Xenobiotic-Free Medium Guarantees Expansion of Adipose Tissue-Derived Canine Mesenchymal Stem Cells Both in 3D Fibrin-Based Matrices and in 2D Plastic Surface Cultures

Autologous Platelet Lysate Is an Alternative to Fetal Bovine Serum for Canine Adipose-Derived Mesenchymal Stem Cell Culture and Differentiation

The use of fetal bovine serum (FBS) in regenerative medicine raises serious ethical and scientific concerns. We have cultured and differentiated the canine mesenchymal stem cells (cMSCs) in five different media combinations of autologous platelet lysate (A-PL) and FBS; consisting of 0% A-PL and 10% FBS (M-1), 2.5% A-PL and 7.5% FBS (M-2), 5% A-PL and 5% FBS (M-3), 7.5% A-PL and 2.5% FBS (M-4), and 10% A-PL and 0% FBS (M-5). The cMSCs were evaluated for their doubling time, differentiation efficiency, and expression of CD73, CD90, CD105, and PDGFRα. The mRNA expression of NT5E, THY1, ENG, PPARγ, FABP4, FAS, SP7, BGLAP, and SPP1 was also assessed. The results indicated non-significant differences in cellular proliferation/viability; positive expression of surface markers, and PDGFRα with substantial adipo/osteogenic differentiation. The expression of adipogenic (PPARγ, FABP4, FAS), and osteogenic (SP7, BGLAP, SPP1) genes were higher (p < 0.05) in the M5 group. In conclusion, A-PL in cMSCs culture did not negatively affect cellular proliferation and viability but also enhanced their genetic potential for multilineage differentiation. Our results indicate that A-PL can be used as an alternative for FBS to develop potent cMSCs under good manufacturing practice protocol for regenerative medicine.

Generation of functional fat organoid from rat superficial fascia

The organoid is a 3D cell architecture formed by self-organized tissues or cells in vitro with similar cell types, histological structures, and biological functions of the native organ. Depending on the unique organ structures and cell types, producing organoids requires individualized design and is still challenging. Organoids of some tissues, including adipose tissue, remain to generate to be more faithful to their original organ in structure and function. We previously established a new model of the origin of adipose cells originating from non-adipose fascia tissue. Here, we investigated superficial fascia fragments in 3D hydrogel and found they were able to transform into relatively large adipocyte aggregates containing mature unilocular adipocytes, which were virtually "fat organoids". Such fascia-originated fat organoids had a typical structure of adipose tissues and possessed the principal function of adipose cells in the synthesis, storage, hydrolysis of triglycerides and adipokines secretion. Producing fat organoids from superficial fascia can provide a new approach for adipocyte research and strongly evidences that both adipose tissues and cells originate from fascia. Our findings give insights into metabolic regulation by the crosstalk between different organs and tissues and provide new knowledge for investigating novel treatments for obesity, diabetes and other metabolic diseases.Abbreviations: 3D: three dimensional; ASC: adipose-derived stromal cells; C/EBP: CCAAT-enhancer-binding protein; EdU: 5-ethynyl-2-deoxyuridine; FABP4: fatty acid-binding protein 4; FAS: fatty acid synthase; FSCs: fascia-derived stromal cells; Plin1: perilipin-1; Plin2: perilipin-2; PPARγ: peroxisome proliferator-activated receptor γ; WAT: white adipose tissue.

