bluuebunny/crossref_metadata_2025 huggingface dataset:
Size, shape, and composition of wear particles from metal–metal hip simulator testing: Effects of alloy and number of loading cycles
Authors: Catelas Isabelle , Bobyn J. Dennis , Medley John B. , Krygier Jan J. , Zukor David J. , Huk Olga L.
Published: September 2003

There has been a revived interest in metal–metal total hip replacements because of their potential for improved wear performance compared with conventional metal–polyethylene implants. The aim of the present study was to characterize metal wear particles isolated from metal–metal hip simulator testing of various clinically relevant alloys and to analyze the effects of these alloys and the number of loading cycles on wear particle characteristics. Implants were manufactured using medical‐grade cobalt–chromium–molybdenum (CoCrMo) alloys that were high‐carbon wrought, low‐carbon wrought, or cast (with solution annealing). Testing was performed in a MATCO orbital bearing hip simulator in 95% bovine calf serum. The wear particles were isolated from the serum at test periods of 0–0.25 million cycles (Mc) (run‐in wear) and 1.75–2 Mc (steady‐state wear) using an enzymatic protocol previously optimized to minimize particle changes due to reagents. Isolated particles embedded in epoxy resin were characterized by transmission electron microscopy (TEM) and energy dispersive X‐ray analysis (EDXA). The EDXA results revealed the predominance of “lighter” particles containing Cr and O (most likely chromium oxide particles from the passivation layer) and fewer darker CoCrMo particles, with varying ratios of Co and Cr (possibly from carbides and from implant matrix material). More CoCrMo particles were observed with the low‐carbon wrought alloy, but the majority of the particles for all three alloys was chromium oxides, especially for the 1.75–2 Mc test period. Image analysis of TEM micrographs revealed that for 0–0.25 Mc, there was up to 21% needle‐shaped particles but that the majority remained round to oval in shape, reflecting the predominance of chromium oxide particles. Particle length averaged about 52 ± 4 nm, with only small differences due to the alloy. For 1.75–2 Mc, most particles were round to oval in shape. They were even less needle‐shaped than at 0.25 Mc, and they had a slightly smaller length, averaging 46 ± 3 nm. In addition to characterizing the size and shape of particles from a MATCO simulator, this study is the first to demonstrate that particles that do not contain Co (presumably chromium oxides) can be predominant in the wear of metal–metal hip implants. It is therefore recommended that future in vitro and in vivo studies include the effects of these particles rather than just the effects of CoCrMo particles on the overall tissue response. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 312–327, 2003
The effects of tubule orientation on fatigue crack growth in dentin
Authors: Arola Dwayne D. , Rouland Joseph A.
Published: September 2003

The fracture of restored teeth is a significant obstacle to lifelong oral health. Recent studies suggest that fatigue cracks originate at flaws introduced during cavity preparation and that fatigue crack growth is a principle cause of restored tooth fractures. In this study, the rate of fatigue crack growth in bovine dentin was estimated under mode I cyclic loading. Double cantilever beam (DCB) specimens were obtained from bovine molars and subjected to high cycle fatigue loading (105 < N < 106). The fatigue crack growth rates were measured and used to estimate the crack growth exponent and coefficient according to the Paris Law. The average fatigue crack growth exponent was 4.7 ± 0.6 for crack growth parallel to the dentin tubules, which was significantly larger than 4.3 ± 0.5 for crack growth perpendicular to the tubules (t‐test, CI > 80%). Although the crack growth rates varied considerably, there was no significant dependence on tubule orientation or tubule density. However, specific features of the fracture surfaces and tendencies for crack curving away from the tubules suggested preferential fatigue crack growth perpendicular to the dentin tubules. Results from this study are being used to guide an experimental investigation of fatigue crack growth in human dentin. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 78–86, 2003
Protein adsorption on mixtures of hydroxyl‐ and methyl‐terminated alkanethiols self‐assembled monolayers
Authors: Martins Ma Cristina L. , Ratner Buddy D. , Barbosa Mário A.
Published: September 2003

The effect of surface composition and wettability on the adsorption of human serum albumin (HSA) was studied. Self‐assembled monolayers (SAMs) containing mixtures of longer chain methyl‐ and shorter chain hydroxyl‐terminated alkanethiols on gold were used to produce a range of surfaces with different wettabilities and exposed functional groups. Different SAMs were characterized by X‐ray photoelectron spectroscopy, water contact angles, and Fourier transform infrared reflection absorption spectroscopy (IRAS). HSA adsorption onto the different SAMs was evaluated by contact angle measurements (wetting tension determinations), radiolabeling of proteins, and IRAS. Concerning HSA adsorption, all the techniques demonstrated higher HSA adsorption on more hydrophobic surfaces. The wetting tension measurements and IRAS suggested a gradual decrease of the HSA adsorption with increases of surface hydrophilicity. Radiolabeled albumin measurements also demonstrated a significant decrease of HSA adsorption on the pure hydroxyl‐terminated SAMs. However, no significant differences were detected between mixed and pure methyl‐terminated SAMs. Studies of HSA exchangeability with human fibrinogen have suggested that an ideal percentage of hydroxyl groups on the surface may increase albumin affinity without fibrinogen adsorption. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 158–171, 2003
Hg2+ and Ni2+ alter induction of heat shock protein‐72 in THP‐1 human monocytes
Authors: Noda M. , Wataha J. C. , Lewis J. B. , Lockwood P. E. , Komatsu H. , Sano H.
Published: September 2003

