目的·探索甲基丙烯酰化透明质酸（hyaluronic acid methacryloyl，HAMA）水凝胶在皮肤创面愈合中的作用，解析创面局部微环境特征。方法·构建小鼠全皮层切除模型，随机分为对照组（n=3）和HAMA组（n=3）；HAMA组在创面覆盖100 μL HAMA水凝胶，对照组在创面覆盖100 μL苯基-2，4，6-三甲基苯甲酰基次膦酸锂（LAP），均用紫外灯照射20 s，分别在第0天、第3天、第7天、第10天和第14天对剩余创面进行测量。通过测量剩余创面面积和苏木精-伊红染色（H-E染色）分析HAMA水凝胶对创面愈合的作用；利用单细胞测序技术分析第14天创面局部皮肤的细胞特征谱，通过免疫组织荧光技术检测创面局部Ⅰ型胶原、Ⅲ型胶原、F4/80、CD206和CD86的表达水平；RT-qPCR检测与HAMA水凝胶共孵育24 h的小鼠巨噬细胞系Raw264.7中Arg1、Nos2、Itgam和Itgb2的mRNA表达水平。利用Seurat软件包对小鼠第14天创面局部皮肤的成纤维细胞和巨噬细胞进行聚类分析，并利用CellChat软件包分析成纤维细胞和巨噬细胞的相互通信状况。结果·HAMA组小鼠皮肤创面愈合的速度显著快于对照组，第14天HMAM组小鼠创面已经愈合，而对照组的创面尚未完全愈合。单细胞测序分析显示，HAMA组中Col3a1高表达的成纤维细胞亚群比例（90.2%）高于对照组（79.8%），而Col1a1高表达的成纤维细胞亚群比例（5.7%）低于对照组（15.9%）。免疫荧光分析结果证实HAMA组创面局部Ⅲ型胶原水平高于对照组（P=0.035），而Ⅰ型胶原水平则低于对照组（P=0.044）。HAMA组小鼠与对照组小鼠创面局部巨噬细胞的比例没有明显差异，但单细胞测序分析结果和HAMA水凝胶体外处理巨噬细胞Raw264.7后均显示Arg1表达水平升高（P<0.001），Nos2表达水平降低（P<0.001），同时HAMA组小鼠创面部位巨噬细胞表达较高水平的CD206（P=0.042），表达较低水平的CD86（P=0.011）。CellChat分析结果显示，相较于对照组，HAMA组小鼠创面部位巨噬细胞和特定成纤维细胞亚群间相互通信的强度增大。结论·HAMA水凝胶处理后的微环境有利于皮肤创面愈合，创面愈合组织局部汇聚更多的抑炎性巨噬细胞和分泌Ⅲ型胶原的成纤维细胞。

Objective ·To explore the roles of hyaluronic acid methacryloyl (HAMA) hydrogel in skin wound healing and to characterize the microenvironmental landscape at wound sites. Methods ·A full-thickness skin excision model was established in mice, which were randomly divided into a control group (n=3) and a HAMA group (n=3). The wound in the HAMA and control groups were covered with 100 μL of HAMA hydrogel and 100 μL of phenyl-2,4,6-trimethylbenzoylphosphonic acid lithium (LAP), respectively. Both groups were then irradiated with a UV lamp for 20 s. The residual wound areas was measured on days 0, 3, 7, 10, and 14. Wound healing effects of HAMA hydrogel were analyzed by measuring the residual wound area and through H-E staining. Single-cell RNA sequencing technology was utilized to analyze the cellular profile of local wound skin tissues at day 14 post-injury. Immunofluorescence assay was used to detect the levels of type I collagen, type Ⅲ collagen, F4/80, CD206, and CD86 in the wound sites. The mRNA expression levels of Arg1, Nos2, Itgam, and Itgb2 in the mouse macrophage cell line Raw264.7 co-cultured with HAMA hydrogel for 24 h were detected by RT-qPCR. The fibroblasts and macrophages in the local skin of the mouse wound on day 14 were analyzed using the Seurat package, and the communication between fibroblasts and macrophages was analyzed using the CellChat package. Results ·Mice treated with HAMA hydrogel exhibited a significantly faster rate of wound healing process compared to the control group. At day 14, wounds in the HAMA-treated mice had already healed, while those in the control group remained unhealed. Single-cell RNA sequencing analysis revealed a remarkable increase in the proportion of fibroblasts in the skin tissues of HAMA-treated wounds. The proportion of the Col3a1-high-expressing fibroblast subset increased (90.2%) compared to the control group (79.8%), while the proportion of the Col1a1-high-expressing fibroblast subset decreased (5.7% vs 15.9%). Immunofluorescence analysis confirmed that the level of type Ⅲ collagen in the wound tissues of the HAMA group was significantly higher than that in the control group (P=0.035), while the level of type Ⅰ collagen was significantly lower (P=0.044). Although there was no significant difference in the proportions of macrophages in the wound tissues between the HAMA-treated and control groups, scRNA sequencing data and in vitro experiments using Raw264.7 cells showed that HAMA hydrogel could induce the expression of Arg1 and decrease the expression of Nos2 in the macrophages (P<0.001). Additionally, macrophages in the HAMA-treated wounds expressed higher levels of CD206 and lower levels of CD86 (P=0.042, P=0.011). The results of the CellChat analysis showed that, compared to the control group, increased communication intensity was observed between macrophages and fibroblasts subsets at the wound sites in the mice of HAMA group. Conclusion ·The microenvironment after HAMA hydrogel treatment is conducive to skin wound healing, characterized by a local aggregation of anti-inflammatory macrophages and fibroblasts that secrete type Ⅲ collagen.