Physicochemical and UV/VIS measurements of UHD solutionsof water, potentized water,and different potencies of organic substance

Conventional science regards the study of UHD (highly homeopathically potentized) solutions as pseudo-science. However, an increasing number of rigorous scientific investigations demonstrate differences in physicochemical and physical characteristics of such solutions. Strictly chemically regarded, they correspond to highly distilled water. Our research team developed a system of physicochemical and UV spectrographic measurements, whereby the differences may be consistently confirmed with high statistical significance.Methods:For measurement of the physicochemical parameters,we usedpH,electrical conductivity,and oxidation-reduction potential (ORP)sensors.For UV/VIS spectroscopymeasurements,we useda Macherey-Nagelspectrophotometer.For UHD research, we used two batches of substances: Russian (R) and Brazilian (B). In R, distilled water (W) was used for dilutions and potencies as follows: potentized water (W cH9), potentized dilution of antibodies to interferon-gamma (Abs IFNγ cH9), the same original substance in the form of a mixture of potencies (Abs IFNγ cH12, cH30, cH50, shortly Abs IFNγ mix). Furthermore, we prepared higher potencies of the substances (supplementary potentiation) in a specially prepared solution and measured their characteristics. In B, the solution was used for further dilutions and potencies as follows: potentized water (W cH1) and Glyphosate potencies (Gly cH6 => cH8, cH30 => cH 32, and cH200 => cH 202).For direct or post-hoc analysis, we used Wilcoxon signed-rank test, two-tailed.Results:UV-VIS spectroscopy (R): measurements of received liquids potentized for further cH1 show statistically significant differences between all substances, except between water W and W cH9 at 260 nm. Significant differences (p-values) were as follows: Abs IFNγ mixvs. W= 0.007; Abs IFNγ mixvs.W cH9=0.008; Abs IFNγ cH9vs. W=0.044; Abs IFNγ cH9vs.W cH9= 0.026; Abs IFNγ mixvs.W cH9= 0.007; W vs.W cH9= 0.506.Physicochemical measurements:R: measurementsdemonstrated statistical difference only in pH (Abs IFNγ mix towards all others). Significant differences (p-values) were as follows: Abs IFNγ mixvs. W=0.022; Abs IFNγ mixvs.W cH9=0.005; Abs IFNγ mixvs.Abs IFNγ cH9=0.025. After supplementarypotentiation, we obtained a more conspicuous picture with many statistical differences in conductivity and ORP, ranging from p= 0.001 to 0.046.A difference between water and potentized water has also been demonstrated.B: the measurements demonstrated statistical differences mainly in pH between Gly cH8 and the rest and between Gly cH202 and W cH1.Significant differences (p-values) were as follows:Gly cH8vs. Gly cH32 =0.027; Gly cH8vs. Gly cH202 = 0.011; Gly cH8vs. W cH1= 0.014; Gly cH202vs. W cH1= 0.034.Conclusion:UV/VIS at wavelength 260 nm Abs IFNγ mix discloses a pattern similar to exclusion zone (EZ)water at 270 nm.By additional potentiation and with physicochemical measurements, we obtained higher statistical differences than in the original dilutions.In contrast, UV/VIS spectroscopy showed more conspicuous results without additional potentiation. However, the very act of succussion becomes very distinct

Additive manufacturing of titanium alloy could modify the pathogenic microbial profile: an in vitro study

Abstract Additive manufacturing (AM) is an emerging process for biomaterials and medical devices. Direct Laser Metal Sintering (DLMS) is an AM technique used to fabricate Ti-6Al-4V implant materials with enhanced surface-related properties compared with wrought samples; thus, this technique could influence microbial adsorption and colonization. Therefore, this in vitro study was conducted to evaluate the impact of different implant production processes on microbial adhesion of periodontal pathogens. Titanium discs produced using two different processes—conventional and AM—were divided into three groups: conventional titanium discs with machined surface (G1), AM titanium discs with chemical treatment (G2) and AM titanium discs without chemical treatment (G3). Subgingival biofilm composed of 32 species was formed on the titanium discs, and positioned vertically in 96-well plates, for 7 days. The proportions of microbial complexes and the microbial profiles were analyzed using a DNA-DNA hybridization technique, and data were evaluated using Kruskal-Wallis and Dunnett tests (p < 0.05). Lower proportions of the red complex species were observed in the biofilm formed in G2 compared with that in G1 (p < 0.05). Moreover, the proportions of the microbial complexes were similar between G2 and G3 (p > 0.05). Compared with G1, G2 showed reduced levels of Porphyromonas gingvalis , Actinomyces gerencseriae, and Streptococcus intermedius , and increased levels of Parvimonas micra , Actinomyces odontolyticus, and Eikenella corrodens (p < 0.05). The microbial profile of G3 did not differ from G1 and G2 (p > 0.05). The results of this in vitro study showed that titanium discs produced via AM could alter the microbial profile of the biofilm formed around them. Further clinical studies should be conducted to confirm these findings.