The biological liabilities that result from the release of metal ions from biomedical alloys, particularly Ni2+ and Hg2+, continue to be a concern. Heat‐shock proteins (HSP) are a class of molecular chaperones that may be induced under conditions of cellular stress, including oxidative stress. Our hypothesis was that because Hg2+ and Ni2+ alter other cellular stress responses such as glutathione levels and cytokine secretion, these metal ions may alter HSP induction in monocytes, which are key cells in the response of tissues to biomedical alloys. THP‐1 monocytes were exposed to sublethal concentrations of Hg2+ or Ni2+ for 1 h with or without heat stress (43°C), then allowed to recover at 37°C for 2–6 h. HSP72 was measured using immunoblotting with phosphorimage quantification. Hg2+ exposures of 2–10 μmol/L induced HSP72 without heat stress. With heat stress, HSP72 levels were altered by Hg2+ versus heat stress alone. The response depended on the concentration of Hg2+ and the recovery time. Hg2+ at 10 μmol/L caused uniformly lower HSP72 levels. Ni2+ exposures of 20–100 μmol/L did not induce HSP72 without heat stress, but significantly altered heat‐induced HSP72 expression, with a significant increase in expression over heat alone at 40 and 100 μmol/L. Results from the current study support the hypothesis that these metal ions can, at concentrations relevant to those released from biomedical alloys, modulate HSP expression in human monocytes. The modulation of HSP expression indicates an early sign of cellular stress that may be important to the overall biological response to biomedical alloys containing and releasing these metal ions. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 240–245, 2003
In vivo biocompatibility of three different chemical compositions of Ricinus communis polyurethane
Authors: Barros Valdemar M. R. , Rosa Adalberto L. , Beloti Márcio M. , Chierice Gilberto
Published: September 2003

Alteration in the chemical composition of a biomaterial may be undertaken to improve its biological properties. The aim of this work was to evaluate the biocompatibility of three chemical compositions of Ricinus communis polyurethane (RCP): RCPp (pure RCP), RCP + CaCO3, and RCP +Ca3(PO4)2. RCP cylinders were surgically implanted in rabbit femurs. After 8, 12, and 16 weeks, the femurs were removed, fixed, sectioned, ground, and stained by Stevenel's blue/Alizarin red S for light microscopy and histomorphometry. The osseointegration and osseoconductivity were calculated by means of image analysis and the data were submitted to the Kruskal‐Wallis test followed by Dunn's test. Osseointegration was already completed after 8 weeks on RCP + Ca3(PO4)2 because similar values were found from week 8 to 16, whereas it showed a time‐dependent increase on RCPp and RCP +CaCO3. The osseointegration was greater on RCP + Ca3(PO4)2 in all periods when compared with RCPp, and after 8 and 12 weeks when compared with RCP + CaCO3. None of the RCP samples presented osseoconductivity. The present results showed that RCP blended with calcium phosphate improved the biocompatibility by both enhancing and accelerating its osseointegration. Based on the absence of osseoconductivity, RCP was considered to be a bioinert material. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 235–239, 2003
Synthesis and physicochemical analysis of interpenetrating networks containing modified gelatin and poly(ethylene glycol) diacrylate
Authors: Burmania Jeanine A. , Martinez‐Diaz Gabriel J. , John Kao Weiyuan
Published: September 2003

The interrelated effects of gelatin modification, content, and poly(ethylene glycol) molecular weight on the melting temperature, surface hydrophilicity, tensile properties, swelling/degradation, and drug‐release kinetics of a novel interpenetrating network (IPN) system containing gelatin and poly(ethylene glycol) diacrylate were evaluated. Gelatin content had a large effect on the IPN melting temperature and ΔH. Modifying gelatin with ethylenediaminetetraacetic acid and/or monomethoxy poly(ethylene glycol) monoacetate ester as well as increasing poly(ethylene glycol) diacrylate molecular weight increased the surface hydrophilicity. Increasing the gelatin weight percent increased the IPN elasticity at room temperature. When buffer and elevated temperature were present in the testing environment, the elasticity of all IPNs tested decreased. IPNs showed an enhanced elasticity and strength when compared with glutaraldehyde‐fixed gelatin hydrogels. The extent of IPN swelling and degradation was increased by increasing the gelatin content or by modifying gelatin. The time to complete sample degradation was longer for IPNs when compared with gelatin crosslinked with glutaraldehyde. Modifications to the IPN system increased the maximum percent of chlorhexidine digluconate released from the IPNs. The rate of complete drug release was slower from IPNs than from glutaraldehyde‐fixed gelatin matrices. A wide range of IPN physicochemical properties was obtained through formulation changes and chemical modifications. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 224–234, 2003
Val‐ala‐pro‐gly, an elastin‐derived non‐integrin ligand: Smooth muscle cell adhesion and specificity
Authors: Gobin Andrea S. , West Jennifer L.
Published: September 2003

