing the encapsulation of several drugs and their controlled release, and thus forming the so-called multidrug therapy systems. To provide the biocompatibility of new polymeric materials the monomer / reactant with proven biocompatibility or naturally occurring in the human body are chosen. According to the assumptions of the project the amphiphilic character of the proposed multi-functional polymeric drug delivery systems is going to enable the encapsulation of at least two drugs, matching latest trends in the research on DDS models in multi-therapy. As an exemplary multi-drug therapy in this project, the combine therapy of peptic ulcer disease was chosen. In this work we would like to present the short review of chitosan based drug delivery systems and the concept of the project as well as preliminary studies on new chitosan derivatives and the possibility of synthesis new micellar structures.
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 27
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation–induced synthesis of polymeric nanogels
Autorzy:
Kadłubowski, S.
Ulański, P.
Rosiak, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/283777.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
nanogels
polymeric materials
radiation
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 33
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibrational spectroscopy investigation of montmorillonite-chitosane nanocomposite materials
Autorzy:
Paluszkiewicz, C.
Stodolak, E.
Powiązania:
https://bibliotekanauki.pl/articles/283827.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
spectroscopy
chitosan
nanocomposite materials
Opis:
Biomaterials basing on natural polysaccharides, i.e. hiauronic acid, alginate, chitosane are an alternative for already applied bioresorbable synthetic materials basing on synthetic polyhydroxy acids. Their main advantages are good accessibility, low cost, easy forming and high biocompatibility. Additionally , they are a perfect matrix for bioactive nanoparticles i.e. hydroxy apatite (HAp), tricalcium phosphate (TCP) and silica (SiO2). The work presents results of research on nanocomposite consisting of chitosane matrix (CS) modified with a nanofiller, which was natural montmorillonite (MMT). Nanocomposite foils were produced by the casting method. In order to induce better biocompatibility, the surface of the CS/MMT composite was neutralized (bath in NaOH solution). The nanocomposite foils were subjected to a bioactivity test by incubation in SBF at 37oC for 7 days. It was observed that the CS/ MMT material surface showed a local supersaturation, which was a result of apatite nucleation. The CS/ MMT nanocomposites were investigated using FT-IR ( Fourier Transform Infrared Spectroscopy) and Fourier Raman Spectroscopy. FTIR measurements o f the samples were carried out on the transmission and reflection modes. The FTIR microscopy spectra were collected using BioRad Excalibur with ATR attachment as well as microscope UMA500 equipped with MCT detector. Spectra were measure at 4 cm -1 resolution in the region from 4 000 cm -1 to 600 cm -1 . FT-Raman spectra were obtained using a FTS 6000 Bio-Rad spectrometer with Ge detector. The samples were excited with a Nd-YAG laser (1064nm). Additional all materials in all steps experiments were observed under Scanning Electron Microscopy (Nova Nano SEM). Vibrational spectroscopy methods (FT Raman and FTIR) can be used for investigation of nanocomposite foils basing on biopolymers. High sensitivity the applied spectroscopy techniques show that in the result of the neutralization of CS/ MMT foil (via incubation in NaOH solution the biopolymer chain breaks. This phenomena is visible by intensity ratio between COC/COH bands. Increase of reactivity of chitosane chain lead to entrapment of PO4+3-, which is the origin of the apatite forms nucleation process. Chemical treatment of the nanocomposite foils, i.e. NaOH washes in fluences their chemical structure and microstructure. Neutralisation of the foils is the first processing stage which precedes the potential use o fCS/ MMT foils in biomedical applications. The materials show a tendency to apatite crystallisation which may support regeneration of damaged bone tissue. The applied spectroscopic methods allowed to observe changes in the whole volume of the sample. Individual ATR measurements taken at various spectral ranges and penetration depths allow to observe subtle changes in the polymer matrix caused by chemical treatment (NaOH and SBF incubation). Results of the investigations indicate that in the CS/ MMT systems new chemical bonds and related to them vibrations appear. Quantity and quality of the interact ions is related to characteristics of the nanoparticle and the presence of forming apatite structures.
