bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo response of porous hydroxyapatite and β‐tricalcium phosphate prepared by aqueous solution combustion method and comparison with bioglass scaffolds
Authors: Ghosh Samir K. , Nandi Samit K. , Kundu Biswanath , Datta Someswar , De Dipak K. , Roy Sujit K. , Basu Debabrata 
Published: December 2007

AbstractPure hydroxyapatite (HAp) and a biphasic calcium phosphate [containing 90% of β‐tri‐calcium phosphate (β‐TCP) and 10% HAp] were tailored through an aqueous solution combustion synthesis. Porous struts were prepared using all the powders along with bioglass, a known bioactive material, and subsequently characterized. Sterilized struts were implanted to the lateral side of radius bone of 24 black Bengal goats of either sex, in which a blank hole was left unfilled in a group of six specimens to act as control. The bone formation response of the three implanting materials in vivo has been studied using scanning electron microscope and histological analysis in contrast with positive controls. Push‐out tests were used to assess the mechanical strength at the bone–biomaterial interface. It was observed that interfacial response was strongly dependent on combinations of different physical and chemical parameters. The surface of β‐TCP exhibited similar characteristics of bone and was distinct from those of intervening apatite layer of bioglass. Lower bone ingrowth and reduced strength was observed with HAp compared to β‐TCP/bioglass‐based implants. Bone formation response of the Ca‐P material varied according to the composition of the implanting material, which could be tailored through this novel synthesis. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Adhesion to chondroitinase ABC treated dentin
Authors: Mazzoni Annalisa , Pashley David H. , Ruggeri Alessandra , Vita Francesca , Falconi Mirella , Di Lenarda Roberto , Breschi Lorenzo 
Published: December 2007

AbstractDentin bonding relies on complete resin impregnation throughout the demineralised hydrophilic collagen mesh. Chondroitin sulphate‐glycosaminoglycans are claimed to regulate the three‐dimensional arrangement of the dentin organic matrix and its hydrophilicity. The aim of this study was to investigate bond strength of two etch‐and‐rinse adhesives to chondroitinase ABC treated dentin. Human extracted molars were treated with chondroitinase ABC and a double labeling immunohistochemical technique was applied to reveal type I collagen and chondroitin 4/6 sulphate distribution under field emission in‐lens scanning electron microscope. The immunohistochemical technique confirmed the effective removal of chondroitin 4/6 sulphate after the enzymatic treatment. Dentin surfaces exposed to chondroitinase ABC and untreated specimens prepared on untreated acid‐etched dentin were bonded with Adper Scotchbond Multi‐Purpose or Prime and Bond NT. Bonded specimens were submitted to microtensile testing and nanoleakage interfacial analysis under transmission electron microscope. Increased mean values of microtensile bond strength and reduced nanoleakage expression were found for both adhesives after chondroitinase ABC treatment of the dentin surface. Adper Scotchbond Multi‐Purpose increased its bond strength about 28%, while bonding made with Prime and Bond NT almost doubled (92% increase) compared to untreated specimens. This study supports the hypothesis that adhesion can be enhanced by removal of chondroitin 4/6 sulphate and dermatan sulphate, probably due to a reduced amount of water content and enlarged interfibrillar spaces. Further studies should validate this hypothesis investigating the stability of chondroitin 4/6 and dermatan sulphate‐depleted dentin bonded interface over time. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Iodine inhibits antiadhesive effect of PEG: Implications for tissue engineering
Authors: Macario Danielle K. , Entersz Ildiko , Bolikal Durgadas , Kohn Joachim , Nackman Gary B. 
Published: December 2007