The elastin‐derived peptide val‐ala‐pro‐gly (VAPG) may be useful as a biospecific cell adhesion ligand for smooth muscle cells. By grafting the peptide sequence into a hydrogel material, we were able to assess its effects on smooth muscle cell adhesion and spreading. These materials are photopolymerizable hydrogels based on acrylate‐terminated derivatives of polyethylene glycol (PEG). Because of their high PEG content, these materials are highly resistant to protein adsorption and cell adhesion. However, PEG diacrylate derivatives can be mixed with adhesive peptide‐modified PEG monoacrylate derivatives to facilitate cell adhesion. Following photopolymerization, PEG monoacrylate derivatives are grafted into the hydrogel network formed by the PEG diacrylate. This results in covalent immobilization of adhesive peptides to the hydrogel via a flexible linker chain. The resistance of PEG to protein adsorption makes it an ideal material for this model system since cell–material interactions are limited to biomolecules that are covalently incorporated into the material. In this case we were able to demonstrate that VAPG is specific for adhesion of smooth muscle cells. It also was shown that fibroblasts, endothelial cells, and platelets cannot adhere to VAPG. In addition, not only was smooth muscle cell adhesion dependent on ligand concentration, but also cell spreading increased with increasing ligand concentration. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 255–259, 2003
Tissue engineered bone: Measurement of nutrient transport in three‐dimensional matrices
Authors: Botchwey Edward A. , Dupree Melissa A. , Pollack Solomon R. , Levine Elliot M. , Laurencin Cato T.
Published: September 2003

The classic paradigm for in vitro tissue engineering of bone involves the isolation and culture of donor osteoblasts or osteoprogenitor cells within three‐dimensional (3D) scaffold biomaterials under conditions that support tissue growth and mineralized osteoid formation. Our studies focus on the development and utilization of new dynamic culture technologies to provide adequate nutrient flux within 3D scaffolds to support ongoing tissue formation. In this study, we have developed a basic one‐dimensional (1D) model to characterize the efficiency of passive nutrient diffusion and transport flux to bone cells within 3D scaffolds under static and dynamic culture conditions. Internal fluid perfusion within modeled scaffolds increased rapidly with increasing pore volume and pore diameter to a maximum of approximately 1% of external fluid flow. In contrast, internal perfusion decreased significantly with increasing pore channel tortuosity. Calculations of associated nutrient flux indicate that static 3D culture and some inappropriately designed dynamic culture environments lead to regions of insufficient nutrient concentration to maintain cell viability, and can result in steep nutrient concentration gradients within the modeled constructs. These quantitative studies provide a basis for development of new dynamic culture methodologies to overcome the limitations of passive nutrient diffusion in 3D cell‐scaffold composite systems proposed for in vitro tissue engineering of bone. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 357–367, 2003
Characterization of implant materials in fetal bovine serum and sodium sulfate by electrochemical impedance spectroscopy. II. Coarsely sandblasted samples
Authors: Contu F. , Elsener B. , Böhni H.
Published: September 2003

Electrochemical impedance spectroscopy is used to investigate the corrosion resistance of coarsely sandblasted implant alloys, commercially pure titanium, Ti6Al4V, Ti6Al7Nb, and CoCrMo in 0.1M sodium sulfate and fetal bovine serum. Coarsely sandblasted samples have a heterogeneous surface constituted by a large number of protrusions and recessions. Impedance spectra collected in sodium sulfate present two time constants (maxima in the phase‐angle of the bode plot) associated with the total surface and with the tips, respectively. In bovine serum, the two maxima in the impedance spectra cannot be distinguished because of the formation of an adsorption layer of organic molecules, which causes a decrease in the values of both the total and tips' capacitances as well as an increase in the polarization resistance. Ti6Al4V and Ti6Al7Nb show the highest corrosion rate both in serum and in sodium sulfate. Based on the capacitance values obtained in sodium sulfate, the real surface area of the coarsely sandblasted electrodes has been estimated relative to mechanically polished surfaces. The values of the effective electrode area correlate with the mechanical properties of the samples: in fact, the softest electrode (commercially pure titanium) shows the largest effective electrode area, whereas the hardest material (CoCrMo alloy) shows the smallest surface area. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 246–254, 2003
Patterning hydroxyapatite biocoating by electrophoretic deposition
Authors: Wang R. , Hu Y. X.
Published: September 2003

