A Silk-Based Patch with Temporary Adhesion and Detachability on the Ocular Surface for Inflammatory Mediator Removal

Corneal alkali burns cause persistent inflammation, leading to corneal vascularization and fibrosis, which severely impair vision. Here, we developed a temporary adhesive silk-based patch to capture and remove inflammatory mediators from the ocular surface. The patch utilizes photocrosslinkable silk for mechanical support, chitosan as the adhesive, hyaluronan for lubrication, and polyamidoamine (PAMAM) dendrimers with heparin to enhance adsorption. After water annealing, the patch exhibited excellent transparency, mechanical strength, and resistance to swelling, remaining attached to the rat ocular surface for 3–5 days. Adsorption tests confirmed that the patch effectively captured small-molecule dyes, proteins, and free DNA. In the rat corneal alkali burn model, imaging and histological evaluations showed significant reductions in vascularization and fibrosis after 3 days of treatment, along with improved corneal transparency. RNA sequencing revealed that patch treatment effectively inhibited the PI3K–AKT inflammatory pathway. This inflammation-removing patch represents an innovative treatment for corneal alkali burns with significant clinical potential. After the corneas were ground, cell lysis buffer was added, and the samples were collected for reverse transcription. Double-stranded cDNA was quantified using a Qubit4 fluorometer (Thermo Fisher, USA). The fragment size of the double-stranded cDNA was assessed using an Agilent 4150 Bioanalyzer (Agilent, China). A sample was considered qualified if the concentration was greater than 1.6 ng/μL and if the main peak was concentrated between 750 and 1500 bp. The library was sequenced on the Illumina HiSeq high-throughput sequencing platform. First, the raw reads in FASTQ format were processed using fastp1 to remove low-quality reads and obtain clean reads for subsequent analysis. The fragments per kilobase of transcript per million mapped reads (FPKM) values were calculated for each gene, and the read counts for each gene were obtained using HTSeq-count. PCA was performed using R (v 4.4.1) to assess sample reproducibility. The differential expression analysis was conducted using DESeq2. A q value < 0.05 and a fold change > 2 or < 0.5 were considered significant. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) pathway enrichment analyses were performed using R (v 4.4.1), with significantly enriched terms filtered by R (v 4.4.1). Bar plots and bubble plots for the significantly enriched terms were generated using R (v 4.4.1) and GraphPad Prism 9.