BIOPRINTING FOR SKIN - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 292

FIGURE 13.10 Presence of blood vessels in the printed skin constructs.
Printed skin constructs were cultivated in the dorsal skin fold chamber in mice for 11 days. Collagen VI expression
(brown) indicates blood vessels. In the skin constructs, small vessels can be found in the Matriderm™, reaching
from the wound bed in the direction of the cells (A). Small and large vessels can be found in normal mouse skin (B).
The respective negative controls are shown in C (Matriderm™) and D (normal mouse tissue). Scale bars represent
200 m m each. Reprint from Michael et al. (2013b) .
Nevertheless, skin constructs can be improved with the addition of further cell types such as en-
dothelial cells for quick blood vessel generation, hair follicle cells, melanocytes for pigmentation,
immune cells (e.g. Langerhans cells, macrophages, leucocytes, plasma cells, and mast cells), nerve and
Schwann cells for perception, or cells present in perspiratory glands to enable sweating and temperature
homeostasis. However, simply adding these cell types may not be enough to create all of the neces-
sary cutaneous appendages. Instead, the correct microenvironments need to be created to enable the
different cell types to fulfill their respective purposes.
Bioprinting offers the possibility of exactly depositing each cell type at its correct 3D location, help-
ing to create the necessary microenvironment for the cells to fulfill their functions. This makes bioprint-
ing such a promising tool for tissue engineering. While several bioprinting setups, commercially avail-
able or individually constructed, are used for tissue engineering research, they have yet to fulfill the
requirements for clinical applications in skin tissue generation. For use in clinical skin reconstruction,