Making the Switch: Alternatives to Fetal Bovine Serum for Adipose-Derived Stromal Cell Expansion

Abstract

Adipose-derived stromal cells (ASCs) are being used extensively in clinical trials. These trials require that ASCs are prepared using good manufacturing practices (GMPs) and are safe for use in humans. The majority of clinical trials in which ASCs are expanded make use of fetal bovine serum (FBS). While FBS is used traditionally in the research setting for in vitro expansion, it does carry the risk of xenoimmunization and zoonotic transmission when used for expanding cells destined for therapeutic purposes. In order to ensure a GMP quality product for cellular therapy, in vitro expansion of ASCs has been undertaken using xeno-free (XF), chemically-defined, and human blood-derived alternatives. These investigations usually include the criteria proposed by the International Society of Cellular Therapy (ISCT) and International Fat Applied Technology Society (IFATS). The majority of studies use these criteria to compare plastic-adherence, morphology, the immunophenotype and the trilineage differentiation of ASCs under the different medium supplemented conditions. Based on these studies, all of the alternatives to FBS seem to be suitable replacements; however, each has its own advantages and drawbacks. Very few studies have investigated the effects of the supplements on the immunomodulation of ASCs; the transcriptome, proteome and secretome; and the ultimate effects in appropriate animal models. The selection of medium supplementation will depend on the downstream application of the ASCs and their efficacy and safety in preclinical studies.

Comparison of human platelet lysate alternatives using expired and freshly isolated platelet concentrates for adipose-derived stromal cell expansion

“…It has been well established that ASCs expanded in pHPL proliferate faster than ASCs expanded in FBS (9,14,15). Although most studies have made use of pHPL that was manufactured from fresh BCs and resuspended in platelet-rich plasma, very little is known about the effects that expired BCs and TSOL have on ASC expansion (19).…”

“…These guidelines propose a set of criteria that need to be met when expanding ASCs which include their ability to adhere to plastic, express a predefined surface marker profile (immunophenotype) and have the ability to differentiate into adipose tissue, bone and cartilage (11,12). In vitro studies that have used human alternatives for ASC expansion have described faster proliferation, better morphology and a comparable immunophenotype for certain surface markers (7)(8)(9)13,14). In contrast, these studies have also reported differing trilineage differentiation capacities.…”

Fetal bovine serum-free culture of endothelial progenitor cells-progress and challenges

“…This leads to inconsistencies in cell propagation protocols, hampering data comparison among different studies and laboratories. Therefore, FBS variability negatively affects results reproducibility and may also mask the actual therapeutic effect of EPC-based treatments (Dessels, Potgieter, & Pepper, 2016;Karnieli et al, 2017;van der Valk et al, 2010;Witzeneder et al, 2013). It often creates the necessity of preselecting and stockpiling adequate FBS lots.…”

Culturing Adult Stem Cells for Cell-Based Therapeutics: Neuroimmune Applications

“…Standard procedures based on single-use bioreactors yield superior quantities and quality of cells when compared to traditional planar multilayer cultivation systems, such as CELLstack, HYPERStack, and CellFactories (Corning, Nalge) [67]. to batch-to-batch variation and to contamination with prions, viral and zoonotic agents [76]. Thus, most clinical trials (phases I to III) used ASCs or other MSCs produced in the presence of FBS, some of them reporting immunogenic effects in patients, elicited by components of FBS (antibodies against components of FBS, Arthus, and anaphylactic reactions) [77][78][79].…”