Abstract：
Meeting the exacting demands of wound healing encompasses rapid coagulation, superior exudate absorption, high antibacterial efficacy, and imperative support for cell growth. In this study, by emulating the intricate structure of natural skin, we prepare a multifunctional porous bilayer artificial skin to address these critical requirements. The bottom layer, mimicking the dermis, is crafted through freeze-drying a gel network comprising carboxymethyl chitosan (CMCs) and gelatin (GL), while the top layer, emulating the epidermis, is prepared via electrospinning poly(l-lactic acid) (PLLA) nanofibers. With protocatechuic aldehyde and gallium ion complexation (PA@Ga) as cross-linking agents, the bottom PA@Ga-CMCs/GL layer featured an adjustable pore size (78-138 μm), high hemostatic performance (67s), and excellent bacterial inhibition rate (99.9%), complemented by an impressive liquid-absorbing capacity (2000% swelling rate). The top PLLA layer, with dense micronanostructure and hydrophobic properties, worked as a shield to effectively thwarted liquid or bacterial penetration. Furthermore, accelerated wound closure, reduced inflammatory responses, and enhanced formation of hair follicles and blood vessels are achieved by the porous artificial skin covered on the surface of wound. Bilayer artificial skin integrates the advantages of nanofibers and freeze-drying porous materials to effectively replicate the protective properties of the epidermal layer of the skin, as well as the cell migration and tissue regeneration of the dermis. This bioabsorbable artificial skin demonstrates structural and functional comparability to real skin, which would advance the field of wound care through its multifaceted capabilities.
摘要：
满足伤口愈合的严格要求包括快速凝固，优越的渗出物吸收，抗菌效率高,以及对细胞生长的必要支持。在这项研究中,通过模仿自然皮肤的复杂结构，我们准备了一个多功能的多孔双层人造皮肤来解决这些关键的要求。底层,模仿真皮，通过冷冻干燥包含羧甲基壳聚糖（CMC）和明胶（GL）的凝胶网络来制作，而顶层，模仿表皮，通过静电纺丝制备聚(1-乳酸)(PLLA)纳米纤维。以原儿茶醛与镓离子络合(PA@Ga)为交联剂,底部PA@Ga-CMCs/GL层具有可调孔径(78-138μm)，高止血性能（67s），和优异的细菌抑制率（99.9％），辅以令人印象深刻的液体吸收能力（2000％的溶胀率）。顶部PLLA层，具有致密的微纳米结构和疏水特性，作为有效阻止液体或细菌渗透的盾牌。此外，加速伤口闭合,减少炎症反应，通过覆盖在伤口表面的多孔人造皮肤实现毛囊和血管的增强形成。双层人造皮肤集成了纳米纤维和冷冻干燥多孔材料的优点，可以有效复制皮肤表皮层的保护性能，以及真皮的细胞迁移和组织再生。这种生物可吸收的人造皮肤具有与真实皮肤的结构和功能可比性，这将通过其多方面的能力推进伤口护理领域。
