Mild Photothermal Therapy Prevents Posterior Capsule Opacification through Cytoskeletal Remodeling

A poly(tannic acid) particle-supported β-glucan/chitosan hydrogel for managing oral ulcers in diabetes

In the management of diabetic oral ulcers, current treatments frequently fall short due to complications from bacterial contamination, oxidative damage, and impaired angiogenesis. These shortcomings highlight the pressing need for more efficacious interventions that not only circumvent these issues but also expedite healing processes. To bridge this gap, we have introduced a novel hydrogel patch, POQ2 [a poly(tannic acid) particle-incorporated oxidized β-glucan/quaternized chitosan hydrogel]. POQ2 demonstrated significant improvements in healing outcomes by enhancing bacterial clearance (up to 99.7 % against Escherichia coli and 99.2 % against Staphylococcus aureus), reducing oxidative stress through efficient ROS scavenging (70.2 % reduction in DPPH radicals), and promoting angiogenesis. In vivo experiments on diabetic rat models showed accelerated wound closure and reduced IL-6 inflammatory markers, with nearly complete ulcer healing within seven days. The introduction of POQ2 into clinical protocols represents a substantial advancement in the management of diabetic oral ulcers, promising not only improved patient outcomes but also a shift in the standard of care in this challenging clinical area. This innovation not only fills a significant gap in diabetic wound care but also sets a new benchmark for the development of future treatments, potentially influencing broader therapeutic strategies for managing complex diabetic wounds.

An ATP-activated spatiotemporally controlled hydrogel prodrug system for treating multidrug-resistant bacteria-infected pressure ulcers

Adenosine triphosphate (ATP)-activated prodrug approaches demonstrate potential in antibacterial uses. However, their efficacy frequently faces obstacles due to uncontrolled premature activation and spatiotemporal distribution differences under physiological circumstances. Herein, we present an endogenous ATP-activated prodrug system (termed ISD3) consisting of nanoparticles (indole-3-acetic acid/zeolitic imidazolate framework-8@polydopamine@platinum, IZPP) embedded in a silk fibroin-based hydrogel, aimed at treating multidrug-resistant (MDR) bacteria-infected pressure ulcers. Initially, an ultraviolet-triggered adhesive ISD3 barrier is formed over the pressure ulcer wound by a simple local injection. Subsequently, the bacteria-secreted ATP prompts the degradation of IZPP, allowing the loaded IAA prodrug and nanozyme to encounter spatiotemporally on a single carrier, thereby efficiently generating reactive oxygen species (ROS). Exposure to 808 nm near-infrared light enhances the catalytic reaction speed, boosting ROS levels for stronger antibacterial action. Once optimal antibacterial action is reached, ISD3 switches to a dormant state, halting any further ROS production. Moreover, the bioactive components in ISD3 can exert anti-inflammatory functions, aiding in pressure ulcer recovery. Overall, our research introduces a hydrogel prodrug strategy activated by bacterial endogenous ATP, which precisely manages ROS generation and accelerates the recovery of MDR bacteria-infected pressure ulcers.

Heat stress regulates the migration and proliferation of lens epithelial cells through ferroptosis and NCOA4-FTH1 interaction

