pH-Responsive Multifunctional Theranostic Rapamycin-Loaded Nanoparticles for Imaging and Treatment of Acute Ischemic Stroke

Construction of fibromodulin and borneol-clacked phosphorus dendrimer nanoparticles to reduce inflammation and oxidative stress in BBB to nursing care and ischemic stroke therapy

The formulation of novel multi-target combination therapies to address ischemic stroke (ICS) continues to pose significant challenges. This work presents a proof-of-concept display of a proficient nanomedicine formulation consisting of macrophage membrane (MM)-camouflaged phosphorous dendrimer (designated as PD)/fibromodulin (FB) nanoparticles (NPs) clacked with the antioxidant borneol (BN) to regulate both microglia and neurons for efficient ICS therapy. The developed MM@PD-FB/BN NPs, averaging 260 nm in size, exhibit excellent colloidal stability, prolonged BN release kinetics, and favorable cytocompatibility. Due to MM decoration, the MM@PD-FB/BN NPs can traverse the blood-brain barrier, influence microglia to produce anti-inflammatory (PD and FB) and antioxidative (FB and BN) effects in vitro, facilitating oxidative stress mitigation, microglia M2 polarization, and decreased proinflammatory cytokine secretion, while also acting on neuronal cells to exhibit anti-apoptotic properties. In a middle cerebral artery occlusion (MCAO) model, engineered MM@PD-FB/BN NPs demonstrate improved antioxidant, anti-inflammatory, and anti-apoptotic therapeutic effects, modulating the brain microenvironment to restore blood flow. The engineered MM-coated NPs, comprising active components of phosphorous dendrimers, FB, and BN, capable of comprehensively modulating the brain's inflammatory milieu, may broaden the treatment and nursing care of ischemic stroke.

Ultrasound Trigger Ultrasmall Multifunction Nanobubbles for Thrombus Visual Treatment

Intravenous injection of thrombolytic drugs is the prevailing strategy for the treatment of thrombotic disease. However, its applications are limited due to hemorrhagic risk and thrombus microenvironment. In pursuit of visualized thrombolysis and inspired by the excessive reactive oxygen species (ROS) and inflammatory factors within the thrombus site, an ultrasmall nanobubble (CeO2/MnOX@UK@PFP) for integration of imaging and therapy by low intensity pulse ultrasound (LIPUS) trigger is designed, which achieved the visual delivery of Urokinas (UK) and ROS scavenging agents to adjust thrombus microenvironment. In this study, CeO2/MnOX with ROS scavenging activity are prepared and wrapped with UK and perfluoropentane (PFP) by lipid layer, forming a CeO2/MnOX@UK@PFP. Under LIPUS, PFP undergoes phase transition from liquid to gas for real-time imaging, meanwhile, CeO2/MnOX@UK@PFP is burst to release UK and CeO2/MnOX. UK is delivered to the side of the clot avoiding hemorrhagic risk. CeO2/MnOX@UK@PFP not only can detect the progression of thrombolytic treatment through ultrasound imaging (US) in real-time but also play an important role in the elimination of excessive ROS at the thrombus microenvironment for protecting endangium. Taken together, the in vitro and in vivo experiments illustrated that CeO2/MnOX@UK@PFP displayed excellent efficiency in thrombolysis visual, anti-inflammation, and ROS scavenging.

Stimuli-Responsive Nano Drug Delivery Systems for the Treatment of Neurological Diseases

Nanomaterials with unparalleled physical and chemical attributes have become a cornerstone in the field of nanomedicine delivery. These materials can be engineered into various functionalized nanocarriers, which have become the focus of research. Stimulus-responsive nanodrug delivery systems (SRDDS) stand out as a sophisticated class of nanocarriers that can release drugs in response to environmental cues. Due to the complex pathogenesis and the multifaceted pathological environment of the nervous system, developing accurate and effective drug therapy with low side-effects is a formidable task. In recent years, SRDDS have been widely used in the treatment of neurological diseases. By customizing SRDDS to align with the specific microenvironment of the nervous system tissues or external stimulation, the efficacy of drug delivery can be enhanced. This review provides an in-depth look at the characteristics of the microenvironment of neurological diseases and highlights case studies of SRDDS tailored to treat these disorders based on the unique stimulation criteria of nervous system tissues or external triggers. Additionally, this review provides a comprehensive overview of the progress and future prospects of SRDDS technology in the treatment of neurological diseases, providing valuable guidance for its transition from fundamental research to clinical application.

Peptide amphiphiles alleviate myocardial endoplasmic reticulum stress to enhance cardiomyocyte-macrophage communication and promote macrophage M2 polarization