AbstractBackground:The success of a biomaterial implant may be affected by the surface chemistry's impact on protein adsorption. We have developed a series of poly(ethylene glycol) (PEG) containing, tyrosine‐derived polycarbonates, which have been rendered radio‐opaque by the iodination of tyrosine units in the copolymer backbone for use in resorbable biomedical implants including vascular stents and grafts. We tested the hypothesis that protein adsorption along with seeding, growth, and migration of human aortic smooth muscle cells (SMC) and human aortic endothelial cells (EC) will be modified by the presence of iodine and PEG within the polymer composition.Methods:Thin films of these polymers were prepared for the protein‐material and cell‐material interaction studies. Dot blot, SDS‐PAGE, and XPS were used to evaluate relative protein adsorption. Cell adhesion and growth studies were performed using an MTS assay. Cell migration was evaluated using an injury model.Results:The presence of PEG attenuated protein adsorption, cell adhesion, and growth. With the subsequent incorporation of iodine, protein adsorption markedly increased while the antiadhesive effect of PEG was counteracted by iodine for EC and SMC adhesion and SMC growth.Conclusion:Iodine incorporation into the polymer resulted in increased protein adsorption thus counteracting the effect of PEG. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Mechanical property, degradation rate, and bone cell growth of chitosan coated titanium influenced by degree of deacetylation of chitosan
Authors: Yuan Youling , Chesnutt Betsy M. , Wright Lee , Haggard Warren O. , Bumgardner Joel D. 
Published: December 2007

AbstractChitosan has shown promise as a coating for dental/craniofacial and orthopaedic implants. However, the effects of degree of deacetylation (DDA) of chitosan on coating bond strength, degradation, and biological performance is not known. The aim of this project was to evaluate bonding, degradation, and bone cell growth on titanium coated with chitosans of different DDA and from different manufacturers. Three different chitosans, 80.6%, 81.7%, and 92.3% DDA were covalently bonded to titanium coupons via silane‐glutaraldehyde molecules. Bond strengths were evaluated in mechanical tensile tests, and degradation, over 5 weeks, was conducted in cell culture medium with and without 100 μg/mL lysozyme. Cytocompatibility was evaluated for 10 days using UMR 106 osteoblastic cells. Results showed that mean chitosan coating bond strengths ranged from 2.2–3.8 MPa, and that there was minimal affect of DDA on coating bond strengths. The coatings exhibited little dissolution over 5 weeks in medium with or without lysozyme. However, the molecular weight (MW) of the chitosan coatings remaining on the titanium samples after 5 weeks decreased by 69–85% with the higher DDA chitosan coatings exhibiting less percent change in MW than the lower DDA materials. The growth of the UMR 106 osteoblast cells on the 81.7% DDA chitosan coating was lower on days 3 and 5, as compared with the other two coatings, but by day 10, there were no differences in growth among three coatings or to the uncoated titanium controls. Differences in growth were attributed to differences in manufacturer source material, though all coatings were judged to be osteocompatible in vitro. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Fatigue crack propagation rates in PMMA bone cement cannot be reduced to a single power law
Authors: Race Amos , Mann Kenneth A. 
Published: December 2007

AbstractCement mantles around metallic implants have pre‐existing flaws (shrinkage induced cracks, laminations, and endosteal surface features) and their fatigue failure is related to the fatigue crack propagation (FCP) rate of bone cement. We estimated the relevant in vivo range of cyclic stress intensity factor (ΔK) around a generic femoral stem (0–1 MPa √m) and determined that previous FCP data did not adequately cover this range of ΔK. Vacuum‐mixed standard bone cement was machined into ASTM E647 standard compact notched tension specimens. These were subject to sinusoidal loading (R = 0.1) at 5 Hz in 37°C DI water, covering a ΔK range of 0.25–1.5 MPa √m (including a decreasing ΔK protocol). FCP‐rate data is normally reduced to a power‐law fit relating crack growth rate (da/dn) to ΔK. However, a substantial discontinuity was observed in our data at around ΔK = 1, so two power‐law fits were used. Over the physiologically plausible range of ΔK, cracks grew at a rate of 2.9 E −8 × ΔK2.6 m/cycle. Our data indicated that FCP‐rates for 0.5 > ΔK > 0.3 MPa √m are between 10 E −8 and 10 E −8 m/cycle, 1 or 2 orders of magnitude greater than predicted by extrapolating from previous models based on higher ΔK data. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Effect of temporary filling materials on repair bond strengths of composite resins
Authors: Erdemir Ali , Eldeniz Ayce Unverdi , Belli Sema 
Published: December 2007

