Tissue specific characteristics of cells isolated from human and rat tendons and ligaments

Abstract

BackgroundTendon and ligament injuries are common and costly in terms of surgery and rehabilitation. This might be improved by using tissue engineered constructs to accelerate the repair process; a method used successfully for skin wound healing and cartilage repair. Progress in this field has however been limited; possibly due to an over-simplistic choice of donor cell. For tissue engineering purposes it is often assumed that all tendon and ligament cells are similar despite their differing roles and biomechanics. To clarify this, we have characterised cells from various tendons and ligaments of human and rat origin in terms of proliferation, response to dexamethasone and cell surface marker expression.MethodsCells isolated from tendons by collagenase digestion were plated out in DMEM containing 10% fetal calf serum, penicillin/streptomycin and ultraglutamine. Cell number and collagen accumulation were by determined methylene blue and Sirius red staining respectively. Expression of cell surface markers was established by flow cytometry.ResultsIn the CFU-f assay, human PT-derived cells produced more and bigger colonies suggesting the presence of more progenitor cells with a higher proliferative capacity. Dexamethasone had no effect on colony number in ACL or PT cells but 10 nM dexamethasone increased colony size in ACL cultures whereas higher concentrations decreased colony size in both ACL and PT cultures. In secondary subcultures, dexamethasone had no significant effect on PT cultures whereas a stimulation was seen at low concentrations in the ACL cultures and an inhibition at higher concentrations. Collagen accumulation was inhibited with increasing doses in both ACL and PT cultures. This differential response was also seen in rat-derived cells with similar differences being seen between Achilles, Patellar and tail tendon cells. Cell surface marker expression was also source dependent; CD90 was expressed at higher levels by PT cells and in both humans and rats whereas D7fib was expressed at lower levels by PT cells in humans.ConclusionThese data show that tendon & ligament cells from different sources possess intrinsic differences in terms of their growth, dexamethasone responsiveness and cell surface marker expression. This suggests that for tissue engineering purposes the cell source must be carefully considered to maximise their efficacy.

Tissue-Specific Ageing of Rat Tendon-Derived Progenitor Cells

“…This is in agreement with findings from other groups showing that ageing reduces stem/progenitor cell numbers [33,34]. All isolated progenitor cells were positive for CD44 and CD90, as reported before by our group [27].…”

“…Fibroblastic-colony-forming-unit culture (CFU-f) assays were performed in triplicates using a method originally established for the analysis of CFU-f in bone marrow but adapted for use with tendon progenitor cells [25][26][27]. Briefly, 1×10…”

Hybrid Carbon-Based Scaffolds for Applications in Soft Tissue Reconstruction

“…2,3 Chemical cross-linkage of tissue scaffolds has been employed in some circumstances to strengthen weak tissues but can result in a prolonged inflammatory response and limit graft integration in vivo. [4][5][6][7][8][9] Partial enzymatic digestion of cadaveric tissues has also been utilized to improve graft porosity, which potentially assists with graft neovascularization, however, this procedure has not been overwhelmingly successful. 8 Proprietary methods of chemically and physically stripping tissues of cellular materials have been commercially developed to minimize graft rejection and loss of essential biologic factors; however, these methods cannot be universally applied to all tissues.…”

“…[4][5][6][7][8][9] Partial enzymatic digestion of cadaveric tissues has also been utilized to improve graft porosity, which potentially assists with graft neovascularization, however, this procedure has not been overwhelmingly successful. 8 Proprietary methods of chemically and physically stripping tissues of cellular materials have been commercially developed to minimize graft rejection and loss of essential biologic factors; however, these methods cannot be universally applied to all tissues. 6,10 GraftJacket Ò Matrix (Wright Medical), 4 an acellular human dermis derived graft, is an example of a commercially available graft that is commonly utilized in surgery for soft tissue augmentation and repair.…”

Therapeutic Strategies for Tendon Healing Based on Novel Biomaterials, Factors and Cells

“…Their use may be limited by availability and accessibility including the risk of donor-site morbidity at the site of harvest. The techniques for their successful expansion in cell culture are still quite limited [41]. Tenocytes or fibroblasts isolated from the rotator cuff [42], patellar and Achilles tendons [20,43,44] or from the tendon sheath present an obvious choice [45] that is being investigated.…”