Hydroxyapatite Nanorod-Modified Sand Blasted Titanium Disk for Endosseous Dental Implant Applications

BACKGROUND: Sand blasted titanium (Ti) is commonly used in designing endosseous dental implants due to its biocompatibility and ability to form bonds with bone tissues. However, titanium implants do not induce strong interactions with teeth bones. To increase strong interactions between Ti disk implants and teeth bones, the L-glutamic acid grafted hydroxyapatite nanorods (nHA) were immobilized on albumin modified Ti disk implants (Ti-Alb). METHODS: For modification of Ti disk implants by nHA, the L-glutamic acid grafted nHA was synthesized and then immobilized on albumin modified Ti disk implants. Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope; energy dispersive spectroscopy and confocal laser scanning microscopy were used to confirm the modification of Ti disk implants. The bioactivity of nHA-modified Ti disk implants was evaluated by seeding MC3T3-E1 cells on Ti-nHA implants. RESULTS: Characterization techniques have confirmed the successful modification of Ti disk implants by L-glutamic acid grafted nHA. The nHA-modified Ti disk implants have shown enhanced adhesion, proliferation and cytotoxicity of MC3T3-E1 cells in comparison to pristine Ti implants. CONCLUSION: The modification of Ti implants by L-glutamic acid grafted nHA has produced highly osteogenic Ti disk plants in comparison to pristine Ti disk implants due to the formation of bioactive surfaces by hydroxyapatite nano rods on Ti disk implants. Ti-nHA disk implants showed enhanced adhesion, proliferation, and MC3T3-E1 cells viability in comparison to pristine Ti disk implants. Thus nHA might be to be useful to enhance the osseointegration of Ti implants with teeth bones.

Effects of acid-treatment conditions on the surface properties of the RBM treated titanium implants / 대한치과재료학회지

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, H2SO4 and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven (37℃). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of H₂SO₄ and temperature of acid-solution. Acid-treatment conditions (concentration of H₂SO₄, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with 90℃ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

Incorporation of silver nanoparticles on the surface of orthodontic microimplants to achieve antimicrobial properties / 대한치과교정학회지

OBJECTIVE: Microbial aggregation around dental implants can lead to loss/loosening of the implants. This study was aimed at surface treating titanium microimplants with silver nanoparticles (AgNPs) to achieve antibacterial properties. METHODS: AgNP-modified titanium microimplants (Ti-nAg) were prepared using two methods. The first method involved coating the microimplants with regular AgNPs (Ti-AgNP) and the second involved coating them with a AgNP-coated biopolymer (Ti-BP-AgNP). The topologies, microstructures, and chemical compositions of the surfaces of the Ti-nAg were characterized by scanning electron microscopy (SEM) equipped with energy-dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Disk diffusion tests using Streptococcus mutans, Streptococcus sanguinis, and Aggregatibacter actinomycetemcomitans were performed to test the antibacterial activity of the Ti-nAg microimplants. RESULTS: SEM revealed that only a meager amount of AgNPs was sparsely deposited on the Ti-AgNP surface with the first method, while a layer of AgNP-coated biopolymer extended along the Ti-BP-AgNP surface in the second method. The diameters of the coated nanoparticles were in the range of 10 to 30 nm. EDS revealed 1.05 atomic % of Ag on the surface of the Ti-AgNP and an astounding 21.2 atomic % on the surface of the Ti-BP-AgNP. XPS confirmed the metallic state of silver on the Ti-BP-AgNP surface. After 24 hours of incubation, clear zones of inhibition were seen around the Ti-BP-AgNP microimplants in all three test bacterial culture plates, whereas no antibacterial effect was observed with the Ti-AgNP microimplants. CONCLUSIONS: Titanium microimplants modified with Ti-BP-AgNP exhibit excellent antibacterial properties, making them a promising implantable biomaterial.