Źródło:
Engineering of Biomaterials; 2011, 14, no. 109-111 spec. iss.; 44
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties of porous collagen/ gelatin/ hydroxyethyl cellulose matrices containing microspheres based on sodium alginate
Autorzy:
Kozlowska, J.
Tybinkowska, O.
Sionkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/284591.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
polymeric materials
microspheres
cellulose
Źródło:
Engineering of Biomaterials; 2018, 21, 148; 84
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alginate/chitosan hybrid materials loaded with ciprofloxacin
Autorzy:
Kyzioł, A.
Mazgała, A.
Michna, J.
Regiel-Futyra, A.
Moreno, I.
Sebastian, V.
Irusta, S.
Powiązania:
https://bibliotekanauki.pl/articles/284972.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
drugs
hybrid materials
biopolymers
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 106
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and properties of ceramic grafting material
Autorzy:
Ulyanova, T. M.
Titova, L. V.
Evtukhov, V. L.
Powiązania:
https://bibliotekanauki.pl/articles/285020.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
materiały ceramiczne
ceramic materials
Źródło:
Engineering of Biomaterials; 2007, 10, no. 63-64; 4-5
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adhesion, growth and differentiation of human osteoblast-like cells on thermally oxidized Ti and TiNb substrates
Autorzy:
Bacakova, L.
Vandrovcova, M.
Jirka, I.
Novotna, K.
Stary, V.
Powiązania:
https://bibliotekanauki.pl/articles/285115.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
osteoblasts
substrates
metallic materials
Opis:
Metallic materials are essential for construction of load-bearing bone implants, such as replacements of hip, knee and other joints. For these applications, modern materials used in advanced tissue engineering, e.g. resorbable porous or fibrous polymeric and ceramic scaffolds are mechanically insufficient, even if these materials enable the ingrowth of bone cells and bone tissue formation. Therefore, searching for new metallic materials and their surface modifications improving their biocompatibility and osseointegration is still desirable. As first metallic materials for bone implantation, AISI 316L stainless steel and Co-Cr alloys were used. In the 1950’s, the Ti-6Al-4V alloy was developed. These materials are still frequently used for construction of implants because of their relatively low price [1]. However, these materials are biomechanically incompatible with the bone tissue, because their Young’s modulus is markedly higher (110-220 GPa) than that of the bone (10-40 GPa). Implants with high stiffness take over a considerable part of load from the bone. This phenomenon, referred as “stress-shielding effect”, can then cause the bone resorption and loosening of the implant [1]. Also chemical compositions of the mentioned metallic materials limit their biocompatibility, because they contain harmful elements as V, Al, Co and Cr, which can act as cytotoxic, catabolic, immunogenic or even carcinogenic agents [2,3], and can also cause serious neurological problems [4]. Due to these adverse reactions, new types of Ti-alloys have been developed, namely low-rigidity β-type Ti alloys, containing non-toxic and non-allergenic elements (Nb, Ta, Zr etc.) and having good mechanical properties and workability [4,5]. The goal of this study was to evaluate the adhesion, growth and differentiation of osteoblast-like MG-63 and Saos-2 cells on titanium-niobium alloys after their surface modification by thermal oxidation at two different temperatures (165°C and 600°C). Pure titanium (treated at 165°C and 600°C) and polystyrene culture dishes (PS) were used as control materials. Possible immune activation of the cells was tested by the levels of TNF-alpha secreted to the cell culture media by murine macrophage-like RAW 264.7 cells cultured on the tested materials. On samples treated at 165°C, the number of initially adhered MG-63 and Saos-2 cells was on an average higher on TiNb than on Ti or PS. On day 3 after seeding, the trend of the cell numbers remained similar, with the highest cell density found on TiNb. Similar results