The effect of intralesional injection of bone marrow derived mesenchymal stem cells and bone marrow supernatant on collagen fibril size in a surgical model of equine superficial digital flexor tendonitis

Abstract

Favouring matrix regeneration over fibrotic repair may not be the mechanism by which autologous mesenchymal stem cells assist healing of tendon injury.

Equine Bone Marrow and Adipose Tissue Mesenchymal Stem Cells: Cytofluorimetric Characterization, In Vitro Differentiation, and Clinical Application

“…Hand walk 20 min twice/d 10- 16 Hand walk 30-40 min twice/d [17][18][19][20][21][22][23][24][25] Hand walk 40 min twice/d and trot 5-30 min/d Gradual increase of exercise level eATMSCs (P > .05). No lag phase was observed during the in vitro culture of both cell lines; in fact, no statistically significant differences in the number of CD were registered among different culture passages (P > .05).…”

“…Even if several articles have recently been written on this topic, in most cases, all markers listed by ISCT are not taken into account [20,21]. Last, the most of the authors that reported cell characterization and clinical application performed cell implantation in lesions induced with collagenase in experimental animals, and the shortterm efficacy was only evaluated [1,[20][21][22]. In the present work, MSCs derived from eAT and eBM were isolated, cultivated, differentiated, and characterized by flow cytometry as postulated by ISCT for human cells.…”

Achilles Tendon Injuries in Elite Athletes: Lessons in Pathophysiology from Their Equine Counterparts

“…More recently there has been considerable interest in using stem cell therapies to improve tendon healing. However, as yet, there are no data to link increased collagen fibril diameter (the desired effect of tendon therapy) with the inoculation of undifferentiated cell populations (Caniglia et al 2012). There is also no indication or expectation that the functionally important fascicular substructure can be regenerated.…”

“…It is also not known how prominent a role enzymatic activity plays at and after the occurrence of tendon rupture. More recently, mild to moderate-severity SDFT core lesions have been created using arthroscopic burrs or blades, with one involving insertion of collagenase gel into a needlecreated defect; some were microscopically and biochemically comparable with spontaneous injury (including MMP upregulation and formation of small-diameter collagen fibrils) with similarly protracted healing (Cadby et al 2013;Caniglia et al 2012;Schramme et al 2010;Watts et al 2012). Although these models might be of use to study postdisruption healing (and controlled therapeutic interventions by injuring tendons bilaterally) (Bosch et al 2011), the acute induction of injury cannot recapitulate the predisposing (exerciseinduced) microdamage that occurs in the natural situation ( potentially for weeks or even years before rupture).…”

Evidence Supporting Intralesional Stem Cell Therapy to Improve Equine Flexor Tendon Healing

“…Accepting the focused nature of the question under review, there was a remarkable degree of variability in the source of 'stem cell' used in these studies (bone marrow [7], blood [1], amnion [1], adipose tissue [2], embryonic [1], and tendon [1]), the protocols used to generate the therapeutic cell populations, donorrecipient matching (three allogeneic sources and 9 autologous sources), the diluents used for the cell injections (saline [5], bone marrow supernatant [4], plasma [1], PRP [1], and fibrin/thrombin [1]) and, in the clinical studies, the specific disciplines the patients were engaged in. Collectively, these sources of variation confounded any coherent meta-analysis.…”