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EN
Purpose: In recent years, it has become extremely important to search for more and more natural and biocompatible materials that allow for the reconstruction of natural tissues with as few side effects as possible. The aim of the present paper is to define mechanical properties such as compressive stress and Young’s Modulus and to estimate the ability of human bone cell strains to form biofilm on bioresorbable composites manufactured of polylactide and poly-l-lactide (PLA and PLLA) and hydroxyapatite and tricalcium phosphate (HA and β-TCP) with the use of Selective Laser Sintering (SLS) method. Methods: Microbiological tests were conducted on three variants of solid specimen made with additive laser technology. Samples with different chemical compositions were made with appropriate manufacturing parameters ensuring stability of both composite ingredients. Microbiological in vitro tests helped to determine cytotoxicity of specific samples toward bone cells. Results: The results obtained indicate significantly increased ability of osteoblasts to form colonies on the surface of materials with higher content of hydroxyapatite ceramics compared to surfaces of lower hydroxyapatite content. Conclusions: The data provided can be useful for future applications of the SLS technology in production of bioresorbable PLA/PLLA/HA/β-TCP medical implants.
3
Content available remote Antimicrobal and ostheointegration activity of bone cement contains nanometals
EN
Purpose: One of the major problems in bone surgery are infections – especially those occurring in the course of the operating on the patients with lowered immunity system, because they carry the danger of complications. In the Mechanical Department of Technical University of Gdansk, there has been carried the research with the use of bone cement and metal nanoparticles. Design/methodology/approach: The bone cement was used without supplement or with one or two drugs. These experiments are the latest, because include pure bone cement (without drugs) with nanometals. The titanium specimens was covering with such compose coating. The implant was inserted into rat`s thigh for six weeks. Afterwards the implant was removed from the body and examined by means of scanning electron microscope. Simultanously biological research was carried out. Bonless samples were placed into bacterial liquid, generated by the researcher (the Patent number P 409082 ) containing five most frequently occurring bacteria in human body. Findings: Result of the SEM research was positive – there was good adhesion of ostheoblasts to the surface and there were no traces of infection. Practical implications: The research concerns bone cement with nanoparticles proves, that nanoparticles are the alternatives to antibiotics.
PL
Tytan i jego stopy są jednymi z najpopularniejszych biomateriałów metalicznych stosowanych w dzisiejszej implantologii. Mimo licznych zalet tych materiałów, wykonane z nich wszczepy często poddaje się dodatkowej obróbce powierzchni, której celem jest polepszenie integracji implantu z otaczającymi go tkankami. Spośród wielu dostępnych technik, jedną z najczęściej wykorzystywanych komercyjnie jest stosunkowo tania i szybka metoda piaskowania, polegająca na wystawianiu danego przedmiotu na kontakt ze strumieniem przyspieszonych cząstek materiału ściernego. Celem tej pracy była analiza wpływu piaskowania ścierniwem o różnej średnicy ziaren na właściwości obrabianej powierzchni elementów na bazie dwóch popularnych stopów tytanu: Ti-6Al-4V i Ti-6Al-7Nb. W celu scharakteryzowania uzyskanych powierzchni przeprowadzono badania ich topografii, składu chemicznego, chropowatości i zwilżalności. Ponadto, aby sprawdzić potencjalną reakcję organizmu na obecność obrobionych w ten sposób elementów dokonano oceny stopnia proliferacji ludzkich komórek kościotwórczych hodowanych w bezpośrednim kontakcie z przygotowanymi powierzchniami. Otrzymane wyniki wykazały wyraźną zależność pomiędzy stopniem chropowatości i składem chemicznym piaskowanych elementów, a zastosowanym do obróbki rodzajem medium ściernego. Badanie zachowania komórek będących w kontakcie z modyfikowanymi próbkami wykazało obniżoną skłonność osteoblastów do przylegania i namnażania na najbardziej chropowatych powierzchniach.
EN
Titanium and its alloys are very popular metallic biomaterials used for medical implants production. Despite numerous advantages of the bulk material, such implants are very often subjected to additional surface treatment in order to improve their integration within the body tissues. Besides many other available techniques, one of the most frequently used in the commercial sector is a fast and economically profitable process of abrasive blasting. It is a method in which a stream of accelerated particles collides with the implant surface what causes changes in the material properties. The following paper presents differences resulting from sandblasting of Ti-6Al-4V and Ti-6Al-7Nb specimens with blasting particles varying in size. In order to characterize the outcome of such the treatment, investigations of surface topography, chemical composition, roughness, and wettability were conducted. Finally, the behaviour of the osteoblast- -like cells adhered to the sandblasted Ti-6Al-4V and Ti-6Al-7Nb surfaces was assessed in order to evaluate potential body response towards the aforementioned materials. The results suggest a strong correlation between surface roughness, its chemistry and the type of blasting medium applied. Evaluation of the cell culture revealed a rapid decrease in cell proliferation rate onto the roughest surfaces.
PL
Poli(ε-kaprolakton) jest materiałem wykorzystywanym jako rusztowanie dla komórek w inżynierii tkankowej kości. Na podstawie danych z literatury oraz naszych własnych badań nad reakcją komórek osteogennych na bezpośredni kontakt z poli(ε-kaprolaktonem) można przypuszczać, iż materiał ten może wpływać na poziom markerów różnicowania komórek w kierunku osteoblastów. Celem niniejszej pracy było zbadanie wpływu poli(ε-kaprolaktonu) na ekspresję oraz aktywność wczesnego markera procesu różnicowania komórek osteogennych, jakim jest fosfataza zasadowa. Przy użyciu reakcji łańcuchowej polimerazy DNA z analizą ilości produktu w czasie rzeczywistym (real-time PCR) analizowano ekspresję genu fosfatazy zasadowej natomiast aktywność enzymu oznaczono kolorymetrycznym testem firmy Sigma. Otrzymane wyniki wskazują, iż kontakt ludzkich osteoblastów z powierzchnią poli(ε-kaprolaktonu) powoduje podwyższoną ekspresję genu fosfatazy zasadowej oraz podwyższoną aktywność tego enzymu. Fosfataza zasadowa nie jest specyficznym markerem osteoblastów, jednakże jej podwyższony poziom towarzyszy wczesnym etapom różnicowania w kierunku fenotypu komórek osteogennych. Uzyskane wyniki uzasadniają podjęcie dalszych badań nad możliwym wpływem poli(ε-kaprolaktonu) na różnicowanie osteoblastów.
