Experimental study on allografts of amniotic epithelial cells in calcaneal tendon lesions of sheep
ABSTRACT An experimental protocol was designed to study the survival and behaviour of an allograft of amniotic epithelial cells (AECs) in an ovine model. The study was conducted on three healthy adult sheep. A core lesion was created in both calcaneal tendons under ultrasound (US) guidance by injecting 400 UI of Type 1A collagenase diluted in 0.6 ml saline. The AECs were obtained from a 60-80-day-old fetus and cultured under standard conditions. After 15 days of collagenase treatment, 2 x 10(6) AECs stained with a vital membrane fluorescent probe (PHK26) were injected under US guidance in 500 microl saline solution into the lesion of one limb. The contralateral untreated limb was used as a control. Animals were euthanatized 7 (1) and 30 (2) days later. Histological analyses performed on explanted tendons clearly demonstrate that AECs survived for at least 1 month inside the lesion without any adverse reactions. The damaged tissue of the treated tendons showed a high number of reparative cells in active proliferation that were accumulating collagen within the extracellular matrix. In addition, after 1 month, the neo-collagen began to be organized into parallel arrays of fibers oriented along the longitudinal axis of the tendon.
Full-textDOI: · Available from: Valentina Russo, Sep 27, 2015
- SourceAvailable from: Annunziata Mauro
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- "All the oAECs with a stable proliferation index, a conserved expression pattern and the ability to undergo in vitro tenogenic cell lineage differentiation, were then stained with the Red Fluorescent Cell Linker dye, PKH26, before storing the cells in vials of 2.5 Â 10 6 by cryopreservation in liquid nitrogen. Cryopreserved, labeled cells were then thawed, washed and suspended in aMEM without any growth factors and FCS before their use either in preclinical (Muttini et al., 2010) or clinical settings. "
ABSTRACT: In vitro expanded and frosted ovine amniotic epithelial cells (oAECs) were evaluated for their phenotype, stemness and attitude to differentiate into tenocytes. Fifteen horses with acute tendon lesions were treated with one intralesional injection of oAECs. Tendon recovery under controlled training was monitored. In vitro expanded oAECs showed a constant proliferative ability, a conserved phenotype and stable expression profile of stemness markers. Differentiation into tenocytes was also regularly documented. US controls showed the infilling of the defect and early good alignment of the fibers and 12 horses resumed their previous activity. Histological and immunohistochemical examinations in an explanted tendon demonstrated the low immunogenicity of oAECs that were able to survive in the healing site. In addition, oAECs supported the regenerative process producing ovine collagen type I amongst the equine collagen fibers. Considering our results, oAECs can be proposed as a new approach for the treatment of spontaneous equine tendon injuries.Research in Veterinary Science 09/2012; 94(1). DOI:10.1016/j.rvsc.2012.07.028 · 1.41 Impact Factor
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- "Currently, many studies performed have been seeking more effective treatments for injuries to the tendons, such as the employment of an allograft of amniotic epithelial cells (Muttini et al., 2010), platelet-rich plasma that contains growth factors (Bosch et al., 2010), metrenperone (Oryan et al., 2010) or mesenchymal stem cells (Schnabel et al., 2009). The aim of these new treatments was to reduce the recurrence of injuries through a remodeling of the extracellular matrix at the site of a tendon injury. "
ABSTRACT: Tendons are formed by dense connective tissue composed of an abundant extracellular matrix (ECM) that is constituted mainly of collagen molecules, which are organized into fibrils, fibers, fiber bundles and fascicles helicoidally arranged along the largest axis of the tendon. The biomechanical properties of tendons are directly related to the organization of the collagen molecules that aggregate to become a super-twisted cord. In addition to collagen, the ECM of tendons is composed of non-fibrillar components, such as proteoglycans and non-collagenous glycoproteins. The capacity of tendons to resist mechanical stress is directly related to the structural organization of the ECM. Collagen is a biopolymer and presents optical anisotropies, such as birefringence and linear dichroism, that are important optical properties in the characterization of the supramolecular organization of the fibers. The objective of this study was to present a review of the composition and organization of the ECM of tendons and to highlight the importance of the anisotropic optical properties in the study of alterations in the ECM.Micron 08/2011; 43(2-3):205-14. DOI:10.1016/j.micron.2011.07.015 · 1.99 Impact Factor
Conference Paper: MATRESHKA-high intensity accelerator of continuous particle beams[Show abstract] [Hide abstract]
ABSTRACT: The MATRESHKA accelerator was developed for the UHF power excitation of many resonator systems with a moderate, for example 5 MW, level for each of them. If the number of resonators are 100, the complete power is 500 MW and with an efficiency of 50%, MATRESHKA's beam power will be about 1000 MW. An electron beam can have such a power with a particle energy of 5 MeV and a current of 200 A. The main design features are givenParticle Accelerator Conference, 1995., Proceedings of the 1995; 06/1995