Rescuing Nucleus Pulposus Cells from ROS Toxic Microenvironment via Mitochondria-Targeted Carbon Dot-Supported Prussian Blue to Alleviate Intervertebral Disc Degeneration

Effects of Hsa-miR-4741/LILRB2 on Senescence of Nucleus Pulposus Cells and Their Prognostic Values in Lumbar Disc Herniation

BACKGROUND

The incidence of lumbar disk herniation (LDH) is usually caused by lumbar disk degeneration. Surgery is a common treatment strategy for LDH, but it can recur, resulting in recurrent disk herniation (RDH).

PURPOSE

To explore the predictive value of hsa-miR-4741 and LILRB2 in the prognosis of LDH surgery and the mechanism of nucleus pulposus senescence.

METHOD

The ROC curves of RDH based on hsa-miR-4741 and LILRB2 were constructed to evaluate their predictive values in the prognosis of LDH surgery. Human nucleus pulposus cells (NPC) was treated by TNF-α to construct a cell senescence model, studying the senescence mechanism. Oxidative stress and senescence markers were detected after overexpression of hsa-miR-4741 and LILRB2 to evaluate their effects on the senescence of NPC. Dual luciferase assay and the transfection of hsa-miR-4741 mimics or inhibitor were used to investigate the targeted regulation of it to LILRB2.

RESULTS

The combination of hsa-miR-4741 and LILRB2 showed higher accuracy in predicting the outcome of RDH (AUC = 0.9367), compared with a single molecule. Overexpression of hsa-miR-4741 enhanced TNF-α-induced oxidative stress and senescence, while LILRB2 overexpression had the opposite effect. Hsa-miR-4741 mimics attenuated the luciferase activity of NPC transfected with wt-LILRB2 vector and significantly down-regulated LILRB2 expression. In addition, the antioxidant NAC reversed the promotion of hsa-miR-4741 on NPC senescence.

CONCLUSION

The combination of hsa-miR-4741 and LILRB2 was a good predictor of LDH prognosis. Hsa-miR-4741 promoted oxidative stress-induced NPC senescence by negatively regulating LILRB2.

Novel pH-responsive lipid nanoparticles deliver UA-mediated mitophagy and ferroptosis for osteoarthritis treatment

Synovial inflammation plays a crucial role in osteoarthritis (OA) development, leading to chronic inflammation and cartilage destruction. Although targeting synovitis can alleviate OA, clinical outcomes have been disappointing due to poor drug targeting and joint cavity heterogeneity. This study presents pH-responsive lipid nanoparticles (LNPs@UA), loaded with Urolithin A (UA), as a potential OA treatment. LNPs@UA showed uniform particle size, low zeta potential, and effective mitochondria-targeting and pH-responsive capabilities. In vitro, LNPs@UA reduced reactive oxygen species (ROS), pro-inflammatory factors (IL-1β, IL-6, TNF-α), and promoted M2 macrophage polarization. It improved mitochondrial structure, enhanced autophagy, and inhibited ferroptosis. In vivo, LNPs@UA alleviated OA progression in an ACLT-induced OA mouse model. Transcriptomic analysis revealed inhibition of NF-κB signaling and activation of repair pathways. These results suggest LNPs@UA could offer a promising therapeutic approach for OA.

Intervening with nanozymes in aging-related diseases: Strategies for restoring mitochondrial function

The decline in mitochondrial function has been identified as one of the central pathological mechanisms underlying a variety of aging-related diseases. Nanozymes are nanomaterials with intrinsic enzyme-like properties and are important alternatives to natural enzymes. As emerging biocatalysts, nanozymes exhibit significant potential in mimicking the activity of natural enzymes, enhancing mitochondrial function, and offering novel therapeutic strategies for aging-related conditions. This review provides an overview of various approaches to modulate the catalytic activity of nanozymes, considering factors such as particle size, shape, surface modifications, and constituent elements. It then examines the role of nanozymes in mitigating aging-related diseases by preserving mitochondrial health, with a particular focus on their ability to regulate three critical aspects: mitochondrial energy metabolism, quality control, and antioxidant capacity. By improving mitochondrial energy generation, supporting mitochondrial integrity, and eliminating excess reactive oxygen species (ROS), nanozymes offer new therapeutic possibilities for neurodegenerative diseases, bone-related disorders, and diabetes. Finally, this article discusses the major challenges faced in this field, including issues such as the scalability, biocompatibility, and targeting ability of nanozymes. It also emphasizes that future research should focus on enhancing clinical translation to ensure that nanozymes can play an effective role in practical therapeutic applications.

