Biomechanical analysis of decellularized dermis and skin: Initial in vivo observations using optical cohesion tomography and vibrational analysis

2018 ◽  
Vol 106 (5) ◽  
pp. 1421-1427 ◽  
Author(s):  
Ruchit G. Shah ◽  
Dale DeVore ◽  
Frederick H. Silver
Keyword(s):  
Vibrational Analysis ◽  
Biomechanical Analysis ◽  
Decellularized Dermis

Load Response of the Tarsal Bones in Patients with Flatfoot Deformity: In Vivo 3D Study

2011 ◽  
Vol 32 (11) ◽  
pp. 1017-1022 ◽  
Author(s):  
Masamitsu Kido ◽  
Kazuya Ikoma ◽  
Kan Imai ◽  
Masahiro Maki ◽  
Ryota Takatori ◽  
...  
Keyword(s):  
Load Condition ◽  
Clinical Analysis ◽  
Biomechanical Analysis ◽  
Talonavicular Joint ◽  
Level Of Evidence ◽  
Tibiotalar Joint ◽  
Talocalcaneal Joint ◽  
Load Response ◽  
Tarsal Bones

Background: The objective of this study was to evaluate the bone rotation of each joint in the hindfoot and compare the load response in healthy feet with that in flatfeet by analyzing the reconstructive three-dimensional (3D) CT image data during weightbearing. Methods: CT scans of 21 healthy feet and 21 feet with flatfoot deformity were taken in non-load condition followed by full-body weightbearing load condition. The images of the hindfoot bones were reconstructed into 3D models. The volume merge method in three planes was used to calculate the position of the talus relative to the tibia in the tibiotalar joint, the navicular relative to the talus in talonavicular joint, and the calcaneus relative to the talus in the talocalcaneal joint. Results: The talar position difference to the load response relative to the tibia in the tibiotalar joint in a flatfoot was 1.7 degrees more plantarflexed in comparison to that in a healthy foot ( p = 0.031). The navicular position difference to the load response relative to the talus in the talonavicular joint was 2.3 degrees more everted ( p = 0.0034). The calcaneal position difference to the load response relative to the talus in the talocalcaneal joint was 1.1 degrees more dorsiflexed ( p = 0.0060) and 1.7 degrees more everted ( p = 0.0018). Conclusion: Referring to previous cadaver study, regarding not only the cadaveric foot, but also the live foot, joint instability occurred in the hindfoot with load in patients with flatfoot. Clinical Relevance: The method used in this study might be applied to clinical analysis of foot diseases such as the staging of flatfoot and to biomechanical analysis to evaluate the effects of foot surgery in the future. Level of Evidence: III

scholarly journals In vivo intervertebral disc deformation: intratissue strain patterns within adjacent discs during flexion–extension

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert L. Wilson ◽  
Leah Bowen ◽  
Woong Kim ◽  
Luyao Cai ◽  
Stephanie Ellyse Schneider ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Biomechanical Analysis ◽  
Resonance Imaging ◽  
Tissue Architecture ◽  
Mechanical Responses ◽  
Flexion Extension ◽  
Adjacent Disc ◽  
Shear Strains ◽  
Magnetic Resonance Imaging Mri

AbstractThe biomechanical function of the intervertebral disc (IVD) is a critical indicator of tissue health and pathology. The mechanical responses (displacements, strain) of the IVD to physiologic movement can be spatially complex and depend on tissue architecture, consisting of distinct compositional regions and integrity; however, IVD biomechanics are predominately uncharacterized in vivo. Here, we measured voxel-level displacement and strain patterns in adjacent IVDs in vivo by coupling magnetic resonance imaging (MRI) with cyclic motion of the cervical spine. Across adjacent disc segments, cervical flexion–extension of 10° resulted in first principal and maximum shear strains approaching 10%. Intratissue spatial analysis of the cervical IVDs, not possible with conventional techniques, revealed elevated maximum shear strains located in the posterior disc (nucleus pulposus) regions. IVD structure, based on relaxometric patterns of T2 and T1ρ images, did not correlate spatially with functional metrics of strain. Our approach enables a comprehensive IVD biomechanical analysis of voxel-level, intratissue strain patterns in adjacent discs in vivo, which are largely independent of MRI relaxometry. The spatial mapping of IVD biomechanics in vivo provides a functional assessment of adjacent IVDs in subjects, and provides foundational biomarkers for elastography, differentiation of disease state, and evaluation of treatment efficacy.

