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

foot wounds, have become a substantial social burden . treatment approach is based on the concept that if the
[2]
Recently, with remarkable progress in regenerative microenvironment is regarded as a macroscopic whole,
medicine related to wound healing, skin tissue engineering the overall regulatory direction is conducive to wound
has spawned the emergence of skin replacement products repair [16,17] . Therefore, we attempted to modify the usual
for wound repair. However, in a 2016 global survey of strategy of in vitro fabrication of highly biomimetic skin
111 specialists, 100% of the participants believed that an substitutes by 3D bioprinting technology to a strategy of
ideal skin substitute had yet to be developed . This is due rapid in vitro fabrication and in vivo maturation in the
[3]
to many factors, such as the material source, preparation microenvironment. Once this attempt can be realized, the
time, storage time, medical expense, physiological preclinical time consumed by 3D bioprinting technology
function, structure reproduction, and biological stability for wound repair will be substantially shortened.
of previously developed tissue-engineered skin [4-7] . Liposuction is a well-established procedure that is

Recently, many tissue engineering studies have widely used in plastic surgery, and the removed fat is
fabricated three-dimensional (3D)-bioprinted, structurally typically discarded as biohazardous waste . This “waste”
[18]
complex scaffolds [8-10] . 3D-bioprinted structures containing contains abundant extracellular matrix (ECM) and
pigments, or sweat glands and hair follicles have been mesenchymal stem cells (MSCs) that fully meet the cell and
successfully constructed in vitro [11,12] . The emergence material requirements for bioactive materials that support
of these constructs is very encouraging, but their long the repair of full-thickness skin defects. ECM is a natural
in vitro culture time may not provide patient satisfaction material derived from the human body that can affect
within a short period of time. By integrating in situ numerous cell processes, including cell spreading, growth,
bioprinting system with image processing technology, proliferation, migration, and differentiation, as well as
autologous or allogeneic dermal fibroblasts and epidermal organoid formation [19,20] . Decellularized ECM (dECM)
keratinocytes can be delivered precisely to the skin defect does not contain cellular or nuclear components, reducing
area, which can accelerate wound healing in vivo . the risk of inflammatory and immune responses upon
[13]
Jorgensen et al. produced three-layer, bioprinted skin implantation, but does retain the structural and functional
model that encapsulated cells from a wider array of properties of ECM, including specific nanostructures,
cell types, such as human keratinocytes, melanocytes, biochemical complexity, and bioinduction properties .
[21]
fibroblasts, dermal microvascular endothelial cells, hair Importantly, dECM can promote the production of
follicle dermal papilla cells, and adipocytes . There is functional tissues in specific parts of the body . These
[22]
[14]
no doubt that the composition or function of the newly advantages make dECM a promising material for
emerging full-thickness skin constructs are increasingly tissue engineering strategies for wound treatment. The
similar to that of natural skin, but we should also note that thermosensitivity of dECM enables physical crosslinking at
most in vitro fabricated 3D-bioprinting scaffold require 37°C, but dECM alone is unsuitable for 3D printing because
a remarkable amount of time to complete material and of the low viscosity . Gelatin methacryloyl (GelMA)
[23]
cell culture preparation. Confronted with urgent clinical has photocrosslinking properties and can promote cell
needs, rapid fabrication of 3D-bioprinting scaffolds is adhesion, proliferation, and spreading . Hyaluronic
[24]
essential for accelerating wound recovery and reducing acid methacryloyl (HAMA) has a high hydrophilicity and
scar formation . There remains a lack of products using considerable cytocompatibility, supporting cell growth,
[15]
human materials and cells that can be fabricated within migration, and differentiation . Photocrosslinked HAMA
[25]
a few days, particularly in terms of material source and can improve the mechanical properties of bioprinted
preparation time. This study will focus on this perspective. implants. Therefore, adipose-derived decellularized
extracellular matrix (adECM), together with GelMA and
If tissue engineering is considered an external tool,
the wound microenvironment itself may serve as an HAMA, as the main components of a bioink, can provide
dual properties of photocrosslinking and thermosensitive
internal tool to promote implant maturation. Therefore, crosslinking, which can further improve the stability of the
these external and internal tools could be combined to scaffold after implantation.
eliminate excessive steps in in vitro fabrication. Therefore,
rapidly fabricated 3D-bioprinted scaffolds that seem like Several studies have demonstrated the potential of
“semifinished products” but possess biological activity could adipose-derived stem cells (ADSCs) to promote wound
be directly implanted into the wound, where their structure healing [26-28] . ADSCs can differentiate into endothelial cells,
and function would continue to improve depending on fibroblasts, and keratinocytes and secrete cytokines that
the wound microenvironment. We believe that this is promote their proliferation and migration [29-32] . Biomaterial
a valuable approach, although many details regarding scaffolds fabricated by 3D bioprinting technology and
the wound microenvironment remain unexplored. This loaded with ADSCs can promote the healing of burn

Volume 9 Issue 4 (2023) 30 https://doi.org/10.18063/ijb.718