bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abrasion resistance of medical glove materials
Authors: Walsh Donna L. , Schwerin Matthew R. , Kisielewski Richard W. , Kotz Richard M. , Chaput Maria P. , Varney George W. , To Theresa M. 
Published: December 2003

AbstractDue to the increasing demand for nonlatex medical gloves in the health‐care community, there is a need to assess the durability of alternative glove materials. This study examines durability characteristics of various glove materials by abrasion resistance testing. Natural rubber latex (latex), polyvinyl chloride (vinyl), acrylonitrile butadiene (nitrile), polychloroprene (neoprene), and a styrene‐ethylene/butylene‐styrene block copolymer (SEBS) were tested. All test specimens, with the exception of the vinyl, were obtained from surgical gloves. Unaged out‐of‐the‐box specimens as well as those subjected to various degrees of artificial aging were included in the study. After the abrasion sequence, the barrier integrity of the material was assessed through the use of a static leak test. Other traditional tests performed on these materials were viral penetration to validate the abrasion data and tear testing for comparative purposes. The results indicate that specific glove‐material performance is dependent upon the particular test under consideration. Most notably, abrasion, even in controlled nonsevere conditions, may compromise to varying degrees the barrier integrity of latex, vinyl, SEBS, nitrile, and neoprene glove materials. However, as evidenced by the results of testing three brands of neoprene gloves, the abrasion resistance of any one glove material may be significantly affected by variations in production processes. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 81–87, 2004
Factors affecting the structure and properties of bioactive foam scaffolds for tissue engineering
Authors: Jones Julian R. , Hench Larry L. 
Published: December 2003

AbstractResorbable 3D macroporous bioactive scaffolds have been produced for tissue‐engineering applications by foaming sol‐gel–derived bioactive glasses of the 58S (60 mol% SiO2, 36 mol% CaO, 4 mol% P2O5) composition with the aid of a surfactant. Bioactive glasses are known to have the ability to regenerate bone, and to release ionic biological stimuli that promote bone‐cell proliferation by gene activation. The foams exhibit a hierarchical structure, with interconnected macropores (10–500 μm), which provide the potential for tissue ingrowth and mesopores (2–50 nm), which enhance bioactivity and release of ionic products. Many factors in the sol‐gel and foaming processes can be used to control these pore sizes and distributions. This work concentrates on the effect of the processing temperature, gelling agent concentration, and the amount of water used for the foam generation on the structure, pore morphology, and the properties of the foam scaffold. The simplest and most reproducible method for controlling the modal pore diameter was by the amount of water added during the foaming process. The in vitro dissolution and bioactivity of the bioactive foams were compared to that of unfoamed monoliths and powders (< 20 μm in diameter) of the same composition. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 36–44, 2004
Tendon surface modification by chemically modified HA coating after flexor digitorum profundus tendon repair
Authors: Yang Chao , Amadio Peter C. , Sun Yu‐long , Zhao Chunfeng , Zobitz Mark E. , An Kai‐Nan 
Published: December 2003

AbstractCarbodiimide derivatized HA (cd‐HA) is less soluble in water than normal HA, and therefore has an increased tissue residence time. The purpose of this study was to study the effect of cd‐HA gel on gliding and repair integrity during simulated repetitive motion of a repaired tendon in vitro. A total of 36 flexor digitorum profundus (FDP) tendons from six adult mongrel dogs were used and divided into three groups of control, simple HA, and cd‐HA. The gliding resistance between the FDP and the proximal pulley, FDS, and bone was measured before laceration and after modified Kessler technique repair at 1, 5, 10, 50, 100, 200, 300, 400, and 500 cycles. After gliding testing, failure load, tendon stiffness, and resistance to gap formation were measured. The results showed from the first cycle to the 10th cycle, there were no significant differences in gliding resistance between the three testing groups (p > 0.05). From the 50th cycle onwards, the friction was significantly lower in the cd‐HA gel group than in the control group (p < 0.05). Neither breaking strength, nor tendon stiffness, nor resistance to gap formation of the repairs were significantly different between the three groups (p > 0.05). © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 15–20, 2004
Does low‐intensity pulsed ultrasound stimulate maturation of tissue‐engineered cartilage?
Authors: Duda Georg N. , Kliche Alexander , Kleemann Ralf , Hoffmann Jan E. , Sittinger Michael , Haisch Andreas 
Published: December 2003

