115In Europe, MSCs are considered as somatic cell therapy products, referred to as
advanced therapy medicinal products (ATMPs), which are under European
Regulation No. 1394/2007. Regulation 1394/2007 contains rules for authorization,
supervision, and technical requirements regarding the summary of product charac-
teristics, labeling, and the package leafl et of ATMPs. In addition, the production and
delivery of MSCs should be performed according to European GMP (Euralex).
In the USA, MSCs are considered as human cell- and tissue-based products
(HCT/Ps). Hence, the production of MSCs must comply with Current Good Tissue
Practice requirements under the Code of Federal Regulations (CFR) [FDA for facil-
ities (Part 1271.190a and b); environmental control (Part 1271.195a); equipment
(Part 1271.200a); supplies and reagents (Part 1271.210a and b); recovery (Part
1271.215); processing and process controls (Part 1271.220); labeling controls (Part
1271.250a and b); storage (Part 1271.260a–d); receipt, pre-distribution shipment,
and distribution of an HCT/P (Part 1271.265a–d); and donor eligibility determina-
tion, screening, and testing (Parts 1271.50, 1271.75, 1271.80, and 1271.85)]. Under
this regulation, MSCs and other cell culture production systems require the use of a
class A cabinet operated in a B class room.
6.5 Production Processes for Non-expanded MSCs
Non-expanded MSCs are directly isolated or enriched from tissue. Studies have
referred to MSCs in peripheral blood, umbilical cord blood , and bone marrow as
mononuclear cells (MNCs). In fact, using centrifugation or other enrichment meth-
ods, MSCs can only be enriched in the MNC fraction. For solid tissues such as
adipose tissue, non-expanded MSCs are enriched after removing contaminating
cells such as adipocytes. Non-expanded MSCs from adipose tissue are the so-called
stromal vascular fraction (SVF).
Although non-expanded MSCs are approved by some countries as a minimal
manipulation of stem cells, non-expanded MSC processing should be performed by
standardized protocols and procedures. In most countries, the stem cell process
must be carried out using FDA-approved or IVD kits in combination with IVD
equipment in GMP facilities.
6.5.1 Isolation of Non-expanded MSCs from Peripheral Blood,
Bone Marrow, and Umbilical Cord Blood
MSCs exist at a low density in peripheral blood, bone marrow, and umbilical cord
blood. Both MSCs and hemopoietic stem cells (HSCs) can be enriched by similar
methods. Although some studies have purifi ed MSCs from blood using kits based
on certain markers , such as the CD117 MicroBead Kit for isolation of MSCs from
bone marrow, non-expanded MSCs as MNCs are enriched from blood, amniotic
6 Production of Clinical-Grade Mesenchymal Stem Cells