Page 92 - IJB-10-4

International Journal of Bioprinting Biomaterials with antibacterial agents

The skin regulates temperature, water content, and the epidermis lies the dermis, which is 1.5–4 mm thick.
electrolyte losses to help maintain homeostasis. The The dermis has a high degree of elasticity and tensile
nerve endings of the skin mainly contribute to its sensory strength and is abundant with extracellular matrix (ECM).
function. Furthermore, the permeability of the skin makes The dermis functions as a water reservoir and is home
it a feasible route for the delivery of drugs with systemic to scavenger cells of the immune system, which ingest
or local effects. On the one hand, the skin can prevent invading organisms. To protect internal organs from
the loss of water and electrolytes and protect interior damage, subcutaneous tissue works as an insulator and
organs and tissues from injury. However, it is capable of shock absorber. This layer divides the dermis from other
feeling pressure, heat, and cold. The basement membrane structures like the fascia, bone, or muscles. In the event
2
connects the dermis and epidermis—the two primary of an injury, the wounded part of the hypodermis layer is
structural layers, forming three distinct layers of the skin, not recoverable; instead, the lost part would be replaced by
as shown in Figure 1. The subcutaneous tissue, which is collagen-rich scar tissue. 5
the hypodermis containing adipose tissue, lies beneath
these layers. It also contains blood vessels, lymph vessels, Wounds constitute a “silent epidemic” that affects
nerves, and cutaneous appendages, such as sweat glands, millions of people worldwide, negatively affecting their
hair follicles, and sebaceous glands. Each layer plays a role social and economic well-being and quality of life.
3
in maintaining the skin’s pathophysiology and structural Nowadays, skin injuries—more especially, burn wounds,
integrity. The epidermis, a stratified squamous keratinized diabetic foot ulcers (DFU), and surgical wounds—are
6,7
epithelium, is the outermost layer of skin, which is in direct regarded as the most common forms of injuries. Wound
contact with the external environment. The epidermis healing is a complex biological process that requires the
safeguards DNA from ultraviolet radiation damage, presence of multiple cell types, growth factors, cytokines,
protects the body from the invasion of bacteria and other and ECM. An area that has recovered from an injury,
8
foreign objects, and clings to water. Immediately beneath restoring its original anatomical structure, function,
4

Figure 1. Schematic illustration of the key layers of skin tissue and the epidermis’ anatomy. The figure was created with BioRender.com.

Volume 10 Issue 4 (2024) 84 doi: 10.36922/ijb.3372