Abstract 17070: Engineering a Novel Ex Vivo Heart Simulator for Biomechanical Analysis of the Aortomitral Junction

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Matthew H Park ◽  
Annabel Imbrie-moore ◽  
Yuanjia Zhu ◽  
Hanjay Wang ◽  
Michael J Paulsen ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Ex Vivo ◽  
Clinical Care ◽  
Biomechanical Analysis ◽  
Future Experimentation ◽  
3D Printed ◽  
Biomechanical Changes ◽  
Predictive Risk ◽  
Future Work

Introduction: Advances in ex vivo heart simulation have enabled the study of valvular biomechanics, disease pathologies, and repair strategies. However, these simulators test the valves in isolation, which does not fully replicate in vivo physiology. We hypothesize that by engineering a simulator that preserves the aortomitral junction, we can better recreate pathophysiologies such as systolic anterior motion (SAM). Here, we present a new heart simulator that preserves and manipulates the native aortomitral physiology. Methods: Our simulator is comprised of three subsystems: the ventricular chamber, atrial chamber, and aortic chamber (Fig A, B). The heart is excised at the apex to preserve the papillary muscles, and the left ventricle, atrial cuff, and aorta are fixed to their respective chambers via hemostatic suturing to 3D-printed elastomeric rings. The chambers are equipped with pressure and flow sensors, and a linear piston pump generates physiologic pressures and flows. The atrial and aortic chambers are mounted on 5-degree-of-freedom arms. To demonstrate system function, we manipulated the aortomitral angle and measured aortic cardiac output. Results: In our testing, we evaluated two unique configurations of an explanted porcine heart, of which the aortomitral angles spanned the SAM predictive risk threshold of <120° (Fig C, D). From the flow readings, we measured a 36% reduction in aortic cardiac output upon decreasing the aortomitral angle by 25°. Conclusions: This work highlights the design and development of an ex vivo heart simulator capable of modeling native aortomitral physiology. Our results point to a clear direction for future experimentation, particularly evaluating the biomechanical changes of the heart based on the aortomitral angle. Future work will utilize this platform to create new models and repair techniques to ultimately improve clinical care of valvular pathologies.

scholarly journals FGF-2-Induced Human Amniotic Mesenchymal Stem Cells Seeded on a Human Acellular Amniotic Membrane Scaffold Accelerated Tendon-to-Bone Healing in a Rabbit Extra-Articular Model

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jun Zhang ◽  
Ziming Liu ◽  
Yuwan Li ◽  
Qi You ◽  
Jibin Yang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Amniotic Membrane ◽  
Bone Healing ◽  
Chondrogenic Differentiation ◽  
Biomechanical Analysis ◽  
Specific Marker ◽  
Amniotic Mesenchymal Stem Cells

