bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication and characterization of biomimetic multichanneled crosslinked‐urethane‐doped polyester tissue engineered nerve guides
Authors: Tran Richard T. , Choy Wai Man , Cao Hung , Qattan Ibrahim , Chiao Jung‐Chih , Ip Wing Yuk , Yeung Kelvin Wai Kwok , Yang Jian 
Published: October 2013

AbstractBiomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane‐doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non‐porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE‐based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2793–2804, 2014.
Biological behavior of neurally differentiated periodontal ligament stem cells on different titanium implant surfaces
Authors: Xiaojie Li , Dapeng Liao , Ping Gong , Yan Dong , Gang Sun 
Published: October 2013

AbstractWe investigated the biological behavior of periodontal ligament stem cells (PDLSCs) induced to differentiate into Schwann cells (SCs) on the surfaces of titanium discs. Two types of titanium surfaces, sand blasted and acid etched (SA) and smooth polished, were prepared on titanium discs, and the behavior of SC‐like cells on these discs was investigated. Cell morphology was examined by scanning electron microscopy, and cell proliferation was assessed using assays for methylthiazol tetrazolium metabolism and total protein content. Real‐time polymerase chain reaction and Western blotting analyses were used to determine the gene and protein expression, respectively, of SC markers by PDLSCs. Differentiated PDLSCs could adhere, proliferate, differentiate, and express SC marker genes and proteins on the prepared titanium surfaces, and the highest levels of SC marker protein expression were observed in PDLSCs on SA titanium surfaces. SA titanium surfaces show good biocompatibility for the SC‐like cells, which is important for the application of these cells in peri‐implant nerve tissue engineering, through which they are expected to improve the osseoperception of dental implants. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2805–2812, 2014.
Cross‐reactivity of cell‐selective CRRETAWAC peptide with human and porcine endothelial cells
Authors: Dudash Lynn A. , Kligman Faina L. , Bastijanic Jennifer M. , Kottke‐Marchant Kandice , Marchant Roger E. 
Published: October 2013

AbstractWe report on the cross‐reactivity of the cell adhesive peptide CRRETAWAC between human and porcine endothelial cells (ECs). CRRETAWAC is a phage display derived peptide which has been shown to bind the α5β1 receptor on human ECs, but does not bind platelets and thus could be incorporated into a coating for cardiovascular biomaterials that resists platelet adhesion and thrombosis, while allowing for endothelialization. To determine the cross‐reactivity of the peptide, attachment and growth of human and porcine ECs on CRRETAWAC fluorosurfactant polymer (FSP) coated surfaces was explored. CRRETAWAC FSP was synthesized and characterized by mass spectrometry, NMR, and IR spectroscopy. pEC attachment and growth on CRRETAWAC FSP was similar to the positive controls, human fibronectin and RGD FSP, achieving confluence in 72 h. Initial adhesion on CRRETAWAC FSP was also similar for porcine and human ECs. Blocking with soluble CRRETAWAC peptide reduced adhesion to CRRETAWAC coated surfaces by over 50%, indicating that the pECs specifically bind CRRETAWAC peptide. With this study, we have demonstrated that CRRETAWAC peptide coated surfaces are capable of binding porcine ECs in a specific manner and supporting a confluent layer of pECs. In vitro validation of the porcine model was critical for ensuring the best chance of success for the in vivo testing of CRRETAWAC coated ePTFE vascular grafts. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2857–2863, 2014.
Dyeing and antibacterial activation with methylene blue of a cyclodextrin modified polyester vascular graft
Authors: Kacem I. , Laurent T. , Blanchemain N. , Neut C. , Chai F. , Haulon S. , Hildebrand H. F. , Martel B. 
Published: October 2013

