Rationale: Corneal transplantation is an effective treatment to corneal blindness. However, the immune rejection imperils corneal allograft survival. An interventional modality is urgently needed to inhibit immune rejection and promote allograft survival. In our previous study, subconjunctival injections of bone marrow-derived mesenchymal stem cells (BM-MSCs) into a rat model of corneal allograft rejection extended allograft survival for 2 d. In this study, we sought to generate IL-10-overexpressing BM-MSCs, aiming to boost the survival-promoting effects of BM-MSCs on corneal allografts and explore the molecular and cellular mechanisms underlying augmented protection. Methods: A population of IL-10-overexpressing BM-MSCs (designated as IL-10-BM-MSCs) were generated by lentivirus transduction and FACS purification. The self-renewal, multi-differentiation, and immunoinhibitory capabilities of IL-10-BM-MSCs were examined by conventional assays. The IL-10-BM-MSCs were subconjunctivally injected into the model of corneal allograft rejection, and the allografts were monitored on a daily basis. The expression profiling of long noncoding RNA (lncRNA) in the allografts was revealed by RNA sequencing and verified by quantitative real-time PCR. The infiltrating immune cell type predominantly upregulating the lncRNA expression was identified by RNAscope in situ hybridization. The function of the upregulated lncRNA was proved by loss- and gain-of-function experiments both in vivo and in vitro . Results: The IL-10-BM-MSCs possessed an enhanced immunoinhibitory capability and unabated self-renewal and multi-differentiation potentials as compared to plain BM-MSCs. The subconjunctivally injected IL-10-BM-MSCs reduced immune cell infiltration and doubled allograft survival time (20 d) as compared to IL-10 protein or plain BM-MSCs in the corneal allograft rejection model. Further, IL-10-BM-MSCs significantly upregulated lncRNA 003946 expression in CD68 + macrophages infiltrating corneal allografts. Silencing and overexpressing lncRNA 003946 in macrophage cultures abolished and mimicked the IL-10-BM-MSCs' suppressing effects on the macrophages' antigen presentation, respectively. In parallel, knocking down and overexpressing the lncRNA in vivo abrogated and simulated the survival-promoting effects of IL-10-BM-MSCs on corneal allografts, respectively. Conclusion: The remarkable protective effects of IL-10-BM-MSCs support further developing them into an effective interventional modality against corneal allograft rejection. IL-10-BM-MSCs promote corneal allograft survival mainly through upregulating a novel lncRNA expression in graft-infiltrating CD68 + macrophages. LncRNA, for the first time, is integrated into an IL-10-BM-MSC-driven immunomodulatory axis against the immune rejection to corneal allograft.

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Establishing antimicrobial photodynamic therapy (PDT) approaches to enhance antimicrobial activities of insoluble photosensitizers in terms of their solubility, stability, and safety is highly desirable yet challenging. Here, we reported super-stable carboxymethyl chitosan-polyethyleneimine-protoporphyrin IX nanoparticles (CMCS-PEI-PpIX NPs) for effective photodynamic inactivation of bacteria and fungi with excellent biocompatibility. CMCS-PEI-PpIX self-assembled into NPs in solution with significantly improved singlet oxygen generation. Consequently, NPs exhibited exceptional photoinactivation toward a broad range of microbes with record low minimal bactericidal concentrations. NPs were highly stable after 28 days of storage. Furthermore, NPs exhibited negligible cytotoxicity without hemolysis on red blood cells. NPs can efficiently attach to the microbial cell through electrostatic interaction to generate singlet oxygen with light irradiation, which caused severe damage to the cell membrane, causing microbial cell death. Overall, the development of CMCS-PEI-PpIX NPs provides a route for improving the microbicidal PDT efficacy, benefiting the clinic treatment of microbial infections.

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Purpose To observe ocular surface changes in Type II diabetic patients with different disease durations and to understand the correlations between clinical parameters and diabetic durations. Methods In this cross-sectional, prospective study, 51 healthy controls and 91 patients with Type II diabetes were enrolled. The diabetics were divided into 3 subgroups according to the disease duration, including duration <10 y group, 10 to 20 y group, and ≥21 y group. All subjects underwent clinical ocular examinations, including lipid layer thickness (LLT), blinking rate, tear meniscus height (TMH), noninvasive tear film break-up time (NI-BUT), meibography, superficial punctate keratopathy (SPK) scoring, corneal sensitivity, and Schirmer I test. They were also evaluated using the standard patient evaluation of eye dryness (SPEED) questionnaire. Results SPEED score, meiboscore, SPK score, LLT, Schirmer I test, and corneal sensitivity differed significantly between the diabetic and healthy control groups. Further, SPEED score, Schirmer I test, corneal sensitivity, meiboscore, and blink rate significantly differed among the 3 diabetic subgroups and the control group. In diabetics, the SPEED score correlated with the SPK score, blink rate, TMH, and LLT; NI-BUT with TMH, LLT, and blink rate; TMH with the SPK score; Schirmer I test with the SPK score; and corneal sensitivity with the meiboscore. More importantly, the Schirmer I test, corneal sensitivity, and SPEED score negatively correlated with diabetic duration. Conclusion Diabetic duration is an important factor that affects functions of the lacrimal functional unit in patients with Type II diabetes. The trends of changes in the ocular parameters vary along the course of diabetes.