AbstractEndodontic access cavities sometimes can be prepared through a permanent composite restoration. Between the appointments, temporary cements are used to seal access cavities and may have negative effect on bonding of further composite restoration. The purpose of this study was to compare shear bond strength of composite to composite which had been in contact with various temporary filling materials. Standard cavities were prepared on 160 acrylic resin blocks, obturated with composite resin (Clearfil AP‐X, Kuraray, Japan) and randomly divided into eight groups (n = 20). Group 1 received no treatment. From group 2–8, composite surfaces were covered with the following cements temporarily: Zinc‐oxide/calcium‐sulphate (Cavit‐G, ESPE, Germany), two different Zinc‐Oxide‐Eugenol materials (ZnOE, Cavex, Holland and IRM, Dentsply, USA), Zinc‐phosphate cement (Adhesor, Spofa‐Dental, Germany), Zinc‐polycarboxylate cement (Adhesor‐Carbofine, Spofa‐Dental, Germany), Glass‐Ionomer‐Cement (Argion‐Molar, Voco, Germany), or light curing temporary material (Clip, Voco, Germany). The cements were removed mechanically after 1 week storage in distilled water at 37°C and composite surfaces were treated with a self‐etch adhesive system (SE‐Bond, Kuraray, Japan). Composite resin build‐ups were created on composite surfaces. Shear bond strength values were measured using universal testing machine at crosshead speed of 1 mm/min. The data was calculated in MPa and statistically analyzed using one‐way ANOVA and Tukey tests. Eugenol‐containing cements significantly reduced shear bond strengths of composite to composite (p < 0.05), while the other temporary materials had no adverse effect on shear bond strength (p > 0.05). These findings suggested that temporary filling materials except eugenol‐containing materials have no negative effect on composite repair bond strengths. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Influences of passivating elements on the corrosion and biocompatibility of super stainless steels
Authors: Yoo Young‐Ran , Jang Soon‐Geun , Oh Keun‐Taek , Kim Jung‐Gu , Kim Young‐Sik 
Published: December 2007

AbstractBiometals need high corrosion resistance since metallic implants in the body should be biocompatible and metal ion release should be minimized. In this work, we designed three kinds of super stainless steel and adjusted the alloying elements to obtain different microstructures. Super stainless steels contain larger amounts of Cr, Mo, W, and N than commercial alloys. These elements play a very important role in localized corrosion and, thus, their effects can be represented by the “pitting resistance equivalent number (PREN).” This work focused on the behavior which can arise when the bare surface of an implant in the body is exposed during walking, heavy exercise, and so on. Among the experimental alloys examined herein, Alloy Al and 316L stainless steels were mildly cytotoxic, whereas the other super austenitic, duplex, and ferritic stainless steels were noncytotoxic. This behavior is primarily related to the passive current and pitting resistance of the alloys. When the PREN value was increased, the passivation behavior in simulated body solution was totally different from that in acidic chloride solution and, thus, the Cr2O3/Cr(OH)3 and [Metal oxide]/[Metal + Metal oxide] ratios of the passive film in the simulated body solution were larger than those in acidic chloride solution. Also, the critical current density in simulated body solution increased and, thus, active dissolution may induce metal ion release into the body when the PREN value and Ni content are increased. This behavior was closely related to the presence of EDTA in the simulated body solution. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Novel extracellular matrix for cell sheet recovery using genetically engineered elastin‐like protein
Authors: Mie Masayasu , Mizushima Yasunori , Kobatake Eiry 
Published: December 2007

AbstractElastin‐like peptides (ELPs) sequences are repeats of the pentapeptide GVGVP, and they have the ability to coaggregate reversibly, depending on the temperature. By exploiting this characteristic, a novel extracellular matrix protein (ECM) containing ELP was developed genetically to harvest a cell sheet from a culture dish. One of the ELP constructs, G288, consisted of 288 repeats of the sequence GVGVGP (G); it was attached to a hydrophobic dish surface. Next, cells with the sequence His‐G36RG36, which has a His tag and an RGD sequence (R) that promotes attachment of the cell between the G36 sequences, consisted of 36 repeats of the sequence GVGVP, were added to the dish. After these cells became confluent, the temperature was changed to 20°C in order to reverse the coaggregation. At this temperature, cells could be detached from the dish as a cell sheet. This genetically engineering method for construction of thermoresponsive ECM would be suitable to modify ECM with further functional domains. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Adhesion of a self‐etching system to dental substrate prepared by Er:YAG laser or air abrasion
Authors: Souza‐Zaroni Wanessa C. , Chinelatti Michelle A. , Delfino Carina S. , Pécora Jesus D. , Palma‐Dibb Regina G. , Corona Silmara A. M. 
Published: December 2007

