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characteristic can maintain the moisture of the wound surface and provide a favorable

pathway for cell metabolism and communication 120 . Dingjun Bai et al. 121 constructed

an injectable self-healing HA hydrogel via a schiff base cross linking method and
loaded the hydrogel with GOx-MnO2 nanoenzymes synthesized by the condensation

reaction and VEGF nanobubbles produced by the double emulsification, thus

establishing an new UGV hydrogel system for diagnosis and treatment. The results

showed that VEGF could be precisely released by ex vivo ultrasound to enhance the

vascularization and accelerate diabetic wound repair. Shaobing Zhou et al. 122 prepared

VEGF plasmedium-loaded macrophage exosomes (Exos) and encapsulated them in

injectable self-healing hydrogels prepared by cross-linking of dynamic Schiff bases.

They enhanced the binding of VEGF to VEGFR2 through VEGF production and release

from Ep, VEGF secretion from M2 macrophages, and the high affinity of SCS, and this

intrinsic immunomodulatory hydrogel effectively promotes angiogenesis. Xiumei

Wang et al. 123 successfully prepared a anisotropic nanofiber hydrogel by fibrin

electrospinning and self-assembling peptide modification. By leveraging the triangular

synergy of the immuno-angiogenic neurogenesis microenvironment, this nanofiber
hydrogel exhibited an ideal directional arrangement of nanoscale fibers and significant

pro-angiogenic bioactivity to improve diabetic wound healing.

Moreover, the abnormal expression of MMPs in diabetic wound was also an

important factor affecting wound healing. In diabetic wounds, the over-expression of

MMPs disrupted the dynamic balance of ECM, leading to excessive degradation of key

ECM components such as collagen and fibronectin, which seriously destroyed the

integrity of tissue structure and made it difficult to form stable granulation tissue, which

further hinders the healing process. 124 The over-expression of MMP-9 hindered the

process of diabetic wounds repair. Therefore, wound dressings that validly prevented

the expression of MMP-9 had important translational potential in clinical practice.

Meng Ren et al. 125 developed a composite hydrogel dressing for locally sustained

delivery of MMP-9 siRNA (siMMP-9). After forming a complex with Gly-TETA,

siMMP-9 was loaded into a thermosensitive hydrogel based on Pluronic F-127 and

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