The potential of solar cells have not been fully tapped due to the lack of energy conversion efficiency. There are three important mechanisms in producing high efficiency cells to harvest solar energy; reduction of light reflectance, enhancement of light trapping in the cell and increment of light absorption. The current work represent studies conducted in surface modification of single-crystalline silicon solar cells using wet chemical etching techniques. Two etching types are applied; alkaline etching (KOH:IPA:DI) and acidic etching (HF:HNO3:DI). The alkaline solution resulted in anisotropic profile that leads to the formation of inverted pyramids. While acidic solution formed circular craters along the front surface of silicon wafer. This surface modification will leads to the reduction of light reflectance via texturizing the surface and thereby increases the short circuit current and conversion rate of the solar cells.

• MeSH
• analýza selhání vybavení MeSH
• design vybavení MeSH
• hydroxidy chemie   MeSH
• křemík chemie   MeSH
• kyseliny chemie   MeSH
• nanočástice chemie   ultrastruktura   MeSH
• povrchové vlastnosti MeSH
• sloučeniny draslíku chemie   MeSH
• sluneční energie * MeSH
• smáčivost MeSH
• zdroje elektrické energie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

PURPOSE: To investigate the effects of different chemically modified titanium surfaces on protein adsorption and the osteoblastic differentiation of human embryonic palatal mesenchymal (HEPM) cells. MATERIALS AND METHODS: Three different surfaces were evaluated. The first, a machined surface (Ti-M), was considered a control. The second surface was acid etched (Ti-AE). The third surface was prepared by exposing the Ti-AE samples to sodium hydroxide (NaOH) solution (Ti-AAE). The surface characteristics of chemically modified titanium were investigated by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and profilometry. To evaluate the production of biomarkers, commercial kits were utilized. RESULTS: Surface composition and morphology affected the kinetics of protein adsorption. Ti-AE surfaces manifested a greater affinity for fibronectin adsorption compared to Ti-M or Ti-AAE surfaces. It was observed that Ti-AE and Ti-AAE surfaces promoted significantly greater cell attachment compared to Ti-M surfaces. Statistically significant differences were also observed in the expression of alkaline phosphatase (ALP) activity, osteocalcin, and osteopontin on all 3 titanium surfaces. ALP activity and osteocalcin production up to day 12 suggested that differentiation of the cells into osteoblasts had occurred and that cells were expressing a bone-forming phenotype. CONCLUSIONS: It was thus concluded from this study that surface morphology and composition play a critical role in enhancing HEPM cell proliferation and differentiation into osteoblast cells.

• MeSH
• adsorpce MeSH
• alkalická fosfatasa chemie   MeSH
• biologické markery analýza   MeSH
• buněčná adheze fyziologie   MeSH
• buněčná diferenciace fyziologie   MeSH
• embryonální kmenové buňky fyziologie   MeSH
• fenotyp MeSH
• fibronektiny chemie   MeSH
• financování organizované MeSH
• hydroxid sodný chemie   MeSH
• kyselina chlorovodíková chemie   MeSH
• leptání zubů kyselinou MeSH
• leptání zubů metody   MeSH
• lidé MeSH
• mezenchymální kmenové buňky fyziologie   MeSH
• osteoblasty fyziologie   MeSH
• osteokalcin chemie   MeSH
• osteopontin chemie   MeSH
• oxid hlinitý chemie   MeSH
• patro embryologie   MeSH
• povrchové vlastnosti MeSH
• proteiny chemie   MeSH
• testování materiálů MeSH
• titan chemie   MeSH
• zubní materiály chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• srovnávací studie MeSH

