bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applied biomaterials standards report
Authors: Daniels A. U. “Dan” 
Published: May 2005

AbstractThe purpose of my column is to provide readers with current information on biomaterials‐related standards produced by both private groups and government agencies, and standards‐related activities. Standards are descriptive documents given official status by their producers, and in the case of biomaterials, they are generally intended to provide formalized descriptions of (a) materials used in the construction of medical devices, (b) materials used directly in surgical repairs, (c) test methods to evaluate materials for such applications, and (d) methods for handling or processing such materials.Please consider this column not only a place to obtain biomaterials standards information but also a place to submit news of biomaterials standards developments in order to get the information before the public. This invitation extends to members of all professional organizations and government agencies in the United States and abroad who are active in standards development and would like specific activities or standards publicized. I will present the information in this column to the extent that allotted space allows.And last, a caveat—since this is a column, it contains both factual information and opinions. I will make every effort to make it clear which is which. Also, as a frame of reference, please note that this column was written and submitted in March 1990.
A method for preparation of etched collagen fibers that support neurite outgrowth
Authors: Wong Eric , Christiansen David , Rizvi Azam , Geller Herbert M. , Silver Frederick H. 
Published: May 2005

AbstractUse of collagenous substrates for growth of attachment‐dependent and attachment‐independent cells have been reported in the literature. Growth of fibroblasts and epithelial cells on collagen sponges and fibers has been previously studied in our laboratory. This article reports the result of studies of neurite outgrowth on etched collagen fibers in cell culture. Collagen fibers with a mean diameter of about 134 μm were etched on glass coverslips using a collagenase solution until individual fibrils of 1 μm in diameter were observed. The kinetics of etching were optimized at a calcium chloride concentration of 5 mM and a collagenase activity of 300 unit/mL. At room temperature an etching time of 10 h maximized the number of fibrils exposed per fiber. Cell culture studies on etched collagen fibers indicate that neurites from rat fetal cortical neurons elongate along the longitudinal axes of collagen fibrils. In some instances the cell body observed was not on top of the collagen fibrils but situated between two parallel fibrils. Results of these experiments indicate that growth of neurites along collagen fibrils in cell culture may be a useful model to evaluate neurite extension in the presence of neurotrophic factors as well as to study optimization of substrates for nerve regeneration.
Performance of the polypropylene fiber tailstring on the copper 7 intrauterine device
Authors: Warner M. S. , Matsuno S. J. , Virgin C. J. , Masterson K. B. , Schneider G. A. , Wright T. E. , Robertson C. R. , Fives‐Taylor P. 
Published: May 2005

AbstractNew and used polypropylene tailstrings from the Copper 7 (Cu‐7) intrauterine device were examined by a combination of analytical techniques. Optical microscopy, scanning acoustic and electron microscopy, x‐ray diffraction, energy dispersive x‐ray analysis, and chemical etching were employed to elucidate both the surface and interior morphology of new Cu‐7 tailstrings. Tailstrings removed from women following varying periods of use were investigated with optical microscopy, scanning and transmission electron microscopy. In addition, a subset of the used tailstrings were cultured to identify the types of microorganisms associated with them. Our findings show that unused Cu‐7 tailstrings are in various stages of degradation owing to a combination of factors which include the high‐draw ratio employed during manufacturing, the method of packaging, and the use of a particulate colourant. Furthermore, it is evident that used Cu‐7 tailstrings undergo major deterioration while in situ because of the unfavorable interactions between the highly drawn polypropylene and the physiological environment. These results indicate that the polypropylene tailstrings as manufactured for use with the Cu‐7 IUD fail to meet accepted design criteria for biomedical implants.
Poly(vinyl alcohol) hydrogel as an artificial articular cartilage: Evaluation of biocompatibility
Authors: Noguchi Takashi , Yamamuro Takao , Oka Masanori , Kumar Praveen , Kotoura Yoshihiko , Hyonyt Suong‐Hyu , Ikadat Yoshito 
Published: May 2005