Research progress on the synthesis, performance regulation, and applications of Prussian blue nanozymes

Nanocatalytic medicine offers a novel solution to address the issues of low efficacy, potential side effects, and the development of drug resistance associated with traditional therapies. Therefore, developing highly efficient and durable nanozymes is of great significance for treating diseases related to oxidative stress. In recent years, prussian blue nanoparticles (PBNPs) have been demonstrated to possess multiple enzyme-like catalytic activities and are thus referred to as prussian blue nanozymes (PBNZs). Their excellent biocompatibility and biodegradability make PBNZs promising candidates as biomedical materials. Due to their remarkable catalytic activities, PBNZs have shown great potential in various biomedical applications, such as heavy metal detoxification, antioxidative damage, and anticancer therapies. This paper systematically summarizes the Synthetic strategies of PBNZs, analyzes the regulatory factors of their catalytic performance, and highlights the corresponding modulation methods. Furthermore, the biomedical applications of PBNZs are also reviewed. This study aims to provide researchers with insights and inspirations for the design and preparation of high-performance PBNZs.

The anti-oxidation related bioactive materials for intervertebral disc degeneration regeneration and repair

Intervertebral disc degeneration (IVDD) is a prevalent chronic spinal condition characterized by the deterioration of the intervertebral discs (IVD), leading to structural damage and associated pain. This degenerative process is closely linked to oxidative stress injury, which plays a pivotal role in its onset and progression. Oxidative stress in IVDD results from the excessive production of reactive oxygen species (ROS) and impaired ROS clearance mechanisms, disrupting the redox balance within the intervertebral disc. Consequently, oxidative stress contributes to the degradation of the extracellular matrix (ECM), promotes cell apoptosis, and exacerbates disc tissue damage. Current treatment options for IVDD face significant challenges in effectively alleviating the oxidative stress-induced damage and facilitating disc tissue repair. However, recent advancements in biomaterials have opened new avenues of hope for IVDD treatment by addressing oxidative stress. In this review, we first provide an overview of the pathophysiological process of IVDD and explore the mechanisms and pathways associated with oxidative stress injury. Then, we delve into the current research on antioxidant biomaterials employed in the treatment of IVDD, and outline the advantages and limitations of hydrogel, nanomaterials, polyphenol and inorganic materials. Finally, we propose the future research direction of antioxidant biomaterials in IVDD treatment. The main idea of this review is shown in Scheme 1.

Nanotechnology-Enhanced Pharmacotherapy for Intervertebral Disc Degeneration Treatment

Intervertebral disc degeneration (IDD) is a primary contributor to chronic back pain and disability globally, with current therapeutic approaches often proving inadequate due to the complex nature of its pathophysiology. This review assesses the potential of nanoparticle-driven pharmacotherapies to address the intricate challenges presented by IDD. We initially analyze the primary mechanisms driving IDD, with particular emphasis on mitochondrial dysfunction, oxidative stress, and the inflammatory microenvironment, all of which play pivotal roles in disc degeneration. Then, we evaluate the application of metal-phenolic and catalytic nanodots in targeting mitochondrial defects and alleviating oxidative stress within the degenerative disc environment. Additionally, multifunctional and stimuli-responsive nanoparticles are explored for their capacity to provide precise targeting and controlled therapeutic release, offering improved localization and sustained delivery. Finally, we outline future research directions and identify emerging trends in nanoparticle-based therapies, highlighting their potential to significantly advance IDD treatment by overcoming the limitations of conventional therapeutic modalities and enabling more effective, targeted management strategies.

Carbon Dots in the Pathological Microenvironment: ROS Producers or Scavengers?

