Skin is constantly regenerating as old skin cells die and shed, replaced by new cells produced at the bottom of the epidermis. This process is known as epidermal turnover.
Here's how it works:
- Stem cells located in the basal layer of the epidermis are responsible for producing new skin cells.
- These stem cells divide and differentiate into keratinocytes, which are the main cell type in the epidermis.
- As new keratinocytes are formed, they push older cells towards the surface.
- As they move upward, keratinocytes undergo a process called keratinization, where they accumulate keratin, a protein that gives skin its strength and structure.
- Eventually, these cells reach the outermost layer of the epidermis, the stratum corneum, where they die and are shed.
Recent advancements in research have enabled the generation of complex skin from human pluripotent stem cells. Scientists have developed organoid culture systems that create hair-bearing skin, complete with sweat glands and hair follicles. This breakthrough holds immense potential for the development of treatments for skin diseases and burns.