Patterned bioceramic coatings may find potential applications in orthopedic implants and biosensors. In this study, various hydroxyapatite (HA) patterns were created on silicon and titanium substrates. Electrophoretic deposition technique was used together with surface patterning of the cathode specimen. When gold/palladium patterns (hexagons, spherical dots, etc.) were created on the cathode surface, HA colloidal particles in ethanol would preferentially deposit on the gold‐coated area and form patterns. When silicon, instead of gold, was evaporated onto a conducting cathode surface, HA mainly deposited on the exposed area of the substrate. Detailed mechanisms for forming HA patterns may involve local concentration of the electric field when a second metal is patterned on the cathode. The difference in electric field across the two metals on the cathode also enhances HA patterning through an electrohydrodynamic process. This study demonstrated the possibility and flexibility of electrophoretic deposition in patterning charged particles onto a substrate. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 270–275, 2003
A centrifugation cell adhesion assay for high‐throughput screening of biomaterial surfaces
Authors: Reyes Catherine D. , García Andrés J.
Published: September 2003

A quantitative analysis of cell adhesion is essential in understanding physiological phenomena and designing biomaterials, implant surfaces, and tissue‐engineering scaffolds. The most common cell adhesion assays used to evaluate biomaterial surfaces lack sensitivity and reproducibility and/or require specialized equipment and skill‐intensive operation. We describe a modified centrifugation cell adhesion assay that uses simple and convenient techniques with standard laboratory equipment and provides reliable, quantitative measurements of cell adhesion. This centrifugation assay applies controlled and uniform detachment forces to a large population of adherent cells, providing robust statistics for quantifying cell adhesion. The applicability of this system to the design and characterization of biomaterial surfaces is shown by evaluating cell adhesion on substrates using different coating proteins, cell types, seeding times, and relative centrifugal forces (RCF). Results verify that this centrifugation cell adhesion assay represents a simple, convenient, and standard method for high‐throughput characterization of a variety of biomaterial surfaces and conditions. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 328–333, 2003
Defect initiation at subsurface grain boundary as a precursor of delamination in ultrahigh molecular weight polyethylene
Authors: Shibata Nobuyuki , Tomita Naohide , Onmori Naoki , Kato Koji , Ikeuchi Ken
Published: September 2003

In order to examine the initiation mechanism of delamination in ultrahigh molecular weight polyethylene (UHMWPE) knee components, a bi‐directional sliding fatigue test was performed for three types of UHMWPE specimens: nonirradiated, gamma‐irradiated (25 kGy) and gamma‐irradiated (25 kGy) with 0.1% vitamin E added. Sliding surfaces of post‐tested UHMWPE specimens were observed using an optical microscope and a scanning electron microscope. Also, surface roughness was measured at the sliding surfaces of UHMWPE specimens. Delamination was observed only in gamma‐irradiated specimens. A networked structure of surface asperity that resembled grain boundary was observed prior to delamination in gamma‐irradiated specimens. Surface roughness in the gamma‐irradiated specimens, higher than in any other specimen, showed a rapid increase prior to delamination. Detailed observation using an optical microscope and a scanning electron microscope showed microscopic crack initiation along subsurface grain boundaries in gamma‐irradiated specimens. These results suggest that subsurface crack initiation is a precursor of delamination and is accelerated by oxidative degradation due to gamma irradiation. Of the three types of specimens, UHMWPE with vitamin E added showed the lowest surface roughness values at all measuring points. The addition of vitamin E is effective in improving wear resistance and fatigue performance of UHMWPE. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 276–284, 2003
Biology of alkali‐ and heat‐treated titanium implants
Authors: Nishiguchi Shigeru , Fujibayashi Shunsuke , Kim Hyun‐Min , Kokubo Tadashi , Nakamura Takashi
Published: September 2003

In cementless fixation systems, surface character is an important factor. Alkali and heat treatments of titanium metal have been shown to produce strong bonding to bone and a higher ongrowth rate. In this study we examined the effect of alkali and heat treatments on titanium rods in an intramedullary rabbit femur model, in regard to the cementless hip stem. The implant rods were 5 mm in diameter and 25 mm in length. Half of the implants were immersed in 5 mol/L sodium hydroxide solution and heated at 600°C for 1 h (AH implants), and the other half were untreated (CL implants). The rods were implanted into the distal femur of the rabbits; AH implants into the left femur and CL implants into the right. The bone‐implant interfaces were evaluated at 3, 6, and 12 weeks after implantation. Pull‐out tests showed that the AH implants had a significantly higher bonding strength to bone than the CL implants at each time point. As postoperative time elapsed, histological examination revealed that new bone formed on the surface of both types of implants, but significantly more bone made direct contact with the surface of the AH implants. At 12 weeks, approximately 56% of the whole surface of the AH implants was covered with the bone. In conclusion, alkali‐ and heat‐treated titanium offers strong bone bonding and a high affinity to bone as opposed to a conventional mechanical interlocking mechanism. Alkali and heat treatments of titanium may be suitable surface treatments for cementless joint replacement implants. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 26–35, 2003
Optimization of bone engineering by means of growth factors in a three‐dimensional matrix
Authors: Arnold Ulrike , Schweitzer Sven , Lindenhayn Klaus , Perka Carsten
Published: September 2003

