The effects of polyester (terylene) fibre implants on normal equine superficial digital flexor tendon

One health in regenerative medicine: report on the second Havemeyer symposium on regenerative medicine in horses

Regenerative medicine is commonly used in human and equine athletes. Potential therapies include culture expanded stem cells, stromal vascular fraction of adipose tissue, platelet-rich plasma, bone marrow concentrate, or autologous conditioned serum. The purpose of this manuscript is to disseminate findings from a workshop on the development of translational regenerative medicine in the equine field. Five themes emerged: stem cell characterization and tenogenic differentiation; interactions between mesenchymal stem cells, other cells and the environment; scaffolds and cell packaging; blood- and bone marrow-based regenerative medicines; clinical use of regenerative therapies. Evidence gained through the use of regenerative medicine applications in the horse should continue to translate to the human patient, bringing novel regenerative therapies to both humans and horses.

The current 'state of play' of regenerative medicine in horses: what the horse can tell the human

The horse is an attractive model for many human age-related degenerative diseases of the musculoskeletal system because it is a large animal species that both ages and exercises, and develops naturally occurring injuries with many similarities to the human counterpart. It therefore represents an ideal species to use as a 'proving ground' for new therapies, most notably regenerative medicine. Regenerative techniques using cell-based therapies for the treatment of equine musculoskeletal disease have been in use for over a decade. This review article provides a summary overview of the sources, current challenges and problems surrounding the use of stem cell and non-cell-based therapy in regenerative medicine in horses and is based on presentations from a recent Havemeyer symposium on equine regenerative medicine where speakers are selected from leading authorities in both equine and human regenerative medicine fields from 10 different countries.

Progress in cell-based therapies for tendon repair

The last decade has seen significant developments in cell therapies, based on permanently differentiated, reprogrammed or engineered stem cells, for tendon injuries and degenerative conditions. In vitro studies assess the influence of biophysical, biochemical and biological signals on tenogenic phenotype maintenance and/or differentiation towards tenogenic lineage. However, the ideal culture environment has yet to be identified due to the lack of standardised experimental setup and readout system. Bone marrow mesenchymal stem cells and tenocytes/dermal fibroblasts appear to be the cell populations of choice for clinical translation in equine and human patients respectively based on circumstantial, rather than on hard evidence. Collaborative, inter- and multi-disciplinary efforts are expected to provide clinically relevant and commercially viable cell-based therapies for tendon repair and regeneration in the years to come.

Clinical and biomechanical evaluation of three bioscaffold augmentation devices used for superficial digital flexor tenorrhaphy in donkeys (Equus asinus): An experimental study

The present study was designed to carry out an in vivo and in vitro comparative evaluation of three bio-scaffold augmentation devices used for superficial digital flexor tenorrhaphy in donkeys. Twenty-four clinically healthy donkeys were assigned for three treatment trials (n = 8) using one of three bioscaffold materials (glycerolized bovine pericardium xenograft, tendon allograft and allograft with glycerolized by bovine pericardium). In addition, eight clinically healthy donkeys were selected to serve as control. Clinical signs of each animal were scored and the sum of all clinical indexes was calculated at each time point of the experiment. Four donkeys from each group were euthanized at 45 and 90 days postoperatively, respectively, for biomechanical and histopathological evaluation of treated superficial digital flexor tendon (SDFT). The failure stress in allograft shielding group significantly increased compared to the corresponding values of the other groups at 45 (62.7 ± 6.5 N mm(-2)) and 90 (88.8 ± 3.5 N mm(-2)) days postoperatively. The fetlock angle in the allograft shielding group at both 45 (112.8° ± 4.4) and 90 (123.8° ± 1.1) days postoperatively showed a significant increase (p < 0.05) relative to the values of the other groups and a significant decrease (p < 0.05) when compared to normal angle (125° ± 0). However, the histomorphological findings revealed no remarkable changes between the treatment groups. In conclusion, the failure stress, fetlock angle and histomorphological findings may provide useful information about the healing characteristics of SDFT tenorrhaphy. The bio-scaffold augmentation devices, either xenogenic or allogenic, provide good alternative techniques accelerating SDFT healing with minimal adhesions in donkeys.