Precise Regulation of Inflammation and Oxidative Stress by ROS‐Responsive Prodrug Coated Balloon for Preventing Vascular Restenosis

ROS-responsive injectable hydrogels loaded with exosomes carrying miR-4500 reverse liver fibrosis

The reversal of liver fibrosis requires effective strategies to reduce oxidative stress and inhibition of hepatic stellate cell (HSC) activation. MiR-4500 regulates pathological angiogenesis and collagen mRNA stability, with the potential to inhibit fibrosis. Herein, we explored the inhibition of HSC activation in vitro by exosomes (Exos) carrying miR-4500 and encapsulated ExosmiR-4500 in an intelligent injectable hydrogel with biological activity and reactive oxygen species (ROS) responsiveness for application in oxidative stress environments. Briefly, reversible boronic ester bonds were integrated into gelatin-based hydrogels through dynamic crosslinking of quaternized chitosan (QCS) and 4-carboxyphenylboronic acid (CPBA)-modified gelatin. The QCS-CPBA-Gelatin (QCG) hydrogel scavenged excess ROS from the local microenvironment and released ExosmiR-4500 through the dissociation of boronic ester bonds, providing a favorable microenvironment and in situ sustained-release drug delivery system for ExosmiR-4500. The results showed that QCG@ExosmiR-4500 hydrogel has biocompatibility, biodegradability, and slow-release ability, which could effectively clear ROS and inhibit HSC activation and pathological angiogenesis in vitro and in vivo. Furthermore, transcriptome analysis suggests that the pharmacological mechanism of the QCG@ExosmiR-4500 hydrogel is mainly related to anti-oxidation, anti-angiogenesis, anti-fibrosis processes, and signaling pathways. Thus, our study demonstrates that an intelligently responsive ExosmiR-4500 delivery system based on injectable hydrogels is a promising strategy for the treatment of liver fibrosis.

Intravascular delivery of an MK2 inhibitory peptide to prevent restenosis after angioplasty

Peripheral artery disease is commonly treated with balloon angioplasty, a procedure involving minimally invasive, transluminal insertion of a catheter to the site of stenosis, where a balloon is inflated to open the blockage, restoring blood flow. However, peripheral angioplasty has a high rate of restenosis, limiting long-term patency. Therefore, angioplasty is sometimes paired with delivery of cytotoxic drugs like paclitaxel to reduce neointimal tissue formation. We pursue intravascular drug delivery strategies that target the underlying cause of restenosis - intimal hyperplasia resulting from stress-induced vascular smooth muscle cell switching from the healthy contractile into a pathological synthetic phenotype. We have established MAPKAP kinase 2 (MK2) as a driver of this phenotype switch and seek to establish convective and contact transfer (coated balloon) methods for MK2 inhibitory peptide delivery to sites of angioplasty. Using a flow loop bioreactor, we showed MK2 inhibition in ex vivo arteries suppresses smooth muscle cell phenotype switching while preserving vessel contractility. A rat carotid artery balloon injury model demonstrated inhibition of intimal hyperplasia following MK2i coated balloon treatment in vivo. These studies establish both convective and drug coated balloon strategies as promising approaches for intravascular delivery of MK2 inhibitory formulations to improve efficacy of balloon angioplasty.

Bacteria-activated macrophage membrane coated ROS-responsive nanoparticle for targeted delivery of antibiotics to infected wounds

Bacterial infections and antibiotic resistance represent significant global public health challenges, necessitating the development of innovative antibacterial agents with targeted delivery capabilities. Our study utilized macrophages' natural ability to recognize bacteria and the increased reactive oxygen species (ROS) at infection sites to develop a novel nanoparticle for targeted delivery and controlled release. We prepared bacteria-activated macrophage membranes triggered by Staphylococcus aureus (Sa-MMs), which showed significantly higher expression of Toll-like receptors (TLRs), compared to normal macrophage membranes (MMs). These Sa-MMs were then used to coat vancomycin-loaded amphiphilic nanoparticles with ROS responsiveness (Van-NPs), resulting in the novel targeted delivery system Sa-MM@Van-NPs. Studies both In vitro and in vivo demonstrated that biocompatible Sa-MM@Van-NPs efficiently targeted infected sites and released vancomycin to eliminate bacteria, facilitating faster wound healing. By combining targeted delivery to infected sites and ROS-responsive antibiotic release, this approach might represent a robust strategy for precise infection eradication and enhanced wound healing.

