Page 175 - IJB-9-5

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

the body to resist various damages from the external passively; these properties are very important for wound
environment, such as mechanical interference, microbial healing [23,24] . Therefore, the addition of functional materials
invasion and ultraviolet (UV) radiation [2,3] . In addition, can endow wound healing materials with a variety of
the skin is equipped with has basic functions such as properties, thus promoting rapid and effective wound
thermoregulation, humoral balance, sensory detection, healing. In addition, in order to provide personalized
and immunological surveillance . However, fragile skin is treatment for different wound types, three-dimensional
[4]
susceptible to external extremes or injuries, which usually (3D) bioprinting technology, which has prominent
lead to skin defects, functional impairment, fluid loss, and advantages in wound healing and tissue regeneration, has
bacterial infections. Wound healing is a medical problem been introduced into wound management .
[5]
on a global scale, placing an enormous burden on human 3D bioprinting is an important branch of 3D printing
health and global healthcare system . Statistics have shown technology applied to life science and medicine. 3D
[5]
that the global medical cost caused by incomplete chronic printing is a rapid prototyping technology that constructs
wounds in 6 million patients is as high as $20 billion [6-8] . 3D geometric shapes through computer-aided design and
Moreover, countless wounds cannot heal naturally due to layer-by-layer deposition of materials. 3D bioprinting
the progressive degeneration and necrosis of tissue cells in is based on the principle of additive manufacturing
the wounds of extensive injury and ulceration . Therefore, to accurately deposit bioinks containing biomaterials,
[9]
establishing a reliable, safe, and simple treatment is an growth factors and even living cells in a controllable space
urgent problem to be solved . to create complex tissue structures to simulate natural
[10]
The wound healing process is complex and dynamic, tissues or organs [25-29] . In skin repair, this technology can
mainly including hemostasis, inflammation, cell precisely match the geometric shape of wound healing
proliferation, and maturation [11,12] . At present, for wounds materials and tissue defects, so as to achieve rapid and
that cannot be healed by the human body, such as large-area effective wound healing . So far, the combination of
[30]
trauma and burns, traditional methods such as autograft , 3D bioprinting technology and a variety of functional
[13]
allograft , cell therapy , and skin substitute are materials can produce the reproducible and personalized
[16]
[15]
[14]
usually used to treat such wounds in clinic. However, these 3D constructions with multiple functions, such as
traditional approaches are often limited by insufficient antibacterial, anti-inflammatory, antioxidant, hemostasis,
donors, small scope of repair, immune rejection, and high and antitumor properties. Liu et al. fabricated a Gel/PCL/
[31]
costs [17,18] . Therefore, a large number of wound dressings PDA cores/shell fiber scaffold for controlled anticancer
and skin tissue engineering scaffolds have been developed drug release by depositing polydopamine (PDA) and
to provide artificial substrates for wound repair and tissue polycaprolactone (PCL) on the surface of 3D-printed
regeneration . In the process of wound repair, traditional drug-loaded alginate-gelatin hydrogel scaffolds. The
[19]
dressings and skin tissue engineering scaffolds usually have scaffold can be implanted at the resection site of patients
problems such as inability to stop bleeding, susceptibility with malignant tumors for local cancer treatment through
to wound infection and inflammation, and difficulty in drug release (doxorubicin) and photothermal therapy. In
achieving vascularization . Among them, infection is addition, it can repair surgically resected defect tissue and
[20]
the main obstacle in the wound healing process, which promote wound repair.
can cause the elevation of reactive oxygen species (ROS) In this article, we describe the principles, advantages,
and protease levels in the wound, excessive inflammation and disadvantages of different 3D bioprinting technologies,
and other problems, and ultimately leads to incomplete and review the fundamentals of the wound healing
wound repair and prolonged repair time . At the same process. In addition, we focus on the classification and
[21]
time, hemostasis is also particularly important for wound characteristics of different functional materials, as well
healing, which is related to the patient’s life and subsequent as the important application of 3D-bioprinted functional
wound healing . Thus, functional materials with some materials for wound healing, aiming to provide new ideas
[22]
or more characteristics have great potential in wound and useful references for the preparation and further
healing treatment. For example, the antibacterial materials development of multifunctional wound healing materials
(such as silver, zinc oxide, and chitosan) can inhibit or using 3D bioprinting technologies in the future.
kill bacteria in wounds through multiple mechanisms:
the anti-inflammatory materials (paeoniflorin, apigenin, 2. Skin wound healing process
and luteolin) can inhibit the production or release of
anti-inflammatory factors to fight inflammation, and the The most significant organ of our body, the skin, has
hemostatic materials (such as chitosan, montmorillonite, numerous important functions such as secretion,
and kaolin) can control wound bleeding either actively or regulation, and protection . However, the structure and
[32]

Volume 9 Issue 5 (2023) 167 https://doi.org/10.18063/ijb.757