AbstractThe purpose of this study was to assess the microtensile bond strength of a self‐etching adhesive system to enamel and dentin prepared by Er:YAG laser irradiation or air abrasion, as well as to evaluate the adhesive interfaces by scanning electron microscopy (SEM). For microtensile bond strength test, 80 third molars were randomly assigned to five groups: Group I, carbide bur, control (CB); II, air abrasion with standard tip (ST); III, air abrasion with supersonic tip (SP); IV, Er:YAG laser 250 mJ/4 Hz (L250); V, Er:YAG laser 300 mJ/4 Hz (L300). Each group was divided into two subgroups (n = 8) (enamel, E and dentin, D). E and D surfaces were treated with the self‐etching system Adper Prompt L‐Pop and composite buildups were done with Filtek Z‐250. Sticks with a cross‐sectional area of 0.8 mm2 (±0.2 mm2) were obtained and the bond strength tests were performed. Data were submitted to ANOVA and Tukey's test. For morphological analysis, disks of 30 third molars were restored, sectioned and prepared for SEM. Dentin presented the highest values of adhesion, differing from enamel. Laser and air‐abrasion preparations were similar to enamel. Dentin air‐abrasion with standard tip group showed higher bond strength results than Er:YAG‐laser groups, however, air‐abrasion and Er:YAG laser groups were similar to control group. SEM micrographs revealed that, for both enamel and dentin, the air‐abrasion and laser preparations presented irregular adhesive interfaces, different from the ones prepared by rotary instrument. It was concluded that cavity preparations accomplished by both Er:YAG laser energies and air abrasion tips did not positively influence the adhesion to enamel and dentin. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Polypeptide nanocoatings for preventing dental and orthopaedic device‐associated infection: pH‐induced antibiotic capture, release, and antibiotic efficacy
Authors: Jiang Bingbing , Li Bingyun 
Published: December 2007

AbstractImplant‐associated infection is one of the most common and problematic complications for dental and orthopaedic patients. Modification of currently used implant surfaces aimed at bestowing them with antibacterial properties is a promising approach in the development of new biomaterials. In this study, a novel nanotechnology, that is, electrostatic self‐assembly, was developed to construct biomimetic polypeptide nanocoatings on commonly used metal implants. A model antibacterial drug, cefazolin, was captured in the polypeptide nanocoating and its release was studied. We have shown that the capture and release of cefazolin was pH‐induced and could be controlled, and the developed antibiotic‐incorporated polypeptide multilayer nanocoatings could prevent Staphylococcus aureus colonization thus showing great potential for preventing implant‐associated infection. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The electrochemical behavior and surface analysis of Ti49.6Ni45.1Cu5Cr0.3 alloy for orthodontic usage
Authors: Zheng Y.‐F. , Wang Q. Y. , Li L. 
Published: December 2007

AbstractThe aim of this study was to investigate the electrochemical behavior of Ti49.6Ni45.1Cu5Cr0.3 (TiNiCuCr) alloy in artificial saliva solutions with a wide rage of pH values and to characterize the surface passive film after polarization tests. This article represents the ideal, static environment and associated electrochemical response and comparison values. The corrosion behavior of TiNiCuCr alloy was systematically studied by open circuit potential, potentiodynamic, potentiostatic, and electrochemical impedance techniques. Potentiodynamic and potentiostatic test results showed that the corrosion behavior of TiNiCuCr was similar to that of NiTi alloy. Both corrosion potential (Ecorr) and pitting corrosion potential (Eb) showed a pH‐dependent tendency that Ecorr and Eb decreased with the increase of the pH value. X‐ray photoelectron spectroscopy results revealed the composition of the passive film consisted mainly of TiO2 with a little amount of Ni oxides (NiO/Ni2O3) that was identical with NiTi alloy. Besides Ni, a Cu enriched sub‐layer was also found. The nickel ion release rate showed a typical time‐related decrease as examined by ICP/OES. In conclusion, the addition of Cu and Cr had little effect on the corrosion behavior of NiTi or on the composition and the structure of the passive film. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Effect of keratin‐gelatin and bFGF‐gelatin composite film as a sandwich layer for full‐thickness skin mesh graft in experimental dogs
Authors: Thilagar S. , Jothi N. Arul , Omar A. R. Sheikh , Kamaruddin M. Y. , Ganabadi Shanthi 
Published: December 2007