Grafting Collagen on Poly (Lactic Acid) by a Simple Route to Produce Electrospun Scaffolds, and Their Cell Adhesion Evaluation

Increasing bioactivity and mechanical properties of polymers to produce more suitable scaffold for tissue engineering is a recurrent goal in the development of new biomedical materials. In this study, collagen-functionalized poly (lactic acid), PLA, was obtained by means of a simple grafting route, and electrospun scaffolds were produced to grow cells in vitro; their bioactivity was compared with scaffolds made of physical blends of PLA and collagen. Grafting was verified via nuclear magnetic resonance, attenuated total reflection-Fourier transform infrared and X-ray photoelectron spectroscopy. The cell adhesion performance of the scaffolds was studied using macrophages. Elastic modulus (74.7 megapascals) and tensile strength (3.0 megapascals) of the scaffold made from PLA grafted with collagen were substantially higher than the scaffolds made from physical blends of collagen and PLA: 32 and 2.16 megapascals, respectively, implying a more resistant material because of the chemical bond of the polypeptide to PLA. Besides, the fibers had more uniform diameter without defects. Scaffolds made from PLA grafted with collagen presented four-fold increase in cell adhesion than those of PLA blended with collagen. Furthermore, cell spreading within the scaffolds occurred only when collagen-functionalized poly (lactic acid) was used. These results open a new option for the easy tailoring of nanofiber-based scaffolds in three dimensions for tissue engineering.

Extracellular Calcium-Binding Peptide-Modified Ceramics Stimulate Regeneration of Calvarial Bone Defects

Secreted protein, acidic, cysteine-rich (SPARC)-related modular calcium binding 1 (SMOC1) has been implicated in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs). In this study, we found that a peptide (16 amino acids in length), which is located in the extracellular calcium (EC) binding domain of SMOC1, stimulated osteogenic differentiation of human BMSCs in vitro and calvarial bone regeneration in vivo. Treatment of BMSCs with SMOC1-EC peptide significantly stimulated their mineralization in a dose-dependent manner without changing their rate of proliferation. The expression of osteogenic differentiation marker genes, including type 1 collagen and osteocalcin, also increased in a dose-dependent manner. To examine the effect of the SMOC1-EC peptide on bone formation in vivo, the peptide was covalently immobilized onto hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) particles. X-ray photoelectron spectroscopy analysis showed that the peptide was successfully immobilized onto the surface of HA/β-TCP. Implantation of the SMOC1-EC peptide-immobilized HA/β-TCP particles into mouse calvarial defects and subsequent analyses using microcomputed tomography and histology showed significant bone regeneration compared with that of calvarial defects implanted with unmodified HA/β-TCP particles. Collectively, our data suggest that a peptide derived from the EC domain of SMOC1 induces osteogenic differentiation of human BMSCs in vitro and efficiently enhances bone regeneration in vivo.

Effects of plasma on polyethylene fiber surface for prosthodontic application

ABSTRACT Plasma technology has the potential to improve the adherence of fibers to polymeric matrices, and there are prospects for its application in dentistry to reinforce the dental particulate composite. Objectives This study aimed to investigate the effect of oxygen or argon plasma treatment on polyethylene fibers. Material and Methods Connect, Construct, InFibra, and InFibra treated with oxygen or argon plasma were topographically evaluated by scanning electron microscopy (SEM), and chemically by X-ray photoelectron spectroscopy (XPS). For bending analysis, one indirect composite (Signum) was reinforced with polyethylene fiber (Connect, Construct, or InFibra). The InFibra fiber was subjected to three different treatments: (1) single application of silane, (2) oxygen or argon plasma for 1 or 3 min, (3) oxygen or argon plasma and subsequent application of silane. The samples (25x2x2 mm), 6 unreinforced and 60 reinforced with fibers, were subjected to three-point loading tests to obtain their flexural strength and deflection. The results were statistically analyzed with ANOVA and the Bonferroni correction for multiple comparison tests. Results SEM analysis showed that oxygen and argon plasma treatments promote roughness on the polyethylene fiber surface. X-ray photoelectron spectroscopy (XPS) analysis shows that both plasmas were effective in incorporating oxygenated functional groups. Argon or oxygen plasma treatment affected the flexural strength and deflection of a fiber reinforced composite. The application of silane does not promote an increase in the flexural strength of the reinforced composites. Conclusions Oxygen and argon plasma treatments were effective in incorporating oxygenated functional groups and surface roughness. The highest strength values were obtained in the group reinforced with polyethylene fibers treated with oxygen plasma for 3 min.

