Allogeneic Umbilical Cord-Derived Mesenchymal Stem Cells as a Potential Source for Cartilage and Bone Regeneration: An in Vitro Study

Umbilical cord (UC) may represent an attractive cell source for allogeneic mesenchymal stem cell (MSC) therapy. The aim of this in vitro study is to investigate the chondrogenic and osteogenic potential of UC-MSCs grown onto tridimensional scaffolds, to identify a possible clinical relevance for an allogeneic use in cartilage and bone reconstructive surgery. Chondrogenic differentiation on scaffolds was confirmed at 4 weeks by the expression of sox-9 and type II collagen; low oxygen tension improved the expression of these chondrogenic markers. A similar trend was observed in pellet culture in terms of matrix (proteoglycan) production. Osteogenic differentiation on bone-graft-substitute was also confirmed after 30 days of culture by the expression of osteocalcin and RunX-2. Cells grown in the hypertrophic medium showed at 5 weeks safranin o-positive stain and an increased CbFa1 expression, confirming the ability of these cells to undergo hypertrophy. These results suggest that the UC-MSCs isolated from minced umbilical cords may represent a valuable allogeneic cell population, which might have a potential for orthopaedic tissue engineering such as the on-demand cell delivery using chondrogenic, osteogenic, and endochondral scaffold. This study may have a clinical relevance as a future hypothetical option for allogeneic single-stage cartilage repair and bone regeneration

Minced Umbilical Cord Fragments as a Source of Cells for Orthopaedic Tissue Engineering: An In Vitro Study

A promising approach for musculoskeletal repair and regeneration is mesenchymal-stem-cell- (MSC-)based tissue engineering. The aim of the study was to apply a simple protocol based on mincing the umbilical cord (UC), without removing any blood vessels or using any enzymatic digestion, to rapidly obtain an adequate number of multipotent UC-MSCs. We obtained, at passage 1 (P1), a mean value of 4, 2 × 106 cells (SD 0,4) from each UC. At immunophenotypic characterization, cells were positive for CD73, CD90, CD105, CD44, CD29, and HLA-I and negative for CD34 and HLA-class II, with a subpopulation negative for both HLA-I and HLA-II. Newborn origin and multilineage potential toward bone, fat, cartilage, and muscle was demonstrated. Telomere length was similar to that of bone-marrow (BM) MSCs from young donors. The results suggest that simply collecting UC-MSCs at P1 from minced umbilical cord fragments allows to achieve a valuable population of cells suitable for orthopaedic tissue engineering

Anomalous Dispersion with Edges in the Soft X-ray Region: First Results of Diffraction from Single Crystals of Trypsin Near the K-Absorption Edge of Sulfur

Anomalous dispersion of X-ray diffraction at wavelengths near the X-ray K-absorption edge of sulfur at wavelengths around 5 Å has been applied to single crystals of trypsin obtained from an ammonium sulfate solution. The multiwavelength anomalous-dispersion method based on 775 unique reflections (+183 Bijvoet mates) measured at three wavelengths near the K-absorption edge of sulfur in trypsin (two methionines and disulfide bridges of six cystines) reproduces the known features of the trypsin structure of a resolution of 4 Å. It appears that there is anisotropic anomalous scattering from the disulfide bridges of cystine. The multiwavelength anomalous solvent contrast shows up at wavelengths near the K-absorption edge of the sulfate ions, which is shifted by 10 eV to higher energies with respect to that of sulfur in trypsin. The influence of the complex contrast of trypsin in 2.5 M ammonium sulfate on the dispersion of a low-order reflection is analyzed. The measurement of anomalous dispersion of X-ray diffraction at long wavelengths beyond 5 Å requires a special diffractometer, the features of which are presented. An outstanding one is a detector system consisting of four multiwire proportional counters. Its efficiency is compared with that of imaging plates. The influence of radiation damage with soft X-ray diffraction from single crystals of trypsin is presented and possible remedies are discussed

Pulsed Electromagnetic Fields Improve Tenogenic Commitment of Umbilical Cord-Derived Mesenchymal Stem Cells :a Potential Strategy for Tendon Repair-An In Vitro Study

Tendon repair is a challenging procedure in orthopaedics. The use of mesenchymal stem cells (MSCs) and pulsed electromagnetic fields (PEMF) in tendon regeneration is still investigational. In this perspective, MSCs isolated from the human umbilical cord (UC) may represent a possible candidate for tendon tissue engineering. The aim of the study is to evaluate the effect of low-frequency PEMF on tenogenic differentiation of MSCs isolated from the human umbilical cord (UC-MSCs) in vitro. 15 fresh UC samples from women with healthy pregnancies were retrieved at the end of caesarean deliveries. UC samples were manually minced into small fragments (less than 4\u2009mm length) and cultured in MSC expansion medium. Part of the UC-MSCs was subsequently cultured with PEMF and tenogenic growth factors. UC-MSCs were subjected to pulsed electromagnetic fields for 2\u2009h/day, 4\u2009h/day, or 8\u2009h/day. UC-MSCs cultured with FGF-2 and stimulated with PEMF showed a greater production of collagen type I and scleraxis. The prolonged exposure to PEMF was also related to the greatest expression of tenogenic markers. Thus, the exposure to PEMF provides a positive preconditioning biophysical stimulus, which may enhance UC-MSC tenogenic potential

Current trends in tendinopathy: consensus of the ESSKA basic science committee : Part I: biology, biomechanics, anatomy and an exercise-based approach

Chronic tendinopathies represent a major problem in the clinical practice of sports orthopaedic surgeons, sports doctors and other health professionals involved in the treatment of athletes and patients that perform repetitive actions. The lack of consensus relative to the diagnostic tools and treatment modalities represents a management dilemma for these professionals. With this review, the purpose of the ESSKA Basic Science Committee is to establish guidelines for understanding, diagnosing and treating this complex pathology

Enhancing Biological and Biomechanical Fixation of Osteochondral Scaffold: A Grand Challenge

Osteoarthritis (OA) is a degenerative joint disease, typified by degradation of cartilage and changes in the subchondral bone, resulting in pain, stiffness and reduced mobility. Current surgical treatments often fail to regenerate hyaline cartilage and result in the formation of fibrocartilage. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bones in the early stage of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available osteochondral (OC) scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, some controversial results are often reported from both clinical trials and animal studies. The objective of this chapter is to report the scaffolds clinical requirements and performance of the currently available OC scaffolds that have been investigated both in animal studies and in clinical trials. The findings have demonstrated the importance of biological and biomechanical fixation of the OC scaffolds in achieving good cartilage fill and improved hyaline cartilage formation. It is concluded that improving cartilage fill, enhancing its integration with host tissues and achieving a strong and stable subchondral bone support for overlying cartilage are still grand challenges for the early treatment of OA