Reactive oxygen species (ROS), as metabolic byproducts, play pivotal role in physiological and pathological processes. Recently, studies on the regulation of ROS levels for disease treatments have attracted extensive attention, mainly involving the ROS-induced toxicity therapy mediated by ROS producers and antioxidant therapy by ROS scavengers. Nanotechnology advancements have led to the development of numerous nanomaterials with ROS-modulating capabilities, among which carbon dots (CDs) standing out as noteworthy ROS-modulating nanomedicines own their distinctive physicochemical properties, high stability, and excellent biocompatibility. Despite progress in treating ROS-related diseases based on CDs, critical issues such as rational design principles for their regulation remain underexplored. The primary cause of these issues may stem from the intricate amalgamation of core structure, defects, and surface states, inherent to CDs, which poses challenges in establishing a consistent generalization. This review succinctly summarizes the recently progress of ROS-modulated approaches using CDs in disease treatment. Specifically, it investigates established therapeutic strategies based on CDs-regulated ROS, emphasizing the interplay between intrinsic structure and ROS generation or scavenging ability. The conclusion raises several unresolved key scientific issues and prominent technological bottlenecks, and explores future perspectives for the comprehensive development of CDs-based ROS-modulating therapy.

TME-responsive nanoplatform for multimodal imaging-guided synergistic precision therapy of esophageal cancer via inhibiting HIF-1α signal pathway

Esophageal cancer (EC) is the sixth leading cause of cancer-related deaths, and its treatment poses significant challenges. In recent years, photodynamic, photothermal, and chemodynamic therapies have emerged as alternative strategies for tumor intervention. However, limitations such as poor tumor targeting, insufficient microenvironment responsiveness, and unclear mechanisms hinder their application. In this study, we found that hypoxia-inducible factor 1 alpha (HIF-1α) was highly expressed in clinical EC samples, which contributed to tumor malignancy and metastasis. We developed a carbon dots (CDs)-based tumor microenvironment (TME)-responsive nanoplatform, CDs-MnO2-Au-Cet (CMAC), designed for multimodal imaging-guided precision therapy in EC. Both in vitro and in vivo experiments demonstrated that CMAC effectively targeted and imaged EC cells and tissues. CMAC significantly inhibited tumor growth by inducing apoptosis and reducing lung metastasis. Mechanistically, CMAC administration led to a substantial downregulation of HIF-1α and its downstream targets, GLUT1 and MMP9. In summary, we presented a novel nanoplatform for imaging-guided synergistic therapy in EC, which demonstrated excellent anti-tumor growth and metastasis capabilities, along with favorable biocompatibility. This study laid the groundwork for developing innovative theranostic strategies for EC.

Targeted mitochondrial nanomaterials in biomedicine: Advances in therapeutic strategies and imaging modalities

Mitochondria, pivotal organelles crucial for energy generation, apoptosis regulation, and cellular metabolism, have spurred remarkable advancements in targeted material development. This review surveys recent breakthroughs in targeted mitochondrial nanomaterials, illuminating their potential in drug delivery, disease management, and biomedical imaging. This review approaches from various application perspectives, introducing the specific applications of mitochondria-targeted materials in cancer treatment, probes and imaging, and diseases treated with mitochondria as a therapeutic target. Addressing extant challenges and elucidating potential therapeutic mechanisms, it also outlines future development trajectories and obstacles. By comprehensively exploring the diverse applications of targeted mitochondrial nanomaterials, this review aims to catalyze innovative treatment modalities and diagnostic approaches in medical research. STATEMENT OF SIGNIFICANCE: This review presents the latest advancements in mitochondria-targeted nanomaterials for biomedical applications, covering diverse fields such as cancer therapy, bioprobes, imaging, and the treatment of various systemic diseases. The novelty and significance of this work lie in its systematic analysis of the intricate relationship between mitochondria and different diseases, as well as the ingenious design strategies employed to harness the therapeutic potential of nanomaterials. By providing crucial insights into the development of mitochondria-targeted nanomaterials and their applications, this review offers a valuable resource for researchers working on innovative treatment modalities and diagnostic approaches. The scientific impact and interest to the readership lie in the identification of promising avenues for future research and the potential for clinical translation of these cutting-edge technologies.