The objective of this study was to evaluate and compare titanium surfaces: machined (MA); sintered ceramic-blasted (HAS); sintered ceramic-blasted and acid-etched (HAS DE) and to determine the effects of surface topography, roughness and chemical composition on human osteoblast cell reaction. Titanium surface samples were analyzed with respect to surface chemical composition, topography, and roughness. The effects of material surface characteristics on osteoblasts was examined by analyzing osteoblast morphology, viability and differentiation. Osteoblasts cultured on these materials had attached, spread and proliferated on every sample. The viability of osteoblasts cultured on HAS and HAS DE samples increased more intensively in time comparing to MA sample. The viability of osteoblast cultured on HAS samples increased more intensively in the early phases of culture while for cells cultured on HAS DE the cells viability increased later in time. Alkaline phosphate activity was the highest for the cells cultured on HAS sample and statistically higher than for the MA sample. The least activity occurred on the smooth MA sample along with the rougher HAS DE samples. All the examined samples were found to be biocompatible, as indicated by cell attachment, proliferation, and differentiation. Titanium surfaces modification improved the dynamics of osteoblast viability increase. Osteoblast differentiation was found to be affected by the etching procedure and presence of Ca and P on the surface.

• MeSH
• alkalická fosfatasa metabolismus   MeSH
• buněčná diferenciace MeSH
• buněčné linie MeSH
• fosfor farmakologie   MeSH
• keramika MeSH
• kultivované buňky MeSH
• lidé MeSH
• osteoblasty fyziologie   ultrastruktura   MeSH
• osteogeneze účinky léků   MeSH
• povrchové vlastnosti MeSH
• proliferace buněk MeSH
• titan chemie   MeSH
• vápník farmakologie   MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

This comparative study of various surface treatments of commercially available implant materials is intended as guidance for orientation among particular surface treatment methods in term of the cell reaction of normal human osteoblasts and blood coagulation. The influence of physicochemical surface parameters such as roughness, surface free energy and wettability on the response of human osteoblasts in the immediate vicinity of implants and on the blood coagulation was studied. The osteoblast proliferation was monitored and the expression of tissue mediators (TNF-alpha, IL-8, MMP-1, bone alkaline phosphatase, VCAM-1, TGF-beta) was evaluated after the cell cultivation onto a wide range of commercially available materials (titanium and Ti6Al4V alloy with various surface treatments, CrCoMo alloy, zirconium oxide ceramics, polyethylene and carbon/carbon composite). The formation of a blood clot was investigated on the samples immersed in a freshly drawn whole rabbit blood using scanning electron microscope. The surfaces with an increased osteoblast proliferation exhibited particularly higher surface roughness (here R(a) 3.5 microm) followed by a high polar part of the surface free energy whereas the effect of wettability played a minor role. The surface roughness was also the main factor regulating the blood coagulation. The blood clot formation analysis showed a rapid coagulum formation on the rough titanium-based surfaces. The titanium with an etching treatment was considered as the most suitable candidate for healing into the bone tissue due to high osteoblast proliferation, the highest production of osteogenesis markers and low production of inflammatory cytokines and due to the most intensive blood clot formation.

• MeSH
• buněčná diferenciace MeSH
• cévní buněčněadhezivní molekula-1 metabolismus   MeSH
• financování organizované MeSH
• interleukin-8 metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• osteoblasty cytologie   metabolismus   MeSH
• povrchové vlastnosti MeSH
• proliferace buněk MeSH
• protézy a implantáty MeSH
• titan chemie   metabolismus   MeSH
• TNF-alfa metabolismus   MeSH
• transformující růstový faktor beta metabolismus   MeSH
• vitalium chemie   metabolismus   MeSH
• Check Tag
• lidé MeSH