were obtained on samples treated at 600°C, where the difference in cell number between TiNb and Ti samples became more apparent. This cell behavior could be attributed to a less negative zeta potential on TiNb samples. In samples treated at 165°C, the zeta potential of TiNb surfaces was on the average less negative than on Ti surfaces, but this difference was not significant. However, in samples treated at 600°C, this difference became much more pronounced, which was probably due to the formation of T-Nb2O5 phase on the surface of the TiNb samples. This phase was of a crystalline structure, while at 165°C, the structure of Nb2O5 was amorphous. In addition, both Ti and TiNb samples treated at 600°C contained rutile, while the samples treated at 165°C contained anatase in their surface layer. It has been shown that rutile films deposited on PEEK enhanced the adhesion and growth of osteoblasts more than anatase films [6]. This phenomenon was explained by an increase in the material surface wettability, and particularly to the presence of –OH- groups on the rutile films. The expression of collagen I and osteocalcin, i.e. an early and late marker of osteogenic cell differentiation, respectively, was higher on Ti than on TiNb samples, and this difference was more apparent in samples treated at 165°C. At the same time, no considerable immune activation of the cells on all tested samples was found. The production of TNF-α by RAW 264.7 cells was very low in comparison with cells grown in the presence of bacterial lipopolysaccharide, and also significantly lower than on untreated samples. These results indicate that TiNb substrates increased the proliferation of human bone cells, while pure Ti rather supported the cell differentiation. The effect on cell proliferation was more apparent in samples treated at the higher temperature (600°C), while the effect on cell differentiation was more pronounced at the lower temperature (165°C). None of the tested samples induce significant cell proinflammatory activation. Thus, all tested samples are suitable as carriers for bone cells; only an appropriate application (i.e., requiring either proliferation or quick differentiation of osteogenic cells) should be selected.
Źródło:
Engineering of Biomaterials; 2013, 16, no. 122-123 spec. iss.; 75-76
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porous hybrid materials as potential drug delivery systems
Autorzy:
Pajchel, Ł.
Szulkowska, A.
Kolmas, J.
Powiązania:
https://bibliotekanauki.pl/articles/283765.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
hybrid materials
drugs
composites
Źródło:
Engineering of Biomaterials; 2018, 21, 148; 43
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combinatorial discovery approaches accelerate the development of bioresorbable medical implants
Autorzy:
Kohn, J.
Powiązania:
https://bibliotekanauki.pl/articles/283833.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
bioresorbable materials
development
CCM
Źródło:
Engineering of Biomaterials; 2009, 12, no. 89-91; 259-260
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and structural characterization of the biodegradable polyester/bisphosphonate conjugates for coating of the apatite materials
Autorzy:
Oledzka, E.
Pachowska, D.
Orłowska, K.
Sobczak, M.
Kolmas, J.
Nałęcz-Jawecki, G.
Powiązania:
https://bibliotekanauki.pl/articles/283941.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biodegradable materials
coatings
biomaterials
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 47
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron work function as a direct parameter for bacterial infection risk of implant surfaces
Autorzy:
Gołda-Cępa, M.
Syrek, K.
Brzychczy-Włoch, M.
Sulka, G. D.
Kotarba, A.
Powiązania:
https://bibliotekanauki.pl/articles/284984.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
bacterial infections
implants
nanoporous materials
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 58
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the degradation process on the PLA/TCP locking bolt thread strength as a part of intramedullary locking nail system
Autorzy:
Gryń, K.
Szaraniec, B.
Ziąbka, M.
Morawska-Chochół, A.
Chłopek, J.
