Safety assessment of bone marrow derived MSC grown in platelet-rich plasma

Autologous angiogenic therapy with cultured mesenchymal stromal cells in platelet-rich plasma for critical limb ischemia

Introduction

The prevalence of diabetes mellitus is increasing globally, including in Japan. Patients with diabetes often experience microangiopathy and macroangiopathy, which lead to difficult-to-treat foot ulcers and diabetic gangrene. Conventional cellular therapies have limited safety and are invasive. In this study, we investigated the use of cultured autologous mesenchymal stromal cells derived from the bone marrow and grown in platelet-rich plasma as a potential treatment for diabetic complications.

Methods

A prospective clinical trial was conducted to assess safety as the primary endpoint and efficacy as the secondary endpoint of the aforementioned therapy in five patients with critical limb ischemia, with or without hemodialysis.

Results

Five patients with critical limb ischemia were enrolled between 2016 and 2019, three of whom underwent hemodialysis. Platelet-rich plasma was obtained from 288 ± 39.6 mL of blood/patient, yielding 31.6 ± 1.67 mL of platelet-rich plasma. Bone marrow aspiration yielded 18.4 ± 4.77 mL/patient, and 4.64 ± 1.51 × 107 cells were incubated for 16 ± 2.8 days to obtain 3.26 ± 0.33 × 107 mesenchymal stromal cells. Although several adverse events were observed, none were directly attributed to cell therapy. Clinical severity, as assessed by both the Fontaine stage and Rutherford category, improved significantly following therapy. This improvement was accompanied by enhancements in the 6-min walking distance, dorsal skin perfusion pressure, ankle transcutaneous partial oxygen pressure, and ankle brachial pressure index.

Conclusion

Autologous angiogenic therapy with cultured mesenchymal stromal cells derived from the bone marrow and grown in platelet-rich plasma is a safe and feasible, and was expected as a potential treatment for critical limb ischemia.

Fabrication and properties of an injectable sodium alginate/PRP composite hydrogel as a potential cell carrier for cartilage repair

Three-dimensional scaffolds like hydrogels can be employed as cell carriers for in vitro or in vivo colonization and have become a major research topic to replace damaged tissue. In the current study, a novel composite hydrogel composed of sodium alginate (SA) and platelet-rich-plasma (PRP) varying in blending ratios, cross-linked with calcium ions, released from calcium carbonate-D-Glucono-d-lactone (CaCO₃ -GDL) was successfully prepared. It was found that addition of PRP changed largely the physical properties and biological performance of the composite hydrogels, which was depending on the blending ratio. The gelation rate and swelling ratio of alginate hydrogels were significantly reduced by the addition of PRP, which produced also a more homogeneous gel structure. Field emission scanning electron microscopy (FE-SEM) investigation confirmed the incorporation of PRP-derived proteins in the hydrogel, where a porous structure with a pore size of 200-300 μm was found. On the other hand, an increase in surface roughness was observed after the addition of PRP. The compressive mechanical strength of SA/PRP composite hydrogel was enhanced in comparison to the pure SA gel. The composite hydrogels with the highest PRP content exhibited at a maximum compressive stress of 0.26 MPa a maximum strain of 55%, while the maximum compressive strain of pure SA hydrogels was only 45% at a stress of 0.08 MPa. It was also found that the in vitro degradation of the alginate gel was accelerated by the addition of PRP. In terms of cellular responses, all gels exhibited an excellent cytocompatibility. Indeed, the composite hydrogels supported bone marrow-derived mesenchymal stem cells proliferation and their chondrogenesis with up-regulation of chondrogenic marker genes Sox9 and Aggrecan. Overall, the present study suggests a great potential of SA/PRP composite hydrogels as cell carriers for cartilage tissue engineering.

Chondrogenic effect of liquid and gelled platelet lysate on canine adipose-derived mesenchymal stromal cells

Osteoarthritis associated with hip dysplasia is one of the most common orthopedic abnormalities in dogs, with an incidence of up to 40% in some breeds. Tissue therapy of cartilage has received great attention, with use of mesenchymal stromal cells and different types of biomaterials. The present study aimed to evaluate the effect of platelet lysate (PL) on the proliferation and differentiation of canine adipose tissue-derived mesenchymal stromal cells (ASCs), in liquid culture or hydrogels. PL was prepared from blood collected from healthy dogs and submitted to freezing-thawing cycles, and hydrogel was formed with canine thrombin. The effect of PL on the proliferation and differentiation of canine ASCs was evaluated in liquid and hydrogel systems, with microscopy, quantification of dsDNA, histology and quantification of glycosaminoglycans. The addition of 5% or 10% PL to the culture medium induced a greater proliferation rate than the presence of 10% fetal bovine serum. The cultivation of ASCs in PL gel, with normal or chondrogenic medium, resulted in maintenance of proliferation level similar to the conventional 2D cultivation, and induction of chondrogenic differentiation, especially in the presence of the chondrogenesis induction medium.

Preclinical Study of Cell Therapy for Osteonecrosis of the Femoral Head with Allogenic Peripheral Blood-Derived Mesenchymal Stem Cells

PURPOSE

To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH).

MATERIALS AND METHODS

rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR.

RESULTS

After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually.

CONCLUSION

We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression.