Mesenchymal stromal/stem cells (MSCs) have been investigated extensively through the past years, proving to have great clinical therapeutic potential. In vitro cultivation of MSCs in three-dimensional (3D) culture systems, such as scaffolds, hydrogels, or spheroids, have recently gained attention for tissue engineering applications. Studies on MSC spheroids demonstrated that such cultivation increased the paracrine immunomodulatory potential of the MSCs, accompanied by phenotypic alterations. In this review, we gather results from recent experimental studies on the immunomodulatory abilities of MSCs when cultured as spheroids or in biomaterials like scaffolds or hydrogels compared to regular two-dimensional (2D) culture and show that alterations occurring to MSCs in spheroids also occur in MSCs in biomaterials. We provide a brief description of known mechanisms of MSC immunomodulatory capacity and how they are altered in the two 3D culture systems, together with phenotypic cellular changes. Based on the present knowledge, we highlight vital areas in need of further investigation. The impact of 3D environments on immunomodulation has great potential for tissue engineering and cellular therapy, and this is the first review to gather this knowledge with a comparison across different 3D environments.

The present first-in-human clinical trial evaluated the safety and feasibility of a newly developed and cryopreserved Cardiology Stem Cell Centre adipose-derived stromal cell (CSCC_ASC) product from healthy donors for intramyocardial injection in ten patients with ischemic heart disease and ischemic heart failure (IHF). Batches of CSCC_ASC were isolated from three healthy donors by liposuction from abdominal adipose tissue. Adipose mesenchymal stromal cells were culture expanded in bioreactors without the use of animal constituents, cryopreserved, and stored in vials in nitrogen dry-storage containers until use. Direct injection of CSCC_ASC into the myocardium did not cause any complications or serious adverse events related to either treatment or cell administration in a 6-month follow-up period. Four out of ten heart failure patients developed donor-specific de novo human leukocyte antigen (HLA) class I antibodies, and two out of ten patients had donor-specific HLA antibodies already at baseline. There were no clinical symptoms or changes in inflammatory parameters in the follow-up period that indicated an ongoing immune response. There was a tendency toward improvement in cardiac function after CSCC_ASC treatment at 6-month follow-up: left ventricular end systolic volume decreased and left ventricular ejection fraction increased. In addition, exercise capacity increased. These changes were independent of the presence or absence of HLA antibodies. It is concluded that the newly developed cryopreserved product CSCC_ASC from healthy donors was a safe and feasible treatment. We observed a tendency toward efficacy in patients with IHF. These findings have to be confirmed in larger placebo controlled clinical trials. Stem Cells Translational Medicine 2017;6:1963–1971

Adipose derived stromal cells (ASCs) are a rich and convenient source of cells for clinical regenerative therapeutic approaches. However, applications of ASCs often require cell expansion to reach the needed dose. In this study, cultivation of ASCs from stromal vascular fraction (SVF) over two passages in the automated and functionally closed Quantum Cell Expansion System (Quantum system) is compared with traditional manual cultivation. Stromal vascular fraction was isolated from abdominal fat, suspended in α-MEM supplemented with 10% Fetal Bovine Serum and seeded into either T75 flasks or a Quantum system that had been coated with cryoprecipitate. The cultivation of ASCs from SVF was performed in 3 ways: flask to flask; flask to Quantum system; and Quantum system to Quantum system. In all cases, quality controls were conducted for sterility, mycoplasmas, and endotoxins, in addition to the assessment of cell counts, viability, immunophenotype, and differentiation potential. The viability of ASCs passage 0 (P0) and P1 was above 96%, regardless of cultivation in flasks or Quantum system. Expression of surface markers and differentiation potential was consistent with ISCT/IFATS standards for the ASC phenotype. Sterility, mycoplasma, and endotoxin tests were consistently negative. An average of 8.0 × 107 SVF cells loaded into a Quantum system yielded 8.96 × 107 ASCs P0, while 4.5 × 106 SVF cells seeded per T75 flask yielded an average of 2.37 × 106 ASCs—less than the number of SVF cells seeded. ASCs P1 expanded in the Quantum system demonstrated a population doubling (PD) around 2.2 regardless of whether P0 was previously cultured in flasks or Quantum, while ASCs P1 in flasks only reached a PD of 1.0. Conclusion: Manufacturing of ASCs in a Quantum system enhances ASC expansion rate and yield significantly relative to manual processing in T-flasks, while maintaining the purity and quality essential to safe and robust cell production. Notably, the use of the Quantum system entails significantly reduced working hours and thereby costs.

Comparison of clinical grade human platelet lysates for cultivation of mesenchymal stromal cells from bone marrow and adipose tissue. . ???aop.label???. doi: 10.3109/00365513.2015.1099723

In vitro expanded adipose-derived stromal cells (ASCs) are a useful resource for tissue regeneration. Translation of small-scale autologous cell production into a large-scale, allogeneic production process for clinical applications necessitates well-chosen raw materials and cell culture platform. We compare the use of clinical-grade human platelet lysate (hPL) and fetal bovine serum (FBS) as growth supplements for ASC expansion in the automated, closed hollow fibre quantum cell expansion system (bioreactor). Stromal vascular fractions were isolated from human subcutaneous abdominal fat. In average, 95 × 10⁶ cells were suspended in 10% FBS or 5% hPL medium, and loaded into a bioreactor coated with cryoprecipitate. ASCs (P0) were harvested, and 30 × 10⁶ ASCs were reloaded for continued expansion (P1). Feeding rate and time of harvest was guided by metabolic monitoring. Viability, sterility, purity, differentiation capacity, and genomic stability of ASCs P1 were determined. Cultivation of SVF in hPL medium for in average nine days, yielded 546 × 10⁶ ASCs compared to 111 × 10⁶ ASCs, after 17 days in FBS medium. ASCs P1 yields were in average 605 × 10⁶ ASCs (PD [population doublings]: 4.65) after six days in hPL medium, compared to 119 × 10⁶ ASCs (PD: 2.45) in FBS medium, after 21 days. ASCs fulfilled ISCT criteria and demonstrated genomic stability and sterility. The use of hPL as a growth supplement for ASCs expansion in the quantum cell expansion system provides an efficient expansion process compared to the use of FBS, while maintaining cell quality appropriate for clinical use. The described process is an obvious choice for manufacturing of large-scale allogeneic ASC products.