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International Journal of Bioprinting 3D-Bioprinted human lipoaspirate-derived cell-laden skin constructs

Figure 1. Schematic illustration of the fabrication and implantation process for ADSC-laden ECM–GelMA–HAMA constructs. (A) Human adipose tissue
was decellularized, and the obtained adECM was prepared as a hydrogel. Three hydrogel materials, adECM, GelMA, and HAMA, were mixed with ADSCs
at predetermined concentrations to form bioink. (B) Bioink was printed layer-by-layer, and the construction was completed by vertical superposition. (C)
Constructs were implanted into the wounds of nude mice for subsequent in vivo studies.

wounds [33,34] . Based on the traditional concept of tissue Senior Department of Burns and Plastic Surgery of the
engineering, predifferentiation of ADSCs should be Fourth Medical Center of PLA General Hospital in Beijing,
completed before the printing of scaffolds; however, this China (No. 2022KY135-KS001). Informed consent was
approach reduces the time efficiency for clinical application. obtained from the human subjects with approval from
Herein, we developed a 3D-printed bioactive scaffold that the local ethics committee of PLA General Hospital. The
can be fabricated using human adECM and ADSCs as decellularization process followed Flynn’s method , with
[35]
bioink compositions and evaluated its effect on the healing one difference involving the isopropyl alcohol extraction
of full-thickness skin defects in nude mice, thereby laying after the first enzymatic digestion, which was replaced every
a methodological foundation for the rapid fabrication of 12 h to maximize lipid removal. Reagents used for enzyme
3D-printed skin substitutes for wound healing (Figure 1). digestion included 0.25% trypsin/0.1% EDTA (Gibco,
Canada), benzonase (1000 U/mL; Merck, Germany),

2. Materials and methods and lipase type II (Solarbio, China). All decellularization
solutions included 100 IU/mL penicillin, 100 mg/mL
2.1. Decellularization of human adipose tissue and streptomycin, 0.625 mg/mL amphotericin (Biosharp,
preparation of hydrogel China), and 1% phenylmethanesulphonylfluoride (Sigma-
Adipose tissue was harvested from the abdomen of healthy Aldrich, USA). Collected adECM was freeze-dried in a
women during routine liposuction procedures at the vacuum freeze-drying machine for 48 h, and the resulting

Volume 9 Issue 4 (2023) 31 https://doi.org/10.18063/ijb.718