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Biomedical Materials

Sherif Ramadan, Narinder Paul, Hani E Naguib
INTRODUCTION: Quantifying the mechanical behaviours of soft biological tissues is of considerable research interest. However, validity and reproducibility between different researchers and apparatus is questionable. This study aims to quantify the mechanical properties of myocardium while investigating methodologies that can standardize biological tissue testing. MATERIALS AND METHODS: Tensile testing was performed to obtain Young���s modulus and a dynamic mechanical analysis (DMA) determined the viscoelastic properties...
January 9, 2017: Biomedical Materials
Agata Przekora, Marta Vandrovcova, Martina Travnickova, Julia Pajorova, Martin Molitor, Grazyna Ginalska, Lucie Bacakova
The opinion regarding the origin of adult stem cells that should be used for living bone construct generation is strongly divided in the scientific community. In this study, the potential of chitosan/β-1,3-glucan/HA material as scaffold for bone regeneration applications was evaluated by behaviour comparison of adult stem cells derived from both origins - adipose tissue (ADSCs) and bone marrow (BMDSCs). In the case of ADSC isolation, low and high negative pressures were applied during liposuction procedure in order to determine if negative pressure settings may have impact on subsequent cell behaviour <i>in vitro</i>...
January 5, 2017: Biomedical Materials
Yuan Shi, Kaili Zhou, Wenjie Zhang, Zhiyong Zhang, Guangdong Zhou, Yilin Cao, Wei Liu
Tendon derived stem cells (TDSCs) are the endogenous cell source for tenocyte turnover and tendon functional maintenance. They are also the important cell source for tendon engineering and regeneration. In addition, TDSCs also play an important role in tendinopathy via their non-tenogenic lineage differentiation. It has been well demonstrated that cell shape could determine mesenchymal stem cell (MSC) lineage differentiation. In this study, a parallel microgrooved polydimethylsiloxane (PDMS) membrane (10 µm groove width and 3 µm depth) was employed to investigate the role of cell elongation via this particular topographic surface in directing murine TDSC (mTDSC) lineage differentiation...
January 10, 2017: Biomedical Materials
Peng Hou, Changli Zhao, Pengfei Cheng, Hongliu Wu, Jiahua Ni, Shaoxiang Zhang, Tengfei Lou, Chunyang Wang, Pei Han, Xiaonong Zhang, Yimin Chai
Magnesium and its alloys have drawn interest as antibacterial biomaterials, owing to their ability to alkalize the surrounding medium during degradation. The antibacterial effect of pure Mg and Mg alloys in vitro has previously been reported. However, the antibacterial property of Mg in vivo might be different because of the apparently dissimilar corrosion characteristics. In this study, pure Mg rods were implanted and bacterial suspension were injected into rat femurs to investigate the antibacterial property of Mg in vivo...
December 9, 2016: Biomedical Materials
Eline-Claire Grosfeld, Jan Willem M Hoekstra, Ralf-Peter Herber, Dietmar J O Ulrich, John A Jansen, Jeroen J J P van den Beucken
Enhancing degradation of poorly degrading injectable calcium phosphate (CaP) cements (CPCs) can be achieved by adding poly(lactic-co-glycolic acid) (PLGA) microparticles, generating porosity after polymer degradation. CPC-PLGA has proven to be biodegradable, although its long-term biological performance is still unknown. Optimization of injectability could be achieved via addition of carboxymethyl cellulose (CMC). Here, we evaluated the long-term in vivo performance of CPC-PLGA with or without the lubricant CMC in comparison to the devitalized bovine bone mineral (DBBM) predicate device Bio-Oss(®)...
December 9, 2016: Biomedical Materials
Ena Bolaina-Lorenzo, Cristina Martínez-Ramos, Manuel Monleón-Pradas, Wilberth Herrera-Kao, Juan V Cauich-Rodríguez, José M Cervantes-Uc
Electrospun polycaprolactone (PCL)/chitosan (CH) blend scaffolds with different CH weight ratios were prepared to study the effect of scaffold composition on its physicochemical and biological properties. Scanning electron microscopy showed bead-free homogeneous randomly arranged nanofibers whose average diameter decreased from 240 to 110 nm with increasing CH content. The infrared spectra of the PCL/CH blends were very similar to the neat PCL scaffold. Energy-dispersive x-ray spectroscopy analysis confirmed the presence of carbon, oxygen and nitrogen in the scaffolds, although fluorine-from chemicals used as solvent-was also detected...
December 9, 2016: Biomedical Materials
Rong Zhu, Xinyu Wang, Jing Yang, Yiyu Wang, Zongrui Zhang, Yuanjing Hou, Fei Lin
The present study describes a series of novel polycarbonate urethane films that were fabricated via the solution-casting method from 4,4'-methylenebis(cyclohexyl isocyanate) (H12MDI) and 1,4-butanediol (BDO) chain extender as hard segments, poly(1,6-hexanediol)carbonate diols (PCDL) and hydroxyl-terminated polydimethylsiloxane (PDMS) as soft segments, with dibutyltin dilaurate as the catalyst. Varied molar ratios of PDMS (less than 30%) were utilized to enhance the mechanical properties and biocompatibilities...