Powiązania:
https://bibliotekanauki.pl/articles/285252.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
degradation
intramedullary nailing
bioresorbable materials
Opis:
Intramedullary nailing has received increased attention for the treatment of distal femoral fractures. There are many types of nailing systems commonly used. Among them there is locked intramedullary nailing, which combines closed nailing with a special locking piece (bolt), which expands distal part of a nail and anchoring it when a central screw is tightened. Compared to other interlocking nail systems it is very effective and not so invasive way of fractured long bone treatment. However, it is not perfect and has one major disadvantage related to material (metal) and necessity of removing all parts of the system after the bone is recovered. The biggest issue is connected with the locking piece removal. That is why there was a need to find a material for this piece which is biodegradable and strong enough to maintain its mechanical function at the same time. Poly-L-lactide (PLA) is nowadays one of the most used bioabsorbable materials. Unfortunately, this polymer may not meet some application requirements due to inadequate mechanical properties and its degradation characteristics. One of the easiest ways to overcome these obstacles is to introduce an inorganic phase into the polymer matrix to create a composite. In this article a production method of a biodegradable composite (PLA/TCP, 90/10) locking piece of an interlocking intramedullary nail called "OLIVE" and the influence of degradation process in simulated physiological conditions (H2O, PBS) on its mechanical properties is shown. Main stress was placed on the inner thread strength to discover how it changes with time. A special device for mechanical testing machine imitating working conditions was fabricated. 148 Based on SEM observations, pH and electric conductivity monitoring after 14 days no degradation was found. However, mechanical testing shown, that after incubation for such period of time the material was more ductile. Instead of cracking, what was observed for not incubated samples, they changed their shape during the testing process. Nevertheless, it didn't radically influence on the inner thread strength and didn't change mechanical function of the olive. No inner thread destruction was discovered contrary to a metallic screws which in all cases were broken. Preliminary results indicate that proposed composite and an implant made of this material might be used as a locking piece in a locked intramedullary nailing system.
Źródło:
Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 148
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential activation of the immune system on metallic materials for bone implants
Autorzy:
Stranavova, L.
Bacakova, M.
Novotna, K.
Bacakova, L.
Fencl, J.
Powiązania:
https://bibliotekanauki.pl/articles/285314.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
bone implants
metallic materials
biomaterials
Opis:
Titanium and stainless steel are metallic materials that have been in use for a long time in orthopedics, traumatology and stomatology. These metals are strong, corrosion-resistant and biocompatible. However, metallic materials have some disadvantages in comparison with the natural bone, particularly their relatively high specific weight and toughness. For example, the Young's modulus of AISI316L stainless steel, Co-Cr alloys and Ti-6Al-4V alloy, i.e. materials frequently used for implantation into bone, ranges between 110-220 GPa, while the Young's modulus of bone tissue is 10-40 GPa [1]. In addition, these metals can release cytotoxic, allergenic and immunogenic ions, which can affect their biocompatibility [2, 3]. Implantation is a special type of transplantation process, in which the implant is inserted into the body, usually in order to replace an irreversibly damaged tissue. However, the immune system recognizes the implant as a foreign substance and attacks it with its effector mechanisms. Just as it can reject other types of transplants, the immune system can reject an artificial implant. To prevent rejection of an implant, it is important to study the potential activation of the immune system. This study has investigated the biocompatibility of samples made of pure titanium (according to quality standard ISO 5832-2) and corrosion-resistant steel (quality standards ISO 5832-1 and AISI 316L), obtained from Beznoska Ltd. (Kladno, Czech Republic), and the potential activation of the immune system by these materials. In addition to Fe, the steel samples contained C (max. 0.025 wt.