AbstractWe have developed a new poly(vinyl alcohol) hydrogel (PVA‐H) of increased physical strength through a new manufacturing process. Its mechanical properties have been found to be preferable as a substitute for articular cartilage. To evaluate its biocompatibility as an artificial articular cartilage, a series of in vivo tests within the intraarticular, as well as the intramuscular, environment were conducted. Tissue reactions of cartilage, bone, synovium, and muscle to PVA‐H were studied histologically. In the experimental group, in which PVA‐H was implanted, inflammatory reactions of all of these tissues were very slight. In the control group, in which ultra‐high molecular weight polyethylene (UHMWPE) was implanted, although tissue reactions of bone and muscle were as slight as in the experimental group, those of cartilage and synovium were somewhat more conspicuous. By way of these findings, the better biocompatibility of PVA‐H was documented.
Orthopedic implant devices: Prevalence and sociodemographic findings from the 1988 National Health Interview Survey
Authors: Moore Roscoe M. , Hamburger Stanford , Jeng Lana L. , Hamilton Peggy M. 
Published: May 2005

AbstractNational population‐based estimates on the magnitude and distribution of orthopedic implant devices in the United States have not been available to date. The Food and Drug Administration's Center for Devices and Radiological Health (FDA/CDRH) collaborated with the Centers for Disease Control's National Center for Health Statistics (CDC/NCHS) in the design and conduct of a nationwide medical device implant survey to generate the first national population‐based prevalence estimates of orthopedic implant devices. A Medical Device Implant Supplement to the 1988 National Health Interview Survey was administered in personal household interviews to a national sample of 47,485 households, which included 122,310 individuals.An estimated 6.5 million orthopedic implants were in use in the general US population in 1988, including 1.6 million artificial joints and 4.9 million fixation devices. As a group, orthopedic implants comprised nearly half of all medical device implants in use, 43.4%. The majority of artificial joint recipients were 65 years of age or older, white, and male. the majority of fixation device recipients were less than 45 years of age, white, and male. The limitations and strengths of these population‐based estimates are discussed.
Application of extracorporeal shock wave lithotripter (ECSWL) in orthopaedics. III. In Vitro and In Vivo studies
Authors: Weinstein J. N. , Loening S. , Park J. B. , Park S. H. , Oster D. 
Published: May 2005

AbstractThe present study was conducted to compare the push‐out strength of the treated and control samples obtained after implantation of intramedullary rod in canine femurs with bone cement to simulate the femoral stem implantation for 2 weeks, 3 and 6 months. Contralateral femur served as control. The result showed a significant decrease in push‐out interfacial strength after shock wave treatment (average 48.4% decrease compared with control, p < 0.0001) which is similar to the in vitro results. There was no significant difference if the shock treatment was applied and left for 2 weeks or 4 weeks compared to the ones tested immediately after sacrifice. There were some soft tissue damage immediately following shock treatment in the focal area but this returned to normal in 2 weeks. Human cadaveric femoral bones and the canine bone (the dosage level was higher for the human bone than canine). The number of impacts used to extract the bone cement plug out of a human femur segment (5‐cm long) decreased about 68% at 23 and 25 kV treatment power level. These preliminary studies indicate that the shock wave can be utilized to reduce the interfacial strength of the bone and bone cement although more studies are needed to assess its efficacy in terms of cost, long‐term effect on patients and the exact mechanism of the loosening before this technique can be used clinically.
The effect of thermoforming on the properties of fiber‐reinforced composite wires
Authors: Patel Anil P. , Jon Goldberg A. , Burstone Charles J. 
Published: May 2005

AbstractThe effects of thermoforming on the instantaneous flexural properties and structure of thermoplastic fiber‐reinforced composite (FRC) wires were studied to determine the preferred temperature range for clinical forming. Five different formulations of FRC wires were heated to clinically relevant thermoforming temperatures in a special mold that was designed to maintain their shape. In addition, one formulation was also heated without the restraining effect of the mold. Flexural properties were determined. A temperature above the Tg is necessary to allow sufficient softening and avoidance of distortion in shape during clinical forming. However, higher temperatures will result in significant structural disintegration of the wires with consequent decrease in flexural modulus. Thus, for every material, there is a heating range or “working range” where the material can be properly formed with minimal changes in the physical properties. This was primarily related to the Tg of the matrix used.
Histologic analysis of a retrieved expanded polytetrafluoroethylene posterior cruciate ligament
Authors: Mantas John P. , Bloebaum Roy D. , Hofmann Aaron A. 
Published: May 2005