Manufacturing Mesenchymal Stromal Cells for the Treatment of Osteoarthritis in Canine Patients: Challenges and Recommendations

The recent interest in advanced biologic therapies in veterinary medicine has opened up opportunities for new treatment modalities with considerable clinical potential. Studies with mesenchymal stromal cells (MSCs) from animal species have focused on in vitro characterization (mostly following protocols developed for human application), experimental testing in controlled studies and clinical use in veterinary patients. The ability of MSCs to interact with the inflammatory environment through immunomodulatory and paracrine mechanisms makes them a good candidate for treatment of inflammatory musculoskeletal conditions in canine species. Analysis of existing data shows promising results in the treatment of canine hip dysplasia, osteoarthritis and rupture of the cranial cruciate ligament in both sport and companion animals. Despite the absence of clear regulatory frameworks for veterinary advanced therapy medicinal products, there has been an increase in the number of commercial cell-based products that are available for clinical applications, and currently the commercial use of veterinary MSC products has outpaced basic research on characterization of the cell product. In the absence of quality standards for MSCs for use in canine patients, their safety, clinical efficacy and production standards are uncertain, leading to a risk of poor product consistency. To deliver high-quality MSC products for veterinary use in the future, there are critical issues that need to be addressed. By translating standards and strategies applied in human MSC manufacturing to products for veterinary use, in a collaborative effort between stem cell scientists and veterinary researchers and surgeons, we hope to facilitate the development of quality standards. We point out critical issues that need to be addressed, including a much higher level of attention to cell characterization, manufacturing standards and release criteria. We provide a set of recommendations that will contribute to the standardization of cell manufacturing methods and better quality assurance.

A Review of Fetal Bovine Serum in the Culture of Mesenchymal Stromal Cells and Potential Alternatives for Veterinary Medicine

Fetal bovine serum (FBS) remains widely used as a supplement in cell culture media used in the isolation and expansion of mesenchymal stromal cells (MSC) despite longstanding practical, clinical, and ethical concerns over its use. As a result, research on alternative culture media supplement solutions that conserve crucial MSC characteristics has become increasingly relevant. Species-specific supplements and serum-free media such as platelet lysate or chemically defined media have been assessed for their effect in MSC cultures regarding proliferation, differentiation, and immunomodulatory capacity. While none of the alternatives offer a complete solution in replacing traditional FBS supplemented media for culturing MSCs for all species, short-term or transitional use of FBS-free media can perform equally well and could address some of the concerns over the use of FBS.

Physiologic isolation and expansion of human mesenchymal stem/stromal cells for manufacturing of cell-based therapy products

The utilization of mesenchymal stem/stromal cells raises new hopes in treatment of diseases and pathological conditions, while at the same time bringing immense challenges for researchers, manufacturers and physicians. It is essential to consider all steps along the in vitro fabrication of cell-based products in order to reach efficient and reproducible treatment outcomes. Here, the optimal protocols for isolation, cultivation and differentiation of mesenchymal stem cells are required. In this review we discuss these aspects and their influence on the final cell-based product quality. We demonstrate that physiological in vitro cell cultivation conditions play a crucial role in therapeutic functionalities of cultivated cells. We show that three-dimensional cell culture, dynamic culture conditions and physiologically relevant in vitro oxygen concentrations during isolation and expansion make a decisive contribution towards the improvement of cell-based products in regenerative medicine.

Case Report: A Novel Ventilated Thermoplastic Mesh Bandage for Post-operative Management of Large Soft Tissue Defects: A Case Series of Three Dogs Treated With Autologous Platelet Concentrates

A ventilated thermoplastic mesh bandage was used for the post-operative management of large soft tissue defects in three dogs. Once the granulation tissue appeared, the wounds were treated with liquid or jellified autologous platelet concentrates, Platelet Rich Plasma (PRP) and Platelet Lysate (PL), to improve the wound healing process. After cleaning the wound with sterile physiological solution, a dressing was performed with several layers of cotton. A window through the layers of cotton was opened above the wound. Then, the platelet concentrate was topically applied, and the bandage was completed by placing, over the access window, a ventilated thermoplastic mesh modeled according to the size and shape of the wound. After 24 h, it was replaced by a low adhesion bandage. The thermoplastic mesh avoids the direct contact between the wound and the external layers of the bandage, preventing the drainage of the topical agent and the removal of the growing healthy granulation tissue. The bandage proposed in this study is easily applied by the veterinarian and well-tolerated by the animal, ensuring high welfare standards in stressed patients presenting compromised clinical conditions.