%), Si (0.6 wt.%), Mn (1.7 wt.%), P (max. 0.025wt.%), S (max. 0.003 wt.%), Cr (17.5 wt.%), Ni (13.5 wt.%), Mo (2.8 wt.%), and Cu (max. 0.1 wt. %). The materials were used in the form of square samples (9x9 mm or 30x30 mm, thick¬ness 1 mm). Both the Ti samples and the steel samples were ground with SiO2. The surface of the steel samples was then treated by polishing with Al2O3 paste (grain size up to 1 um), while the surface of the Ti samples, i.e. a material not suitable for polishing, was finished by brushing using another type of Al2O3 paste with slightly larger grains. Thus, the surface of the steel samples was finally smoother and glossy, while the Ti surface was rougher and matte. For the in vitro biocompatibility tests, human osteoblast-like MG 63 cells (European Collection of Cell Cultures, Salisbury, UK) were used. The smaller samples (9x9 mm) were inserted into polystyrene 24-well cell culture plates (TPP, Trasadingen, Switzerland; well diameter 1.5 cm). Each well contained 25 000 cells (approx. 14 150 cells/cm2) and 1.5 ml of Dulbecco's Modified Eagle Minimum Essential Medium (DMEM; Sigma, USA, Cat. No. 10270-106) supplemented with 10% foetal bovine serum (FBS; Gibco, Cat. No. 10270-106) and gentamicin (40 /jg/ml, LEK, Slovenia). These samples were used for evaluating the size of the cell spreading area (day 1), and for evaluating cell shape and cell viability (days 1, 4 and 7 after seeding). The size of the cell spreading area was measured using Atlas Software (Tescan Ltd., Brno, Czech Republic). The viability of the cells was determined by the LIVE/ DEAD viability/cytotoxicity kit for mammalian cells (Invitrogen, Molecular Probes, USA). The larger samples (30x30 mm) were inserted into GAMA polystyrene dishes (diameter 5 cm; GAMA Group Joint-Stock Company, Ceske Budejovice, Czech Republic) and seeded with 300 000 cells/dish (approx. 15 300 cells/cm2) suspended in 9 ml of the above mentioned culture medium. These samples were used for evaluating the cell number on days 1, 4 and 7 after seeding, using a Beckman Vi-CELL XR Cell Analyser automatic cell counter. For the in vitro analysis of markers of osteogenic differentiation and cell immune activation, human osteoblast-like MG 63 cells (European Collection of Cell Cultures, Salisbury, UK) were used. The samples (9x9 mm) were inserted into polystyrene 24-well cell culture plates (TPP, Trasadingen, Switzerland; well diameter 1.5 cm). Each well contained 25 000 cells (approx. 14 150 cells/cm2) and 1.5 ml of Dulbecco's Modified Eagle Minimum Essential Medium (DMEM; Sigma, USA, Cat. No. 10270-106) supplemented with 10% foetal bovine serum (FBS; Gibco, Cat. No. 10270-106) and gentamicin (40 jg/ml, LEK, Slovenia). The cells were cultured for 1, 4, or 7 days at 37°C in a humidified atmosphere of 5% of CO2 in the air. On day 4 after seeding, the medium was changed; one half of the samples contained standard medium DMEM with 10% foetal bovine serum and gentamicin (40 jg/ml) mentioned above, and the second half contained osteogenic medium, i.e. the standard medium further supplemented with ß-glycerophosphate, L-glutamin, ascorbic acid, dihydroxyvitamin D3, dexamethason, 10% foetal bovine serum and gentamicin (40 jg/ml). Using an Enzyme-Linked ImmunoSorbent Assay (ELISA), we measured the concentration of the Inter¬cellular Adhesion Molecule-1 (ICAM-1, a marker of cell immune activation) and osteocalcin (a marker of osteogenic cell differentiation). These measurements were performed in homogenates of cells on days 4 and 7 after seeding, and the concentration of both markers was measured per cell or per mg of protein. On day 7, the amount of osteocalcin was measured and compared in cells cultured in the standard and osteogenic media. We also measured TNF-а and IL- 1ß, i.e. other markers of cell immune activation. These cytokines are important mediators of the inflammatory response, and they are involved in a variety of cellular activities, including cell proliferation and differentiation. We measured the secretion of these markers into the cell culture medium in murine macrophage-like RAW264.7 cells (American Type Culture Collection, Manassas, VA). The samples (9x9 mm) were inserted into polystyrene 24-well cell culture plates (TPP, Tra- sadingen, Switzerland; well diameter 1.5 cm). Each well contained 30,000 (approx. 