An injectable thermoresponsive-hydrogel for lamellar keratoplasty: In-situ releases celastrol and hampers corneal scars.

Corneal stromal fibrosis is a common cause of visual impairment resulting from corneal injury, inflammation and surgery. Therefore, there is an unmet need for inhibiting corneal stromal fibrosis. However, bioavailability of topical eye drops is very low due to the tear and corneal barriers. In situ delivery offers a unique alternative to improve efficacy and minimize systemic toxicity. Herein, a drug delivery platform based on thermoresponsive injectable hydrogel/nano-micelles composite with in situ drug-controlled release and long-acting features is developed to prevent corneal scarring and reduce corneal stromal fibrosis in lamellar keratoplasty. The in-situ gelation hydrogels enabled direct delivery of celastrol to the corneal stroma. In vivo evaluation with a rabbit anterior lamellar keratoplasty model showed that hydrogel/micelles platform could effectively inhibit corneal stromal fibrosis. This strategy achieves controlled and prolonged release of celastrol in the corneal stroma of rabbit. Following a single corneal interlamellar injection, celastrol effectively alleviated fibrosis via mTORC1 signal promoting autophagy and inhibiting TGF-ß1/Smad2/3 signaling pathway. Overall, this strategy demonstrates promise for the clinical application of celastrol in preventing corneal scarring and reducing corneal stromal fibrosis post-lamellar keratoplasty, highlighting the potential benefits of targeted drug delivery systems in ocular therapeutics.

Dual-Atom Nanozyme Eye Drops Attenuate Inflammation and Break the Vicious Cycle in Dry Eye Disease.

Dry eye disease (DED) is a major ocular pathology worldwide, causing serious ocular discomfort and even visual impairment. The incidence of DED is gradually increasing with the high-frequency use of electronic products. Although inflammation is core cause of the DED vicious cycle, reactive oxygen species (ROS) play a pivotal role in the vicious cycle by regulating inflammation from upstream. Therefore, current therapies merely targeting inflammation show the failure of DED treatment. Here, a novel dual-atom nanozymes (DAN)-based eye drops are developed. The antioxidative DAN is successfully prepared by embedding Fe and Mn bimetallic single-atoms in N-doped carbon material and modifying it with a hydrophilic polymer. The in vitro and in vivo results demonstrate the DAN is endowed with superior biological activity in scavenging excessive ROS, inhibiting NLRP3 inflammasome activation, decreasing proinflammatory cytokines expression, and suppressing cell apoptosis. Consequently, the DAN effectively alleviate ocular inflammation, promote corneal epithelial repair, recover goblet cell density and tear secretion, thus breaking the DED vicious cycle. Our findings open an avenue to make the DAN as an intervention form to DED and ROS-mediated inflammatory diseases.

M2 macrophages promote subconjunctival fibrosis through YAP/TAZ signalling.

PURPOSE: To evaluate the role of M2 macrophages in subconjunctival fibrosis after silicone implantation (SI) and investigate the underlying mechanisms. MATERIALS AND METHODS: A model of subconjunctival fibrosis was established by SI surgery in rabbit eyes. M2 distribution and collagen deposition were evaluated by histopathology. The effects of M2 cells on the migration (using wound-scratch assay) and activation (by immunofluorescence and western blotting) of human Tenon's fibroblasts (HTFs) were investigated. RESULTS: There were more M2 macrophages (CD68+/CD206+ cells) occurring in tissue samples around silicone implant at 2 weeks postoperatively. Dense collagen deposition was observed at 8 weeks after SI. In vitro experiment showed M2 expressed high level of CD206 and transforming growth factor-ß1 (TGF-ß1). The M2-conditioned medium promoted HTFs migration and the synthesis of collagen I and fibronectin. Meanwhile, M2-conditioned medium increased the protein levels of TGF-ß1, TGF-ßR II, p-Smad2/3, yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ). Verteporfin, a YAP inhibitor, suppressedTGF-ß1/Smad2/3-YAP/TAZ pathway and attenuated M2-induced extracellular matrix deposition by HTFs. CONCLUSIONS: TGF-ß1/Smad2/3-YAP/TAZ signalling may be involved in M2-induced fibrotic activities in HTFs. M2 plays a key role in promoting subconjunctival fibrosis and can serve as an attractive target for anti-fibrotic therapeutics.

Antibiotic Delivery System for Treating Bacteria-Induced Anterior Blepharitis.

The eyelid-related disease of blepharitis remains a tricky ocular disorder and affects patient compliance. However, there is no available and effective treatment, making it extremely challenging. Herein, an antibacterial system based on antibiotic delivery was developed and applied in a blepharitis model induced by bacteria. The antibacterial tests against Staphylococcus aureus both in vitro and in vivo demonstrated that the system shows a favorable bactericidal effect. Then, histological evaluation indicated that the system shows both antibacterial and anti-inflammatory effects. This facile design provided an effective ocular infection management, which displays a promising prospect while addressing other complex ocular disorders.

Novel technique for amniotic membrane transplantation for acute Stevens-Johnson syndrome/toxic epidermal necrolysis patients.