Posterior capsule opacification (PCO) due to the proliferation and migration of lens epithelial cells (LECs) is the main complication after surgery. Heat stress has demonstrated impressive results in halting cell proliferation and migration, while also facilitating cell death. This study aimed to investigate the role and mechanism of ferroptosis in the proliferation and migration of LECs under heat stress. CCK-8 assays, scratch assays, and transcriptome analysis were used to evaluate the impact of temperature on human lens epithelial cells (HLECs) and explore the potential mechanisms. The role of ferroptosis in the proliferation of HLECs induced by heat was investigated using the ferroptosis inhibitor Fer-1 and siRNA-mediated NCOA4 protein interference. Fluorescence staining and Western blot experiments were used to detect the expression of Fe2+, reactive oxygen species (ROS), and ferroptosis-related proteins NCOA4, FTH1, and SLC3A2. The results of CCK-8 assays, scratch assays, and transcriptome analysis demonstrated significant thermal effects on HLEC behavior. After heat treatment, there were significant changes in the fluorescence expression of Fe2+ and ROS in the HLECs and lens explant. In addition, the expression of NCOA4, FTH1, and SLC3A2 also changed significantly. Using Fer-1 or NCOA4 siRNA-mediated interference restored cell viability decreased by thermal stress. Furthermore, interference with NCOA4 protein effectively restored the expression of Fe2+, ROS, and FTH1. In conclusion, heat stress has a significant effect on LECs by regulating ferroptosis and the interaction between NCOA4 and FTH1 proteins play an important role.

Injectable and pH-Responsive Metformin-Loaded Hydrogel for Active Inhibition of Posterior Capsular Opacification

Posterior capsular opacification (PCO) is a common complication following cataract surgery, which can lead to a significant vision loss. This study introduces a facile method for developing a metformin-derived hydrogel (HCM6) stabilized by dynamic covalent bonds among natural polymers. This hydrogel demonstrates antifibrotic properties, on-demand drug release, pH responsiveness, injectability, and self-healing capabilities. Our in vitro experiments confirmed that the HCM6 hydrogel exhibits excellent biocompatibility, inhibiting lens epithelial cell migration, and transforming growth factor-2β (TGFβ2)-induced α-smooth muscle actin (α-SMA) expression in lens epithelial cells. In vivo studies conducted in a rat extracapsular lens extraction (ECLE) model revealed that HCM6 significantly suppressed PCO after 21 days of implantation with no observed pathological effects on surrounding tissues or the optic nerve. According to our experimental results, the inhibitory mechanism of PCO may be attributed to metformin's suppressive effect on lens cell migration, epithelial-mesenchymal transition (EMT), and lens fiber formation. In summary, the long-acting, controllable, and on-demand release characteristics of the HCM6 hydrogel not only provide an effective strategy for preventing PCO but also offer new avenues for treating undesirable proliferative conditions in ophthalmology and beyond.

Exploring the potential of nanoparticles-based polydopamine for effective treatment of refractory keratitis: Mild photothermal loop therapy

Keratitis is the leading cause of blindness worldwide. In refractory cases, it can even lead to eyeball enucleation. The critical challenges of refractory keratitis are the drug-resistant bacteria and bacterial biofilms formation. Therefore, we established an innovative therapeutic approach for keratitis based on mild photothermal loop (MPL) therapy. First, we analyzed the bactericidal effect of methicillin-resistant Staphylococcus aureus (MRSA) under various loops and temperature durations to determine the optimal condition. Then, RAN-seq was applied to explore the underlying mechanisms. Additionally, we formulated a dual-purpose polyvinyl alcohol-polydopamine (PDA/PVA) hydrogel system and explored its effects on the reactive oxygen species (ROS) scavenging capability, antibacterial properties, and anti-inflammatory properties in vitro, as well as its effect in vivo. The results indicated substantial bactericidal properties after exposure in four loops, each lasting 10 min at 45 °C. RNA-seq revealed the altered genes related to virulence and biofilm formation. In addition to good photothermal performance, the PDA/PVA system could effectively eliminate MRSA, reduce ROS, inhibit biofilm formation, and decrease inflammatory factors expression. Moreover, the in vivo results demonstrated the potential of MPL for bacterial keratitis. This study serves as the first attempt to use MPL therapy for refractory keratitis, offering a new approach for clinical practice.

TiO2-Nanoparticle-Enhanced Sonodynamic Therapy for Prevention of Posterior Capsular Opacification and Ferroptosis Exploration of Its Mechanism

Purpose

To explore the application and potential ferroptosis mechanisms of sonodynamic therapy (SDT) using titanium dioxide nanoparticles (TiO2-NPs) as sonosensitizers for the prevention of posterior capsule opacification (PCO).

