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Aiming to achieve suitable polymeric biomaterials with controlled physical properties for hard and soft tissue replacements, we have developed a series of blends consisting of two photo-cross-linkable polymers: polypropylene fumarate (PPF) and polycaprolactone fumarate (PCLF). Physical properties of both un-cross-linked and UV cross-linked PPF/PCLF blends(More)
Indentation and histological analysis of the porcine iris were done to assess the relative stiffness of the anterior (stroma) and posterior (dilator and sphincter) layers. The dimensions of the constituent structures were documented histologically by staining with a monoclonal anti-human α-smooth muscle actin antibody to determine the location of the(More)
Failure properties of cartilage are important in injury repair and disease, but few methods exist for measuring these properties, especially in small animals. To meet this need, a new indentation/penetration method for measuring fracture toughness of cartilage is proposed. During indentation, a conical tip is displaced into the surface of the cartilage,(More)
The tensile stiffness of tissue grown from chondrocyte culture was both measured experimentally and predicted using a composites model theory relating tissue microstructure to macroscopic material stiffness. The tissue was altered by several treatment protocols to provide a wide range of collagen fibril volume fraction (0.015-0.15). The rate of change of(More)
A method for fitting parameters in a poroviscoelastic (PVE) model of articular cartilage in the mouse is presented. Indentation is performed using two different sized indenters and then these data are fitted using a PVE finite element program and parameter extraction algorithm. Data from a smaller indenter, a 15 mum diameter flat-ended 60 deg cone, is first(More)
Segmented polyurethane multiblock polymers containing polydimethylsiloxane and polyether soft segments form tough and easily processed thermoplastic elastomers (PDMS-urethanes). Two commercially available examples, PurSil 35 (denoted as P35) and Elast-Eon E2A (denoted as E2A), were evaluated for abrasion and fatigue resistance after immersion in 85 °C(More)
Our preliminary indentation experiments showed that the equilibrium elastic modulus of murine tibial cartilage increased with decreasing indenter size: flat-ended 60 deg conical tips with end diameters of 15 microm and 90 microm gave 1.50+/-0.82 MPa (mean+/-standard deviation) and 0.55+/-0.11 MPa, respectively (p<0.01). The goal of this paper is to(More)
OBJECTIVE This paper examines the hypothesis that the dermatan sulfate (DS) chain on decorin is a load carrying element in cartilage and that its damage or removal will alter the material properties. METHODS To test this hypothesis, indentation and tensile testing of cartilage from bovine patella were performed before and after digestion with(More)
Recordings of cardiac surface potentials from animal hearts can be mapped into human torso and used as source potentials for torso simulation. However, geometric registration of the heart can introduce changes in the effective conduction velocity due to change in relative positions of the recording sites. We developed a time dilation technique to ensure(More)