Early osseointegration driven by the surface chemistry and wettability of dental implants

Objective The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration. The surfaces were sandblasting and acid etching (Group 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2). Material and Methods X-ray photoelectron spectroscopy (XPS) was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM) and confocal microscopy (CM), respectively. Contact angle analysis (CAA) was employed for wetting evaluation. Bone-implant-contact (BIC) and bone area fraction occupied (BAFO) analysis were performed on thin sections (30 μm) 14 and 28 days after the installation of 10 implants from each group (n=20) in rabbits' tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables. Results Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05). BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p<0.05). Conclusion The surface chemistry and wettability implants of Group 2 accelerate osseointegration and increase the area of the bone-to-implant interface when compared to those of Group 1. .

TiO₂nanotubes functionalized with recombinant human bone morphogenetic protein-2 enhance biological activity in vitro / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of TiO₂nanotube arrays covalently modified by recombinant human bone morphogenetic protein- 2(rhBMP- 2) on the early bioactivity of mesenchymal stem cells (MSC) in vitro and to provide experimental evidence for the biochemical modification of titanium implants.</p><p><b>METHODS</b>In the experiment group, double titanium nanotube arrays were prepared by anodization, and were chemically grafted with rhBMP- 2. Mechanically polished pure titanium was used as blank control group, and titanium dioxide nanotubes was used as negative control A group, and titanium dioxide nanotubes + carbonyldiimidazole as negative control B group. Field emission scanning electron microscope (FE- SEM) and X- ray photoelectron spectroscopy (XPS) were used to detect the morphology and physicochemical properties of the experiment group, blank control group and the negative control group. Cell adhesion on the specimen surface of the experiment group, blank control group and negative control group on the 1st day was tested. Cell proliferation on the 1st, 3rd and 5th day and alkaline phosphatase activity on the 5th, 7th and 11th day was also tested.</p><p><b>RESULTS</b>FE- SEM showed that the surface of titanium nanotubes loaded with rhBMP- 2 possessed visible miliary particulate matter. XPS showed that nitrogen peak in the group of titanium nanotubes loaded with rhBMP-2 was significantly greater that those in the other groups. FE- SEM showed that the cells on the surface of the experimental group on the 1st day spread well, better than those in the control group and negative control group. Cell proliferation activity on the 1st day in different groups was not obvious (P>0.05), the A value of the experimental group on the 3rd and 5th day (3.295 ± 0.153, 3.823 ± 0.059) were significantly higher than those in the control group (2.479 ± 0.064, 3.131 ± 0.096) and negative control A group (2.715 ± 0.075, 3.371 ± 0.047) and negative control B group (2.756 ± 0.132, 3.637 ± 0.047) (P<0.05). Alkaline phosphatase activity on the 5th, 7th and 11th day in the experimental group (0.0477 ± 0.0287, 0.0615 ± 0.0016, 0.0667 ± 0.0018) were better than those in the control group, negative control A group and negative control B group (P<0.05).</p><p><b>CONCLUSIONS</b>Titanium nanotube arrays can be loaded with rhBMP-2 by biochemical methods and have good biocompatibility.</p>

Efficacy of various cleaning solutions on saliva-contaminated zirconia for improved resin bonding