AbstractSkin grafts are indicated when there is a major loss of skin. Full‐thickness skin graft is an ideal choice to reconstruct defect of irregular surface that is difficult to immobilize. Full‐thickness mesh grafts can be applied to patch large skin defect when there is less donor site in extensively traumatized and burned surgical patients. The concept of using natural biomaterials such as keratin, basic fibroblast growth factor is slowly gaining popularity in the field of medical research to achieve early healing. The main objective of this study is to evaluate the efficacy of gelatin conjoined with keratin processed from the poultry feather and commercially available basic fibroblast growth factor (bFGF) as a sandwich layer in promoting the viability of full‐thickness skin mesh grafts. The efficacy was assessed from the observation of clinical, bacteriological, and histopathological findings in three groups of experimental dogs. The clinical observations such as color, appearance and discharge, and hair growth were selected as criteria which indicated good and early acceptance of graft in keratin‐gelatin (group II). On bacteriological examination, Staphylococcus aureus and Proteus was identified in few animals. Histopathological study of the patched graft revealed early presences of hair follicles; sebaceous gland, and normal thickness of the epidermis in keratin‐gelatin in group II treated animals compared with other group (group I‐control, group III‐bFGF‐gelatin). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Preparation of a bonelike apatite–polymer fiber composite using a simple biomimetic process
Authors: Yokoyama Yoshiro , Oyane Ayako , Ito Atsuo 
Published: December 2007

AbstractA bonelike apatite–polymer fiber composite may be useful as an implant material to replace bone, the enthesis of a tendon, and the joint part of a ligament. We treated an ethylene‐vinyl alcohol copolymer (EVOH) plate and knitted EVOH fibers with an oxygen plasma to produce oxygen‐containing functional groups on their surfaces. The plasma‐treated samples were alternately dipped in alcoholic calcium and phosphate ion solutions three times to deposit apatite precursors onto their surfaces. The surface‐modified samples formed a dense and uniform bonelike surface apatite layer after immersion for 24 h in a simulated body fluid with ion concentrations approximately equal to those of human blood plasma. The adhesive strength between the apatite layer and the sample's surface increased with increasing power density of the oxygen plasma. The apatite–EVOH fiber composite obtained by our process has similarities to natural bone in that apatite crystals are deposited on organic polymer fibers. The resulting composite would possess osteoconductivity due to the apatite phase. With proper polymer selection and optimized synthesis techniques, a composite could be made that would have bonelike mechanical properties. Hence, the present surface modification and coating process would be a promising route to obtain new implant materials with bonelike mechanical properties and osteoconductivity. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Prevention of postoperative adhesions by a novel honeycomb‐patterned poly(lactide) film in a rat experimental model
Authors: Fukuhira Yukako , Ito Masaya , Kaneko Hiroaki , Sumi Yoshihiko , Tanaka Masaru , Yamamoto Sadaaki , Shimomura Masatsugu 
Published: December 2007

AbstractIntraperitoneal adhesion is a serious problem concerning abdominal surgery. This study evaluated the performance of a honeycomb‐patterned poly(lactide) (HCPLA) film as a physical barrier for preventing postoperative adhesion. HCPLA films were prepared using dioleoylphosphatidylethanolamine (DOPE) or a copolymer of dodecylacrylamide and ω‐carboxyhexylacrylamide (CAP) as a surfactant (HCPLA‐DOPE and HCPLA‐CAP, respectively). In an in vivo adhesion prevention experiment, male Sprague‐Dawley rats underwent standard cecum abrasion before midline laparotomy. We placed 2 cm × 2 cm HCPLA and flat films on the gliding interfaces; untreated rats formed the control group. After 1 week, adhesion was scored from 0 to 4. No significant difference was observed in the scores among groups, but macroscopic differences in adhesion prevention were observed. The adhesive strength of HCPLA‐DOPE (18.1 ± 1.2 g) to skinless chicken breast was significantly higher than that of the flat film (15.2 ± 0.8 g, p < 0.05). Further, the adhesion score after 1 week for the HCPLA‐DOPE group (1.6 ± 0.2) was significantly lower than that for the control group (3.0 ± 0.3, p < 0.05) but comparable to that for the Seprafilm™ group (1.4 ± 0.3). These results demonstrated the potential of HCPLA‐DOPE as a physical barrier for preventing postoperative adhesion. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008