Adhesion Strength of Human Ligament Fibroblasts

1994 ◽  
Vol 116 (3) ◽  
pp. 237-242 ◽  
Author(s):  
K.-L. Paul Sung ◽  
Michael K. Kwan ◽  
Fausto Maldonado ◽  
Wayne H. Akeson
Keyword(s):  
Adhesion Strength ◽  
Cell Function ◽  
Adhesion Force ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Matrix Proteins ◽  
Functional Relationships ◽  
Seeding Time ◽  
Adhesive Interactions ◽  
Anterior Cruciate

The adhesive interactions of cells with other cells and the extracellular matrix (ECM) play a fundamental role in the organization of cells in differentiated organs, cell motility, and the healing process. The adhesion characteristics of ligament fibroblasts depend on the expression of cell surface molecules and their interaction with the ECM. Although many receptors mediating the effects of ECM components on ligament cell function remain poorly defined, it is known that fibronectin (FN) allows ligament cells to adhere through the VLA-5 receptor (α5β1). A direct measurement of the adhesion between anterior cruciate ligament (ACL) or medial collateral ligament (MCL) fibroblasts and fibronectin matrix proteins was achieved by using a micromanipulation technique to determine the force required to detach an ACL or MCL cell from fibronectin-coated glass. We have found that the adhesion strength is not random, but has well-defined functional relationships with the FN concentration and the seeding time (time allowed for the cell to establish attachment). The adhesion strength (i.e., force required to detach) of ACL cells shows a stronger dependence on FN concentration (1, 2, and 5 μg/ml) for short seeding times (15-30 min) than for long seeding times (38-75 min). For MCL cells, the effect of the seeding time on adhesion strength was apparent for all concentrations. For all the seeding times studied and FN concentrations used, MCL cells had higher adhesion strength than ACL cells. The adhesion strengths of ACL and MCL fibroblasts to FN are correlated to cell adhesion area. The normalized adhesion strength (adhesion force/adhesion area) of MCL fibroblasts is approximately 0.025 mdynes/μm2, which is the same as ACL cells for a seeding time from 18 to 50 minutes.

scholarly journals Evaluation of Adjustable Loop Suspensory Anterior Cruciate Ligament Fixation Devices

2019 ◽  
Vol 5 (1) ◽  
pp. 505-507
Author(s):  
Mira Dreier ◽  
Samuel Bachmayer ◽  
Christian Baumgartner ◽  
Jörg Schröttner
Keyword(s):  
Anterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Bone Tunnel ◽  
Test Series ◽  
Fixation Device ◽  
Test Protocol ◽  
Graft Tension ◽  
Fixation Devices ◽  
Anterior Cruciate

AbstractAlong with increasing enthusiasm for sports comes an increase of sport related injuries. One of the most common injuries in the human knee is the tear of the anterior cruciate ligament (ACL). The selection of a graft fixation device is an important factor that determines the outcome of an anterior cruciate ligament reconstruction. Before the healing process is completed, the graft is dependent on tibial and femoral fixation devices to maintain normal ACL graft tension. Among various devices, the use of an adjustable loop suspensory fixation device (ALD) in soft-tissue graft reconstruction attracts current interest. An advantage of the ALD is the ability to draw the graft to the depth of the bone tunnel to achieve adequate graft tension while minimizing the empty space in the tunnel. In this study a comprehensive controlled laboratory investigation is performed to examine the biomechanical properties of commonly used cortical fixation devices, with the aim of implementing a standard testing procedure for adjustable loop devices. The procedure consists of three test series, a loop shortening test and two different stability test series (singe device and tendon device test). Those test series are used to compare the performance of a new ALD from Arthrex (Naples, USA) with five competitor devices already on the market. In order to obtain representative results eight samples of each device are tested. In comparison to the previously performed studies, a complete unloading is applied in the stability tests, which allows for a detailed examination of the ALDs locking mechanisms in dynamically loaded test situations. Furthermore, the performed loop shortening tests reveal important aspects, such as the shortening accuracy and settling effects of the loops, that are not found in previous studies. Therefore, the used test protocol can be recommended for further testing.