PURPOSE: This study aimed to investigate the efficacy of cleaning solutions on saliva-contaminated zirconia in comparison to air-abrasion in terms of resin bonding. MATERIALS AND METHODS: For saliva-contaminated airabraded zirconia, seven cleaning methods)-no contamination (NC), water-spray rinsing (WS), additional airabrasion (AA), and cleaning with four solutions (Ivoclean [IC]; 1.0 wt% sodium dodecyl sulfate [SDS], 1.0 wt% hydrogen peroxide [HP], and 1.0 wt% sodium hypochlorite [SHC])-were tested. The zirconia surfaces for each group were characterized using various analytical techniques. Three bonded resin (Panavia F 2.0) cylinders (bonding area: 4.5 mm2) were made on one zirconia disk specimen using the Ultradent jig method [four disks (12 cylinders)/group; a total of 28 disks]. After 5,000 thermocycling, all specimens were subjected to a shear bond strength test with a crosshead speed of 1.0 mm/minute. The fractured surfaces were observed using an optical and scanning electron microscope (SEM). RESULTS: Contact angle measurements showed that groups NC, AA, IC, and SHC had hydrophilic surfaces. The X-ray photoelectron spectroscopy (XPS) analysis showed similar elemental distributions between group AA and groups IC and SHC. Groups IC and SHC showed statistically similar bond strengths to groups NC and AA (P>.05), but not groups SDS and HP (P<.05). For groups WS, SDS, and HP, blister-like bubble formations were observed on the surfaces under SEM. CONCLUSION: Within the limitations of this in vitro study, some of the cleaning solutions (IC or SHC) were effective in removing saliva contamination and enhancing the resin bond strength.

Cell attachment and proliferation of bone marrow-derived osteoblast on zirconia of various surface treatment

PURPOSE: This study was performed to characterize the effects of zirconia coated with calcium phosphate and hydroxyapatite compared to smooth zirconia after bone marrow-derived osteoblast culture. MATERIALS AND METHODS: Bone marrow-derived osteoblasts were cultured on (1) smooth zirconia, (2) zirconia coated with calcium phosphate (CaP), and (3) zirconia coated with hydroxyapatite (HA). The tetrazolium-based colorimetric assay (MTT test) was used for cell proliferation evaluation. Scanning electron microscopy (SEM) and alkaline phosphatase (ALP) activity was measured to evaluate the cellular morphology and differentiation rate. X-ray photoelectron spectroscopy (XPS) was employed for the analysis of surface chemistry. The genetic expression of the osteoblasts and dissolution behavior of the coatings were observed. Assessment of the significance level of the differences between the groups was done with analysis of variance (ANOVA). RESULTS: From the MTT assay, no significant difference between smooth and surface coated zirconia was found (P>.05). From the SEM image, cells on all three groups of discs were sporadically triangular or spread out in shape with formation of filopodia. From the ALP activity assay, the optical density of osteoblasts on smooth zirconia discs was higher than that on surface treated zirconia discs (P>.05). Most of the genes related to cell adhesion showed similar expression level between smooth and surface treated zirconia. The dissolution rate was higher with CaP than HA coating. CONCLUSION: The attachment and growth behavior of bone-marrow-derived osteoblasts cultured on smooth surface coated zirconia showed comparable results. However, the HA coating showed more time-dependent stability compared to the CaP coating.

Production of yttrium aluminum silicate microspheres by gelation of an aqueous solution containing yttrium and aluminum ions in silicone oil

Radioactive yttrium glass microspheres are used for liver cancer treatment. These yttrium aluminum silicate microspheres are synthesized from yttrium, aluminum and silicone oxides by melting. There are two known processes used to transform irregular shaped glass particles into microspheres, these 'spheroidization by flame' and 'spheroidization by gravitational fall in a tubular furnace'. Yttrium aluminum silicate microspheres with the approximate size of 20-50 microm were obtained when an aqueous solution of YCl3 and AlCl3 was added to tetraethyl orthosilicate [TEOS] and pumped in to silicone oil and stirred constantly the temperature of 80°C. The resulting spherical shapes were then investigated for crystallization, chemical bonds, composition and distribution of elements by scanning electron microscopy [SEM], X-ray diffraction [XRD], Fourier transform infrared spectroscopy [FTIR], carbon/sulfur analysis, X-ray photoelectron spectroscopy [XPS] and SEM/EDS analysis. The particles produced by the above-mentioned method were regular and nearly spherical in shape. The results of topographical analysis of a cross-section showed that form of the microspheres had formed a 'boiled egg' structure. This method has an advantage over other methods in that the process does not require high temperatures. This paper reports on a novel method to produce yttrium glass microspheres. The resulting microspheres were formed with a silicon crust so the proposed method is expected to be suitable for application in the production of radioactive seed sources for implantation in tumors and cancer tissue