AbstractTraumatic events are a primary cause of local lesions of articular cartilage. Tissue engineered, cartilage‐like structures represent an alternative to current treatment methods. The time necessary for tissue maturation and the mechanical quality of the regenerate at implantation are both critical factors for clinical success. Low‐intensity pulsed ultrasound has proven to accelerate chondrogenesis in vitro. The goal of this study was to evaluate whether low‐intensity pulsed ultrasound is capable of accelerating the process of cartilage maturation and increasing regenerate stability. Hyaline‐like cartilage specimens were generated in vitro and subcutaneously implanted in the backs of nude mice. Twenty‐eight animals received 20 min of low‐intensity pulsed ultrasound treatment daily, and 28 animals received a sham treatment. Specimens were explanted after 1, 3, 6, and 12 weeks, mechanically tested with the use of an indentation test, histologically examined, and processed for RT‐PCR. The Young's moduli significantly increased from 3 to 12 weeks, and at 6 weeks were comparable to those of native articular cartilage. In histological examination, specimens showed neocartilage formation. There was no significant difference between ultrasound‐treated and sham‐treated groups. The mechanical stability of the neocartilage specimens increased with treatment time and reached values of native cartilage after 6 weeks in vivo. Low‐intensity pulsed‐ultrasound stimulation showed no stimulatory effect on tissue maturation. In contrast, ultrasound‐treated specimens showed a reduced Col 2 expression at 1 week and were significantly less stiff compared to native cartilage at 6 and 12 weeks. An acceleration of the maturation of tissue‐engineered neocartilage in a clinical setting by means of low‐intensity pulsed ultrasound therefore appears rather unrealistic. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 21–28, 2004
Attachment of artificial cartilage to underlying bone
Authors: Ushio Kazuyasu , Oka Masanori , Hyon Suong‐Hyu , Hayami Takashi , Yura Shigeto , Matsumura Kazuaki , Toguchida Junya , Nakamura Takashi 
Published: December 2003

AbstractThe key problem with artificial joint materials is obtaining quick and firm attachment onto the underlying bone. In developing artificial articular cartilage, composed of polyvinyl alcohol hydrogel (PVA‐H), this problem was solved by using a composite osteo‐chondral device (COD). This enables attachment within four weeks post‐operation by massive bone ingrowth into the pores. The COD consists of PVA‐H as an artificial cartilage and titanium fiber mesh (TFM) as porous artificial bone. In this study, the strength of the shear resistance force at the interface of the PVA‐H and the TFM fabricated by injection molding and the changes in the mechanical properties of the PVA‐H fabricated by high temperature during the injection‐molding process were examined. The shear resistance force was strengthened markedly by using injection molding and no important deterioration of the PVA‐H was found. Morphological examination of canine spines, to which artificial intervertebral discs made of the COD were implanted, showed good bonding of the COD with the vertebral bodies for an extended period of 30 months, and encouraged us to use the COD clinically. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 59–68, 2004
The effects of lubricant composition on in vitro wear testing of polymeric acetabular components
Authors: Wang A. , Essner A. , Schmidig G. 
Published: December 2003