16 980 cells/cm2) cells and 1.5 ml of the culture medium. RAW 264.7 cells were cultured in the RPMI-1640 medium (Sigma; 10% fetal bovine serum, 40 jg/mL gentamicin). After 7 days of cultivation, the cell culture medium was collected and used for measuring the concentration of TNF-а and IL-1ß by a sandwich ELISA using commercially available kits. A mouse TNF-а kit and an IL- 1ß Quantikine ELISA kit were used for the RAW 264.7 cells. Both kits were purchased from R and D Systems (Minneapolis, MN) and used according to the manufacturer's protocol. The results indicated that the number of initially adhering MG 63 cells on day 1 after seeding was significantly lower on the titanium (5320±390 cells/cm2) and on the stainless steel (4110±370 cells/cm2) than on the control polystyrene culture dishes (7740±350 cells/cm2). However, on day 4 after seeding, the cell population density on both metallic materials became significantly higher than on the control polystyrene dishes (75200±2890 cells/cm2 on Ti and 90 870±2350 cells/cm2 on steel vs. 56440±1180 cells/cm2 on polystyrene). This suggests faster cell proliferation on both metallic materials than on polystyrene. At the same time, the cell number on the stainless steel samples was significantly higher than on the Ti samples. On day 7, the differences in the number of adhered cells on the two metals and on the control polystyrene substrate was on an average similar (from 328780±680 cells/cm2 to 362200±760 cells/cm2). The cell viability on all tested materials was almost 100% in all culture intervals. The morphology of the cells adhered on the studied materials was similar to the morphology of the cells on the control polystyrene dishes, i.e. the cells were mostly flat and polygonal, and the size of their cell spreading areas was similar on all tested materials. The cells were distributed homogeneously on the entire material surface, and on day 4 they started to form confluent cell layers. On day 4, we measured the amount of ICAM-1 by the ELISA test. This immunoglobulin molecule is typically expressed on cells of the immune system, but it is also expressed on other cell types, including MG 63, during their immune activation, e.g. by an artificial growth support. In this case, ICAM-1 molecules on cells are bound byß2-integrin receptors on inflammatory cells (for a review, see [4]). Surprisingly, titanium seemed to be more immunogenic than stainless steel, which was indicated by a higher concentration of ICAM-1 per cell and mg of protein in cells on day 4 after seeding. However, on day 7, there was no difference between the concentrations of ICAM-1 per cell and mg of protein in cells on titanium and on stainless steel. The second molecule that we measured was osteocalcin, a calcium-binding extracellular matrix glycoprotein, an important marker of the bone formation process. The concentration of osteocalcin on day 4 in the standard culture medium was higher in MG 63 cells on the titanium and stainless steel than on the control polystyrene samples. This could be explained by the fact that the metals are harder than polystyrene. It is known that harder substrates promote osteogenic cell differentiation, while softer substrates direct the cell differentiation towards neural or muscle phenotype [5]. In addition, the osteogenic differentiation was further supported by the osteogenic medium, as indicated by a higher concentration of osteocalcin in cells grown in this medium compared to cells in the standard medium on day 7 after seeding. On day 7 after seeding murine macrophage-like RAW264.7 cells on the tested materials, the concentration of TNF-а in the culture medium ranged on an average from 57.10 to 79.39 pg per 2000000 cells. The concentration of TNF-а in the medium from Ti and Fe was significantly higher than in the medium from the control polystyrene dishes. The highest value (79.39 pg/2000000 cells) was found in the medium taken from RAW264.7 cells on Ti. The second molecule that we tested was IL-1ß. No significant differences in the concentration of IL-1ß were detected in the culture medium obtained from RAW264.7 cells on all tested materials. In other words, neither type of metallic material, i.e. Ti and Fe, evoked significantly higher production of IL-1ß by RAW 264.7 cells than standard polystyrene cell culture dishes. It can be concluded that the tests of biocompatibility and immune activation confirmed that titanium and stainless are promising for construction of bone implants and for good integration with the surrounding bone tissue.
Źródło:
Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 130-131
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł

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