Platelet Membrane-Encapsulated Poly(lactic-co-glycolic acid) Nanoparticles Loaded with Sildenafil for Targeted Therapy of Vein Graft Intimal Hyperplasia

Autologous vein grafts have attracted widespread attention for their high transplantation success rate and low risk of immune rejection. However, this technique is limited by the postoperative neointimal hyperplasia, recurrent stenosis and vein graft occlusion. Hence, we propose the platelet membrane-coated Poly(lactic-co-glycolic acid) (PLGA) containing sildenafil (PPS). Platelet membrane (PM) is characterised by actively targeting damaged blood vessels. The PPS can effectively target the vein grafts and then slowly release sildenafil to treat intimal hyperplasia in the vein grafts, thereby preventing the progression of vein graft restenosis. PPS effectively inhibits the proliferation and migration of vascular smooth muscle cell (VSMCs) and promotes the migration and vascularisation of human umbilical vein endothelial cells (HUVECs). In a New Zealand rabbit model of intimal hyperplasia in vein grafts, the PPS significantly suppressed vascular stenosis and intimal hyperplasia at 14 and 28 days after surgery. Thus, PPS represents a nanomedicine with therapeutic potential for treating intimal hyperplasia of vein grafts.

A Multi-functional Hybrid System Comprised of Polydopamine Nanobottles and Biological Effectors for Cartilage Repair

Biological effectors play critical roles in augmenting the repair of cartilage injuries, but it remains a challenge to control their release in a programmable, stepwise fashion. Herein, a hybrid system consisting of polydopamine (PDA) nanobottles embedded in a hydrogel matrix to manage the release of biological effectors for use in cartilage repair is reported. Specifically, a homing effector is load in the hydrogel matrix, together with the encapsulation of a cartilage effector in PDA nanobottles filled with phase-change material. In action, the homing effector is quickly released from the hydrogel in the initial step to recruit stem cells from the surroundings. Owing to the antioxidation effect of PDA, the recruited cells are shielded from reactive oxygen species. The cartilage effector is then slowly released from the nanobottles to promote chondrogenic differentiation, facilitating cartilage repair. Altogether, this strategy encompassing recruitment, protection, and differentiation of stem cells offers a viable route to tissue repair or regeneration through stem cell therapy.

Polyphenol enhances the functionality of borate hydrogel in wound repair by regulating the wound microenvironment

Wound infections represent a significant clinical challenge. In this study, a polyphenol (tannic acid, TA)-enhanced borate hydrogel modulating the tissue microenvironment to promote wound healing was designed as an antimicrobial hydrogel. The physical properties of the multiply cross-linked borate hydrogel were analyzed using a combination of techniques, including FT-IR, 1H NMR, SEM, and rheological analysis. The combination of polyvinyl alcohol (PVA), phenylboronic acid-functionalized chitosan (N-PBACS), and TA resulted in the formation of multi-crosslinked networks (PVA@N-PBACS, TA@PVA, and TA@N-PBACS) that markedly enhanced the hydrogel's mechanical strength, deformability (compression and tensile), and adhesion properties. The multi-crosslinked hydrogels exhibited broad-spectrum antimicrobial activity and antioxidant effects in vitro, as well as excellent biocompatibility and the promotion of cell proliferation, migration and vascularisation behaviours. The in vivo results demonstrated that the hydrogel had enhanced properties. Furthermore, it exhibits good biocompatibility, reactive oxygen species (ROS) scavenging ability, antimicrobial properties, and the ability to modulate immune status. In an in vivo bacterial infection model, the multi-crosslinked hydrogel effectively modulated the wound microenvironment through antimicrobial effects, oxidative stress, ROS levels, and immunity modulation. This study offers a promising solution for improving wound care and provides insight into potential future therapeutic strategies.