The direction and acceleration of differentiation by administering growth factors is one of the ways of optimizing bone engineering. The present study considered the influence of the growth factors factor XIII, TGF‐β1, and b‐FGF on the proliferation and osteogenic differentiation of porcine periosteal cells in a three‐dimensional carrier matrix (bead), consisting of a fibrin–alginate–hydroxyapatite composite. F XIII, TGF‐β1, and b‐FGF were added to the culture medium of monolayer culture and fibrin beads in different concentrations. The monolayer culture was assessed on the basis of cell counts, while DNA, osteocalcin, osteonectin, and collagen content and alkaline phosphatase activity were determined, and microscopic and immunohistologic evaluations were performed for the beads. In the monolayer, the addition of b‐FGF led to a significantly shorter time up to the confluence of the cells. In the bead, cell proliferation was accelerated by b‐FGF and TGF‐β1. With regard to alkaline phosphatase activity, factor XIII led to significantly higher values, while b‐FGF and TGF‐β1 resulted in lower activities. Osteocalcin content was significantly increased by the application of b‐FGF. For the osteonectin content the addition of growth factors did not produce any changes. The application of TGF‐β1 during the monolayer culture significantly increased the primary collagen content of the beads. The administration of different growth factors opens up new ways of optimizing cell growth in vitro and of directing the osteogenic differentiation of periosteal cells, without one universally applicable factor having been demonstrated. It will be the task of further studies to analyze the interaction of individual factors and the chronologic dependency of the action, on the way to in vitro bone generation. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 260–269, 2003
Protein adsorption on titanium surfaces and their effect on osteoblast attachment
Authors: Yang Yunzhi , Cavin Renee , Ong Joo L
Published: September 2003

The objective of this study was to investigate the adsorption of albumin and fibronectin on titanium (Ti) surfaces and the effect of preadsorbed albumin and fibronectin on osteoblast attachment in vitro. Bovine serum albumin and bovine fibronectin were used in this study. Maximum adsorption of bovine serum albumin and fibronectin on Ti surfaces was observed to occur after 180‐min incubation. In the presence of preadsorbed proteins, osteoblast attachment on Ti surfaces was observed to be enhanced compared to control Ti surfaces. However, cell attachment was affected by the types of protein adsorbed. Preadsorbed albumin was observed to have no significant effect on the amount of osteoblast cells attached. In comparison to control Ti surface and Ti surfaces preadsorbed with albumin, Ti surfaces preadsorbed with fibronectin for 15 min was observed to significantly increase osteoblast cell attachment, whereas Ti surfaces preadsorbed with fibronectin for 180 min did not affect cell attachment. In addition, cell morphology of the attached cells on protein preadsorbed Ti surfaces was not affected by the type of protein used in this study. It was concluded from this study that the concentration of fibronection adsorbed on Ti surfaces was higher compared to albumin. In addition, it was also concluded that the concentration of fibronectin on Ti surfaces plays a role in governing cell attachment. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 344–349, 2003
Bioengineered human bone tissue using autogenous osteoblasts cultured on different biomatrices
Authors: Hofmann A. , Konrad L. , Gotzen L. , Printz H. , Ramaswamy A. , Hofmann C.
Published: September 2003

Surgical treatment of critical‐size posttraumatic bone defects is still a challenging problem, even in modern bone and joint surgery. Progress in cellular and molecular biology during the last decade now permits novel approaches in bone engineering. Recent conceptual and technical advances have enabled the use of mitotically expanded, bone‐derived cells as a therapeutic approach for tissue repair. Using three different tissue carrier systems, we successfully cultivated human osteoblasts in a newly developed perfusion chamber. We studied cell proliferation and the expression of osteocalcin, osteopontin, bone morphogenetic protein‐2A, alkaline phosphatase, and vascular endothelial growth factor as parameters for osteoblast function and viability. Adherence of highly enriched human osteoblasts had already started after 1 h and resulted in completely overgrown human bone pieces after 10 days. Expression analysis of bone‐specific alkaline phosphatase indicated differentiating osteoblasts, whereas the high mRNA expression of osteocalcin and osteopontin revealed terminally differentiated osteoblasts and the process of mineralization. Additionally, gene expression was significantly higher when demineralized bone was used as biomatrix, compared to autoclaved bone and hydroxyapatite ceramics. We conclude that with our newly developed perfusion culture system, vital autogenous bone implants of clinically applicable size can be generated within 17 days in order to manage critical‐size bone defects. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 191–199, 2003
Ocular biocompatibility of a poly(ortho ester) characterized by autocatalyzed degradation
Authors: Einmahl Suzanne , Ponsart Stéphanie , Bejjani Riad A. , D'Hermies François , Savoldelli Michelle , Heller Jorge , Tabatabay Cyrus , Gurny Robert , Behar‐Cohen Francine
Published: September 2003