Effect of silica coating and silane surface treatment on the bond strength of soft denture liner to denture base material

OBJECTIVE: This study investigated the effects of different surface treatments on the tensile bond strength of an autopolymerizing silicone denture liner to a denture base material after thermocycling. MATERIAL AND METHODS: Fifty rectangular heat-polymerized acrylic resin (QC-20) specimens consisting of a set of 2 acrylic blocks were used in the tensile test. Specimens were divided into 5 test groups (n=10) according to the bonding surface treatment as follows: Group A, adhesive treatment (Ufi Gel P adhesive) (control); Group S, sandblasting using 50-µm Al2O3; Group SCSIL, silica coating using 30-µm Al2O3 modified by silica and silanized with silane agent (CoJet System); Group SCA, silica coating and adhesive application; Group SCSILA, silica coating, silane and adhesive treatment. The 2 PMMA blocks were placed into molds and the soft lining materials (Ufi Gel P) were packed into the space and polymerized. All specimens were thermocycled (5,000 cycles) before the tensile test. Bond strength data were analyzed using 1-way ANOVA and Duncan tests. Fracture surfaces were observed by scanning electron microscopy. X-ray photoelectron spectrometer (XPS) and Fourier Transform Infrared spectrometer (FTIR) analysis were used for the chemical analysis and a profilometer was used for the roughness of the sample surfaces. RESULTS: The highest bond strength test value was observed for Group A (1.35±0.13); the lowest value was for Group S (0.28±0.07) and Group SCSIL (0.34±0.03). Mixed and cohesive type failures were seen in Group A, SCA and SCSILA. Group ...

Effect of magnesium and calcium phosphate coatings on osteoblastic responses to the titanium surface

PURPOSE: The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium. MATERIALS AND METHODS: Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed. RESULTS: Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group. CONCLUSION: Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.

Zinc ion implantation-deposition modification of titanium for enhanced adhesion of focal plaques of osteoblast-like cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Surface modification by ion implantation-deposition is well established in materials science and can be an effective way to improve biocompatibility. The aim of this study is to evaluate the chemical composition of a modified titanium (Ti) surface after zinc (Zn) ion implantation and deposition and examine the effect of the modification on the formation of cellular focal adhesion plaques in vitro.</p><p><b>METHODS</b>cp-Ti discs were modified with Zn ion implantation and deposition via PIIID. The chemical composition of the surface modification was characterized by X-ray photoelectron spectroscopy (XPS). The formation of focal adhesion plaques on the modified Ti was investigated with human osteoblast-like MG-63 cells that were seeded onto the Ti surfaces and quantified by morphometric analysis under a confocal microscope.</p><p><b>RESULTS</b>XPS data revealed that the modified Zn-Ti surface consisted of Ti, oxygen, Zn, and carbon. In addition, Gaussian fitting of the spectra indicated that the modified surface contained titanium dioxide and zinc oxide. After 6 hours of MG-63 cell culture, there were significantly more focal adhesion plaques on the modified surfaces than observed on the nonmodified Ti (P < 0.05).</p><p><b>CONCLUSION</b>Zn ion implantation and deposition greatly improved the biocompatibility of Ti for the growth of MG-63 cells.</p>