EN
Poly(ε-caprolactone) is a material used as a scaffold for cells in bone tissue engineering. On the basis of data from literature as well as own research it was concluded that this material can influence the levels of markers of cell differentiation towards osteoblasts. The aim of this paper was to investigate the effect of poly(ε-caprolactone) on the expression and the activity of the early marker of the cell osteogenic differentiation process – alkaline phosphatase (ALP). Using the quantitative real time polymerase chain reaction (real-time PCR) gene expression of the alkaline phosphatase was analyzed; however, the activity of the enzyme was determined with colorimetric assay from the Sigma company. The obtained results indicated that the contact of human osteoblasts with the surface of poly(ε-caprolactone) causes an increased gene expression of alkaline phosphatase and an increased activity of this enzyme. Although a high level of ALP does not prove the PCL influence on the osteogenic differentiation of cells into mature osteoblasts, because this enzyme is a non-specific marker of the differentiation process. The obtained results justify undertaking further studies on the possible impact of poly(ε-caprolactone) on osteoblast differentiation.
EN
Collagen type I and glycosaminoglycans (GAGs) were immobilized on the surfaces of two types of porous biodegradable poly(L-lactide-co-glycolide) (PLGA) scaffolds with pore size in the range of 250-320 µm and 400-600 µm. Two methods of coating were evaluated differing in the way of how the fibrillogenesis solution was introduced into the pores. The distribution of the immunostained collagen in the volume of the scaffolds was analysed with a laser confocal microscope (LSM). The total amount of collagen and GAGs was measured by Sirius Red and Toluidine Blue assays, respectively. The potential of the scaffolds for cell colonization and differentiation was tested in a dynamic cell culture system using human osteosarcoma cells (SAOS-2). The proliferation of SAOS-2 cells was measured by determining the DNA content on days 2 and 7, while differentiation was analyzed by Calcium- and Phosphate-Assays on days 7 and 14. Differentiation of cells was improved by increasing the pore diameter of the scaffolds, and artificial extracellular matrix (aECM) coatings had an additional positive effect for the scaffolds of both pore sizes.
EN
Degradable copolymers of glycolide and L-lactide (PGLA), glycolide and epsylon-caprolactone (PGCap) and terpolymer of glycolide, L-lactide and epyslon-caprolactone (PGLCap) were synthesized by ring opening polymerization using zirconium acetylacetonate (Zr(acac)4) as a biocompatible initiator. The structure and physicochemical surface properties of the materials were studied by NMR spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy and senssile drop. The interaction of polymeric films produced by slip-casting with osteoblast-like MG63 cells were tested in vitro. The number of adhering cells, their shape and the size of cell-material contact area were evaluated from day 1 to 7 after seeding. It was found that the cell behaviour on PGLA and PGLCap was very similar as on control tissue culture polystyrene (TCPS). On PGCap, however, the number of initially adhering cells was significantly lower (by 84% than on TCPS) and cell spreading area smaller (by 50% than on TCPS). On day 7 after seeding, these cells reached the lowest population density (by 30% smaller than TCPS). We hypothesize that the lower cell adhesion and growth of MG63 cells on PGCap was caused by the highest hydrophobicity of this material among all studies samples.
PL
Niniejsza praca przedstawia metodę izolacji i określenia fenotypu osteoblastów ludzkich. Zastosowano zmodyfikowaną metodę izolacji osteoblastów wykorzystującą samorzutnie wydostawanie się komórek z kości. Odpowiednio przygotowane amputowane kawałki kości umieszczono w pożywce w naczyniu hodowlanym. Po upływie ok. 1-2 tygodni obserwowano pojedyncze komórki lub grupy komórek, przylegające do dna naczynia. Jednolitą warstwę osteoblastów uzyskiwano po 2-8 tygodniach. W celu sprawdzenia fenotypu komórek wyizolowanych z kości oznaczono poziom osteokalcyny, aktywność fosfatazy zasadowej - podstawową i w odpowiedzi na dihydroksycholakalciferol, a także zdolność mineralizacji macierzy zewnątrzkomórkowej. Jako kontrolę przy badaniach fenotypu wykorzystano hodowle fibroblastów ludzkich izolowanych z amputowanych śródoperacyjnie fragmentów torebki stawowej.
EN
A method of human osteoblast isolation and evaluation of their phenotype hale been described in his paper. The modified method of isolation using a bone chips culture was employed. Appropriately prepared amputated bone fragments were placed in culture dishes in culture medium. After approximately 1-2 weeks single cells or groups of cells adhering to the bottom of culture dishes were observed. A monolayer of cells was obtained after 2-8 weeks. Osteocalcin level and alkaline phosphatase activity - basal and in reaction to dihydroxycholecalciferol (1,25(OH)2D3) were measured and ability to mineralize extracellular matrix was estimated in order to check the phenotype of cells isolated from bone. Human fibroblasts cultures were isolated from joint fibrous capsule fragments amputated during surgery and served as control cells in osteoblast phenotype investigation.
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