Mechanical Properties and Related Histological Alterations of Engineered Tendons In Vivo

2005 ◽  
Vol 288-289 ◽  
pp. 11-14 ◽  
Author(s):  
Ting Wu Qin ◽  
Shujiang Zhang ◽  
Zhi Ming Yang ◽  
Xiang Tao Mo ◽  
Xiu Qun Li
Keyword(s):  
Mechanical Properties ◽  
Collagen Synthesis ◽  
Biomechanical Properties ◽  
Biomechanical Test ◽  
Histological Alterations ◽  
Normal Tendon ◽  
Tendon Cells ◽  
Biomechanical Stimulation

The purpose of this research is to find out the interaction between histological alterations and mechanical properties of engineered tendon implanted in situ. Defects of 0.5cm-1.0cm were made at deep flexor tendons by surgical procedure. Engineered tendons using degradable scaffolds polyglytic acid (PGA) mesh and tendon cells were implanted to repair the defects. Chickens were killed respectively at 2 weeks, 4 weeks, 6 weeks, and 8 weeks after surgery. The implants were taken out for histological examination, biomechanical test, and collagen synthesis assay. The results showed that after surgery the PGA scaffolds degraded fast and took precedence of collagen synthesis. There were not enough amount and maturation of the collagen fibers of the new tendon at 2-8 weeks after surgery. The biomechanical properties of new tendons were less than those of the normal tendon. Therefore, it is necessary to construct engineered tendons with better degradation rate of scaffolds and suitable biomechanical stimulation so that more collagen synthesis and better biomechanical properties of new tendons can be developed early after implantation.

scholarly journals Fabrication, Crystalline Behavior, Mechanical Property and In-Vivo Degradation of Poly(l–lactide) (PLLA)–Magnesium Oxide Whiskers (MgO) Nano Composites Prepared by In-Situ Polymerization

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1123 ◽  
Author(s):  
Hui Liang ◽  
Yun Zhao ◽  
Jinjun Yang ◽  
Xiao Li ◽  
Xiaoxian Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Oxide ◽  
Bone Repair ◽  
In Situ Polymerization ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Biomedical Material ◽  
In Vivo Degradation

The present work focuses on the preparation of poly(l–lactide)–magnesium oxide whiskers (PLLA–MgO) composites by the in-situ polymerization method for bone repair and implant. PLLA–MgO composites were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and solid-state 13C and 1H nuclear magnetic resonance spectroscopy (NMR). It was found that the whiskers were uniformly dispersed in the PLLA matrix through the interfacial interaction bonding between PLLA and MgO; thereby, the MgO whisker was found to be well-distributed in the PLLA matrix, and biocomposites with excellent interface bonding were produced. Notably, the MgO whisker has an effect on the crystallization behavior and mechanical properties; moreover, the in vivo degradation of PLLA–MgO composites could also be adjusted by MgO. These results show that the whisker content of 0.5 wt % and 1.0 wt % exhibited a prominent nucleation effect for the PLLA matrix, and specifically 1.0 wt % MgO was found to benefit the enhanced mechanical properties greatly. In addition, the improvement of the degrading process of the composite illustrated that the MgO whisker can effectively regulate the degradation of the PLLA matrix as well as raise its bioactivity. Hence, these results demonstrated the promising application of PLLA–MgO composite to serve as a biomedical material for bone-related repair.

