Page 14 - manuscript_ijb05596

CMA can still undergo UV crosslinking, and the photoinitiator Irgacure 2959 remains

intact and non-toxic, with good biocompatibility. The resulting 3D printed dressings

exhibited both antibacterial and pro-angiogenic properties, significantly enhancing the
wound healing with complete healing within 17 days, accompanied by hair follicle

regeneration and angiogenesis. This work not only provided a new strategy for creating

highly self-supporting biopolymers inks, but also paved the way for advanced

41
personalized wound dressings. Lie Zhu et al. fabricated a multifunctional hydrogel
dressing via DLP technology based on the ECM properties of Acomys (African agouti)

during wound healing. They modified the methyl acryloyl groups of GelMA and

hyaluronic acid (HAMA) with methyl acryloyl, making the molecular chains contain

photosensitive groups, which can undergo free radical polymerization reactions under

the irradiation of photoinitiators and ultraviolet light, forming a covalent cross-linked

network structure. The precise control of the structure, mechanical properties and

biological functions of hydrogels was achieved through the photosensitivity of
42
GelMA/HAMA and DLP light-curing printing. Lei Chen et al. fabricated an ECM-

based 3D-printed dermal hydrogel scaffold loaded with Cu-EGCG. Researchers reacted
cell-free ECM (dECM) derived from pigskin with methacrylate anhydride (GMA),

introducing photo-crosslinkable methacrylate groups to form ECMMA (EM). Then it

was mixed with the photoinitiator LAP to prepare bio-ink. Under ultraviolet light (350

nm) irradiation, the double bonds in EM undergo photo-initiated free radical

polymerization reactions, forming covalently cross-linked hydrogels. It was worth

noting that the EM hydrogel used in this study itself also has temperature-sensitive

properties, it was in a sol state at low temperatures and transforms into a gel state near

body temperature. This combination of physical crosslinking and chemical crosslinking

makes the material not only easy to print and form but also possess excellent

mechanical properties and biological activity. This hydrogel scaffold inhibited

excessive inflammation by promoting the macrophages polarization from M1 to M2,

while supporting endothelial cells in forming stable tubular structures essential for

33
neovascularization. Chunmao Han et al. used the same method and simultaneously

13