title: Periodontal ligament cells as alternative source for cell-based therapy of tendon injuries: in vivo study of full-size Achilles tendon defect in a rat model.
abstract: Tendon's natural healing potential is extremely low and inefficient, with significant dysfunction and disability due to hypocellularity and hypovascularity of tendon tissues. The application of stem cells can aid in significantly enhanced repair of tendon rupture; therefore, the main aim of this study is to assess the potential of using periodontal ligament cells (PDL), usually obtained from patients undergoing orthodontic treatment, as a novel cell source for cell-based therapy for tendon injuries in a clinically relevant rat full-size Achilles tendon defect. In addition, the study compares the differences between the healing effects of Achilles tendon-derived cells (AT) versus PDL and, hence, comprises of four experimental groups, native tendon (NT), empty defect (ED), PDL and human AT (hAT). The tendon healing in each group was assessed in the late remodelling phase at 16 weeks after surgery using a combination of methods, including evaluation of gross morphological appearance; various histological and immunohistological stainings; and detailed analyses of cell morphometry. Based on these outcome measures, PDL cell-implanted tendons exhibited not only advanced tissue maturation, less ectopic fibrocartilage formation, more organised collagen fibres, tendon matrix expression corresponding to the final healing stage, and better cell-morphometry parameters when compared with the ED group, but were also very similar to the tendons treated with hAT-derived cells. Taken together, our study clearly demonstrates the feasibility of using PDL cells as a novel cell source for tendon repair and strongly recommends this cell type for the future development of innovative regenerative applications for treatment of different tendon or ligament pathologies.
authors.affiliation: Director of Laboratory of Experimental Trauma Surgery, Department of Trauma Surgery, University Regensburg Medical Centre, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.denitsa.docheva@ukr.de.
authors.forename: C-F
authors.initials: CF
authors.lastname: Hsieh
authors.forename: P
authors.initials: P
authors.lastname: Alberton
authors.forename: E
authors.initials: E
authors.lastname: Loffredo-Verde
authors.forename: E
authors.initials: E
authors.lastname: Volkmer
authors.forename: M
authors.initials: M
authors.lastname: Pietschmann
authors.forename: P E
authors.initials: PE
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Schieker
authors.forename: D
authors.initials: D
authors.lastname: Docheva
mesh_terms: D000125:Achilles Tendon / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D001718:Birefringence; D002114:Calcinosis / Q000473:pathology; D002452:Cell Count; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D006801:Humans; D010513:Periodontal Ligament / Q000637:transplantation*; D011509:Proteoglycans / Q000378:metabolism; D051381:Rats; D013708:Tendon Injuries / Q000473:pathology* / Q000628:therapy*
chemical_list: D011509:Proteoglycans; D003094:Collagen