Surface characteristics and bioactivity of an anodized titanium surface

PURPOSE: The aim of this study was to evaluate the surface properties and biological response of an anodized titanium surface by cell proliferation and alkaline phosphatase activity analysis. METHODS: Commercial pure titanium (Ti) disks were prepared. The samples were divided into an untreated machined Ti group and anodized Ti group. The anodization of cp-Ti was formed using a constant voltage of 270 V for 60 seconds. The surface properties were evaluated using scanning electron microscopy, X-ray photoelectron spectroscopy, and an image analyzing microscope. The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were analyzed. Cell adhesion, cell proliferation, and alkaline phosphatase activity were evaluated using mouse MC3T3-E1 cells. RESULTS: The anodized Ti group had a more porous and thicker layer on its surface. The surface roughness of the two groups measured by the profilometer showed no significant difference (P>0.001). The anodized Ti dioxide (TiO2) surface exhibited better corrosion resistance and showed a significantly lower contact angle than the machined Ti surface (P>0.001). Although there was no significant difference in the cell viability between the two groups (P>0.001), the anodized TiO2 surface showed significantly enhanced alkaline phosphatase activity (P<0.001). CONCLUSIONS: These results suggest that the surface modification of Ti by anodic oxidation improved the osteogenic response of the osteoblast cells.

Effect of Electron-beam Irradiaton on the Artificial Bone Substitutes Composed of Hydroxyapatite and Tricalcium Phosphate Mixtures with Type I Collagen

Porous Polyurethane Scaffold as a Tracheal Prosthesis Material / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The purpose of this study was to confirm the usefulness of the porous polyurethane scaffold as a tracheal prosthesis for repair of partial tracheal defect. SUBJECTS AND METHOD: A porous polyurethane (PU) scaffold was manufactured by salt-leaching method. Polyethylene glycol (PEG) was grafted onto the surface of the PU scaffold following surface ozonation treatment. Scanning electro-microscopy (SEM) was then performed to evaluate the morphklogy. For the biocompatibility evaluation, a 5x5 mm sized PU scaffold was implanted into the rabbit's ear. A histological examination was performed with the tissue one month later. Polymerase chain reaction for tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, procollagen, fibromodulin, fibronectin, and actin was also performed. The tensile strength was measured and compared with beagle's trachea to evaluate the mechanical property of the prosthesis. RESULTS: The effect of ozonation and surface grafting with PEG was on the porous scaffold was confirmed by SEM and X-ray photoelectron spectroscopy. The histological examination showed a large amount of fibrous tissue and capillary had grown through the pores of the porous scaffold. The inflammatory reaction was not so severe. TNF-alpha and IL-6 were slightly elevated in the PU scaffold transplanted tissue. However, the concentration levels of the other cytokines were similar between transplanted tissue and normal tissue. The tensile strength was very similar with the beagle's normal trachea. CONCLUSION: The polyethylene grafted polyurethane scaffold is a good candidate prosthesis for tracheal reconstruction.

Studies on the saliva adsorption and the salivary film property on the hydroxyapatite surface / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the thickness and viscoelasticity of whole saliva (WS), parotid saliva (PS) and submandibular/sublingual gland saliva (SMSLS) film adsorption on the hydroxyapatite (HA) surface.</p><p><b>METHODS</b>Ultra-thin layer of HA nanocrystals was coated on the dissipation TiO(2) sensor of gold quartz crystal microbalance using electrophoretic deposition technique. The thickness of the HA layer was measured by the ellipsometer, and element analysis was conducted using X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscope were used to observe its morphology. The in-situ adsorption thickness, the shear elastic modulus and the shear viscosity of salivary layers (WS, PS and SMSLS) on HA surfaces were investigated. The statistical data were analysed by an one-way ANOVA analysis followed by a SNK-q test.</p><p><b>RESULTS</b>The results show that the HA layer was a plate-like morphology with 1.53 ± 0.12 in Ca/P molar ratio, (19.1 ± 0.9) nm in the thickness and (6.5 ± 1.6) nm in the roughness. The thickness of salivary film was SMSLS [(21.84 ± 1.25) nm] > WS[(17.91 ± 1.35) nm] > PS [(14.30 ± 1.03 nm) (P < 0.05). The shear elastic modulus of salivary film was PS [(0.61 ± 0.01) MPa] > SMSLS [(0.31 ± 0.09) MPa] and WS [(0.25 ± 0.03) MPa] (P < 0.05). The trend of the shear viscosity was opposite to one of thickness.</p><p><b>CONCLUSIONS</b>The characteristics of saliva adsorption on HA surface suggest that the thicker, softer and more hydrated properties for the SMSLS and WS films are likely to afford a stronger lubrication to protect oral surfaces from wear and dehydration. The viscoelasticity of the PS film is probably related to the retention covering the oral cavity.</p>