Purpose: To report a novel technique to facilitate amniotic membrane transplantation (AMT) for acute stage Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Design: Laboratory investigation and retrospective, single-center case series. Methods: The polylactic acid (PLA) amniotic fornical ring (AFR) have been successfully manufactured by three-dimensional (3D) printing technology for AMT. This study retrospectively analyzed the medical records of 5 SJS/TEN patients at the acute stage between 2019 and 2023. Patients were surgically treated with AFR or sutured amniotic membrane transplant (SAMT). Epidemiology, best-corrected visual acuity (BCVA), acute ocular severity score, operative duration, epithelial healing time, amniotic dissolution and follow-up time were evaluated. Results: Of all five patients, three patients (6 eyes) received AFR/AMT (Group A), and 2 patients (4 eyes) received SAMT (Group B). There were no significant differences between two groups in the mean preoperative days and vision changes. The mean operation duration was 11.7 ± 3.8 mins in group A. Compared with the SAMT (48.8 ± 5.3 mins), the operation duration was reduced by 76.02%. The mean times for epithelial healing were 32.5 ± 29.2 days in group A and 12.0 ± 0.0 days in group B. In addition, there were no significant side effects of 3D-printed sterile AFR on the eyes. Conclusions: 3D-printed PLA scaffolds could be used as an AFR device for acute SJS/TEN. In addition, personalized 3D-printed AFR is superior to conventional SAMT in operation duration.

Carboxymethyl chitosan regulates macrophages polarization to inhibit early subconjunctival inflammation in conjunctival injury.

Persistent subconjunctival inflammation leads to subconjunctival fibrosis and eventual visual impairment. There is an unmet need for how to effectively inhibit subconjunctival inflammation. Herein, the effect of carboxymethyl chitosan (CMCS) on subconjunctival inflammation was investigated and the mechanism was involved. The evaluation of cytocompatibility demonstrated that CMCS had good biocompatibility. The in vitro results showed that CMCS inhibited secretions of pro-inflammatory cytokines (IL-6, TNF-α, IL-8 and IFN-γ) and chemokines (MCP-1), and downregulated TLR4/MyD88/NF-κB pathway in M1. The in vivo results displayed that CMCS alleviated conjunctival edema and congestion, and improved conjunctival epithelial reconstruction significantly. Both in vitro and in vivo results demonstrated that CMCS inhibited the infiltration of macrophages and reduced the expressions of iNOS, IL-6, IL-8 and TNF-α in the conjunctiva. Given that CMCS indicated the activities of inhibiting M1 polarization, NF-κB pathway, and subconjunctival inflammation, which may be employed as a potent treatment for subconjunctival inflammation.

Personalized 3D-printed amniotic fornical ring for ocular surface reconstruction.

In the present work, we used three-dimensional (3D) printing technology to make a polylactic acid (PLA) amniotic fornical ring (AFR) for ocular surface reconstruction. This work is a retrospective and interventional case series of patients with ocular surface diseases who underwent either personalized 3D-printed AFR-assisted amniotic membrane transplantation (AMT) or sutured AMT (SAMT). Patient epidemiology, treatment, operative duration, epithelial healing time, retention time, vision changes, morbidity, and costs were analyzed. Thirty-one patients (40 eyes) and 19 patients (22 eyes) were enrolled in the 3D-printed AFR group and the SAMT group, respectively. The clinical indications of AFR and SAMT were similar, such as corneal and/or conjunctival epithelial defects due to chemical burns, thermal burns, Stevens-Johnson syndrome (SJS), or toxic epidermal necrolysis (TEN). The mean dissolution time was 15 ± 11 days in the AFR group, compared with 14 ± 7 days in the SAMT group. The percentage of healed corneal area was 90.91% (66.10%-100.00%) for AFR and 93.67% (60.23%-100.00%) for SAMT. The median time for corneal epithelial healing was 14 (7-75) days in the AFR group and 30 (14-55) days in the suture AMT group. There were no significant differences in the initial visual acuity, final visual acuity, or improvement in visual acuity between the two groups. The operation duration in the AFR group was significantly shorter than that in the SAMT group. Regarding the cost analysis, the average cost per eye in the AFR group was significantly lower than that in the SAMT group. Furthermore, 3D-printed and sterile AFR showed no obvious side effects on the eyes. Our results suggested that 3D-printed PLA scaffolds could be used as an AFR device for ocular surface disease. In addition, personalized 3D-printed AFR is superior to conventional AMT in operation duration and cost effectiveness, thereby reducing the financial burden on our health care system.

A chitosan-based self-healing hydrogel for accelerating infected wound healing.

Wound infection causes irregular tissue closure, often with prolonged healing. Traditional therapies based on antibiotic delivery have resulted in reduced therapeutic efficiency and drug resistance. Such features make it highly desirable to develop an antibiotic-free material for wound infection in clinical applications. Herein, a self-healing antibacterial hydrogel was designed to realize the treatment of S. aureus-infected wounds. The design of the dynamic imine bond endows hydrogels with self-healing and adaptive properties, which could cover the irregular wound and improve the safety of administration. In addition, benefiting from quaternized chitosan, the designed hydrogels also present fascinating antimicrobial properties and favorable biocompatibility. The evaluation in a rat skin wound infection model indicates that the fascinating antimicrobial effect accelerates wound healing by the designed hydrogels. This facile design of an antibiotic-free material allows effective wound infection management, which may be promising in coping with other complex wound healings.