Journal of the mechanical behavior of biomedical materials
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J Mech Behav Biomed Mater · Sep 2016
Preparation of a partially carboxymethylated cotton gauze and study of its hemostatic properties.
In this study, we attempted to modify cotton gauze by partial carboxymethylation by varying the reaction time and concentration of monochloroacetic acid and sodium hydroxide. For each experiment, the relative value of the degree of substitution (DS) of the modified cotton gauze was evaluated and the whole blood clotting time (WBCT) and water absorption property were compared with cotton gauze and Surgicel. This revealed that, following an initial decrease, WBCT gradually increased. ⋯ The average bleeding times in the presence of modified cotton gauze in the rabbit ear arteries and the liver were 51.7s and 60.6s, while those with Surgicel and the unmodified cotton gauze were 76.8s and 95.5s, and 93.2s and 129.2s, respectively. The hemostatic and biocompatibility properties were evaluated using in vivo degradation experiments. This revealed that the modified gauze and Surgicel were totally degraded within 6 weeks.
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J Mech Behav Biomed Mater · Aug 2016
Nanofibrous biomimetic mesh can be used for pelvic reconstructive surgery: A randomized study.
Implantation of nonabsorbable polypropylene (PP) mesh in the vagina is the main surgical treatment for pelvic organ prolapse (POP); however, clinical outcomes remain controversial and far from satisfactory. In particular, reducing the exposure or erosion of vaginal implants to obtain improved functional reconstruction is challenging. There is an urgent need for the development of new materials and/or products for POP treatment. A nanofibrous biomimetic mesh was recently developed to address this issue. ⋯ The nanofibrous biomimetic mesh is a candidate for reinforcing pelvic reconstruction. The mesh could be improved by decreasing its weight and stiffness and increasing its porosity. This mesh could serve as a carrier for stem cells in future regenerative medicine and tissue engineering research.
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J Mech Behav Biomed Mater · Apr 2016
Development of skull fracture criterion based on real-world head trauma simulations using finite element head model.
The objective of this study was to enhance an existing finite element (FE) head model with composite modeling and a new constitutive law for the skull. The response of the state-of-the-art FE head model was validated in the time domain using data from 15 temporo-parietal impact experiments, conducted with postmortem human surrogates. The new model predicted skull fractures observed in these tests. ⋯ The proposed tolerance limit for 50% risk of skull fracture was associated with 453mJ of internal energy. Statistical analyses were extended for individual impact locations (frontal, occipital and temporo-parietal) and separate injury risk curves were obtained. The 50% risk of skull fracture for each location: frontal: 481mJ, occipital: 457mJ, temporo-parietal: 456mJ of skull internal energy.
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J Mech Behav Biomed Mater · Aug 2015
Derivation of inter-lamellar behaviour of the intervertebral disc annulus.
The inter-lamellar connectivity of the annulus fibrosus in the intervertebral disc has been shown to affect the prediction of the overall disc behaviour in computational models. Using a combined experimental and computational approach, the inter-lamellar mechanical behaviour of the disc annulus was investigated under conditions of radial loading. Twenty-seven specimens of anterior annulus fibrosus were dissected from 12 discs taken from four frozen ovine thoracolumbar spines. ⋯ The interface stiffness values of the outer annulus were from 43% to 75% higher than those of the inner annulus. Tangential stiffness values for the interface were from 6% to 39% higher than normal stiffness values within each group and similar to values reported by other investigators. These results reflect the intricate fibrous nature of the inter-lamellar connectivity and provide values for the representation of the inter-lamellar behaviour at a continuum level.
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J Mech Behav Biomed Mater · Jul 2015
Tissue mechanics of piled critical size biomimetic and biominerizable nanocomposites: Formation of bioreactor-induced stem cell gradients under perfusion and compression.
Perfusion bioreactors are used to solve problems in critical size bone tissue engineering. Biominerizable and biocompatible nanocomposites are suitable scaffold materials for this purpose because they offer mineral components in organic carriers. Human adipose derived stem cells (ASCs) can potentially be used to increase bone healing. ⋯ The fabrication of a critical size bone graft is presented based on a biominerizable bone-biomimetic nanocomposite with preserved stiffness when seeded with ASCs. The cell densities of ASCs inside the piled construct varied with a linear gradient. Beginning osteogenesis was triggered by the dynamic culture conditions including perfusion and compression.