AbstractAn expanded polytetrafluoroethylene (PTFE) prosthesis used to reconstruct the posterior cruciate ligament in a 37‐year‐old Caucasian male was retrieved and histologically examined in this study. Backscattered electron (BSE) microscopy, utilized to observe the mineralized tissue ingrowth into the retrieved specimen, revealed an absence of bony ingrowth within the graft. Light microscopy demonstrated an exuberant foreign body giant cell response surrounding and invading the substance of the graft, and also revealed evidence of graft degradation. These observations indicate that PTFE may not be as favorable a material for reconstruction of ligamentous tissues as previously reported.
Biomaterials education: An academic viewpoint
Authors: Black Jonathan , Shalaby Shalaby W. , Laberge Martine 
Published: May 2005

AbstractBiomaterials is emerging as an identifiable intellectual field of study. There are necessary preparatory studies to equip individuals to work within the field at various levels. The formal and informal instructional requirements are considered within the context of the academic program of the Department of Bioengineering at Clemson University, one of the first US university programs to focus on instruction and research in biomaterials.
The effect of egg phosphatidylcholine on antibiotics retention and release from hydroxyapatite
Authors: Iwata Hisashi , Yamamura Keiko , Zhao Xue Zhu 
Published: May 2005

AbstractHydroxyapatite (HAP) has been used in orthopedics as an aid in bone grafts following surgery of bone tumors and osteoarthrosis, often promoting osteoconduction. The incorporation of antibiotics into HAP beads to prevent local infection would seem to be therapeutically effective. This report describes in vitro and in vivo release rate of cefotiam hydrochloride (CTM, 3.5 mg/bead) loaded into HAP beads (8.48 mm in diameter). Egg phosphatidylcholine (EPC) was also incorporated into HAP to control the rate of release of CTM. In vitro, 100% of CTM was released within 3 h from the EPC‐free HAP beads. The rate of diffusion of CTM from HAP was prlonged with the incorporation of EPC. In vivo, 100% of CTM of the EPC‐free CTM was released within 7 h but the rate of release of CTM from the EPC‐CTM was extended. In vivo, the serum level of CTM reflected the rate of release of the antibiotics from the HAP bead. We conclude that EPC is useful in controlling the diffusion rate of CTM from HAP. © 1992 John Wiley & Sons, Inc.
Biological response of intramedullary bone to poly‐L‐lactic acid
Authors: Suganuma Jun , Alexander Harold 
Published: May 2005