AbstractThe aim of this study was to develop an antiseptic and blue dyed polyester (PET) vascular graft in order to reach two distinct properties: (i) the prevention of postoperative infections, (ii) the improvement of the graft compatibility with the coelioscopy surgical technique. This work consisted of dyeing a vascular prosthesis with methylene blue (MB) which is known as a cationic dye with antiseptic properties. Therefore, the functionalization of the PET fibers of the prosthesis with a cyclodextrin–citric acid polymer (PolyCD) was achieved in order to improve its sorption capacity. The NMR experiments demonstrated that a 1:2 complex occurred between hydroxypropyl β‐cyclodextrin (HP‐βCD) and MB. Kinetic and sorption isotherm studies showed that an impregnation of the polyCD modified prosthesis (PET‐CD) in a 1 g L−1 of MB solution for 150 min was sufficient to reach the saturation of the device. Results proved that the adsorption mechanism followed the Langmuir model and a maximum of 20 mg g−1 of MB on the graft. A sustained release of MB in batch tests was observed in PBS and in vitro microbiological assays displayed a prolongation of the bactericidal effect of PET‐CD whose extent varied with the amount of MB preliminarily adsorbed onto the PET‐CD. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2942–2951, 2014.
Surface reconstruction and hemocompatibility improvement of a phosphorylcholine end‐capped poly(butylene succinate) coating
Authors: Hao Ni , Wang Yan‐Bing , Zhang Shi‐Ping , Shi Su‐Qing , Nakashima Kenichi , Gong Yong‐Kuan 
Published: October 2013

AbstractControl over cell–material surface interactions is the key to many new and improved biomedical devices. In this study, we present a simple yet effective surface modification method that allows for the surface reconstruction and formation of cell outer membrane mimetic structure on coatings that have significantly increased hemocompatibility. To achieve this, a phosphorylcholine end‐capped poly(butylene succinate) (PBS‐PC) was synthesized and dip‐coated on coverslips. The surface structure of the amphiphilic PBS‐PC film was reconstructed by heating in a vacuum oven to obtain the less hydrophilic surface and by immersing in hot water to obtain the more hydrophilic surface. Significant changes in the surface element concentration were observed by X‐ray photoelectron spectroscopy analysis and changes in surface wettability were measured by sensitive dynamic contact angle technique. Scanning electron microscope images showed different morphologies of the reconstructed surfaces. Interestingly, the reconstruction between the less hydrophilic and more hydrophilic surfaces is reversible. More importantly, both the reconstructed surfaces are stable in room condition for more than 6 months, and both the surfaces show significant improvement in hemocompatibility as revealed by protein adsorption and platelet adhesion measurements. This reversible surface reconstruction strategy and the interesting results may be significant for fabricating stable and hemocompatible surfaces on differently shaped biomedical devices. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2972–2981, 2014.
Immature muscular tissue differentiation into bone‐like tissue by bone morphogenetic proteins in vitro, with ossification potential in vivo
Authors: Hayashi Tatsuhide , Kobayashi Syuichiro , Asakura Masaki , Kawase Mayu , Ueno Atsuko , Uematsu Yasuaki , Kawai Tatsushi 
Published: October 2013

AbstractThe objective of this study was to induce bone formation from immature muscular tissue (IMT) in vitro, using bone morphogenetic proteins (BMPs) as a cytokine source and an expanded polytetrafluoroethylene (ePTFE) scaffold. In addition, cultured IMTs were implanted subcutaneously into Sprague‐Dawley (SD) rats to determine their in vivo ossification potential. BMPs, extracted from bovine cortical bones, were applied to embryonic SD rat IMT cultures, before 2 weeks culture on ePTFE scaffolds. Osteoblast‐like cells and osteoid tissues were partially identified by hematoxylin–eosin staining 2 weeks after culture. Collagen type I (Col‐I), osteopontin (OP), and osteocalcin (OC) were detected in the osteoid tissues by immunohistochemical staining. OC gene expression remained low, but OP and Col‐I were upregulated during the culture period. In vivo implanted IMTs showed slight radiopacity 1 week after implantation and strong radiopacity 2 and 3 weeks after implantation. One week after implantation, migration of numerous capillaries was observed and ossification was detected after 2 weeks by histological observation. These results suggest that IMTs are able to differentiate into bone‐like tissue in vitro, with an ossification potential after implantation in vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3112–3121, 2014.
Acceleration of bone formation during fracture healing by injectable collagen powder and human basic fibroblast growth factor containing a collagen‐binding domain from Clostridium histolyticum collagenase
Authors: Saito Wataru , Uchida Kentaro , Ueno Masaki , Matsushita Osamu , Inoue Gen , Nishi Nozomu , Ogura Takayuki , Hattori Shunji , Fujimaki Hisako , Tanaka Keisuke , Takaso Masashi 
Published: October 2013