The biocompatibility of autocatalyzed poly(ortho ester) (POE70LA30), a viscous, hydrophobic, bioerodible polymer, was investigated. POE70LA30 was synthesized, sterilized by gamma irradiation, and injected in rabbit eyes at adequate volumes through subconjunctival, intracameral, intravitreal, and suprachoroidal routes. Clinical examinations were performed postoperatively at regular time points for 6 mo, and histopathologic analysis was carried out to confirm tissular biocompatibility. After subconjunctival injection, the polymer was well tolerated and persisted in the subconjunctival space for about 5 weeks. In the case of intracameral injections, polymer biocompatibility was good; the POE70LA30 bubble was still present in the anterior chamber for up to 6 mo after injection. No major histopathologic anomalies were detected, with the exception of a localized Descemet membrane thickening. After intravitreal administration, POE70LA30 biocompatibility was excellent, and no inflammatory reaction could be detected during the observation period. The polymer was degraded in approximately 3 mo. Suprachoroidal injections of POE70LA30 were reproducible and well tolerated. POE70LA30 triggered a slight elevation of the retina and choroid upon clinical observation. The polymer was detectable in the suprachoroidal space for about 6 mo. No inflammatory reaction and no major retinal anomalies could be detected by histology. In conclusion, POE70LA30 appears to be a promising biomaterial for intraocular application, potentially providing sustained drug delivery over an extended period of time, with a good tolerance. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 44–53, 2003
Effects of polyglycolic acid on porcine smooth muscle cell growth and differentiation
Authors: Higgins Steven P. , Solan Amy K. , Niklason Laura E.
Published: September 2003

Polyglycolic acid (PGA) is commonly used as a scaffold for tissue engineering. Recent studies utilized PGA as a scaffold for vascular tissue engineering using bovine and porcine smooth muscle cells (SMCs). In engineered vessels, the SMCs displayed high rates of mitosis and dedifferentiation in areas where PGA fragments were present. We hypothesized that PGA breakdown products, sequestered within a SMC vessel at the conclusion of culture, led to increased proliferation and dedifferentiation of vascular SMCs. To test this hypothesis, the current study assessed possible means by which PGA breakdown products could lead to changes in SMC phenotype. SMCs grown in high concentrations of PGA breakdown products showed, by Western blotting, decreased expression of calponin, a marker for SMC differentiation. The same was true for SMCs grown in glycolic acid (GA), which also showed decreased expression of proliferating cell nuclear antigen (PCNA), a marker for SMC proliferation. In contrast, cells grown in varying amounts of NaCl or HCl showed little change in differentiation. We conclude that, independent of acidity or osmolality, plausible products of PGA degradation appear to induce dedifferentiation of porcine SMCs in vitro. Because of dedifferentiation and decreased mitosis, commercially available PGA may not represent an optimal scaffold for vascular tissue engineering. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 295–302, 2003
Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin‐related peptides
Authors: Klueh U. , Bryers J. D. , Kreutzer D. L.
Published: September 2003

Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH3 terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin‐related (BRP‐A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP‐A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP‐A was quantified using 125I‐FN, and monoclonal antibodies. 125I‐FN was used to quantitate FN binding to peptide‐coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP‐A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti‐C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti‐N terminus antibodies to peptide‐bound FN occurred. We believe that the data that indicate an enhanced binding of anti‐C antibodies reactive to anti‐N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP‐A on the polystyrene surface. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36–43, 2003
Engineering porcine arteries: Effects of scaffold modification
Authors: Prabhakar Vikas , Grinstaff Mark W. , Alarcon Javier , Knors Chris , Solan Amy K. , Niklason Laura E.
Published: September 2003

Techniques have been developed to culture bovine or porcine vascular cells on polyglycolic acid (PGA) scaffolds to form engineered vessels. Previously, it was shown that smooth muscle cells (SMCs) that were in close proximity to PGA remnants after 8 weeks of culture had lower expression of SMC markers of differentiation and were more mitotic compared with SMCs that were distant from polymer residuals. Modifications of PGA were explored as a means to minimize residual polymer fragments after culture. To hasten degradation, polymer was treated with heat, NaOH, or γ‐irradiation. Differential scanning calorimetry, mass and tensile strength degradation, and inherent viscosity were used to assess polymer characteristics. When polymer was maintained in aqueous conditions, tensile strength of treated PGA degraded to zero within 3 weeks for each treatment. Engineered vessel constructs cultured on NaOH and γ‐treated polymer displayed smooth muscle α‐actin throughout the vessel wall. Scaffold treatment impacted graft morphology, cellular differentiation, and mechanical integrity. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 303–311, 2003
Housing satisfaction for persons with psychiatric disabilities
Authors: Tsemberis Sam , Rogers E. Sally , Rodis Eleni , Dushuttle Patricia , Skryha Vicki
Published: September 2003