Bilayer Scaffolds Synergize Immunomodulation and Rejuvenation via Layer-Specific Release of CK2.1 and the "Exercise Hormone" Lac-Phe for Enhanced Osteochondral Regeneration

Repairing osteochondral defects necessitates the intricate reestablishment of the microenvironment. The cartilage layer consists of a porous gelatin methacryloyl hydrogel (PGelMA) covalently crosslinked with the chondroinductive peptide CK2.1 via a "linker" acrylate-PEG-N-hydroxysuccinimide (AC-PEG-NHS). This layer is optimized for remodeling the senescent microenvironment in the cartilage region, thereby establishing a regenerative microenvironment that supports chondrogenesis. For the bone layer, silk fibroin methacryloyl (SilMA) is coated onto a three dimensional (3D)-printed 45S5 bioactive glass scaffold (BG scaffold). The "exercise hormone" N-lactoyl-phenylalanine (Lac-Phe) is loaded onto the SilMA, endowing it with diversified functions to regulate the osteogenic microenvironment. Systematic analysis in vitro reveals that PGelMA-CK2.1 shifts the microenvironment from a pro-inflammatory into an anti-inflammatory condition, and alleviates cellular senescence, thus modifying the cartilage microenvironment to improve the recruitment, proliferation and chondral differentiation of bone marrow mesenchymal stem cells (BMSCs). The scaffold bone layer enhances microvascular endothelial cell proliferation, migration, and angiogenic activities, which, couple with increased BMSC recruitment and regulatory mechanisms directing BMSC differentiation, favor a shift in the "osteogenesis-adipogenesis" balance toward enhanced osteogenesis. In vivo, it is found that this biphasic biomimetic scaffold favors simultaneous dual tissue regeneration. This approach facilitates the development of bioactive regenerative scaffolds and holds great potential for clinical application.

Nanotechnology-Mediated Immunomodulation Strategy for Inflammation Resolution

Inflammation serves as a common characteristic across a wide range of diseases and plays a vital role in maintaining homeostasis. Inflammation can lead to tissue damage and the onset of inflammatory diseases. Although significant progress is made in anti-inflammation in recent years, the current clinical approaches mainly rely on the systemic administration of corticosteroids and antibiotics, which only provide short-term relief. Recently, immunomodulatory approaches have emerged as promising strategies for facilitating the resolution of inflammation. Especially, the advanced nanosystems with unique biocompatibility and multifunctionality have provided an ideal platform for immunomodulation. In this review, the pathophysiology of inflammation and current therapeutic strategies are summarized. It is mainly focused on the nanomedicines that modulate the inflammatory signaling pathways, inflammatory cells, oxidative stress, and inflammation targeting. Finally, the challenges and opportunities of nanomaterials in addressing inflammation are also discussed. The nanotechnology-mediated immunomodulation will open a new treatment strategy for inflammation therapy.

A glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy

Diabetic nephropathy is a severe complication of diabetes. Treatment of diabetic nephropathy is an important challenge due to persistent hyperglycemia and elevated levels of reactive oxygen species (ROS) in the kidney. Herein, we designed a glycopolymersome that can treat type 2 diabetic nephropathy by effectively inhibiting hyperglycemia and ROS-associated diabetic nephropathy pathogenesis. The glycopolymersome is self-assembled from phenylboronic acid derivative-containing copolymer, poly(ethylene oxide)45-block-poly[(aspartic acid)13-stat-glucosamine24-stat-(phenylboronic acid)18-stat-(phenylboronic acid pinacol ester)3] [PEO45-b-P(Asp13-stat-GA24-stat-PBA18-stat-PAPE3)]. PBA segment can reversibly bind blood glucose or GA segment for long-term regulation of blood glucose levels; PAPE segment can scavenge excessive ROS for renoprotection. In vitro studies confirmed that the glycopolymersomes exhibit efficient blood glucose responsiveness within 2 h and satisfactory ROS-scavenging ability with 500 μM H2O2. Moreover, the glycopolymersomes display long-acting regulation of blood glucose levels in type 2 diabetic nephropathy mice within 32 h. Dihydroethidium staining revealed that these glycopolymersomes reduced ROS to normal levels in the kidney, which led to 61.7% and 76.6% reduction in creatinine and urea levels, respectively, along with suppressing renal apoptosis, collagen accumulation, and glycogen deposition in type 2 diabetic nephropathy mice. Notably, the polypeptide-based glycopolymersome was synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs), thereby exhibiting favorable biodegradability. Overall, we proposed a new glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy, which could be extended to encompass the design of various multifunctional nanoparticles targeting diabetes and its associated complications.

