ReviewTechniques for biological characterization of tissue-engineered tendon and ligament
Introduction
Over 800,000 people seek medical attention each year for injuries to ligaments, tendons, or the joint capsule [1]. Ruptures and other damage to tendons and ligaments can cause great pain and decrease the functionality of the joint complex. There are numerous areas throughout the body where tendons and ligaments experience such injuries. These include the patellar tendon [2], the anterior cruciate ligament [3], the posterior cruciate ligament [4], and the medial collateral ligament [5] in the knee; the Achilles tendon [6] at the heel; the anterior talofibular ligament [7] and the calcaneofibular ligament [8] in the ankle; the radial ulnohumeral ligament [9] and the lateral ulnar collateral ligament [10] in the elbow; the digital flexor tendon [3], [6] and the ulnar collateral ligament [11] in the hand; the scapholunate ligament [12] in the wrist; the rotator cuff tendons [3], the acromioclavicular ligament [13], the coracoclavicular ligament [14], and the coracohumeral ligament [15] at the shoulder; and the gluteus medius tendon [16] at the hip.
Often, natural healing of these injuries is insufficient since many tendons and ligaments possess a limited capacity to regenerate [6], [17]. While certain tendons and ligaments can be repaired by suturing the injured tissue back together, some heal poorly in response to this type of surgery, so the use of grafts is required [18]. Unfortunately, finding suitable graft material can be problematic. Autografts from the patient may result in donor site morbidity, while allografts from cadavers may cause a harmful response from the immune system and are limited in supply [19]. In both cases, the graft often does not match the strength of undamaged tissue [19].
Such shortcomings in repair of tendons and ligaments may be overcome through tissue-engineering approaches. Tissue-engineering strategies involve the use of a biomaterial carrier, cells, and/or bioactive factors to promote tissue regeneration via natural processes in the body [20]. One common tissue-engineering approach involves using a three-dimensional (3D) scaffold to direct pre-seeded cells to create viable tendon/ligament tissue [21], [22], [23], [24], [25]. In order to determine the relative success between different tissue-engineering techniques, specific outcome measures (success criteria) are required. Biological assessment, in conjunction with other tests, is a crucial part of the optimization and final clinical application of tissue-engineered tendons and ligaments, and, thus, is the subject of this review. A variety of techniques exist to characterize biological components of tendon and ligament tissue, but only a subset of these methods has been employed to evaluate tissue-engineered tendons and ligaments. Therefore, this review focuses on those most commonly used to assess biological parameters of tissue-engineered tendon/ligament constructs.
Section snippets
Function and structure of tendon and ligament tissue
Biological evaluation is carried out on tissue-engineered constructs to determine to what extent the construct tissue replicates the structure and chemical composition of native tendon/ligament tissue. Thus, a brief review of the structure and function of tendons and ligaments is included in this section.
Tissue-engineering approaches
There are many approaches that exist for tissue engineering of tendons and ligaments. Commonly, a 3D scaffold housing a specific cell type that can be directed to form tendon/ligament tissue is employed. 3D culture offers the advantage of more closely recreating the spatial organization of native tissue than two-dimensional culture.
There are many considerations that should be taken into account when engineering tendon or ligament tissue [1]. The scaffold should encourage cellular recruitment
Types of biological characterization techniques
A variety of techniques are available to examine construct characteristics, including histology, microscopy, colorimetry, and reverse transcriptase-polymerase chain reaction (RT-PCR). The basic theory behind each method is explained in this section, while examples of how these techniques are used to assess tissue-engineered tendon and ligament are found in Section 5.
Examples of biological assessment of tendon and ligament constructs
When determining the success of tendon and ligament tissue-engineering techniques, the viability and proliferation of the cells in the construct, the amount and type of ECM production, and the spatial organization of the ECM components should be taken into account. Since the cells are the source of ECM and renewal of the tissue, their viability is crucial to the success of the tissue-engineering technique. The ECM molecules that the cells secrete are the largest component of tendon and ligament
Conclusions
Tissue engineering provides the possibility for repair and regeneration of tendon and ligament injuries. In order to determine the success of tissue-engineering methods, it is important to assess biological characteristics of the newly formed tissue, including cellularity and ECM production and structure. While established techniques, such as those described here, have provided valuable basic insights, each has its own associated limitations. More sophisticated analysis of tissue-engineered
Acknowledgments
This work was supported in part by the Georgia Tech/Emory Center for the Engineering of Living Tissues, a National Science Foundation Research Center (EEC-9731643).
References (135)
- et al.
Table top relocation test—new clinical test for posterolateral rotary instability of the elbow
J Shoulder Elbow Surg
(2006) - et al.