Background. FGF-2 (basic fibroblast growth factor) has a positive effect on the proliferation and differentiation of many kinds of MSCs. Therefore, it represents an ideal molecule to facilitate tendon-to-bone healing. Nonetheless, no studies have investigated the application of FGF-2-induced human amniotic mesenchymal stem cells (hAMSCs) to accelerate tendon-to-bone healing in vivo. Objective. The purpose of this study was to explore the effect of FGF-2 on chondrogenic differentiation of hAMSCs in vitro and the effect of FGF-2-induced hAMSCs combined with a human acellular amniotic membrane (HAAM) scaffold on tendon-to-bone healing in vivo. Methods. In vitro, hAMSCs were transfected with a lentivirus carrying the FGF-2 gene, and the potential for chondrogenic differentiation of hAMSCs induced by the FGF-2 gene was assessed using immunofluorescence and toluidine blue (TB) staining. HAAM scaffold was prepared, and hematoxylin and eosin (HE) staining and scanning electron microscopy (SEM) were used to observe the microstructure of the HAAM scaffold. hAMSCs transfected with and without FGF-2 were seeded on the HAAM scaffold at a density of 3×105 cells/well. Immunofluorescence staining of vimentin and phalloidin staining were used to confirm cell adherence and growth on the HAAM scaffold. In vivo, the rabbit extra-articular tendon-to-bone healing model was created using the right hind limb of 40 New Zealand White rabbits. Grafts mimicking tendon-to-bone interface (TBI) injury were created and subjected to treatment with the HAAM scaffold loaded with FGF-2-induced hAMSCs, HAAM scaffold loaded with hAMSCs only, HAAM scaffold, and no special treatment. Macroscopic observation, imageological analysis, histological assessment, and biomechanical analysis were conducted to evaluate tendon-to-bone healing after 3 months. Results. In vitro, cartilage-specific marker staining was positive for the FGF-2 overexpression group. The HAAM scaffold displayed a netted structure and mass extracellular matrix structure. hAMSCs or hAMSCs transfected with FGF-2 survived on the HAAM scaffold and grew well. In vivo, the group treated with HAAM scaffold loaded with FGF-2-induced hAMSCs had the narrowest bone tunnel after three months as compared with other groups. In addition, macroscopic and histological scores were higher for this group than for the other groups, along with the best mechanical strength. Conclusion. hAMSCs transfected with FGF-2 combined with the HAAM scaffold could accelerate tendon-to-bone healing in a rabbit extra-articular model.

Flexor Tendon Repair With a Knotless, Bidirectional Barbed Suture: An In Vivo Biomechanical Analysis

2015 ◽  
Vol 40 (5) ◽  
pp. 963-968 ◽  
Author(s):  
Grady E. Maddox ◽  
Jonathan Ludwig ◽  
Eric R. Craig ◽  
David Woods ◽  
Aaron Joiner ◽  
...  
Keyword(s):  
Flexor Tendon ◽  
Tendon Repair ◽  
Biomechanical Analysis ◽  
Barbed Suture ◽  
Flexor Tendon Repair

Imaging Sarcomeres of Extensor Carpi Radialis Brevis in Humans Using Minimally Invasive Microendoscopy

2009 ◽  
Author(s):  
Melinda J. Cromie ◽  
Gabriel N. Sanchez ◽  
Mark J. Schnitzer ◽  
Scott L. Delp
Keyword(s):  
Minimally Invasive ◽  
Fluorescent Dyes ◽  
Second Harmonic ◽  
Human Subjects ◽  
The Body ◽  
Biomechanical Analysis ◽  
Capacity Measurement ◽  
Generating Capacity ◽  
Extensor Carpi Radialis

Sarcomeres are the smallest contractile elements of muscle. Muscle generates force when overlapping myosin and actin filaments within the sarcomere interact to generate force. The amount of force these interactions generate depends on sarcomere length. The range of sarcomere lengths over which a muscle normally operates in the body is an important factor in analyzing a muscle’s force generating capacity. Measurement of sarcomere lengths in vivo is limited by their small size (2–4 μm) and the inability to use fluorescent dyes in humans. We recently developed a microendoscopy system to image sarcomeres in humans via Second Harmonic Generation (SHG) [1]. Here we demonstrate the use of this microendoscopy system as a robust, minimally-invasive tool for biomechanical analysis by measuring sarcomere lengths of the forearm muscle extensor carpi radialis brevis (ECRB) in 5 human subjects.