Using ultrasound transmission velocity to analyse the mechanical properties of teeth after in vitro, in situ, and in vivo irradiation

2000 ◽  
Vol 4 (3) ◽  
pp. 168-172 ◽  
Author(s):  
B. Al-Nawas ◽  
K. A. Grötz ◽  
E. Rose ◽  
H. Duschner ◽  
P. Kann ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Transmission Velocity

scholarly journals Compressional Optical Coherence Elastography of the Cornea

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 111
Author(s):  
Manmohan Singh ◽  
Achuth Nair ◽  
Salavat R. Aglyamov ◽  
Kirill V. Larin
Keyword(s):  
Rabbit Model ◽  
Biomechanical Properties ◽  
Clinical Applications ◽  
Optical Coherence ◽  
Collagen Crosslinking ◽  
Corneal Collagen Crosslinking ◽  
Corneal Biomechanical Properties ◽  
Corneal Collagen

Assessing the biomechanical properties of the cornea is crucial for detecting the onset and progression of eye diseases. In this work, we demonstrate the application of compression-based optical coherence elastography (OCE) to measure the biomechanical properties of the cornea under various conditions, including validation in an in situ rabbit model and a demonstration of feasibility for in vivo measurements. Our results show a stark increase in the stiffness of the corneas as IOP was increased. Moreover, UV-A/riboflavin corneal collagen crosslinking (CXL) also dramatically increased the stiffness of the corneas. The results were consistent across 4 different scenarios (whole CXL in situ, partial CXL in situ, whole CXL in vivo, and partial CXL in vivo), emphasizing the reliability of compression OCE to measure corneal biomechanical properties and its potential for clinical applications.

A Triphasic Analysis of Indentation on Articular Cartilage

1999 ◽  
Author(s):  
D. N. Sun ◽  
X. E. Guo ◽  
W. M. Lai ◽  
V. C. Mow
Keyword(s):  
Articular Cartilage ◽  
Biomechanical Properties ◽  
Joint Surface ◽  
Specimen Preparation ◽  
Experimental Configuration ◽  
Indentation Experiment ◽  
Articulating Surface ◽  
Non Destructive

Abstract The indentation experiment is one of the most frequently used methods for studying biomechanical properties of articular cartilage. This experimental configuration is attractive because it does not require special specimen preparation [1,2]. Indentation can be performed on an articulating surface with the cartilage attached on the bone, a condition resembling closer to the physiologic and anatomic condition than compression of osteochondral plugs excised from the joint surface. It provides a non-destructive method to determine the variation of cartilage properties over the joint surface and has a potential for in vivo applications of determining mechanical and electrochemical properties of articular cartilage. Numerous theoretical and numerical analyses of indentation on articular cartilage have been performed and used to calculate the in situ mechanical material constants (Ha, k, v) of the tissue [e.g., 1–3].

Mechanical Properties and Related Histological Alterations of Engineered Tendons In Vivo

2005 ◽  
pp. 11-14
Author(s):  
Ting Wu Qin ◽  
Shujiang Zhang ◽  
Zhi Ming Yang ◽  
Xiang Tao Mo ◽  
Xiu Qun Li
Keyword(s):  
Mechanical Properties ◽  
Histological Alterations

The Inhomogeneous Mechanical Properties of the Pericellular Matrix of Articular Cartilage Measured In Situ by Atomic Force Microscopy

2009 ◽  
Author(s):  
Rebecca E. Wilusz ◽  
Eric M. Darling ◽  
Michael P. Bolognesi ◽  
Stefan Zauscher ◽  
Farshid Guilak
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Articular Cartilage ◽  
Biomechanical Properties ◽  
Human Articular Cartilage ◽  
Pericellular Matrix ◽  
Force Microscopy ◽  
Narrow Region ◽  
Atomic Force

Articular cartilage is the connective tissue that lines the articulating surfaces of diarthrodial joints, providing a low-friction, load-bearing surface during joint motion. Articular cartilage comprises of a single cell type, the chondrocyte, embedded within an extensive extracellular matrix (ECM). Each chondrocyte is surrounded by a narrow region called the pericellular matrix (PCM) that is distinct from the ECM in both its biochemical composition [1] and biomechanical properties [2]. While multiple techniques have been used to measure the mechanical properties of the PCM, including micropipette aspiration of isolated chondrons [2], these studies required mechanical or enzymatic extraction of the chondrocyte and surrounding PCM (i.e., the “chondron” [1]) from the cartilage, and the influence of this isolation process on PCM properties is unknown. Atomic force microscopy (AFM) provides a high resolution form of nano- and microindentation approaches that can be used to measure local mechanical properties in situ [3,4]. The objective of this study was to use AFM to quantify the biomechanical properties of the ECM and PCM of human articular cartilage in situ.

