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Bench test for magnesium scaffold
Published in Yoshinobu Onuma, Patrick W.J.C. Serruys, Bioresorbable Scaffolds, 2017
Daniel Lootz, Wolfram Schmidt, Peter Behrens, Klaus-Peter Schmitz, Michael Haude, Ron Waksman
The main function of a scaffold, just like that of a stent, is to support the vessel and keep the lumen open. This ability can be characterized by the acute recoil, i.e., the reduction in scaffold diameter between the expanded state (on the pressurized balloon) and after balloon deflation. The amount of acute recoil is governed by two effects: the elastic recoil (load-free spring-back of the structure due to the elastic-plastic material behavior), and the radial load applied by the overstretched vessel balanced by the radial force of the scaffold. Generally, those two effects are investigated by independent in vitro tests.
Application of an in silico approach identifies a genetic locus within ITGB2, and its interactions with HSPG2 and FGF9, to be associated with anterior cruciate ligament rupture risk
Published in European Journal of Sport Science, 2023
Senanile B. Dlamini, Colleen J. Saunders, Mary-Jessica N. Laguette, Andrea Gibbon, Junaid Gamieldien, Malcolm Collins, Alison V. September
No independent associations were identified for HSPG2. HSPG2 encodes for perlecan, a major heparin sulfate proteoglycan found in basement membranes which has been implicated to play a key role in binding and delivering growth factors such as platelet derived and fibroblast growth factors to the extracellular space (Melrose et al., 2006). Evidence suggests it plays a role in facilitating (i) several cellular environmental interactions and (ii) interactions between several extracellular matrix (ECM) components and thereby it may contribute to regulating tissue homeostasis (Melrose et al., 2006; Whitelock & Iozzo, 2005). Perlecan is composed of five domains each with specific functions, the rs2291826 and rs2291827 variants localise within the third domain responsible for cell surface binding and secretion into the extracellular space (Colognato & Yurchenco, 2000; Melrose et al., 2006). The function of these SNPs has not been investigated in ACL ruptures. It is interesting to note that perlecan and elastin were found to colocalise within connective tissues such as the ACL attachment regions to bone, paraspinal stromal tissues and synovial tissues of the bovine knee joint (Hayes et al., 2011). These findings suggest the potential significant interactive properties between the two proteins and importance of perlecan in contributing to ligament elasticity. Elastin is regarded as one of the major structural components of elastic fibres that give tendons and ligaments elastic recoil properties (Hayes et al., 2011).
Characterization of a heparinized decellularized scaffold and its effects on mechanical and structural properties
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Ji Li, Zhiwen Cai, Jin Cheng, Cong Wang, Zhiping Fang, Yonghao Xiao, Zeng-Guo Feng, Yongquan Gu
Mechanical strength is one of the key parameters that determine the suitability of a vessel graft for clinical implantation [84]. Therefore, mechanical testing was carried out to determine the effect on the overall mechanical response of the tissues. The arterial tissue was a composite structure composed of three relevant layers with different mechanical properties. A mixture of ECM components, particularly elastin and collagen, collectively contribute to mechanical behavior [85]. Collagen provides strength and elastin provides elastic recoil. The elastin fibers contained in the elastic lamellae of media of elastic arteries are circumferentially oriented, and of the internal and external elastic lamina (IEL and EEL) are longitudinally oriented [86]. Collagen fiber alignment analyzed by second harmonic generation microscopy revealed that the collagen fibers were mainly oriented circumferentially in the outer adventitia and media [87]. The collagen fibers that were distributed near the regions of internal and external elastic lamina were mainly longitudinally oriented similar to the elastin fibers [87]. Thus, the uniaxial tensile properties were performed on both longitudinal and circumferential directions.
Lung volume reduction with endobronchial valves in patients with emphysema
Published in Expert Review of Medical Devices, 2018
Marieke C. Van Der Molen, Karin Klooster, Jorine E. Hartman, Dirk-Jan Slebos
Several bronchoscopic techniques were developed to induce volume reduction in patients with hyperinflation. Treatments can be divided into ‘blocking’ and ‘non-blocking’ techniques. In treatment with non-blocking techniques, patients with hyperinflation qualify for intervention regardless of the presence of collateral ventilation. Non-blocking techniques focus on restoring elastic recoil or improving compliance in the emphysematous lung. This can be accomplished by the insertion of endobronchial coils (Figure 6(c)) [58], by inducing fibrosis via thermal vapor ablation [59], or the appliance of lung sealant [60]. Another non-blocking alternative is to create an airway bypass, whereby collateral ventilation is used to deflate the hyperinflated lung lobe into the adjacent lobe. However, because of loss of patency of the bypass over months, these effects are temporary and further research is needed to optimize this approach [61].