Bioactive Tape With BMP-2 Binding Peptides Captures Endogenous Growth Factors and Accelerates Healing After Anterior Cruciate Ligament Reconstruction

2018 ◽  
Vol 46 (12) ◽  
pp. 2905-2914 ◽  
Author(s):  
João F. Crispim ◽  
Sai C. Fu ◽  
Yuk W. Lee ◽  
Hugo A.M. Fernandes ◽  
Pascal Jonkheijm ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Growth Factors ◽  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Enzyme Linked Immunosorbent Assay ◽  
In Vivo Experiments ◽  
Binding Peptides ◽  
Anterior Cruciate

Background: The anterior cruciate ligament (ACL) has poor regenerative capacity, and an injury leads to loss of function, limiting quality of life and increasing the incidence of osteoarthritis. Surgical interventions can stabilize the joint and improve functional recovery. The delivery of growth factors (GFs) enhances the healing process; however, this is complex in its regulation, is high in costs, has side effects, and can only be accomplished with supraphysiological concentrations and thus is currently not clinically feasible. However, the immobilization of a patient’s endogenous GFs in biomaterials can overcome these problems. Purpose: To develop a method to capture endogenous bone morphogenetic protein–2 (BMP-2) and ultimately show enhanced ACL healing in vivo using this novel methodology. Study Design: Controlled laboratory study. Methods: BMP-2 binding peptides were synthetized, purified, and immobilized on polycaprolactone (PCL) films. The affinity between the peptide and human BMP-2 (hBMP-2) was confirmed with immunofluorescence and enzyme-linked immunosorbent assay. The C2C12 Luc reporter cell line was used to confirm the bioactivity of immobilized BMP-2. For in vivo experiments, the same functionalization technology was applied to the commercially available Polytape, and the functionalized tape was sutured together with the graft used for ACL reconstruction in rats. Each animal underwent reconstruction with either native Polytape (n = 3) or Polytape with BMP-2 binding peptides (n = 3). At 2 and 6 weeks after surgery, the graft was assessed by histology and micro–computed tomography. Results: The covalent immobilization of the peptide in PCL was successful, allowing the peptide to capture hBMP-2, which remained bioactive and led to the osteogenic differentiation of C2C12. In vivo experiments confirmed the potential of the Polytape functionalized with the BMP-2 binding peptide to capture endogenous BMP-2, leading to enhanced bone formation inside the femoral and tibial tunnels and ultimately improving the graft’s quality. Conclusion: The incorporation of BMP-2 binding peptides into materials used for ACL reconstruction can capture endogenous hBMP-2, which enhances the healing process inside the bone tunnels. Clinical Relevance: These results demonstrate the potential of using synthetic peptides to endow biomaterials with novel biological functions, namely to capture and immobilize endogenous GFs.

scholarly journals Biological enhancement of graft-tunnel healing in anterior cruciate ligament reconstruction

Joints ◽  
2016 ◽  
Vol 04 (03) ◽  
pp. 174-182
Author(s):  
Maristella Saccomanno ◽  
Luigi Capasso ◽  
Luca Fresta ◽  
Giuseppe Milano
Keyword(s):  
Anterior Cruciate Ligament ◽  
Clinical Practice ◽  
Clinical Studies ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Bone Tunnel ◽  
Therapeutic Effects ◽  
Tunnel Length ◽  
Acl Graft ◽  
Anterior Cruciate

The sites where graft healing occurs within the bone tunnel and where the intra-articular ligamentization process takes place are the two most important sites of biological incorporation after anterior cruciate ligament (ACL) reconstruction, since they help to determine the mechanical behavior of the femur-ACL graft-tibia complex. Graft-tunnel healing is a complex process influenced by several factors, such as type of graft, preservation of remnants, bone quality, tunnel length and placement, fixation techniques and mechanical stress. in recent years, numerous experimental and clinical studies have been carried out to evaluate potential strategies designed to enhance and optimize the biological environment of the graft-tunnel interface.Modulation of inflammation, tissue engineering and gene transfer techniques have been applied in order to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of native ligament, and to accelerate the healing process of tendon grafts within the bone tunnel. Although animal studies have given encouraging results, clinical studies are lacking and their results do not really support the use of the various strategies in clinical practice. Further investigations are therefore needed to optimize delivery techniques, therapeutic concentrations, maintenance of therapeutic effects over time, and to reduce the risk of undesirable effects in clinical practice.

Use of Extracellular Matrix Bioscaffolds to Enhance ACL Healing: A Multidisciplinary Approach in a Goat Model

2010 ◽  
Author(s):  
Matthew B. Fisher ◽  
Ho-Joong Jung ◽  
Rui Liang ◽  
Kwang Kim ◽  
Patrick J. McMahon ◽  
...  
Keyword(s):  
Cruciate Ligament ◽  
Healing Process ◽  
Donor Site ◽  
Donor Site Morbidity ◽  
Surgical Reconstruction ◽  
Suture Repair ◽  
Joint Stability ◽  
Tissue Replacement ◽  
Anterior Cruciate ◽  
And Function