scholarly journals Differences in the Mechanical Properties of the Rat Carotid Artery In Vivo, In Situ, and In Vitro

Hypertension ◽  
1998 ◽  
Vol 32 (1) ◽  
pp. 180-185 ◽  
Author(s):  
Anne Zanchi ◽  
Nikos Stergiopulos ◽  
Hans R. Brunner ◽  
Daniel Hayoz
Keyword(s):  
Mechanical Properties ◽  
Carotid Artery

Biomechanical Properties of Abdominal Organs In Vivo and Postmortem Under Compression Loads

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Jacob Rosen ◽  
Jeffrey D. Brown ◽  
Smita De ◽  
Mika Sinanan ◽  
Blake Hannaford
Keyword(s):  
Surgical Procedures ◽  
Biomechanical Properties ◽  
Model Parameters ◽  
Loading Conditions ◽  
Tissue Properties ◽  
Surgical Simulators ◽  
Surgical Tools ◽  
Abdominal Organs

Accurate knowledge of biomechanical characteristics of tissues is essential for developing realistic computer-based surgical simulators incorporating haptic feedback, as well as for the design of surgical robots and tools. As simulation technologies continue to be capable of modeling more complex behavior, an in vivo tissue property database is needed. Most past and current biomechanical research is focused on soft and hard anatomical structures that are subject to physiological loading, testing the organs in situ. Internal organs are different in that respect since they are not subject to extensive loads as part of their regular physiological function. However, during surgery, a different set of loading conditions are imposed on these organs as a result of the interaction with the surgical tools. Following previous research studying the kinematics and dynamics of tool/tissue interaction in real surgical procedures, the focus of the current study was to obtain the structural biomechanical properties (engineering stress-strain and stress relaxation) of seven abdominal organs, including bladder, gallbladder, large and small intestines, liver, spleen, and stomach, using a porcine animal model. The organs were tested in vivo, in situ, and ex corpus (the latter two conditions being postmortem) under cyclical and step strain compressions using a motorized endoscopic grasper and a universal-testing machine. The tissues were tested with the same loading conditions commonly applied by surgeons during minimally invasive surgical procedures. Phenomenological models were developed for the various organs, testing conditions, and experimental devices. A property database—unique to the literature—has been created that contains the average elastic and relaxation model parameters measured for these tissues in vivo and postmortem. The results quantitatively indicate the significant differences between tissue properties measured in vivo and postmortem. A quantitative understanding of how the unconditioned tissue properties and model parameters are influenced by time postmortem and loading condition has been obtained. The results provide the material property foundations for developing science-based haptic surgical simulators, as well as surgical tools for manual and robotic systems.

Assessment of a Novel Technique for In-Vivo Investigation of Joint Cartilage Deformation Characteristics

2007 ◽  
Author(s):  
Ion Robu ◽  
Janet L. Ronsky ◽  
Richard Frayne ◽  
Ayman H. Habib
Keyword(s):  
Biomechanical Properties ◽  
Morphological Properties ◽  
Elastic Behavior ◽  
Unconfined Compression ◽  
Indentation Tests ◽  
Magnetic Resonance Imaging Mri ◽  
Cadaveric Knee

Cartilage is characterized by unique biomechanical and morphological properties. These properties are dictated mainly by the visco-elastic behavior of the interstitial matrix. Attempts to quantify the biomechanical properties of cartilage have been based on in-vitro confined and unconfined compression experiments and indentation tests, in-situ measurements of intact cadaveric knee joint specimens under loading using Magnetic Resonance Imaging (MRI), numerical modeling, or in-vivo techniques such as those applying arthroscopic indentation or loading with MR imaging.

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