Provision of residential services to people with mental illness has assumed increasing importance since deinstitutionalization and as community‐ based services have increased. This large‐scale multisite study of housing programs specifically for persons with mental illness examines one of the factors that lead to successful residential tenure for persons with serious mental illness. To date, the Lehman Quality of Life Scale has been used primarily to assess satisfaction with housing in studies of residential services. This article reports on a new measure of housing satisfaction. This new 25‐item instrument was developed, field tested in a variety of housing settings across the country, and analyzed for reliability and validity by a group of housing researchers and clinicians. The implications of using this instrument for future evaluation and research on housing for persons with mental illness are examined. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 581–590, 2003.
A case report of a community‐based response to domestic violence in Chile
Authors: Arón Ana María , Lorion Raymond P.
Published: September 2003

The conceptual and programmatic elements of a community‐based approach to the prevention and treatment of victims of domestic violence in Chile are presented. The program reflects the tenets of a psychosocial wellness model focusing on individual and community competencies and resources to solve human problems. The intervention incorporates elements of crisis intervention with strategies to identify and empower natural social support networks. As necessary, victims are referred to specialized physical and mental health services. During its initial stages, the program was provided to physicians and allied medical staff of a local hospital. Participants included nurse‐aides, nurses, doctors, social workers, social work‐aides, and other personnel from medical units providing emergency, pediatric, and obstetric care. Team cohesion was emphasized and information regarding domestic violence, crisis intervention, and referral strategies was provided. During the program's second stage, prevention and education strategies were targeted to community organizations and educational institutions. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 561–579, 2003.
Relations among mother and home visitor personality, relationship quality, and amount of time spent in home visits
Authors: Sharp Elizabeth A. , Ispa Jean M. , Thornburg Kathy R. , Lane Valerie
Published: September 2003

Evaluations of a variety of home‐based early childhood intervention programs show that home visit rates fall short of the number prescribed. In an attempt to add to knowledge about reasons for this phenomenon, the current study explored associations among mother and home visitor personality, relationship quality, and time spent in home visits. Maternal negative emotionality was positively related to both time spent in home visits and relationship quality. Maternal positive emotionality was inversely related to time spent in home visits. Home visitor negative emotionality was also positively related to mothers' assessments of relationship quality; however, it was inversely related to the amount of time spent in home visits. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 591–606, 2003.
Initial development of a measure of religious coping among Hindus
Authors: Tarakeshwar Nalini , Pargament Kenneth I. , Mahoney Annette
Published: September 2003

We developed and validated a measure that would comprehensively capture religious coping strategies used by Hindus in the United States (U.S.). Based on qualitative interviews with Hindus (N = 15) and existing religious coping measures, a Hindu religious coping scale was constructed. After a pilot test of this scale among Hindus in the Midwest (N = 42), a sample of Hindus across the U.S. (N = 164) completed the Hindu religious coping scale along with measures of mental health. Results indicated that religious coping was a salient construct for Hindus and related to better mental health. Empirical data revealed specific forms of religious coping that are characteristic of Hindu theology. Further, results of the factor analyses of the Hindu religious coping scale yielded three factors, “God‐focused” religious coping, “Spirituality‐focused” religious coping, and “Religious guilt, anger, and passivity.” Findings provided support for the reliability and validity of the Hindu religious coping scale. Implications for theory and practice were discussed. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 607–628, 2003.
Mental illness depiction in children's films
Authors: Wahl Otto , Wood Amy , Zaveri Parin , Drapalski Amy , Mann Brittany
Published: September 2003

Forty‐nine children's (G‐ and PG‐rated) films were viewed and rated with respect to the depiction of mental illnesses. Material about mental illnesses was included in 33 (67%) of these films. Twelve (24%) had one or more characters labeled as having a mental illness; an additional 21 films contained references to mental illnesses. Characters with mental illnesses tended to be male, adult, Caucasian, single or of unknown marital status, and identified by disparaging slang terms rather than formal diagnoses. Of the 12 movies containing characters with mental illnesses, 8 (67%) included depictions where that character was violent. Other characters responded in generally favorable ways to the mentally ill characters: most worked cooperatively with the character and helped and trusted the character. However, nearly two‐thirds also showed fear of the character. Results suggest that mental illness depictions are common in children's films, and that, despite some positive responses from other characters, mentally ill characters tend to be feared and disparaged. Study limitations and possible implications for children's developing understanding of mental illnesses are discussed. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 553–560, 2003.
Roles assumed by a community coalition when creating environmental and policy‐level changes
Authors: Snell‐Johns Jessica , Imm Pamela , Wandersman Abraham , Claypoole Jack
Published: September 2003

