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EN
Biocompatibility of two-dimensionally reinforced carbon-carbon composites infiltrated and coated with pyrolytic carbon was evaluated in vitro by seeding them with smooth muscle cells derived from the rat aorta. The cells adhered to the composites in numbers comparable with those found on standard plastic culture dishes and these numbers tended to be positively correlated with the open porosity of the material surface. In contrast, the following proliferation was rather negatively related to the open porosity. The maximum population density of cells growing on the composites was similar or lower than that on standard culture plastic. These results suggest relatively good biocompatibility of the pyrolytic-carbon infiltrated and coated carbon composites and their suitability for future biomedical applications.
EN
The biocompatibility of unidirectionallv reinforced carbon-carbon composites (carbon fibre T300, phenolformaldehyde resin based matrix) with different surface roughness and chemical composition was tested in cell culture conditions. The surface of the composites was polished, covered with amorphous or pyrolytic carbon and seeded with rat aortic smooth muscle cells. Coating with amorphous carbon significantly lowered the number of initially adbered cells. In these samples, the surface roughness had no significant effect on the number of initially adbering cells nor their subsequent proliferation, In contrast, coating with pyrolitic carbon improved significantly both cell adhesion and growth, especially on the polished surfaces. In addition, the layer of pyrolitic carbon was more resistant to mechanical damage than the film of amorphous carbon. It is concluded that polished composites covered by pyrolytic carbon could be suitable for the future application in medicine and biotechnology.
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Content available Biocidal properties of copper nanoparticles
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EN
Metal nanoparticles (NPs) with antibacterial properties represent a promising alternative approach to antibiotics, whose overuse has led to the appearance of drug-resistant bacteria. This article addresses particularly copper (Cu) nanoparticles since Cu is a structural constituent of many enzymes in living microorganisms. In addition, Cu has a better antibacterial effect and minimal cost compared to silver. The properties of Cu nanoparticles are described here: antibactericide, toxicity mechanisms, oxidation, and copper oxide biocompatibility for medical applications. Along with the advantages of Cu nanoparticles, the nanotoxicity still remains to take into consideration such as in targetting different bacteria strains, bacteria’s resistance, the effect of size, the effect of NP chemical composition, the effect of oxidation, and the corona phenomenon effect. The methodology of Cu nanoparticles synthesis, related to the biocidal effect, is illustrated by some limitations and some breakthrough such as chitosan stabilizer (CS), laser ablation, plasma induction, and flow-levitation method (FL). Although Cu nanoparticles are beneficial for bacterial elimination, these nanoparticles are graded harmful to the human body and the environment because of their toxic effects. Thus, it requires further improvement and further investigation to create super antibacterial Cu nanoparticles, to develop some interesting research work around this subject, and to reveal some promising medical findings.
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EN
The aim of the study was to investigate the immune-modulatory potential of commercially available PTFE and polyester vascular grafts with and without gelatine-coating. The biomaterial-cell-interaction was characterized by changes of established parameters such as PMN-related receptors/mediators, phagocytosis potential and capacity as well as the effect of an additional plasma-dependent modulation. Material and methods. By means of a standardized experimental in vitro model, various vascular graft material (PTFE/polyester/uncoated/gelatine-coated) was used for incubation with or without plasma and co-culturing with human neutrophile granulocytes (PMN) followed by analysis of representative receptors and mediators (CD62L, CD11b, CXCR2, fMLP-R, IL-8, Elastase, LTB4 ). Oxidative burst assessed phagocytosis capacity. Results. Comparing the vascular grafts, un-coated PTFE induced the lowest magnitude of cell stimulation whereas in case of gelatine-coating, cell response exceeded those of the other vascular grafts. This was also found comparing the polyester-based prosthetic material. Gelatine-coated polyester led to a more pronounced release of elastase than gelatine- coated PTFE and the uncoated materials. The results of oxidative burst indicated a reduced phagocytosis capacity in case of gelatine-coated polyester. Plasma incubation did also provide an impact on the cellular response. While in case of gelatinecoating, PMN-related receptor stimulation became lower, it increased by native polyester. The latter one did also induce more mediators such as IL-8 and LTB4 than gelatine-coated material. Conclusions. There have been no extensive data on cell-cell interactions, cytokines and general histo-/hemocompatibility of human cells by the new generation of vascular grafts. It remains still open whether healing process and infectious resistance can be compromised by material-dependent overstimulation or reduced phagocytosis potential of the immune cells of the primary unspecific immune response induced by gelatine-coated materials.
EN
The surface of unidirectionally reinforced carbon-carbon composites was modified either by polishing or coating with a carbon-titanium layer. In culture conditions; the composites were seeded with vascular smooth muscle cells derived from the rat aorta. On both types of modified samples, the number of initially adhered cells, degree of their spreading and their subsequent growth were significantly higher than on untreated samples, and in the case of carbon-titanium-covered composites, also higher than on standard plastic culture dishes Sterilin. These results obtained in vitro suggest possible good biointegration of the polished and carbon-titanium-covered carbon-carbon composites with the surrounding tissue in situ after their use in transplantation medicine for the construction of artificial implants.
