Page 183 - IJB-9-5

International Journal of Bioprinting Functional materials of 3D bioprinting for wound healing

As science and technology continue to advance, dressings [43,140] . Over the past few decades, thousands of
current bioprinting techniques are also improved. For wound dressings have been developed to treat wounds
example, microfluidics-assisted extrusion bioprinting is a or burns [141] . In addition to basic barrier functions, some
micro-device printing technology based on microfluidics, wound dressings have antimicrobial and moisturizing
which enables precisely controlled deposition of multiple properties, in addition to mechanical strength and
materials to obtain 3D structures in a relatively short histocompatibility [135] .
period of time [124] (Figure 3f and 3f ). As an additive [6]
2
1
bio-manufacturing technique, 3D bioprinting can offer At present, there are many types of wound dressings .
an essential strategy for wound dressings or skin tissue Traditional wound dressings mainly prevent infection
engineering to manufacture personalized construct and help wound healing by providing a physical barrier
precisely and dexterously in a short time, which would and absorbing wound exudate, but they are still unable to
shorten the waiting time and reduce the suffering of the prevent and treat wound infection, and thus, there is still
[19]
patients as well as accelerate regeneration of skin function. a need to develop fully functional wound dressings .
With the development of biomatrix materials, the
5. Applications of functional materials application of 3D bioprinting technology and the addition
for 3D-bioprinted dressings and tissue of functional materials, the manufactured 3D-bioprinted
wound dressings not only have the functions of traditional
engineering scaffolds wound dressings, but also can stimulate cell migration and
Every year, many people suffer from skin damage or burns promote ECM production during wound healing [44,142] .
of varying degrees due to carelessness or force majeure. [130]
In wound treatment, wound dressings and skin tissue Zhao et al. used photoactive cationic conjugated
engineering scaffolds, which have become an integral part polyphenylene vinylene derivatives (PPV), gelatin (Gel),
of clinical skin defect treatment, can protect wounds and hyaluronic acid (HA), and alginate (Alg) for the fabrication
accelerate wound healing [127,128] . of bioinks (Figure 4a), where cationic PPV conferred
excellent photodynamic therapy (PDT)-based resistance
The application of traditional wound dressings and to S. aureus to the artificial skin patch. Figure 4b shows
skin tissue engineering scaffolds in promoting wound the process of printing a skin patch using a 3D bioprinter.
healing have attained great progress, but there are still The 3D-bioprinted large-scale antibacterial skin patch
limitations such as inability to fit irregular wounds and Gel/Alg/HA/PPV has a certain flexibility, as shown in
poor vascularization . 3D bioprinting technology Figure 4c. While printing the letters “ICCAS” using Gel/
[19]
has advantages in treating wound healing and tissue Alg/HA/PPV bioink, further demonstrating printability
regeneration, and can make geometric shape accurately (Figure 4d). In vivo anti-infection test of the artificial skin
match tissue defects. In recent years, many researchers patch using a rat model of S. aureus infection showed
have combined 3D bioprinting technology with various that on the fourth day after photodynamic therapy, no
matrix biomaterials, functional materials, and other active infection occurred around the dry wounds treated with
ingredients in a controlled manner to generate viable the PPV skin patch, indicating that it has the ability to
structures to fabricate wound dressings and skin tissue resist infection in vivo (Figure 4e). Diffusion plate assay
engineering scaffolds that fully adapt to irregular wounds of S. aureus-infected wound sites further demonstrated
to promote wound repair and tissue regeneration [129] . the excellent antimicrobial properties of PPV skin patch
(Figure 4f). In addition, the antibacterial skin patch Gel/
5.1. Wound dressings Alg/HA/PPV also had accelerated in vivo biodegradability
Wound dressings are applied to the wound surface to and wound healing.
support various stages of wound healing [139] . The earliest
use of wound dressings dates back to 2500 BC, when the Although topical wound dressings promote wound
Sumerians used resin, honey, or mud and herbs to cover healing by preventing or reducing skin inflammation, the
wounds after washing them with milk or water . In development of new alternative dressings to effectively
[6]
460–370 BC, the ancient Greeks used wine or vinegar to clear excess inflammation and infection in the initial stages
clean wounds. In the late 20th century, people began to of the healing mechanism is warranted . Recently, Yang
[50]
use occlusive dressings to provide moisture to wounds, et al. [131] added CeO /N-halamine hybrid nanoparticles
2
protect wounds, and reduce wound infection [140] . With (NPs) as antibacterial components into the matrix of
the remarkable development of microbiology and gelatin methacryloyl (GelMA), carboxymethylcellulose
cytopathology, Winter proposed in 1962 that a moist sodium (CMC), and xanthan gum, and then prepared a
wound microenvironment could accelerate wound repair, new 3D-bioprinted GCX-CeO /APSGH-Cl antibacterial
2
laying the foundation for the development of wound dressing by photocrosslinking. The results of antibacterial

Volume 9 Issue 5 (2023) 175 https://doi.org/10.18063/ijb.757