AbstractLubricant composition is known to affect in vitro (simulator) wear of polymeric acetabular components. Clinical acetabular components, fabricated from both ultrahigh molecular weight polyethylene (UHMWPE) and polytetrafluoroethylene (PTFE), were tested against cobalt–chromium 32‐mm ball heads, with the use of various lubricants, with different compositions and concentrations of bovine and calf serum as well as hyaluronic acid, in tests which lasted one million cycles. The type of proteins and their relative concentration in the lubricant affected the wear rate of both UHMWPE and PTFE. Increasing protein concentration reduced the UHMWPE wear rate but increased the PTFE wear rate. For a given total protein concentration, increasing the albumin/globulin (A/G) ratio led to a significant reduction in the wear rate for PTFE. A similar but smaller effect was found for UHMWPE. The relative wear‐rate ratio between PTFE and UHMWPE depends on both the total protein concentration and the specific protein concentration (albumin/globulin ratio). The average clinical wear rates for both PTFE and UHMWPE and the average wear‐rate ratios between them were reproduced when the serum lubricant contained total protein concentration and A/G ratio within normally observed physiological ranges. It is recommended that lubricants for simulator testing be standardized to control total protein content as well as albumin/globulin ratio. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 45–52, 2004
Deproteinizing effects on resin–tooth bond structures
Authors: Yoshida Eiji , Hashimoto Masanori , Hori Minoru , Kaga Masayuki , Sano Hidehiko , Oguchi Haruhisa 
Published: December 2003

AbstractThis study investigated the effects of NaOCl on resin–tooth bonds to simulate the situations of long‐term durability and caries invasion. Resin–tooth bonded specimens were produced with the use of two resin adhesives (Excite and One‐Bond). Resin–tooth bonded beams (adhesive area; 0.9 mm2) were serially sectioned and the specimens were immersed in 10% NaOCl medium for 0 (control), 2, 4, and 6 h after being stored in water for 24 h. After immersion, microtensile bond tests were performed. SEM fractography was conducted to calculate each failure mode by image analysis. In addition, the adhesive interface was examined with the use of TEM. In the control specimens, enamel bond strengths had no difference between Excite (45.6 ± 15.0) and One‐Bond (56.9 ± 12.9). On the other hand, dentin bond strengths had significant difference between Excite (80.6 ± 21.2) and One‐Bond (50.7 ± 11.2). The bond strengths decreased with increased storage time for both systems with enamel and dentin bonds. The deteriorated mineralized dentin of beams resulted in bond‐strength reduction for resin–enamel bonds. For dentin bonding, the adhesive interface was gradually dissolved from the outer to the center portion of the beam. The depletion of collagen fibrils within the demineralized dentin or hybrid layer deformation was found under SEM and TEM examinations. These morphological changes are responsible for bond strength reduction of resin‐dentin bonds. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 29–35, 2004
Comparison of Th1/Th2 cytokine profiles of initial wound healing of rats induced by PDCM and e‐PTFE
Authors: Lu Hsein‐Kun , Ko Meng‐Tsung , Wu Ming‐Fang 
Published: December 2003

AbstractBecause periodontal regeneration is vital in the modern treatment of periodontal defects, artificial membranes have become a key component for predictable outcomes. Herein a new ranking system to analyze the expression of different cytokines around regenerative membranes is introduced. Porcine dermal collagen membranes (PDCMs) and GORE‐TEX® (e‐PTFE) membranes were used for implantation in a Sprague Dawley rat model. Tissue samples were harvested at three time intervals (7, 10, and 14 days); then an immunohistochemical ranking process was conducted to determine the intensity of the selected Th1/Th2 cytokines [Th1: interleukin‐2 (IL‐2) and interferone‐γ (IFN‐γ); Th2: IL‐4, IL‐10, and IL‐13]. The results show that the intensities of IL‐2 cytokine in PDCM groups were slightly higher than those of e‐PTFE groups but without statistical significance. The level of interferon‐γ in PDCM groups was lower than that of e‐PTFE groups, but also without significant differences. However, expressions of Th2 cytokines (IL‐4, IL‐10, and IL‐13) induced by e‐PTFE were generally higher than those of PDCM and control groups at all times (Mann‐Whitney U test, p < 0.05). In a comparison of the mean ratio of IL‐2/IL‐4 with the use of the Mann‐Whitney U test, data for the PDCM group were generally higher than those of the e‐PTFE group, with statistical significance at all time intervals (p < 0.05). A descending order of the intensity ratio of IL‐2/IL‐4 was PDCM groups > control groups > e‐PTFE groups. These findings indicate that the cytokine profiles of PDCM, in connection with the GTR technique, demonstrate a higher trend toward Th1‐dominated responses and may protect against periodontal tissue destruction, as compared to the Th2‐dominated responses of e‐PTFE. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 75–80, 2004
Platelet adhesion and aggregation on polyethylene: Effect of exhaustive exercise
Authors: Bonifazi Marco , Aloisi Anna Maria , Ceccarelli Ilaria , Lamponi Stefania , Lodi Leda , Scaramuzzino Andrea , Stabile Elena , Lupo Concetta 
Published: December 2003