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The objective of our in vivo study was to investigate the biocompatibility of polymer foils enriched with chitosan. Methods: three types of chitosan: non-modified(jp), and modified with montmorillonite K5 and montmorillonite K10 (p2-p3) were prepared. The in vivo studies were carried out using the rat soft tissues as a model. Small pieces of foils (2mm x 4mm)used in the experiment were sterilized by UV radiation. Next they were implanted under sterile conditions into the gluteus muscle of adult male outbred Wistar rats. Each animal received two implants: the modified foil into the right muscle, and the unmodifiedfoil used as a control into the left one. All procedures were conducted in sterile conditions and under anaesthesia. Animals were anesthetized with intraperitoneal injection of xylazine and ketamine (Biowet Puławy, Poland). Skin in the site of surgery was shaved and disinfected, and a small incision was made in the gluteus muscle. Equal pieces of foils were inserted into the such created pouch. The muscle and skin wounds were closed with 5/0 PDSII (polydioxanone) monofilament absorbable sutures (Ethicon Ltd., UK). All animals survived the surgery. No wound healing complications were observed after the surgery. The animals were maintained under standard conditions with free access to food and water. After 7, and 30 days from the surgery, at each time point 12animals were sacrificed. Tissue specimens containing the implanted materials were excised and immediately frozen in liquid nitrogen. Next they were cut into 8μm thick slides in a Shandon cryostat (Thermo-Scientific, UK) at -22°C. Obtained slides were investigated through histological and histochemical methods to estimate the intensity of inflammation, production of collagen, and metabolic activity of connective and muscle tissues surrounding implant. In order to estimate the effect of the implants on the metabolic state of surrounding tissues, activities of the marker metabolic enzymes: cytochrome c oxidase, and NADH dehydrogenase were examined. The activity of acid phosphatase was used to assess the extent of inflammation around the implants. The presence and thickness of fibrous capsule around the implants were estimated on slides stained by van Gieson’s method. Results: Differences between non-modified and modified with chitosan materials were not manifested in short, 7- and 30 days series. The activities of mitochondrial oxidative enzymes, cytochrome c oxidase and NADH dehydrogenase, in muscle fibres in close proximity to the implants were slightly lower than in those further away. Probably one month was too short period to obtain the whole recovery after the surgery. At the same time the process of regeneration seemed to be intense: numerous regenerating muscle fibres infiltrated the granulation tissue around the implanted foils were observed The inflammation respone was visibly lower in 30days series compared to7days ones what indicate that the inflammation was evoked in higher degree by surgery than by the presence of the implanted materials. The fibrous capsule around foils was thin or not present at all – there were places where pieces of foils were in direct contact with the muscle tissue. After one month experiment there were no signs of degradation of materials. The experiment has been continued to compare abilities of biomaterials in long term series. Conclusion: The regeneration and enzymic activity of muscle tissue together with the lack of continuous fibrous capsule suggest that the materials used in our study are biocompatibile and are suitable for the treatment of tissue injury.
PL
Celem badań było określenie charakteru odpowiedzi komórkowej i stopnia biozgodności tkankowej dla wszczepionego w mięśnie pośladkowe biomateriału Sz2.
EN
The aim of the study was to determine a character of cellular response and a degree tissue biocompatibility and bio-material Sz2 implanted in the gluteal muscles.
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Content available remote Synthesis and characterization of nanostructured CaSiO3 biomaterial
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EN
Here we report a successful preparation of nanostructured calcium silicate by wet chemical approach. The synthesized sample was characterized by various physico-chemical methods. Thermal stability was investigated using thermo-gravimetric and differential thermal analysis (TG-DTA). Structural characterization of the sample was carried out by the X-ray diffraction technique (XRD) which confirmed its single phase hexagonal structure. Transmission electron microscopy (TEM) was used to study the nanostructure of the ceramics while homogeneous grain distribution was revealed by scanning electron microscopy studies (SEM). The elemental analysis data obtained from energy dispersive X-ray spectroscopy (EDAX) were in close agreement with the starting composition used for the synthesis. Superhydrophilic nature of CaSiO3 was investigated at room temperature by sessile drop technique. Effect of porous nanosized CaSiO3 on early adhesion and proliferation of human bone marrow mesenchymal stem cells (BMMSCs) and cord blood mesenchymal stem (CBMSCs) cells was measured in vitro. MTT cytotoxicity test and cell adhesion test showed that the material had good biocompatibility and promoted cell viability and cell proliferation. It has been stated that the cell viability and proliferation are significantly affected by time and concentration of CaSiO3. These findings indicate that the CaSiO3 ceramics has good biocompatibility and that it is promising as a biomaterial.
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