AbstractGrowth factor delivered with implantable biomaterials has been used to both accelerate and ensure healing of open fractures in human patients. However, a major limitation of implantable biomaterials is the requirement for open surgical placement. Here, we developed an injectable collagen material‐based bone formation system consisting of injectable collagen powder with fibril morphology and collagen triple helix conformation, and basic fibroblast growth factor (bFGF) fused to the collagen‐binding domain (CBD) of Clostridium histolyticum collagenase. The affinity of the CBD towards collagen was confirmed by the results of collagen‐binding assays. Moreover, the combination of the collagen binding‐bFGF fusion protein (CB‐bFGF) with injectable collagen powder induced bone formation at protein concentrations lower than those required for bFGF alone in mice fracture models. Taken together, these properties suggest that the CB‐bFGF/collagen powder composite is a promising injectable material for bone repair in the clinical setting. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3049–3055, 2014.
Enhanced osteoconductivity of titanium implant by polarization‐induced surface charges
Authors: Nozaki Kosuke , Wang Wei , Horiuchi Naohiro , Nakamura Miho , Takakuda Kazuo , Yamashita Kimihiro , Nagai Akiko 
Published: October 2013

AbstractThis study introduces the application of method for electrically polarizing titanium implants coated with anatase TiO2 using microarc oxidation. It also describes the features of the electrically polarized titanium implants, on which surface charges are generated by the dipole moment of the TiO2, and describes how the surface charges affect the implants' in vivo bone–implant integration capability. A comprehensive assessment using biomechanical, histomorphological, and radiographic analyses in a rabbit model was performed on polarized and nonpolarized implants. The electrically polarized surfaces accelerated the establishment of implant biomechanical fixation, compared with the nonpolarized surfaces. The percentage of the bone–implant contact ratio was higher using polarized implants than using nonpolarized implants. In contrast, the bone volume around the implants was not affected by polarization. Thus, using the polarized implant, this study identified that controlled surface charges have a significant effect on the properties of titanium implants. The application of the electrical polarization process and the polarization‐enhanced osteoinductivity, which resulted in greater bone–implant integration, was clearly demonstrated. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3077–3086, 2014.
Self‐assembled apatite on multiwalled carbon nanotubes substrates support osteogenic cell function
Authors: Emohare Osa , Rushton Neil 
Published: October 2013

AbstractThe properties of multiwalled carbon nanotubes (MWCNT) make them attractive for use in biological matrices, especially in the development of bone‐like materials. However, their inherent hydrophobicity is a factor that has impeded broader use. A simple, novel method for coating MWCNT in apatite was developed and evaluated to enable their use in tissue engineering. This apatite coating was deposited on the nanotubes (which had been embedded in high‐density polyethylene) and facilitated the growth and differentiation of osteoblasts in a manner comparable to that of traditional tissue culture surfaces. Different levels of MWCNT purity (>90 and >95%) and chemical functionalization (carboxylation) were found to be amenable to deposition of an apatite coating and subsequent cell culture. The modalities evaluated were cell metabolic activity (MTS assay), cell proliferation (CyQuant assay), and cell differentiation (alkaline phosphatase assay); release of lactate dehydrogenase provided an indication of cytotoxicity. Although broadly comparable to traditional tissue culture surfaces, the carboxyl‐functionalized surfaces were associated with lower levels of growth and differentiation. The noncarboxylated surfaces proved to be broadly comparable to tissue culture plastic in terms of cell function. Therefore, apatite‐coated MWCNT provide a surface capable of supporting osteogenic cells. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 543–550, 2014.
Hydrothermal fabrication of ZSM‐5 zeolites: Biocompatibility, drug delivery property, and bactericidal property
Authors: Guo Ya‐Ping , Long Teng , Song Zhen‐Fu , Zhu Zhen‐An 
Published: October 2013