Methods

We fabricated TiO2-NP-coated intraocular lenses (TiO2-IOLs) using the spin-coating method, followed by ultrasound activation of the photosensitizer TiO2. In vitro experiments were performed with human lens epithelial cells (HLECs) to explore the appropriate concentration of TiO2 and ultrasonic parameters. Investigations included reactive oxygen species (ROS) generation, glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4) western blot analysis, lipid peroxidation assays, and transcriptomics analysis. Finally, TiO2-IOLs were implanted in rabbit eyes to explore the in vivo performance of SDT.

Results

Through both in vitro and in vivo experiments, the study determined that the ultrasound parameters of 5-minute duration, 1-MHz frequency, 50% duty cycle, and 1.2-W/cm2 intensity were reliable and valid for killing HLECs without damaging other ocular structures. In vitro experiments demonstrated that SDT generated excess ROS, which disrupted the mitochondrial membrane potential and significantly reduced the GSH content. Additionally, the downregulation of GPX4, accumulation of lipid peroxides, and alteration of mitochondrial morphology were observed, suggesting that ferroptosis may be the underlying mechanism. The RNA-sequencing analysis results also showed an increase in the expression of multiple pro-ferroptosis genes and the ferroptosis marker gene PTGS2. Animal experiments preliminarily demonstrated the safety and effectiveness of SDT in treating PCO in vivo.

Conclusions

TiO2-IOLs combined with SDT effectively prevented PCO by generating ROS and intracellular ferroptosis.

Cytoskeleton-modulating nanomaterials and their therapeutic potentials

The cytoskeleton, an intricate network of protein fibers within cells, plays a pivotal role in maintaining cell shape, enabling movement, and facilitating intracellular transport. Its involvement in various pathological states, ranging from cancer proliferation and metastasis to the progression of neurodegenerative disorders, underscores its potential as a target for therapeutic intervention. The exploration of nanotechnology in this realm, particularly the use of nanomaterials for cytoskeletal modulation, represents a cutting-edge approach with the promise of novel treatments. Inorganic nanomaterials, including those derived from gold, metal oxides, carbon, and black phosphorus, alongside organic variants such as peptides and proteins, are at the forefront of this research. These materials offer diverse mechanisms of action, either by directly interacting with cytoskeletal components or by influencing cellular signaling pathways that, in turn, modulate the cytoskeleton. Recent advancements have introduced magnetic field-responsive and light-responsive nanomaterials, which allow for targeted and controlled manipulation of the cytoskeleton. Such precision is crucial in minimizing off-target effects and enhancing therapeutic efficacy. This review explores the importance of research into cytoskeleton-targeting nanomaterials for developing therapeutic interventions for a range of diseases. It also addresses the progress made in this field, the challenges encountered, and future directions for using nanomaterials to modulate the cytoskeleton. The continued exploration of nanomaterials for cytoskeleton modulation holds great promise for advancing therapeutic strategies against a broad spectrum of diseases, marking a significant step forward in the intersection of nanotechnology and medicine.

Construction of a novel mRNA-miRNA-lncRNA/circRNA triple subnetwork associated with immunity and aging in intervertebral disc degeneration

OBJECTIVE

Intervertebral disk degeneration (IVDD) is one of the most common causes of low back pain. However, in the etiology of IVDD, the specific method by which nucleus pulposus (NP) cell senescence and the immune response induce disease is uncertain.

METHODS

Gene Expression Omnibus database was used to find differentially expressed genes (DEGs), differentially expressed miRNAs (DE miRNAs), differentially expressed lncRNAs (DE lncRNAs), and differentially expressed circRNAs (DE circRNAs). Functional enrichment analysis was performed through Enrichr database. Potential regulatory miRNAs, lncRNAs and circRNAs of mRNAs were predicted by ENCORI and circBank, respectively.

