Adipose tissue is a specialized connective tissue made up of cells rich in lipids and fatty acids are known as adipocytes. As adipose tissue constitutes 20-25% of total body weight in healthy individuals, it is mainly used to store energy as lipids (fat). Based on its distribution, fat tissue is classified as parietal and visceral.
Different morphological features of fat cells will produce two different types of fatty tissue, as listed below.
1. White adipose tissue
This type of tissue is the result of storing excess calories and is found in adults.
2. Brown adipose tissue
This type of tissue generates heat by burning calories and is mainly found in infants.
The adipose tissue of the human body is placed in two compartments:
- Parietal or subcutaneous fat is the type of fat that is visible under the skin. It is also known as jiggly fat.
- Visceral fat is the type that is around the abdominal organs deep inside the body.
The extracellular matrix and cells within fat tissue act together to form this tissue. This tissue contains a large number of cells.
Adipose tissue is composed of adipose cells, also called adipocytes. Adipocytes are not the only cell type present in adipocytes; there are also polymorphonuclear cells, capillary endothelium, macrophages, and stem cells. The stromal vascular fraction is made up of adipose tissue and non-adipocyte cells. These cells protect the adipocytes and support them.
The extracellular matrix is synthesized both by adipocytes and stromal cells. This is produced from a finely divided network of reticular fibers (type III collagen), which are responsible for pulling the cells together. Adipose tissue has a rich supply of both blood vessels and unmyelinated nerve fibers.
Functions of Adipose Tissue
Adipocytes play an essential role in body insulation and energy storage by storing fat in the form of triglycerides. This helps maintain optimal levels of free fatty acids in the blood.
Aside from storing energy, fat tissue performs many other crucial functions within the human body. They can perform many functions, including insulating the tissues, cushioning the organs, and inflammation.
In recent years, the way adipose tissue is perceived has changed dramatically, thanks to the extensive research that has taken place. ASCs can be regarded as potential stem cells with self-renewal properties and are differentiated into more than one type. Later this tissue becomes a potential stem cell source, rather than a passive energy source.
Unlike bone marrow-derived stem cells, adult stem cells (ASCs) are widely available and can be isolated in more significant amounts than BMSCs. SVF, or fresh stromal vascular fraction. It is an effective way to treat radiation injury, burns, or nonhealing wounds, such as diabetic ulcers when used directly.
It is a very fast-growing field of medicine that gives the opportunity to harvest and collect adipose tissue easily through a power-assisted machine that forms sterile canisters.
American CryoStem, for example, used proprietary transportation media in CELLECT® collection and transportation bags to prevent cells from being damaged during shipment. Once collected, the tissue can be used for various tissue-engineering processes.