Figure 1.

The main purpose of the microneedles (MNs) patch application is to deliver the active biomolecules to the close or remote sites inside the body

(A) A cutaneous tissue consists of three layers: epidermis, dermis, and hypodermis.

(B) The outermost layer, the epidermis, is a keratinized stratified squamous epithelium with closely packed epithelial cells. The dermis layer lies beneath the epidermis and is composed of connective tissue with vessels and nerves ending. The innermost layer of the skin is so-called hypodermis, which is characterized by the loose connective tissue and the existence of adipocytes.