AbstractThis study focuses on examining the biological response of intramedullary bone to poly‐L‐lactic acid (PLLA), particularly during the PLLA degradation phase. To study the influence of spherical crystals (spherulites) of PLLA on intramedullary bone response, two different types of PLLA coupon, with and without spherulites but with the same molecular weight, were used. Chambers containing PLLA coupons were implanted into the right femur of eight dogs, four with and four without spherulites; chambers containing stainless steel (SS) coupons (as a control) were implanted in the left femurs of all eight. Two dogs, one with and one without spherulites, were sacrificed at 3, 6, 12, and 24 weeks postoperatively. Histomorphometric evaluation and histophathological assessment were used to compare the response to PLLA and SS. Scanning electron micrographs showed that there were minimal changes in the surface of PLLA coupons at 3 and 6 weeks. But at 12 and 24 weeks, there were many cracks and holes on the surfaces of the coupons, and some parts of the surface were scaling off. The cross‐sectional area of PLLA coupons showed no change at 3 and 6 weeks, but started to decrease by 12 weeks. The amount of ingrown bone between PLLA coupons was significantly greater than that between SS coupons at 3 and 6 weeks, but had decreased dramatically by 12 weeks. Extensive bone resorption around PLLA coupons occurred by 12 weeks accompanied by infiltration of inflammatory cells. An abundance of histiocytes, giant cells, and leucocytes were seen, along with a few histiocytes that had phagocytized PLLA particles of less than 2 μm. By contrast, no inflammatory reaction was seen in SS samples at any period up to and including 24 weeks. PLLA demonstrated excellent biocompatibility with intramedullary bone for the first 6 weeks in this model. Once degradation commenced, however, biocompatibility decreased dramatically. Our study detected no difference between coupons with and without spherulites. It thus appears that the existence of relatively large PLLA particles did not influence the response of intramedullary bone to PLLA, but rather that it was the smaller particles (< 2 μm) released from the PLLA that induced foreign‐body inflammatory reactions and bone resorption. It is also possible that a local decrease in pH occurred around PLLA coupons, which could have influenced vital kinetics. © 1993 John Wiley & Sons, Inc.
Hydroxyapatite‐coated strain gauges for long‐term in vivo bone strain measurements
Authors: Maliniak Mary M. , Szivek John A. , DeYoung Donald W. , Emmanual Janson 
Published: May 2005

AbstractThe aim of this study was to examine the bonding process between hydroxyapatite‐coated strain gauges and bone in order to continue development of a long term in vivo strain measurement device. Two types of commercially available hydroxyapatite (HA) particles were applied to the sensing surface of uniaxial strain gauges using a polysulfone solution as an adhesive. Characterization by scanning electron microscopy and x‐ray diffraction (XRD) was used to determine materials property differences between the two powders. Interfacial strengths between the HA coatings and the strain gauges were tested and found comparable to interfacial strength obtained by a plasma sprayed HA coating on the surface of a titanium implant.Gauges were surgically placed on the periosteal surface of greyhound femora. Three groups of dogs were implanted with gauges for periods of 3, 6, and 12 weeks using cyanoacrylate, resorbable sutures, and cable ties to initially hold the gauge against the surface of the bone.Following euthanasia, the femora of the dogs were explanted and subjected to cantilever loading. Response of the implanted HA‐coated gauges were compared to a control set that had been freshly glued onto the contralateral femur. Full response, that is, 100h% of the strain measurement with respect to the control, was obtained after 12 weeks in vivo. Attachment of HA‐coated gauges with a circumferential suture showed bonding, while HA‐coated gauges attached with cyanoacrylate did not bond to bone.After mechanical testing, femora were embedded in polymethylmethacrylate, cut, ground, and polished. Sections were stained using mineralized bone stain (MIBS) and optical microscopy was performed using transmitted and fluorescent light to allow analysis of remodeling occurring in the region of the strain gauges. Bone formation occurred at the HA surface of sutured gauges, and a fibrous tissue layer developed between the bone and HA coating when the tissue adhesive was used to initially bond the gauge. Fluorescence microscopy indicated an increase in the number of areas of bone remodeling adjacent to the gauge but a normal rate of remodeling of 0.93 ± 0.07 μm/day was observed. No gross bone remodeling due to strain gauge placement was observed. Backscattered electron imaging (BSE) indicated new bone apposition at all time periods. © 1993 John Wiley & Sons, Inc.
A synthetic membrane for testing needle penetration
Authors: Pavlovich Lucas J. , McClung W. Lyle , Thacker John G. , Edlich Richard F. , Rodeheaver George T. 
Published: May 2005

AbstractNeedle performance is primarily judged by its penetration through tissue. For detailed studies of needle performance, tissue is too heterogeneous and unstable and difficult to obtain. A homogeneous, stable, and readily available polyurethane substrate has been evaluated as a suitable alternative to biological tissue for evaluation of needle penetration. The needle penetration profiles through the synthetic substrate correlated very well with those through natural tissue. In addition, the synthetic substrate was sensitive enough to easily detect a 20% increase in the force necessary to penetrate natural tissue. This polyurethane substrate offers a valid alternative to biological tissue for the testing of needle penetration performance. © 1993 John Wiley & Sons, Inc.
Tensile and bend relationships of several surgical needle materials
Authors: Bendel Lee P. , Trozzo Lawrence P. 
Published: May 2005