December 9, 2016: Biomedical Materials
Sidi Li, Jianwei Wang, Lifeng Song, Yalin Zhou, Jin Zhao, Xin Hou, Xubo Yuan
In situ injectable double-crosslinked hydrogels containing thiol functionalized poly(amido-amine) dendrimers (Gn-PAMAM-NH2-X) and oxidized dextrans (ODex) were prepared under physiological conditions without using potentially cytotoxic cross-linkers. The double-crosslinked structure was created by Schiff's base reaction and the formation of disulfide bonds. The morphology of the hydrogels was characterized by scanning electron microscopy. The gelation time, swelling and rheological behaviors of the hydrogels were investigated...
December 9, 2016: Biomedical Materials
Yuqiao Sun, Yongnu Zhang, Lingling Tian, Yuyuan Zhao, Dongni Wu, Wei Xue, Seeram Ramakrishna, Wutian Wu, Liumin He
In the current study, we present three designer self-assembling peptides (SAPs) by appending RADA 16-I with epitopes IKVAV, RGD, and YIGSR, which have different net charges and amphiphilic properties at neutral pH. The self-assembly of the designer SAPs is intensively investigated as a function of pH, canion type, and assembly time. The morphologies of the designer SAPs were studied by atomic force microscope. The secondary structure was investigated by circular dichroism. The dynamic viscoelasticity of designer SAP solutions was examined during titration with different alkaline reagents...
December 9, 2016: Biomedical Materials
Robert P Howlin, Christopher Winnard, Connor J Frapwell, Jeremy S Webb, John J Cooper, Sean S Aiken, Paul Stoodley
Biofilm formation represents a key stage in the pathogenesis of prosthetic infections (PIs). More tolerant to antibiotics than their planktonic counterparts, biofilm bacteria are difficult to eradicate using conventional therapeutic regimes. A common approach in PI management is the adjunctive use of localised antibiotics in addition to systemic administration in an attempt to protect the implant from colonisation by infiltrating bacteria. This study evaluates the antibacterial and antibiofilm efficacy of antibiotic-loaded dissolvable calcium sulphate, previously shown to be effective against key gram-positive pathogens, against gram-negative species important in the establishment of chronic infection in PIs...
December 2, 2016: Biomedical Materials
Yi Liu, Dan Li, Zongqi Yin, Xusong Luo, Wei Liu, Wenjie Zhang, Zhiyong Zhang, Yilin Cao, Yu Liu, Guangdong Zhou
Synthetic biodegradable scaffolds such as polylactic acid coated polyglycolic acid (PLA-PGA) are especially suitable for engineering shaped cartilage such as auricle, but they induce a serious inflammatory reaction particularly in the immunologically aggressive subcutaneous site, leading to resorption of the engineered autologous cartilage. Our previous study in a rabbit model has demonstrated 2 weeks of in vitro precultivation could significantly alleviate the post-implantation inflammation induced by PLA-PGA engineered cartilaginous grafts, but reproduction of this result failed in a preclinical goat model...
December 2, 2016: Biomedical Materials
Yu-Chih Huang, Wei-Zhen Lew, Sheng-Wei Feng, Wei-Yi Lai, Yoshimitsu Abiko, Haw-Ming Huang
Human particulate dentin (HPD) shows potential as an alternative bone grafting material. However, the mechanism of bone healing at the molecular level after grafting with HPD is unclear. This study assessed the histological and global gene expression of bone tissues grafted with HPD. The HPD was prepared to 250-500 µm in size. X-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDX) were performed to confirm the crystal structure, organic compound residues, and surface morphology, respectively...
December 2, 2016: Biomedical Materials
Giuseppe Pezzotti, B Sonny Bal, Elisa Casagrande, Nobuhiko Sugano, Bryan J McEntire, Wenliang Zhu, Leonardo Puppulin
The chemical interaction of femoral heads with polyethylene liners is an important new area of research in total hip arthroplasty (THA) as a consequence of an unabating quest for elongated artificial joint lifetimes. It is a topic that goes beyond simple mechanical behavior or wear. It seeks to describe the prosthetic device as a whole by adding chemical considerations to mechanics and abrasion. One of the poorly understood chemical interactions is oxygen affinity of the femoral heads. While oxygen unavoidably diffuses into the non-crystalline enclaves of the polyethylene liner as a result of its contact with the tribolayer, a ceramic femoral head can either attract or release oxygen due to its tribochemical interactions...
December 2, 2016: Biomedical Materials
Xing Yang, Yuanyuan Li, Xujie Liu, Qianli Huang, Wei He, Ranran Zhang, Qingling Feng, Dafna Benayahu
Silica-based materials with favourable biocompatibility are generally considered as excellent candidates for applications in biomedical fields. However, previous researches mainly focused on the safety of silica-based materials, their effects on osteogenic differentiation of human mesenchymal stem cells (hMSCs) still need further investigations. In this study, core-shell fluorescent silica nanoparticles (silica NPs) with three different sizes (S1 ~ 50 nm, S2 ~ 200 nm, S3 ~ 400 nm, respectively) were prepared according to the Stöber method...
