Table 2.

FDA Definitions of relevant terminology as quoted from Regulatory Considerations for Human Cells, Tissues, and Cellular and Tissue-based Products: Minimal Manipulation and Homologous Use (2020).

BLA	Biologic License Application
IND	Investigational New Drug Application
IDE	Investigational Device Exemption
Class I, II, or III Device	Devices are categorized based on risk to patient or user: Class I (low to moderate risk); Class II (moderate to high risk); Class III (high risk)
HCT/P	Human cells, tissues, and cellular and tissue-based product, i.e., bone, ligament, skin, dura mater, heart valve, cornea, hematopoietic stem/progenitor cells derived from peripheral and cord blood, manipulated autologous chondrocytes, epithelial cells on a synthetic matrix, and semen or other reproductive tissue
Non-HCT/P	(1) Vascularized human organs for transplantation; (2) Whole Blood or blood components or blood derivative products; (3) Secreted or extracted human products, such as milk, collagen, and cell factors, except semen, are considered an HCT/P; (4) Minimally manipulated bone marrow for homologous use and not combined with another article (except for water, crystalloids, or a sterilizing, preserving, or storage agent, if the addition of the agent does not raise new clinical safety concerns with respect to the bone marrow); (5) Ancillary products used in the manufacture of HCT/P; (6) Cells, tissues, and organs derived from animals other than humans; (7) In vitro diagnostic products; and (8) Blood vessels recovered with an organ, as defined in 42 CFR 121.2 that are intended for use in organ transplantation and labeled “For use in organ transplantation only” (21 CFR 1271.3(d))
Processing of HCT/P	Any activity performed on an HCT/P, other than recovery, donor screening, donor testing, storage, labeling, packaging, or distribution, such as testing for microorganisms, preparation, sterilization, steps to inactivate or remove adventitious agents, preservation for storage, and removal from storage (21 CFR 1271.3(ff)). Processing also includes cutting, grinding, shaping, culturing, enzymatic digestion, and decellularization.
Homologous use	The repair, reconstruction, replacement, or supplementation of a recipient's cells or tissues with an HCT/P that performs the same basic function or functions in the recipient as in the donor: a.Recipient cells or tissues that are identical (e.g., skin for skin) to the donor cells or tissues, and perform one or more of the same basic functions in the recipient as the cells or tissues performed in the donor; or, b.Recipient cells or tissues that may not be identical to the donor's cells or tissues but that perform one or more of the same basic functions in the recipient as the cells or tissues performed in the donor
Structural tissue	Tissues that physically support or serve as a barrier or conduit, or connect, cover, or cushion in the donor, i.e., adipose tissue, amniotic membrane and umbilical cord, articular cartilage, blood vessel, bone, non-articular cartilage, skin, tendon or ligament
Non-structural tissue	Tissues that serve predominantly metabolic or other biochemical roles in the body such as hematopoietic, immune, and endocrine functions, i.e., hematopoietic stem/progenitor cells (e.g., cord blood), lymph nodes and thymus, reproductive cells or tissues (e.g., oocytes) .
Minimal manipulation (structural tissue)	The processing of the HCT/P does not alter the original relevant characteristics of the tissue relating to the tissue's utility for reconstruction, repair, or replacement
Minimal manipulation (non-structural tissue)	The processing of the HCT/P does not alter the relevant biological characteristics of cells or tissues