AbstractFour stainless steel alloys, commonly used for surgical needles were tensile and bend tested. The materials included: ASTM 42000, ASTM 45500, ASTM 30200, and a Fe–12Cr–8.5Ni–3.2Mo–1.9Ti alloy. Small diameter wires in a wide range of strength levels were produced using various heat treatments and/or cold drawing. Samples from each processing condition were tensile and bend tested. Calculated yield moment and ultimate moment were determined using tensile yield strength, the flexural formula (M(y) = σ(y) I/C), and the shape factor for circular cross sections (M(u)/M(y) = 1.7). A deviation was observed between the theoretically calculated yield moment and a 2° offset measured yield moment. This was expected because moment‐strain diagrams provide only an approximation of yield moment due to the gradual departure from linearity. The 2° offset yield was termed the surgical yield because it represents the strain at which a surgical needle would start to lose functionality. A nonlinear relationship (R) was observed between measured and calculated values. The relationship (R) proved to be a function of cold work by wire drawing as measured by the change in wire length (ΔL), R = a − b * In(ΔL). This suggests that engineers selecting materials for bending applications such as surgical needles cannot use tensile data alone to predict bend strength. Processing history must also be known. © 1993 John Wiley & Sons, Inc.
A comparison of a new polypropylene suture with prolene
Authors: Chu C. C. , Pratt L. , Zhang L. , Hsu A. , Chu A. 
Published: May 2005

AbstractThe purpose of this paper is to examine the performance of the newly available monofilament polypropylene suture (Surgipro) manufactured by U.S. Surgical and compared it with commercial Prolene sutures for determining the merit of this new suture. Two different sizes of Surgipro sutures were esused. They were 4/0 and 0 sizes and were tested in terms of their fundamental properties: level of crystallinity, melting temperature, fiber morphology, and mechanical properties including knot strength and knot security. The effect of three different sterilization methods on the mechanical and fundamental properties of the new polypropylene (PP) sutures was also examined. In general, the new Surgipro sutures performed as good as Prolene sutures in terms of mechanical properties; but there were some differences in fundamental properties between these two types of PP sutures, particularly in finer size PP sutures. The major differences were in interior fiber morphology, level of crystallinity, and melting temperature. Surgipro suture fibers showed homogeneous interior morphology, while Prolene fibers exhibited two distinctive fiber morphologies. These two types of PP suture fibers also responded differently to the three sterilization methods tested. Surgipro sutures are less affected by different sterilization methods than the same size Prolene control. Except for the Co60 gamma sterilization, Surgipro suture fibers did not exhibit statistically significant differences in tensile breaking strength between sterilized and control. Ethylene oxide and autoclave sterilized Prolene suture fibers, however, showed statistically (p < 0.05) consistently lower tensile breaking strength than their unsterilized controls. One should be aware of the fact that suture manufacturers are constantly improving their manufacturing processes. The difference between these two types of PP suture fibers may disappear in the future. © 1993 John Wiley & Sons, Inc.
Influence of surgeon's tying technique on knot security
Authors: Batra Erich K. , Franz David A. , Towler Mike A. , Rodeheaver George T. , Thacker John G. , Zimmer Christopher A. , Edlich Richard F. 
Published: May 2005

AbstractThe purpose of this study was to determine the influence of the surgeon's tying techique on knot security using 0 and 2‐0 monofilament and multifilament nylon sutures. Using an Instron® Tensile Tester and a portable tensiometer, knot security was achieved with these sutures using four‐throw square knots (1=1=1=1). After didactic and psychomotor skill training, medical students were taught to construct the four‐throw square knot using either a two‐hand tie or an instrument tie. Using the portable tensionmeter, their knot tying techniques were judged to be superior to those used by surgeons. The surgeon's faulty technique can easily be corrected by didactic information and psychomotor skill training. © 1993 John Wiley & Sons, Inc.