AbstractThe bone graft‐associated infection is widely considered in orthopedic surgery, which may lead to implant failure, extensive bone debridement, and increased patient morbidity. In this study, we fabricated ZSM‐5 zeolites for drug delivery systems by hydrothermal method. The structure, morphology, biocompatibility, drug delivery property, and bactericidal property of the ZSM‐5 zeolites were investigated. The ZSM‐5 zeolites have mordenite framework inverted‐type structure and exhibit the disk‐like shape with the diameter of ∼350 nm and thickness of ∼165 nm. The biocompatibility tests indicate that human bone marrow stromal cells spread out well on the surfaces of the ZSM‐5 zeolites and proliferate significantly with increasing culture time. As compared with the conventional hydroxyapatite particles, the ZSM‐5 zeolites possess greater drug loading efficiency and drug sustained release property because of the ordered micropores, large Brunauer‐Emmett‐Teller (BET) surface areas, and functional groups. For the gentamicin‐loaded ZSM‐5 zeolites, the sustained release of gentamicin minimizes significantly bacterial adhesion and prevents biofilm formation against Staphylococcus epidermidis. The excellent biocompatibility, drug delivery property, and bactericidal property of the ZSM‐5 zeolites suggest that they have great application potentials for treating implant‐associated infections. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 583–591, 2014.
CLCN7 and TCIRG1 Mutations Differentially Affect Bone Matrix Mineralization in Osteopetrotic Individuals
Authors: Barvencik Florian , Kurth Ingo , Koehne Till , Stauber Tobias , Zustin Jozef , Tsiakas Konstantinos , Ludwig Carmen F , Beil F Timo , Pestka Jan M , Hahn Michael , Santer Rene , Supanchart Chayarop , Kornak Uwe , Fattore Andrea Del , Jentsch Thomas J , Teti Anna , Schulz Ansgar , Schinke Thorsten , Amling Michael 
Published: October 2013

ABSTRACT

Osteopetrosis is an inherited disorder of impaired bone resorption, with the most commonly affected genes being CLCN7 and TCIRG1, encoding the Cl−/H+ exchanger CLC-7 and the a3 subunit of the vacuolar H+-ATPase, respectively. We and others have previously shown that the disease is frequently accompanied by osteomalacia, and that this additional pathology is also found in Tcirg1-deficient oc/oc mice. The remaining question was whether osteoid enrichment is specifically associated with TCIRG1 inactivation, or whether CLCN7 mutations would also cause skeletal mineralization defects. Here we describe a complete osteologic assessment of one family carrying a novel mutation in CLCN7 (D145G), which impairs the activation and relaxation kinetics of the CLC-7 ion transporter. The two siblings carrying the mutation in the homozygous state displayed high bone mass, increased serum levels of bone formation markers, but no impairment of calcium homeostasis when compared to the other family members. Most importantly, however, undecalcified processing of an iliac crest biopsy from one of the affected children clearly demonstrated a pathological increase of trabecular bone mass, but no signs of osteomalacia. Given the potential relevance of these findings we additionally performed undecalcified histology of iliac crest biopsies from seven additional cases with osteopetrosis caused by a mutation in TNFRSF11A (n = 1), CLCN7 (n = 3), or TCIRG1 (n = 3). Here we observed that all cases with TCIRG1-dependent osteopetrosis displayed severe osteoid accumulation and decreased calcium content within the mineralized matrix. In contrast, there was no detectable bone mineralization defect in the cases with TNFRSF11A-dependent or CLCN7-dependent osteopetrosis. Taken together, our analysis demonstrates that CLCN7 and TCIRG1 mutations differentially affect bone matrix mineralization, and that there is a need to modify the current classification of osteopetrosis. © 2014 American Society for Bone and Mineral Research.
Risedronate Slows or Partly Reverses Cortical and Trabecular Microarchitectural Deterioration in Postmenopausal Women
Authors: Bala Yohann , Chapurlat Roland , Cheung Angela M , Felsenberg Dieter , LaRoche Michel , Morris Edward , Reeve Jonathan , Thomas Thierry , Zanchetta Jose , Bock Oliver , Ghasem-Zadeh Ali , Djoumessi Roger Martin Zebaze , Seeman Ego , Rizzoli René 
Published: October 2013