A significant amount of federal, state, and local resources are spent organizing large‐scale community coalitions designed to address the issues of alcohol, tobacco, and other drug (ATOD) use in communities. Thus far, results regarding the effectiveness of community coalitions in reducing ATOD rates are mixed. This article discusses the importance of strategies designed to impact environmental‐level changes (e.g., policies, laws), which, in turn, can impact individual use. The development of prevention structures that consistently and continuously promote prevention efforts must be established before significant change in use rates can occur and be sustained. In order to identify the roles assumed by a coalition in order to affect policy‐level changes, this article examines the specific efforts of the Lexington/Richland Drug and Alcohol Abuse Coalition in Columbia, South Carolina. Review of meeting minutes and interviews with staff and coalition members suggest that the coalition assumed three central roles: developer, facilitator, and arbitrator. The coalition's success in influencing community policies and sanctions is attributed to its responsiveness and ability to assume diverse roles, depending on the specific needs of the community. Changes in policies/laws and sanctions are presented as evidence of the coalition's success in impacting and reinforcing community‐wide prevention structures thought to reduce the abuse of alcohol and other drugs. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 661–670, 2003.
Measuring behavior change in young children receiving intensive school‐based mental health services
Authors: Hussey David L. , Guo Shenyang
Published: September 2003

An innovative urban school‐based mental health program was developed to treat the subset of elementary school‐referred children who are experiencing severe emotional and behavioral difficulties. The program served a group of 201 students and their families, referred from 15 elementary schools through a large urban school district in Ohio (K through fifth grade). The children in the sample are predominantly African‐American (N = 157, 78.1%), and male (N = 154, 76.6%), with an average age at admission of 9.23 years (SD = 1.75). Parents and teachers provided behavioral rating data using a standardized psychiatric assessment instrument (i.e., the Devereux Scales of Mental Disorders—DSMD). Results showed that at intake 68.7% of children scored above the clinical cutoff score of 60 on the conduct disorder subscale of the DSMD, with more than 40.8% of youth scoring 70 or higher. On the depression subscale 55.7% scored above the cutoff score, with slightly less than a third (30.8%) scoring 70 or higher. Hierarchical linear modeling (HLM) was used to measure longitudinal behavior change. Children evidenced statistically significant reductions in conduct disordered behavior ( p < .01), attention deficit/hyperactivity ( p < .05), and depressive symptomatology ( p < .01) over the course of approximately 1 year. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 629–639, 2003.
Structured leisure activities in middle childhood: Links to well‐being
Authors: Fletcher Anne C. , Nickerson Pamela , Wright Kristie L.
Published: September 2003

Associations between children's (N = 147) participation in structured leisure activities and their adjustment were examined. Caregivers provided lists of extracurricular activities (clubs, sports, and church activities) in which children participated. Children and caregivers participated in interviews and completed questionnaires designed to measure children's adjustment in four domains (academic competence, psychosocial development, externalizing behavior, and internalizing behavior). Classroom teachers completed additional measures of children's academic and social competence. Greater participation in club activities was linked with higher academic grades and more positive teacher ratings of academic competence. Greater participation in sports was associated with higher levels of psychosocial maturity and more positive teacher ratings of social competence. There were no associations between involvement in church activities and any indicators of adjustment. Activity involvement was unassociated with externalizing or internalizing behavior. Findings are discussed in terms of both selection into different types of extracurricular activities and the skills emphasized in the pursuit of such activities. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 641–659, 2003.
Ontogenesis of the scapula in marsupial mammals, with special emphasis on perinatal stages of didelphids and remarks on the origin of the therian scapula
Authors: Sánchez‐Villagra Marcelo R. , Maier Wolfgang
Published: September 2003

The development of the scapula was studied in embryonic and postnatal specimens of Monodelphis domestica and perinatal specimens of Philander opossum, Caluromys philander, and Sminthopsis virginiae using histological sections and 3D reconstructions. Additionally, macerated skeletons of postnatal M. domestica were examined. This study focused on the detachment of the scapulocoracoid from the sternum and on the acquisition of a supraspinous fossa, a supraspinatus muscle, and a scapular spine, all these events associated with the origin of the therian shoulder girdle. In none of the specimens is there a continuity of the cartilaginous scapulocoracoid with the sternum, even though the structures are in close proximity, especially in S. virginiae. At birth, the first rib laterally presents a pronounced boss that probably contacts the humerus during certain movements. Only the acromial portion of the scapular spine, which originates from the anterior margin of the scapular blade, is preformed in cartilage. The other portion is formed by appositional bone (“Zuwachsknochen”), which expands from the perichondral ossification of the scapula into an intermuscular aponeurosis between the supra‐ and infraspinous muscles. This intermuscular aponeurosis inserts more or less in the middle of the lateral surface of the developing scapula. Thus, the floor of the supraspinous fossa is present from the beginning of scapular development, simultaneously with the infraspinous fossa. The homology of the therian spine with the anterior border of the sauropsid and monotreme scapula is questioned. We consider the dorsal portion (as opposed to the ventral or acromial portion) of the scapular spine a neomorphic structure of therian mammals. J. Morphol. 258:115–129, 2003. © 2003 Wiley‐Liss, Inc.