Cíl: pomocí pokusů in vitro studovat vliv povrchových vlastností vybraných implantačních materiálů na adherenci některých krevních složek (plazma, sérum) a sledovat vliv těchto adsorbovaných proteinů na povrchu implantátu na adhezi i syntetickou aktivitu kultivovaných osteoblastů. Metodika: U zvolených materiálů : titan leptaný (Ti-Etch), titan plazma-sprayovaný (Ti-PlaSpray), titan s hydroxyapatitovou vrstvou (Ti-HA), a uhlíkový kompozit (C/C) byly stanoveny fyzikálně-chemické parametry povrchu (drsnost, smáčivost a volná povrchová energie). Jako kontrola sloužil polystyren kultivačních destiček pro tkáňové kultury (TCPS). Biologická úprava materiálů byla provedena pokrytím jednou ze dvou vybraných krevních komponent–plazma nebo sérum. Na materiálech bez pokrytí i s biologickou úpravou byly kultivovány osteoblasty a následně byla z mitochondriální oxidační aktivity monolayeru buněk (MTT test) vyhodnocena jejich proliferace. V získaném kultivačním médiu byla pomocí enzymoimunosorbentní analýzy (ELISA) stanovena aktivita osteoblastů jako hladina kostní alkalické fosfatázy (BAP) a produkce zánětlivých cytokinů (TNF-?, IL-8). Výsledky: Vysoká drsnost implantátů ovlivnila zvýšenou proliferaci u titanových materiálů (Ti-PlaSpray). Nízká proliferace C/C je přičítána téměř nulové hodnotě polární složky povrchové energie. Potažení materiálů aktivovanou plazmou (fibrinovou sítí) vedlo ke vzniku unifikovaného povrchu jak z hlediska proliferace, tak i z hlediska syntetické aktivity. Oproti tomu při potažení implantátů sérem (albuminem) nebyl pozorován takový stimulační efekt na osteoblasty jaký jsme předpokládali. Závěr: Pokrytí vybraných implantačních materiálů aktivovanou plazmou (tj. fibrinovou sítí) vede k vytvoření povrchu s potřebnou rovnováhou mezi mírou proliferace a syntetickou aktivitou osteoblastů jako modelu imunitní odpovědi organizmu na zavedený implantát.

Aim of the study: To study the impact of surface properties of selected implant materials on adherence of some blood components (plasma, serum), and the impact of these proteins, adsorbed on the implant surface, on the adhesion and synthetic activity of cultured osteoblasts using in vitro experiments. Methods: In selected materials such as etched titanium (Ti-Etch), plasma-sprayed titanium (Ti-PlaSpray), titanium with hydroxyapatite layer (Ti-HA), and carbon composite (C/C), the physiochemical parameters were determined (roughness, wettability, and free surface energy). Tissue culture polystyrene (TCPS) was used as a control. Biological modification of materials was performed by overlaying of one of two selected blood components – plasma or serum. Osteoblasts were cultured on materials without overlay, as well as materials with biological modification, and consequently, the proliferation of osteoblasts was evaluated due to the mitochondrial oxidation activity of monolayer (MTT assay). In the obtained culture medium, the activity of osteoblasts was determined as the level of bone alkaline phosphatase (BAP) and the production of inflammatory cytokines (TNF-?, IL-8) using enzyme-linked immunosorbent assay (ELISA). Results: High roughness of implants affected the increased proliferation in titanium materials (Ti-PlaSpray). A decreased proliferation of C/C is attributed to almost zero value of polar component of surface energy. Overlaying of materials by activated plasma (fibrin network) led to formation of unified surface in terms of both proliferation and synthetic activity. However, overlaying of implants by serum (albumin) did not have the anticipated stimulatory effect on osteoblasts. Conclusion: Overalying of selected implant materials by activated plasma (i.e. fibrin network) leads to formation of a surface with required balance between the proliferation rate and synthetic activity of osteoblasts as a model of organisms’s immune response to an applied implant. Key words:

• MeSH
• adhezivita MeSH
• cytokiny imunologie   MeSH
• ELISA metody   využití   MeSH
• financování organizované MeSH
• krevní buňky metabolismus   MeSH
• krevní plazma fyziologie   metabolismus   MeSH
• lidé MeSH
• osteoblasty metabolismus   MeSH
• povrchové napětí MeSH
• povrchové vlastnosti MeSH
• proliferace buněk MeSH
• protézy a implantáty škodlivé účinky   MeSH
• sérum fyziologie   metabolismus   MeSH
• smáčivost MeSH
• Check Tag
• lidé MeSH