Multifunctional Cerium Oxide Nanozyme for Synergistic Dry Eye Disease Therapy

Dry eye disease (DED) is a chronic multifactorial ocular surface disease mainly caused by the instability of tear film, characterized by a series of ocular discomforts and even visual disorders. Oxidative stress has been recognized as an upstream factor in DED development. Diquafosol sodium (DQS) is an agonist of the P2Y2 receptor to restore the integrity/stability of the tear film. With the ability to alternate between Ce3+ and Ce4+, cerium oxide nanozymes could scavenge overexpressed reactive oxygen species (ROS). Hence, a DQS-loaded cerium oxide nanozyme was designed to boost the synergistic treatment of DED. Cerium oxide with branched polyethylenimine-graft-poly(ethylene glycol) as nucleating agent and dispersant was fabricated followed with DQS immobilization via a dynamic phenylborate ester bond, obtaining the DQS-loaded cerium oxide nanozyme (defined as Ce@PBD). Because of the ability to mimic the cascade processes of superoxide dismutase and catalase, Ce@PBD could scavenge excessive accumulated ROS, showing strong antioxidant and anti-inflammatory properties. Meanwhile, the P2Y2 receptors in the conjunctival cells could be stimulated by DQS in Ce@PBD, which can relieve the incompleteness and instability of the tear film. The animal experiments demonstrated that Ce@PBD significantly restored the defect of the corneal epithelium and increased the number of goblet cells, with the promotion of tear secretion, which was the best among commercial DQS ophthalmic solutions.

Novel Hydrogel Adjuvant of Chinese Medicine External Preparations for Accelerated Healing of Deep Soft Tissue Injuries

Traditional Chinese medicine external prescriptions have displayed excellent clinical effects for treating deep soft tissue injuries. However, the effects cannot be fully utilized due to the limitations of their dosage forms and usage methods. It is still a challenge to develop a satisfactory adjuvant of traditional Chinese medicine external prescriptions. Herein, a hydrogel adjuvant was prepared based on gallic acid coupled ε-poly-l-lysine and partially oxidized hyaluronic acid. The resulting adjuvant shows great physicochemical properties, low hemolysis rate (still much less than 5% at 5 mg/mL), excellent antibacterial ability (about 95% at 2 mg/mL), strong antioxidant ability (1.687 ± 0.085 mmol FeSO4/(g hydrogel) at 1 mg/mL), as well as outstanding biocompatibility. A clinically used Chinese medicine external preparation was selected as an example to investigate the effectiveness of the adjuvant in treating deep soft tissue injuries. The results show that the prescription can be evenly dispersed in the adjuvant. Moreover, the introduction of the prescription has not significantly changed these advanced properties of the adjuvant. Importantly, the hydrogel adjuvant significantly improves the effectiveness of the prescription in treating deep soft tissue injuries. This work offers an alternative approach to the development of a new-type adjuvant of Chinese medicine external preparations and also provides a new strategy for the combination of traditional Chinese medicine and hydrogel to treat clinical diseases.