Due to the poor healing potential of the anterior cruciate ligament (ACL) of the knee, surgical reconstruction using soft tissue replacement grafts is performed to restore knee stability and function. However, the surgery has serious complications including a high incidence of donor site morbidity and the development of osteoarthritis in the long-term. Recently, functional tissue engineering approaches to heal an injured ACL using biological stimulation via growth factors and bioscaffolds have yielded some positive clinical and laboratory results. As the healing process for the ACL is slow, additional suture repair of the ACL has been needed to provide initial joint stability and to reduce the risk of injury to neighboring tissues.

scholarly journals A Novel In Vivo Joint Loading System to Investigate the Effect of Daily Mechanical Load on a Healing Anterior Cruciate Ligament Reconstruction

2010 ◽  
Vol 4 (1) ◽  
Author(s):  
Mark Stasiak M. Eng ◽  
Carl Imhauser ◽  
Jonathan Packer ◽  
Asheesh Bedi ◽  
Robert Brophy ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Joint ◽  
Bone Healing ◽  
Structural Changes ◽  
Mechanical Load ◽  
Tracking System ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Anterior Cruciate

We designed and validated a novel knee joint fixation/distraction system to study tendon–to-bone healing in an in vivo rat model of anterior cruciate ligament (ACL) reconstruction. The system uses an external fixator to apply a cyclic distraction of the knee joint while monitoring the resultant force developed across the joint, thus providing a temporal indication of structural changes during the healing process of the bone-tendon-bone reconstruction. The validation was performed using an optical kinematic tracking system to determine the local displacement of the knee. The average system compliance was determined to be 42.4±8.8 μm/N with a coefficient of variation of 20.7%. The compliance was used to obtain a best fit correction factor which brought the total root mean square error of knee joint distraction to within 179 μm (16.1%) of the applied distraction. We performed a pilot study using 15 rats that had ACL reconstructions using a flexor digitorum longus tendon autograft and found that the animals tolerated the indwelling fixator and daily anesthesia over a 10 day loading protocol. Our knee joint fixation/distraction system provides a valuable tool to study how mechanical stimuli affect in vivo bone-tendon-bone healing.

scholarly journals BIOLOGICAL ENHANCEMENTS FOR ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

2019 ◽  
Vol 27 (6) ◽  
pp. 325-330
Author(s):  
Chilan Bou Ghosson Leite ◽  
Marco Kawamura Demange
Keyword(s):  
Anterior Cruciate Ligament ◽  
Ligament Reconstruction ◽  
Standard Treatment ◽  
Cruciate Ligament ◽  
Healing Process ◽  
Knee Stability ◽  
Level Of Evidence ◽  
Biological Perspective ◽  
Anterior Cruciate ◽  
Rate Of Failure

ABSTRACT The anterior cruciate ligament (ACL) is mostly responsible for providing knee stability. ACL injury has a marked effect on daily activities, causing pain, dysfunction, and elevated healthcare costs. ACL reconstruction (ACLR) is the standard treatment for this injury. However, despite good results, ACLR is associated with a significant rate of failure. In this context, the mechanical and biological causes must be considered. From a biological perspective, the ACLR depends on the osseointegration of the graft in the adjacent bone and the process of intra-articular ligamentization for good results. Here, we discuss the mechanisms underlying the normal graft healing process after ACLR and its biological modulation, thus, presenting novel strategies for biological enhancements of the ACL graft. Level of evidence III, Systematic review of level III studies.

scholarly journals the mechanics of healing

2010 ◽  
Vol 132 (10) ◽  
pp. 22-25
Author(s):  
Daniel Wiznia
Keyword(s):  
New York ◽  
Cruciate Ligament ◽  
Current Model ◽  
Healing Process ◽  
Continuous Passive Motion ◽  
Engineering Programs ◽  
Acl Surgery ◽  
Special Surgery ◽  
Anterior Cruciate ◽  
Hospital For Special Surgery

This chapter discusses research and engineering programs undertaken to study knees and machines to help ligament-graft patients get on their feet. At the Hospital for Special Surgery in New York, researchers are investigating the biological mechanisms of how tendon heals to bone to ultimately influence rehabilitative protocols for the anterior fibula. The lab has been focusing on how mechanical loads placed on tendons affect the healing process by initiating biological signals. The current model involves studying rodents that have undergone anterior cruciate ligament (ACL) reconstruction to examine the effect of mechanical loading on tendon biology. The team will develop empirical evidence that is expected to lead to future protocols for therapy—in short, to have people heal and return to their normal lives.. One therapy that has demonstrated some success in patients recovering from ACL surgery has been continuous passive motion (CPM). The clinical CPM design has been rendered in Solidworks. The lab built a device and is now testing it on cadaver rats before moving on to live subjects.

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