AbstractThe aim of the present study was to evaluate the effect of an exhaustive exercise on platelet adhesion and aggregation on polyethylene (PE) in relation to changes in plasma cortisol concentration in order to ascertain the effect of physical stress response in the blood‐contacting properties of polymeric materials. Twelve healthy sedentary subjects, six males and six females, were studied. Each subject performed an exercise test on a bicycle ergometer at intensity corresponding to 70% VO2 max until exhaustion. One month after the exercise session, each subject participated in a control rest session. In both sessions, blood samples were drawn every 5 min for cortisol, lactate, hemoglobin, and hematocrit determinations and every 15 min for evaluation of platelet adhesion and aggregation. Individual comparisons between the rest and exercise cortisol patterns identified three categories of cortisol responders to exercise: positive responders (C +, showing higher concentrations during exercise than during rest), negative responders (C −, showing lower concentrations during exercise than during rest), and nonresponders (NR, showing similar concentrations during exercise and rest). The results revealed that C + had lower platelet adhesion and aggregation scores during exercise than during rest; moreover C − had higher scores than C + and NR during exercise. The results obtained demonstrated no effects of sex or exercise on either cortisol plasma levels or platelet adhesion and aggregation on PE surface. With regard to cardiovascular risk, the results suggest that exercise favorably affects platelet functions when mechanisms of metabolic adaptation to prolonged muscular work, expressed by a cortisol increase, are activated during exercise. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 53–58, 2004
Chemical, structural properties, and osteoconductive effectiveness of bone block derived from porcine cancellous bone
Authors: Kim Su‐Hyang , Shin Jung‐Wook , Park Su‐A , Kim Young Kon , Park Mun Soo , Mok James M. , Yang Woo Ick , Lee Jin Woo 
Published: December 2003

AbstractThe purpose of this study is to determine the efficacy of bioactive calcium phosphate obtained from porcine cancellous bone for the treatment of bone defects and nonunion. Porcine cancellous bone blocks were heat treated at 1300 °C for 2 h. The chemical composition, calcium‐to‐phosphate ratio, and microstructure of the porcine bone blocks were examined. For in vivo implantation, bone defects were created on the anteromedial aspect of the proximal tibia in seven beagle dogs and the xenograft bone blocks were placed into these defects. Plain radiographs were taken at 2‐week intervals for roentgenographic evaluation. At 12 weeks, the specimens were stained with hematoxylin and eosin (H&E). The composition and morphology of heat‐treated porcine cancellous bone were found to be similar to heat‐treated human cancellous bone. Radiographs showed union between the host bone/bone‐block interfaces. At 12 weeks, uniform and substantial new bone formation was observed. It is concluded that heat‐treated porcine cancellous bone demonstrated effective osteoconductivity. This high‐temperature heat‐treatment technique has several advantages, including decreased risk of disease transmission and immunoreactivity, while also offering excellent biocompatibility. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 69–74, 2004
Porous Ti‐6Al‐4V alloy fabricated by spark plasma sintering for biomimetic surface modification
Authors: Kon Masayuki , Hirakata Luciana M. , Asaoka Kenzo 
Published: December 2003