RESULTS

We identified 198 upregulated and 131 downregulated genes, 39 upregulated and 22 downregulated miRNAs, 2152 upregulated and 564 downregulated lncRNAs, and 352 upregulated and 279 downregulated circRNAs as DEGs, DE miRNAs, DE lncRNAs, DE circRNAs, respectively. Functional enrichment analysis revealed that they were significantly enriched in Toll-like receptor signaling route and the NF-kappa B signaling pathway. An mRNA-miRNA-lncRNA/circRNA network linked to the pathogenesis of NP cells in IVDD was constructed based on node degree and differential expression level. Eight immune-related DEGs (6 upregulated and 2 downregulated genes) and five aging-related DEGs (3 upregulated and 2 downregulated genes) were identified in the critical network.

CONCLUSION

We established a novel immune-related and aging-related triple regulatory network of mRNA-miRNA-lncRNA/circRNA ceRNA, among which all RNAs may be utilized as the pathogenesis biomarker of NP cells in IVDD.

A double-network porous hydrogel based on high internal phase emulsions as a vehicle for potassium sucrose octasulfate delivery accelerates diabetic wound healing

Diabetic wounds are a difficult medical challenge. Excessive secretion of matrix metalloproteinase-9 (MMP-9) in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage, which seriously hinders diabetic wound healing. To solve these issues, a double-network porous hydrogel composed of poly (methyl methacrylate-co-acrylamide) (p(MMA-co-AM)) and polyvinyl alcohol (PVA) was constructed by the high internal phase emulsion (HIPE) technique for the delivery of potassium sucrose octasulfate (PSO), a drug that can inhibit MMPs, increase angiogenesis and improve microcirculation. The hydrogel possessed a typical polyHIPE hierarchical microstructure with interconnected porous morphologies, high porosity, high specific surface area, excellent mechanical properties and suitable swelling properties. Meanwhile, the p(MMA-co-AM)/PVA@PSO hydrogel showed high drug-loading performance and effective PSO release. In addition, both in vitro and in vivo studies showed that the p(MMA-co-AM)/PVA@PSO hydrogel had good biocompatibility and significantly accelerated diabetic wound healing by inhibiting excessive MMP-9 in diabetic wounds, increasing growth factor secretion, improving vascularization, increasing collagen deposition and promoting re-epithelialization. Therefore, this study provided a reliable therapeutic strategy for diabetic wound healing, some theoretical basis and new insights for the rational design and preparation of wound hydrogel dressings with high porosity, high drug-loading performance and excellent mechanical properties.

Pyrrole-Doped Polydopamine-Pyrrole (PDA-nPY) Nanoparticles with Tunable Size and Improved NIR Absorption for Photothermal Therapy

Polydopamine (PDA) as a melanin-like biomimetic material with excellent biocompatibility, full spectrum light absorption capacity and antioxidation property has been extensively applied in the biomedical field. Based on the high reactivity of dopamine (DA), exploiting new strategies to fabricate novel PDA-based nano-biomaterials with controllable size and improved performance is valuable and desirable. Herein, we reported a facile way to synthesize pyrrole-doped polydopamine-pyrrole nanoparticles (PDA-nPY NPs) with tunable size and enhanced near-infrared (NIR) absorption capacity through self-oxidative polymerization of DA with PY in an alkaline ethanol/H2O/NH4OH solution. The PDA-nPY NPs maintain excellent biocompatibility and surface reactivity as PDA. By regulating the volume of added PY, PDA-150PY NPs with a smaller size (<100 nm) and four-fold higher absorption intensity at 808 nm than that of PDA can be successfully fabricated. In vitro and in vivo experiments effectively further demonstrate that PDA-150PY NPs can effectively inhibit tumor growth and completely thermally ablate a tumor. It is believed that these PY doped PDA-nPY NPs can be a potential photothermal (PT) agent in biomedical application.