ROS-responsive & scavenging NO nanomedicine for vascular diseases treatment by inhibiting endoplasmic reticulum stress and improving NO bioavailability

Vascular diseases seriously threaten human life and health. Exogenous delivery of nitric oxide (NO) represents an effective approach for maintaining vascular homeostasis during pathological events. However, the overproduction of reactive oxygen species (ROS) at vascular injury sites would react with NO to produce damaging peroxynitrite (ONOO-) species and limit the therapeutic effect of NO. Hence, we design a ROS-responsive NO nanomedicine (t-PBA&NO NP) with ROS scavenging ability to solve the dilemma of NO-based therapy. t-PBA&NO NP targets NO and anti-oxidant ethyl caffeate (ECA) to the injury sites via collagen IV homing peptide. The ROS-triggered ROS depletion and ECA release potently alleviate local oxidative stress via ROS scavenging, endoplasmic reticulum and mitochondrial regulation. It subsequently maximizes vascular modulation effects of NO, without production of harmful compounds, reactive nitrogen species (RNS). Therefore, it significantly increases competitiveness of human umbilical vein endothelial cells (HUVECs) over human aortic smooth muscle cells (HASMCs) both in vitro and in vivo. The strategy proved effective in inducing faster re-endothelialization, inhibiting neointimal formation and restoring vascular homeostasis. The synergy between ROS depletion and NO therapy served as a new inspiration for the treatment of cardiovascular diseases and other ROS-associated illnesses.

Diamond-Like Carbon Depositing on the Surface of Polylactide Membrane for Prevention of Adhesion Formation During Tendon Repair

Post-traumatic peritendinous adhesion presents a significant challenge in clinical medicine. This study proposes the use of diamond-like carbon (DLC) deposited on polylactic acid (PLA) membranes as a biophysical mechanism for anti-adhesion barrier to encase ruptured tendons in tendon-injured rats. The results indicate that PLA/DLC composite membrane exhibits more efficient anti-adhesion effect than PLA membrane, with histological score decreasing from 3.12 ± 0.27 to 2.20 ± 0.22 and anti-adhesion effectiveness increasing from 21.61% to 44.72%. Mechanistically, the abundant C=O bond functional groups on the surface of DLC can reduce reactive oxygen species level effectively; thus, the phosphorylation of NF-κB and M1 polarization of macrophages are inhibited. Consequently, excessive inflammatory response augmented by M1 macrophage-originated cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) is largely reduced. For biocompatibility evaluation, PLA/DLC membrane is slowly absorbed within tissue and displays prolonged barrier effects compared to traditional PLA membranes. Further studies show the DLC depositing decelerates the release of degradation product lactic acid and its induction of macrophage M2 polarization by interfering esterase and PLA ester bonds, which further delays the fibrosis process. It was found that the PLA/DLC membrane possess an efficient biophysical mechanism for treatment of peritendinous adhesion.

Regulation of Photophysical Behaviors in Hyperbranched Aggregation-Induced Emission Polymers for Reactive Oxygen Species Scavenging

Developing nonconjugated materials with large Stokes shifts is highly desired. In this work, three kinds of hyperbranched aggregation-induced emission (AIE) polymers with tunable n/π electronic effects were synthesized. HBPSi-CBD contains alkenyl groups in the backbone and possesses a promoted n-π* transition and red-shifted emission wavelength with a large Stokes shift of 186 nm. Experiments and theoretical simulations confirmed that the planar π electrons in the backbone are responsible for the red-shifted emission due to the strong through-space n···π interactions and restricted backbone motions. Additionally, the designed HBPSi-CBD could be utilized as an ROS scavenger after coupling with l-methionine. The HBPSi-Met exhibits remarkable ROS scavenging properties with a scavenging capacity of 77%. This work not only gains further insight into the structure-property relationship of nonconjugated hyperbranched AIE polymers but also provides a promising ROS-scavenging biomaterial for the treatment of ROS-related diseases.