December 2, 2016: Biomedical Materials
Hengjie Su, Kwei-Yu Liu, Anastasios Karydis, Daniel G Abebe, Chaoxi Wu, Kenneth M Anderson, Najib Ghadri, Pradeep Adatrow, Tomoko Fujiwara, Joel D Bumgardner
Electrospun chitosan membranes have been investigated for guided bone regeneration but are susceptible to swelling, dissolution, and loss of biomimetic nanofiber structure due to residual acid salts. A novel process was investigated for acidic salt removal from chitosan electrospun in 70% trifluoroacetic acid (TFA) by treating with triethylamine (TEA)/acetone and di-tert-butyl dicarbonate (tBOC) instead of the common Na2CO3 treatment. TFA salt removal and nanofiber structure stabilization were confirmed by EDS, FTIR, (19)F NMR and electron microscopy before and after soaking in water...
December 2, 2016: Biomedical Materials
Satomi Tsukawaki, Tomoaki Murakami, Kazuhiko Suzuki, Yasumoto Nakazawa
Amyloid A (AA) amyloidosis can be induced by the administration of amyloid fibrils to animals under inflammatory conditions. Silk fibroin (SF) is a main component protein of bombic silk and has amyloid-like features. The amyloidogenesis of SF solution in mice has been previously reported. Recently, the biochemical properties of silk have attracted increasing attention, and research and development have been undertaken regarding applications other than as a clothing material. However, the risk of AA amyloidosis from exposure to SF-related products is unknown...
November 21, 2016: Biomedical Materials
Timothy E L Douglas, Agata Łapa, Katarzyna Reczyńska, Małgorzata Krok-Borkowicz, Krzysztof Pietryga, Sangram Keshari Samal, Heidi A Declercq, David Schaubroeck, Marijn Boone, Pascal Van der Voort, Karel De Schamphelaere, Christian V Stevens, Vitaliy Bliznuk, Lieve Balcaen, Bogdan V Parakhonskiy, Frank Vanhaecke, Veerle Cnudde, Elżbieta Pamuła, Andre G Skirtach
The suitability of hydrogel biomaterials for bone regeneration can be improved by incorporation of an inorganic phase in particle form, thus maintaining hydrogel injectability. In this study, carbonate microparticles containing different amounts of calcium (Ca) and magnesium (Mg) were added to solutions of the anionic polysaccharide gellan gum (GG) to crosslink GG by release of Ca(2+) and Mg(2+) from microparticles and thereby induce formation of hydrogel-microparticle composites. It was hypothesized that increasing Mg content of microparticles would promote GG hydrogel formation...
November 21, 2016: Biomedical Materials
Sunyoung Joo, Seh-Hoon Oh, Sivanandane Sittadjody, Emmanual C Opara, John D Jackson, Sang Jin Lee, James J Yoo, Anthony Atala
The in vivo function and phenotype of ovarian follicle cells are determined by many factors. When these cells are removed from the in vivo microenvironment and grown in a 2D in vitro environment, the function of the follicular cells is difficult to preserve. A collagen hydrogel was used to examine the hormone and oocyte maturation of ovary follicles in a 3D culture system. Ovarian follicles from rats were isolated and cultured in various concentration of type I collagen hydrogels ranging from 1% to 7% (weight/volume)...
November 11, 2016: Biomedical Materials
Xudong Wen, Hongbo Huan, Xiaojun Wang, Xuejiao Chen, Lili Wu, Yujun Zhang, Weihui Liu, Ping Bie, Feng Xia
Recellularized liver, as an approach for hepatic tissue engineering, is an effective alternative to orthotopic liver transplantation for end-stage hepatic failure. When compared with normal liver, recellularized liver has a disparity in hepatocyte viability and function, owing to the difficulty of fully simulating the microenvironment of liver. Although the sympathetic nervous system (SNS) is considered an important constituent of liver function, few studies have examined the effect of the SNS on hepatic tissue engineering...
November 4, 2016: Biomedical Materials
Lin Wang, Ping Wang, Michael D Weir, Mark A Reynolds, Liang Zhao, Hockin H K Xu
Human induced pluripotent stem cells (hiPSCs), human embryonic stem cells (hESCs) and human umbilical cord mesenchymal stem cells (hUCMSCs) are exciting cell sources for use in regenerative medicine. There have been no reports on long hydrogel fibers encapsulating stem cells inside an injectable calcium phosphate cement (CPC) scaffold for bone tissue engineering. The objectives of this study were: (1) to develop a novel injectable CPC construct containing hydrogel fibers encapsulating cells for bone engineering, and (2) to investigate and compare cell viability, proliferation and osteogenic differentiation of hiPSC-MSCs, hESC-MSCs and hUCMSCs in injectable CPC...
November 4, 2016: Biomedical Materials
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