Injectable Inflammation-Responsive Hydrogels for Microenvironmental Regulation of Intervertebral Disc Degeneration

Chronic local inflammation and excessive cell apoptosis in nucleus pulposus (NP) tissue are the main causes of intervertebral disc degeneration (IDD). Stimuli-responsive hydrogels have great potential in the treatment of IDD by facilitating localized and controlled drug delivery. Herein, an injectable drug-loaded dual stimuli-responsive adhesive hydrogel for microenvironmental regulation of IDD, is developed. The gelatin methacryloyl is functionalized with phenylboronic acid groups to enhance drug loading capacity and enable dual stimuli-responsive behavior, while the incorporation of oxidized hyaluronic acid further improves the adhesive properties. The prepared hydrogel exhibits an enhanced drug loading capacity for diol-containing drugs, pH- and reactive oxygen species (ROS)-responsive behaviors, excellent radical scavenging efficiency, potent antibacterial activity, and favorable biocompatibility. Furthermore, the hydrogel shows a beneficial protective efficacy on NP cells within an in vitro oxidative stress microenvironment. The in vivo results demonstrate the hydrogel's excellent therapeutic effect on treating IDD by maintaining water retention, restoring disc height, and promoting NP regeneration, indicating that this hydrogel holds great potential as a promising therapeutic approach for regulating the microenvironment and alleviating the progression of IDD.

Target-Oriented Synthesis of Triphenylphosphine Functionalized Carbon Dots with Negative Charge for ROS Scavenging and Mitochondrial Targeting

Triphenylphosphine functionalized carbon dots (TPP-CDs) showcase robust mitochondria targeting capacity owing to their positive electrical properties. However, TPP-CDs typically involve complicated synthesis steps and time-consuming postmodification procedures. Especially, the one-step target-oriented synthesis of TPP-CDs and the regulation of TPP linkage modes remain challenges. Herein, we propose a free-radical-initiated random copolymerization in combination with hydrothermal carbonation to regulate the TPP backbone linkage for target-oriented synthesis of triphenylphosphine copolymerization carbon dots (TPPcopoly-CDs). The linkage mechanism of random copolymerization reactions is directional, straightforward, and controllable. The TPP content and IC50 of hydroxyl radicals scavenging ability of TPPcopoly-CDs are 53 wt % and 0.52 mg/mL, respectively. TPP serves as a charge control agent to elevate the negatively charged CDs by 20 mV. TPPcopoly-CDs with negative charge can target mitochondria, and in the corresponding mechanism the TPP moiety plays a crucial role in targeting mitochondria. This discovery provides a new perspective on the controlled synthesis, TPP linkage modes, and mitochondrial targeting design of TPP-CDs.

The mitochondrial UPR induced by ATF5 attenuates intervertebral disc degeneration via cooperating with mitophagy

Intervertebral disc degeneration (IVDD) is an aging disease that results in a low quality of life and heavy socioeconomic burden. The mitochondrial unfolded protein response (UPRmt) take part in various aging-related diseases. Our research intents to explore the role and underlying mechanism of UPRmt in IVDD. Nucleus pulposus (NP) cells were exposed to IL-1β and nicotinamide riboside (NR) served as UPRmt inducer to treat NP cells. Detection of ATP, NAD + and NADH were used to determine the function of mitochondria. MRI, Safranin O-fast green and Immunohistochemical examination were used to determine the degree of IVDD in vivo. In this study, we discovered that UPRmt was increased markedly in the NP cells of human IVDD tissues than in healthy controls. In vitro, UPRmt and mitophagy levels were promoted in NP cells treated with IL-1β. Upregulation of UPRmt by NR and Atf5 overexpression inhibited NP cell apoptosis and further improved mitophagy. Silencing of Pink1 reversed the protective effects of NR and inhibited mitophagy induced by the UPRmt. In vivo, NR might attenuate the degree of IDD by activating the UPRmt in rats. In summary, the UPRmt was involved in IVDD by regulating Pink1-induced mitophagy. Mitophagy induced by the UPRmt might be a latent treated target for IVDD.