Gluteus tendon rupture is underrecognized by French orthopedic surgeons: results of a mail survey
Jt Bone Spine
(2006) - et al.
Biomechanics of knee ligaments: injury, healing, and repair
J Biomech
(2006) - et al.
Tendons and ligaments
- et al.
Evaluation of the anterior cruciate ligament, medial collateral ligament, Achilles tendon and patellar tendon as cell sources for tissue-engineered ligament
Biomaterials
(2006) - et al.
Alginate and chitosan polyion complex hybrid fibers for scaffolds in ligament and tendon tissue engineering
J Orthop Sci
(2005) - et al.
Silk matrix for tissue engineered anterior cruciate ligaments
Biomaterials
(2002) - et al.
Anterior cruciate ligament regeneration using braided biodegradable scaffolds: in vitro optimization studies
Biomaterials
(2005) Mechanobiology of tendon
J Biomech
(2006)- et al.
Biomechanics of tendon injury and repair
J Biomech
(2004)
Variation of biomechanical, structural, and compositional properties along the tendon to bone insertion site
J Orthop Res
Proteoglycans and glycosaminoglycan fine structure in the mouse tail tendon fascicle
J Orthop Res
The classical collagens: types I, II, and III
Molecular site specificity of pyridinoline and pyrrole cross-links in type I collagen of human bone
J Biol Chem
Regulation of cell behavior by matricellular proteins
Repair of patellar tendon injuries using a cell-collagen composite
J Orthop Res
Mechanical characterization of collagen fibers and scaffolds for tissue engineering
Biomaterials
Collagen hybridization with poly(l-lactic acid) braid promotes ligament cell migration
Mater Sci Eng C
Biomimetic approaches to tendon repair
Comp Biochem Physiol A: Mol Integr Physiol
The effect of selected growth factors on human anterior cruciate ligament cell interactions with a three-dimensional collagen-GAG scaffold
J Orthop Res
The use of porcine small intestinal submucosa to enhance the healing of the medial collateral ligament—a functional tissue engineering study in rabbits
J Orthop Res
Silk-based biomaterials
Biomaterials
Ligament tissue engineering: an evolutionary materials science approach
Biomaterials
Adhesion strength of human tenocytes to extracellular matrix component-modified poly(dl-lactide-co-glycolide) substrates
Biomaterials
Tissue engineered composite of a woven fabric scaffold with tendon cells, response on mechanical simulation in vitro
Compos Sci Technol
Functional tissue engineering: assessment of function in tendon and ligament repair
Revision total knee arthroplasty with the total condylar III system: a comparative analysis of 71 consecutive cases of osteoarthritis or inflammatory arthritis
Acta Orthop
Mechanical properties of ligament and tendon. Skeletal tissue mechanics
Anatomy and function of the posterior cruciate ligament
Clin Sports Med
Magnetic resonance imaging in the evaluation of tibial eminence fractures in adults
J Knee Surg
Tissue engineered tendon
Evaluation of anterior talofibular ligament lesion using 3-dimensional computed tomography
J Comput Assist Tomogr
MR-imaging of anterior tibiotalar impingement syndrome: agreement, sensitivity and specificity of MR-imaging and indirect MR-arthography
Eur J Radiol
Posterolateral rotary instability of the elbow
Instr Course Lect
US diagnosis of UCL tears of the thumb and Stener lesions: technique, pattern-based approach, and differential diagnosis
Radiographics
Expression of extracellular matrix molecules typical of articular cartilage in the human scapholunate interosseous ligament
J Anat
Surgical treatment of acute complete acromioclavicular dislocation: comparison of coracoclavicular screw fixation supplemented with tension band wiring of ligament transfer
Chang Gung Med J
Surgical treatment for distal clavicle fracture associated with coracoclavicular ligament rupture using a cannulated screw fixation technique
J Trauma
Ultrasound in adhesive capsulitis of the shoulder: is assessment of the coracohumeral ligament a valuable diagnostic tool?
Skeletal Radiol
Ligament injury and repair
Part A: graft choices and the biology of graft healing
Novel chitosan-based hyaluronan hybrid polymer fibers as a scaffold in ligament tissue engineering
J Biomed Mater Res A
Ligament biochemistry and physiology
Unstable molecules form stable tissues
Proc Natl Acad Sci
Extracellular matrix: The cellular environment
News Physiol Sci
Tendon proteoglycans: biochemistry and function
J Musculoskelet Neuronal Interact
Interdependence between structure and function in collagenous tissues
Cross-linking
Molecular structure and stabilization of the collagen fibre
Differential metabolic responses of periarticular ligaments and tendon to joint immobilization
J Appl Physiol
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