ABSTRACT

During early menopause, steady-state bone remodeling is perturbed; the number of basic multicellular units (BMUs) excavating cavities upon the endosteal surface exceeds the number (generated before menopause) concurrently refilling. Later in menopause, steady-state is restored; the many BMUs generated in early menopause refill as similarly large numbers of BMUs concurrently excavate new cavities. We hypothesized that risedronate reduces the number of cavities excavated. However, in younger postmenopausal women, the fewer cavities excavated will still exceed the fewer BMUs now refilling, so net porosity increases, but less than in controls. In older postmenopausal women, the fewer cavities excavated during treatment will be less than the many (generated during early menopause) now refilling, so net porosity decreases and trabecular volumetric bone mineral density (vBMD) increases. We recruited 324 postmenopausal women in two similarly designed double-blind placebo-controlled studies that included 161 younger (Group 1, ≤ 55 years) and 163 older (Group 2, ≥ 55 years) women randomized 2:1 to risedronate 35 mg/week or placebo. High-resolution peripheral computed tomography was used to image the distal radius and tibia. Cortical porosity was quantified using the StrAx1.0 software. Risedronate reduced serum carboxyterminal cross-linking telopeptide of type 1 bone collagen (CTX-1) and serum amino-terminal propeptide of type 1 procollagen (P1NP) by ∼50%. In the younger group, distal radius compact-appearing cortex porosity increased by 4.2% ± 1.6% (p = 0.01) in controls. This was prevented by risedronate. Trabecular vBMD decreased by 3.6% ± 1.4% (p = 0.02) in controls and decreased by 1.6% ± 0.6% (p = 0.005) in the risedronate-treated group. In the older group, changes did not achieve significance apart from a reduction in compact-appearing cortex porosity in the risedronate-treated group (0.9% ± 0.4%, p = 0.047). No between-group differences reached significance. Results were comparable at the distal tibia. Between-group differences were significant for compact-appearing cortex porosity (p = 0.005). Risedronate slows microstructural deterioration in younger and partly reverses it in older postmenopausal women, features likely to contribute to antifracture efficacy. © 2014 American Society for Bone and Mineral Research.
Assessment of Bone Microarchitecture in Postmenopausal Women on Long-Term Bisphosphonate Therapy With Atypical Fractures of the Femur
Authors: Zanchetta Maria Belen , Diehl Maria , Buttazzoni Mirena , Galich Ana , Silveira Fernando , Bogado Cesar E , Zanchetta Jose Rubén 
Published: October 2013

ABSTRACT

Reports of atypical femoral fractures (AFFs) in patients receiving long- term bisphosphonate therapy have raised concerns regarding the genesis of this rare event. Using high-resolution peripheral quantitative computed tomography (HR-pQCT), we conducted a study to evaluate bone microarchitecture in patients who had suffered an AFF during long-term bisphosphonate treatment. The aim of our study was to evaluate if bone microarchitecture assessment could help explain the pathophysiology of these fractures. We compared bone volumetric density and microarchitectural parameters measured by HR-pQCT in the radius and tibia in 20 patients with AFFs with 35 postmenopausal women who had also received long-term bisphosphonate treatment but had not experienced AFFs, and with 54 treatment-naive postmenopausal women. Control groups were similar in age, body mass index (BMI), and bone mineral density (BMD). Mean age of the 20 patients with AFFs was 71 years, mean lumbar spine T-score was −2.2, and mean femoral neck T-score was −2. Mean time on bisphosphonate treatment was 10.9 years (range, 5–20 years). None of the patients had other conditions associated with AFFs such as rheumatoid arthritis, diabetes or glucocorticoid use. There were no statistically significant differences in any of the parameters measured by HR-pQCT between postmenopausal women with or without treatment history and with or without history of atypical fractures. We could not find any distinctive microarchitecture features in the peripheral skeleton of women who had suffered an atypical fracture of the femur while receiving bisphosphonate treatment. This suggests that risk of developing an atypical fracture is not related to bone microarchitecture deterioration. Our results indicate that there may be other individual factors predisposing to atypical fractures in patients treated with bisphosphonates, and that those are independent of bone microarchitecture. In the future, identification of those factors could help prevent and understand the complex physiopathology of these rare events. © 2014 American Society for Bone and Mineral Research.