Establishing Corneal Cross-Linking With Riboflavin and UV-A in the Mouse Cornea In Vivo: Biomechanical Analysis

2015 ◽  
Vol 56 (11) ◽  
pp. 6581 ◽  
Author(s):  
Arthur Hammer ◽  
Sabine Kling ◽  
Marc-Olivier Boldi ◽  
Olivier Richoz ◽  
David Tabibian ◽  
...  
Keyword(s):  
Biomechanical Analysis ◽  
Cross Linking

scholarly journals Development of a Detailed Volumetric Finite Element Model of the Spine to Simulate Surgical Correction of Spinal Deformities

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mark Driscoll ◽  
Jean-Marc Mac-Thiong ◽  
Hubert Labelle ◽  
Stefan Parent
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Ex Vivo ◽  
Spinal Instrumentation ◽  
Element Model ◽  
Patient Data ◽  
Biomechanical Analysis ◽  
Published Data

A large spectrum of medical devices exists; it aims to correct deformities associated with spinal disorders. The development of a detailed volumetric finite element model of the osteoligamentous spine would serve as a valuable tool to assess, compare, and optimize spinal devices. Thus the purpose of the study was to develop and initiate validation of a detailed osteoligamentous finite element model of the spine with simulated correction from spinal instrumentation. A finite element of the spine from T1 to L5 was developed using properties and geometry from the published literature and patient data. Spinal instrumentation, consisting of segmental translation of a scoliotic spine, was emulated. Postoperative patient and relevant published data of intervertebral disc stress, screw/vertebra pullout forces, and spinal profiles was used to evaluate the models validity. Intervertebral disc and vertebral reaction stresses respected publishedin vivo,ex vivo, andin silicovalues. Screw/vertebra reaction forces agreed with accepted pullout threshold values. Cobb angle measurements of spinal deformity following simulated surgical instrumentation corroborated with patient data. This computational biomechanical analysis validated a detailed volumetric spine model. Future studies seek to exploit the model to explore the performance of corrective spinal devices.

In Vivo Characterization of a Decellularized Dermis-Polymer Complex for Use in Percutaneous Devices

2014 ◽  
Vol 38 (12) ◽  
pp. 1060-1065 ◽  
Author(s):  
Kwangwoo Nam ◽  
Rie Matsushima ◽  
Tsuyoshi Kimura ◽  
Toshiya Fujisato ◽  
Akio Kishida
Keyword(s):  
Polymer Complex ◽  
In Vivo Characterization ◽  
Decellularized Dermis

scholarly journals Plasma Electrolytic Oxidation as a Feasible Surface Treatment for Biomedical Applications: an in vivo study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tárik Ocon Braga Polo ◽  
William Phillip Pereira Silva ◽  
Gustavo Antonio Correa Momesso ◽  
Tiburtino José Lima-Neto ◽  
Stéfany Barbosa ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Immunohistochemical Analysis ◽  
Elisa Test ◽  
Biomechanical Analysis ◽  
Control Surface ◽  
Bone Maturation ◽  
Reverse Torque ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Abstract Objectives: In this in vivo animal study, we evaluated the effect of plasma electrolytic oxidation (PEO) coating on the topographic and biological parameters of implants installed in rats with induced osteoporosis and low-quality bones. Materials and methods: In total 44 Wistar rats (Rattus novergicus), 6 months old, were submitted to ovariectomy (OXV group) and dummy surgery (SHAM group). After 90 days, the ELISA test was performed and the ovariectomy effectiveness was confirmed. In each tibial metaphysis, an implant with PEO coating containing Ca2+ and P5+ molecules were installed, and the other tibia received an implant with SLA acid etching and blasting (AC) (control surface). After 42 days, 16 rats from each group were euthanized, their tibias were removed for histological and immunohistochemical analysis (OPG, RANKL, OC and TRAP), as well as reverse torque biomechanics. Data were submitted to One-way ANOVA or Kruskal-Wallis tests, followed by a Tukey post-test; P < 0.05. Histological analyses showed higher bone neoformation values among the members of the PEO group, SHAM and OVX groups. Immunohistochemical analysis demonstrated equilibrium in all groups when comparing surfaces for TRAP, OC and RANKL (P > 0.05), whereas OPG showed higher PEO labeling in the OVX group (P < 0.05). Biomechanical analysis showed higher reverse torque values (N.cm) for PEO, irrespective of whether they were OVX or SHAM groups (P < 0.05). Conclusion: The results indicated that the PEO texturing method favored bone formation and showed higher bone maturation levels during later periods in osteoporotic rats.

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