AbstractPorous compacts with both biological and biomechanical compatibilities and high strength were developed. Spherical powders of Ti‐6Al‐4V alloy, which were either as received or surface modified with the use of calcium ions by hydrothermal treatment (HTT), were fabricated by a spark plasma sintering process. The porous compacts of pure Ti were used as reference materials. Porosity was approximately 30%, and compressive strengths were 113 and 125 MPa for the as‐received Ti alloy powders and those modified by the HTT process, respectively. The bending strength and elastic modulus of as‐received Ti alloy powders were 128–178 MPa and 16–18 GPa, respectively. Each of the compacts was immersed in simulated body fluid (SBF). The amount of adsorption/precipitation of calcium phosphate through the compacts was measured by weight change and was observed by SEM. The compacts were covered with calcium phosphate after 2 weeks of immersion in SBF. The compacts of Ti alloy had plenty of precipitated apatite crystals, and modification by HTT accumulated more precipitation. Because calcium phosphate is a mineral component of bone, apatite, which is precipitated on the surface of the compacts, could adsorb proteins and/or drugs such as antibiotics. It is expected that a large amount of proteins and/or drugs could be impregnated when the porous compacts developed are used. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 88–93, 2004
Injectable acrylic bone cements for vertebroplasty with improved properties
Authors: Carrodeguas Raúl García , Lasa Blanca Vázquez , del Barrio Julio San Román 
Published: December 2003

AbstractCurrently commercially available acrylic bone cements lack adequate radiopacity and viscosity when they are used in percutaneous vertebroplasty (PVP). In this work improved formulations of radiopaque and injectable poly(methyl methacrylate) bone cements were prepared with different amounts (10–50 wt.%) of BaTiO3 or SrTiO3 particles as the radiopaque agent. Two sets of cements were prepared by using untreated or silanated radiopaque particles, respectively. The influence of the content and nature of the radiopaque agent as well as its silanation with 3‐(trimethoxysilyl) propyl methacrylate (γ‐MPS), on the curing parameters, residual monomer content, radiopacity, mechanical properties, and injectability of the resulting materials, was examined. Doughing and setting times, maximum temperature, and compressive strength of all formulations fulfilled the requirements of standard specifications, with values of peak temperature in the range 57–72 °C and those of compressive strength between 114 and 135 MPa. Formulations containing at least 20 wt.% BaTiO3 or SrTiO3 had radiopacities equal to or greater than that corresponding to 2 mm of Al as required for surgical plastics. Injectability of any of the formulations provided 75–80 wt.% of the total mass manually injected through a conventional biopsy needle 4 min after mixing. Silanation of the BaTiO3 or SrTiO3 particles led to formulations with improved mechanical properties and injectability compared to those obtained with the untreated fillers. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 94–104, 2004
Influence of mixing method on the cement temperature‐mixing time history and doughing time of three acrylic cements for vertebroplasty
Authors: Baroud G. , Samara M. , Steffen T. 
Published: December 2003

AbstractAcrylic cements are increasingly being used to augment osteoporotic vertebrae in a procedure called vertebroplasty. Two significant factors that may complicate the use of acrylic cements are: (a) short handling time, which may result in insufficient filling of the vertebra; and (b) exothermic setting (curing) behavior, which may result in thermal damage of the surrounding tissue. It has been previously reported1 that mixing the cement components under oscillation, as compared to manual mixing, increases the handling time. More specifically, it seems that oscillatory mixing slows down the cement polymerization process and, consequently, widens the time window during which cement is injectable. However, the effect of oscillatory mixing on the exothermic setting behavior of cement undergoing polymerization has not been examined. In this study, the exothermic setting behavior of three commercially available acrylic cements— Antibiotic Simplex®, DP‐Pour&trade, and Vertebroplastic™—were examined for both manual and oscillatory mixing methods. For each combination of cement and mixing method, the parameters that were measured were the exothermic setting curve (and hence the cement setting temperature and setting time) and the cement doughing time. It was found that oscillatory mixing had no significant effect on any of these parameters. Based on the results of this study, it can be concluded that, for the tested cements, the setting process is a reaction‐controlled process rather than a diffusion‐controlled one. Clinically, this implies that oscillatory mixing may be used to increase the working period for acrylic cements without increasing the risk of thermal damage to surrounding tissue. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 68B: 112–116, 2004