Functional Polyphenol-Based Nanoparticles Boosted the Neuroprotective Effect of Riluzole for Acute Spinal Cord Injury

Riluzole is commonly used as a neuroprotective agent for treating traumatic spinal cord injury (SCI), which works by blocking the influx of sodium and calcium ions and reducing glutamate activity. However, its clinical application is limited because of its poor solubility, short half-life, potential organ toxicity, and insufficient bioabilities toward upregulated inflammation and oxidative stress levels. To address this issue, epigallocatechin gallate (EGCG), a natural polyphenol, was employed to fabricate nanoparticles (NPs) with riluzole to enhance the neuroprotective effects. The resulting NPs demonstrated good biocompatibility, excellent antioxidative properties, and promising regulation effects from the M1 to M2 macrophages. Furthermore, an in vivo SCI model was successfully established, and NPs could be obviously aggregated at the SCI site. More interestingly, excellent neuroprotective properties of NPs through regulating the levels of oxidative stress, inflammation, and ion channels could be fully demonstrated in vivo by RNA sequencing and sophisticated biochemistry evaluations. Together, the work provided new opportunities toward the design and fabrication of robust and multifunctional NPs for oxidative stress and inflammation-related diseases via biological integration of natural polyphenols and small-molecule drugs.

Achieving Clearance of Drug-Resistant Bacterial Infection and Rapid Cutaneous Wound Regeneration Using an ROS-Balancing-Engineered Heterojunction

Intractable infected microenvironments caused by drug-resistant bacteria stalls the normal course of wound healing. Sono-piezodynamic therapy (SPT) is harnessed to combat pathogenic bacteria, but the superabundant reactive oxygen species (ROS) generated during SPT inevitably provoke severe inflammatory response, hindering tissue regeneration. Consequently, an intelligent nanocatalytic membrane composed of poly(lactic-co-glycolic acid) (PLGA) and black phosphorus /V2C MXene bio-heterojunctions (2D2-bioHJs) is devised. Under ultrasonication, 2D2-bioHJs effectively eliminate drug-resistant bacteria by disrupting metabolism and electron transport chain (ETC). When ultrasonication ceases, they enable the elimination of SPT-generated ROS. The 2D2-bioHJs act as a "lever" that effectively achieves a balance between ROS generation and annihilation, delivering both antibacterial and anti-inflammatory properties to the engineered membrane. More importantly, in vivo assays corroborate that the nanocatalytic membranes transform the stalled chronic wound environment into a regenerative one by eradicating the bacterial population, dampening the NF-κB inflammatory pathway and promoting angiogenesis. As envisaged, this work demonstrates a novel tactic to arm membranes with programmed antibacterial and anti-inflammatory effects to remedy refractory infected wounds from drug-fast bacteria.

Prussian blue nanozymes: progress, challenges, and opportunities

Prussian Blue Nanozymes (PBNZs) have emerged as highly efficient agents for reactive oxygen species (ROS) elimination, owing to their multiple enzyme-like properties encompassing catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities. As a functional nanomaterial mimicking enzyme, PBNZs not only surmount the limitations of natural enzymes, such as instability and high manufacturing costs, but also exhibit superior stability, tunable activity, low storage expenses, and remarkable reusability. Consequently, PBNZs have gained significant attention in diverse biomedical applications, including disease diagnosis and therapy. Over the past decade, propelled by advancements in catalysis science, biotechnology, computational science, and nanotechnology, PBNZs have witnessed remarkable progress in the exploration of their enzymatic activities, elucidation of catalytic mechanisms, and wide-ranging applications. This comprehensive review aims to provide a systematic overview of the discovery and catalytic mechanisms of PBNZ, along with the strategies employed to modulate their multiple enzyme-like activities. Furthermore, we extensively survey the recent advancements in utilizing PBNZs for scavenging ROS in various biomedical applications. Lastly, we analyze the existing challenges of translating PBNZs into therapeutic agents for clinical use and outline future research directions in this field. By presenting a comprehensive synopsis of the current state of knowledge, this review seeks to contribute to a deeper understanding of the immense potential of PBNZs as an innovative therapeutic agent in biomedicine.