Preparation of Platelet Lysates for Mesenchymal Stem Cell Culture Media

Short Communication

J Stem Cells Res, Rev & Rep. 2015; 2(1): 1021.

Preparation of Platelet Lysates for Mesenchymal Stem Cell Culture Media

Gerhard Gstraunthaler¹*, Caroline Rauch¹, Elisabeth Feifel¹ and Toni Lindl²

¹Division of Physiology, Medical University Innsbruck, Austria

²Institute for Applied Cell Culture, Munich, Germany

*Corresponding author: Gerhard Gstraunthaler, Division of Physiology, Medical University Innsbruck, Schöpstraße 41, A-6020 INNSBRUCK, Austria

Received: October 13, 2015; Accepted: December 23, 2015; Published: December 31, 2015

Abstract

Large scale in vitro expansion of human mesenchymal stem cells still involves the supplementation of culture media with Fetal Bovine Serum (FBS). However, in order to avoid the risks of contaminants by FBS and xenogenic compounds, respectively, clinical grade stem cell culture should turn to other options. Chemically defined, serum-free culture media have been developed for specific cultures, but are not universally applicable yet. Another successful approach in replacing FBS in stem cell culture is the use of human platelet preparations, whereby bulk thrombocytic growth factors are added to basal culture media, thereby providing a human-based, xeno-free culture system. Platelet-Rich Plasma (PRP) has a long clinical history in bone regeneration therapy. Since most of the growth factors entrapped in platelet α-granules are also essential mitogens for cells in in vitro culture, lysates of human thrombocytes have attracted attention as an effective supplement for cell culture media. There is still some confusion in the terminology of PRP, leukocyte-PRP (L-PRP), platelet releasate, and platelet lysate. Another uncertainty is the amount of plasma and plasma proteins, respectively, in the preparations and the effects on the cultured cells. We developed lysates of washed human platelets obtained by apheresis, yielding a cell-free, low protein extract, highly enriched in thrombocytic growth factors (human platelet lysates, hPL). In the present report we briefly review the rationale behind the use of platelet extracts, will bring some systematic order into the terminology, and will provide guidelines for the preparation of a cell-free, low protein hPL.

Keywords: Platelet lysates; Platelet releasates; Platelet-rich plasma; Fetal bovine serum; Serum alternatives

Introduction

The supplementation of basal cell culture media with Fetal Bovine Serum (FBS) has become a well accepted routine practice in cell and tissue culture [1-3]. FBS provides hormones, growth factors and cytokines, and attachment factors required for growth and proliferation, and for attachment of human and animal cells in vitro.

However, FBS is a cocktail of undefined qualitative and quantitative composition, which is added to a chemically defined basal medium. In addition, considerable ethical concerns in terms of the 3Rs (replacement, reduction, refinement; [4]) were raised regarding the mode of blood collection and FBS harvest, respectively, from bovine fetuses [5,6]. Furthermore, since FBS is a by-product of the beef industry, global supply and availability of FBS is dependent on many factors and can be highly fluctuating [7]. Finally, the fraudulent blending of FBS batches with adult bovine serum albumin, water and cell growth promoting additives further questioned the use of FBS [8,9].

The advent of stem cell technologies paved the way for new developments in cell therapy and regenerative medicine. However, clinical trials and any future therapeutic application of mesenchymal stem cells recommends to avoid any usage of animal serum in in vitro cell expansion. The risk of contamination and immunogenicity of FBS revealed the necessity of animal-derived component-free (xeno-free) stem cell culture conditions [10-12]. The use of FBS in manufacturing medicinal products is seen critically by EMA, the European Medicines Agency, and new guidelines were drafted recently (www.ema.europa.eu/ema/pages/includes/document/open_ document.jsp?webContentId=WC500143930).

Thus, human-based, xeno-free culture conditions are desirable [13]. The method of choice would be the supplementation of basal culture media with growth factors of human origin that support cell growth and proliferation in vitro. During wound healing after tissue injury e. g., multifarious endogenous growth factors are released from activated, degranulating thrombocytes, and assisting in blood clotting and vessel repair [14].

In this respect, in the past decade, human Platelet Lysates (hPL) have been proven a valuable non animal-derived alternative to FBS in culture media for animal and human cells [15], including mesenchymal stem cells [16,17]. HPL as well as other lysate preparations (see below, and Table 1) represent an allogenic, even autologous medium supplement for the propagation of all kinds of human cells, without any xenogenic or immunogenic risks.

Citation: Gstraunthaler G, Rauch C, Feifel E and Lindl T. Preparation of Platelet Lysates for Mesenchymal Stem Cell Culture Media. J Stem Cells Res, Rev & Rep. 2015; 2(1): 1021. ISSN:2381-9073