Page 403 - IJB-9-2

International Journal of Bioprinting 3D-printed skin substitute accelerates wound healing in vivo

printing, can accelerate wound healing and improve healing quality by promoting angiogenesis. The hADSCs and the
stable 3D-printed stereoscopic grid-like scaffold structure play a critical role in promoting wound healing.

Keywords: Biomaterials; 3D printing; Scaffolds; Adipose-derived mesenchymal stem cells; Skin tissue engineering

1. Introduction engineering are fibroblasts and keratinocytes. However,
it is difficult to obtain these cells from patients when
As the largest soft-tissue organ, skin is in direct contact skin defects are extensive or deep. Stem cells-based
with external environment and is most vulnerable to tissue engineering has shown great potential in tissue
various injuries, such as burns or trauma. The lack of repair. As the application of liposuction is getting more
autologous skin grafts is a common problem among common, adipose-derived stem cells (ADSCs), which can
patients with large-area skin defects. Without appropriate be obtained in high purity, can rapidly proliferate in vitro
grafts, it is almost impossible for skin to heal properly, and have low immunogenicity, are readily available in
which is usually accompanied by impaired wound healing, large quantities.
resulting in scar formation or significant morbidity and
mortality . Thus, seeking an ideal treatment method Adipose tissue decellularized extracellular matrix
[1]
to promote wound healing and skin regeneration is key (dECM), retaining the complex composition of peptides
to solving this problem. The often-used treatment for and glycosaminoglycans in native ECM, can promote cell
skin defects in clinical practice is autologous skin or flap accumulation, proliferation and differentiation, and in
transplantation. However, limited number of donors, turn stimulate angiogenesis and tissue repair. It can self-
poor survival of skin grafts, scar formation, bloated assemble to form hydrogel, which is a promising new
flap appearance, and inability to regenerate cutaneous treatment for wound healing [5,6] . The mMethacrylated
appendages limit the application of these methods. Thus, it is gelatin (GelMA)-methacrylated hyaluronic acid (HAMA)
still a big challenge to restore the shape and function of skin, hybrid hydrogel, crosslinked by photocuring, displays
and it is imperative to find an efficient wound management excellent rheological and mechanical properties, 3D
and skin regeneration strategy. Tissue-engineered skin printability and biocompatibility. GelMA-HAMA hybrid
substitute, composed of scaffold, cells and bioactive factor, hydrogel is a promising biomaterial for 3D printing
[7]
is a promising approach to treating skin defect . At skin substitute . To improve the printability of dECM
[2]
present, most of the developed skin substitutes are used pre-gel, GelMA-HAMA polymer solution was added to
as dermal scaffold to induce cells to produce extracellular dECM pre-gel to form composite hydrogel scaffold. The
matrix (ECM) and form dermal-like tissue, but due to slow aim of this research was to fabricate a 3D-printed tissue-
vascularization and delayed epithelialization, most of them engineered skin substitute using innovative biomaterial
require secondary skin grafting, which prolongs the time loaded with human adipose-derived stem cells (hADSCs)
of hospitalization and impairs life quality of patients . In and investigate its effect on wound healing.
[3]
traditional tissue engineering, cells were seeded on scaffold
materials. Then, the tissue-engineered skin was cultured 2. Materials and methods
in vitro and implanted into the corresponding damaged site. 2.1. hADSCs culture and expansion
However, it is difficult to control distribution and density of The hADSC cell lines (HUXMD-01001) was purchased
cells precisely inside the scaffold material using this method, from OriCell (Guangzhou, China). hADSCs were grown
®
which is also time-consuming. Three-dimensional (3D) in Dulbecco’s Modified Eagle Medium/Nutrient Mixture
printing technology, with the characteristics of timeliness, F-12 (DMEM/F12; Gibco, CA, USA) supplemented with
high throughput, and high repeatability, can integrate seed 10% (v/v) fetal bovine serum (FBS; Gibco, CA, USA) and
cells with biomaterials to fabricate scaffold with sophisticated 1% (v/v) penicillin-streptomycin (Gibco, CA, USA) and
macroscopic outlines and internal microstructures. It were incubated at 37°C in a 5% CO incubator. When
allows cells to be distributed evenly, prepares personalized cell density reached 80–90%, the cells were digested with
2
prosthesis, and restores the microenvironment similar to 0.25% trypsin-EDTA (Gibco, Grand Island, USA), washed
that of native tissue and has attracted increasing attention in and passaged, and the hADSCs at passage 4 were digested,
the field of skin tissue engineering .
[4]
resuspended with phosphate-buffered saline (PBS) and the
Seed cells and biomaterials play important roles in hADSCs at passage 4 were digested, resuspended with PBS
skin 3D bioprinting. The often-used cells in skin tissue and counted.

Volume 9 Issue 2 (2023) 395 https://doi.org/10.18063/ijb.v9i2.674