Myocardial ischemia-reperfusion (I/R) injury represents a significant clinical challenge with limited therapeutic options. Single-cell RNA sequencing and bioinformatics analyses have revealed complex cellular interactions within cardiac tissue, highlighting the crucial role of cardiomyocytes in intercellular communication. During I/R injury, cardiomyocytes experience severe endoplasmic reticulum (ER) stress, leading to detrimental intercellular communication that affects surrounding cells, particularly promoting the transformation of macrophages toward a pro-inflammatory phenotype. This amplifies the inflammatory cascade and exacerbates tissue damage. Targeting injured cardiomyocytes and inhibiting their ER stress presents a promising therapeutic strategy to restore beneficial intercellular communication and maintain myocardial homeostasis, thereby reducing I/R injury. However, the lack of an effective ER stress inhibitor specifically targeting damaged cardiomyocytes constitutes a major barrier to translating mechanistic understanding into therapeutic implementation. Peptide amphiphiles (PA), with their unique amphiphilicity and bioactive functions, constitute ideal candidates for targeted drug delivery. In this study, we developed a cascade-responsive drug delivery system, CT-PA@Sal, which selectively targets damaged cardiomyocytes and controls the release of the ER stress inhibitor Salubrinal. CT-PA@Sal demonstrates superior targeting efficiency and enhanced drug bioavailability, enabling responsive release within injured cardiomyocytes. In vitro and in vivo experiments further show that CT-PA@Sal improves cardiomyocyte-macrophage communication, reduces cardiomyocyte apoptosis, and promotes anti-inflammatory M2 macrophage polarization. These effects preserve cardiac function and enhance tissue recovery following I/R injury. We envision that this investigation offers a prospective framework for developing targeted drugs to treat myocardial I/R injury.

Role of Nanotechnology in Ischemic Stroke: Advancements in Targeted Therapies and Diagnostics for Enhanced Clinical Outcomes

Each year, the number of cases of strokes and deaths due to this is increasing around the world. This could be due to work stress, lifestyles, unhealthy food habits, and several other reasons. Currently, there are several traditional methods like thrombolysis and mechanical thrombectomy for managing strokes. The current approach has several limitations, like delayed diagnosis, limited therapeutic delivery, and risks of secondary injuries. So, there is a need for some effective and reliable methods for the management of strokes, which could help in early diagnosis followed by the treatment of strokes. Nanotechnology has played an immense role in managing strokes, and recently, it has emerged as a transformative solution offering innovative diagnostic tools and therapeutic strategies. Nanoparticles (NPs) belonging to several classes, including metallic (metallic and metal oxide), organic (lipids, liposome), and carbon, can cross the blood-brain barrier and may exhibit immense potential for managing various strokes. Moreover, these NPs have exhibited promise in improving imaging specificity and therapeutic delivery by precise drug delivery and real-time monitoring of treatment efficacy. Nanomaterials like cerium oxide (CeO2) and liposome-encapsulated agents have neuroprotective properties that reduce oxidative stress and promote neuroregeneration. In the present article, the authors have emphasized the significant advancements in the nanomedicine management of stroke, including NPs-based drug delivery systems, neuroprotective and neuroregenerative therapies, and multimodal imaging advancements.

Revolutionizing Stroke Care: Nanotechnology-Based Brain Delivery as a Novel Paradigm for Treatment and Diagnosis

Stroke, a severe medical condition arising from abnormalities in the coagulation-fibrinolysis cycle and metabolic processes, results in brain cell impairment and injury due to blood flow obstruction within the brain. Prompt and efficient therapeutic approaches are imperative to control and preserve brain functions. Conventional stroke medications, including fibrinolytic agents, play a crucial role in facilitating reperfusion to the ischemic brain. However, their clinical efficacy is hampered by short plasma half-lives, limited brain tissue distribution attributed to the blood-brain barrier (BBB), and lack of targeted drug delivery to the ischemic region. To address these challenges, diverse nanomedicine strategies, such as vesicular systems, polymeric nanoparticles, dendrimers, exosomes, inorganic nanoparticles, and biomimetic nanoparticles, have emerged. These platforms enhance drug pharmacokinetics by facilitating targeted drug accumulation at the ischemic site. By leveraging nanocarriers, engineered drug delivery systems hold the potential to overcome challenges associated with conventional stroke medications. This comprehensive review explores the pathophysiological mechanism underlying stroke and BBB disruption in stroke. Additionally, this review investigates the utilization of nanocarriers for current therapeutic and diagnostic interventions in stroke management. By addressing these aspects, the review aims to provide insight into potential strategies for improving stroke treatment and diagnosis through a nanomedicine approach.

Advances of Stimuli-Responsive Amphiphilic Copolymer Micelles in Tumor Therapy

Amphiphilic copolymers are composed of both hydrophilic and hydrophobic chains, which can self-assemble into polymeric micelles in aqueous solution via the hydrophilic/hydrophobic interactions. Due to their unique properties, polymeric micelles have been widely used as drug carriers. Poorly soluble drugs can be covalently attached to polymer chains or non-covalently incorporated in the micelles, with improved pharmacokinetic profiles and enhanced efficacy. In recent years, stimuli-responsive amphiphilic copolymer micelles have attracted significant attention. These micelles can respond to specific stimuli, including physical triggers (light, temperature, etc). chemical stimuli (pH, redox, etc). and physiological factors (enzymes, ATP, etc). Under these stimuli, the structures or properties of the micelles can change, enabling targeted therapy and controlled drug release in tumors. These stimuli-responsive strategies offer new avenues and approaches to enhance the tumor efficacy and reduce drug side effects. We will review the applications of different types of stimuli-responsive amphiphilic copolymer micelles in tumor therapy, aiming to provide valuable guidance for future research directions and clinical translation.

A multiple targeting rapamycin and SS31 conjugate enhances ischemic stroke therapy

BACKGROUND

The identification of drugs targeting multiple pathways is essential for comprehensive protection against cerebral ischemia-reperfusion injury.

RESEARCH DESIGN AND METHODS

This study aimed to develop RS31, a multi-target cytoprotectant composed of SS31 (an oxidative stress mitigator) and rapamycin (Rapa), contributes anti-inflammatory and blood-brain barrier protection. RS31 was synthesized using click chemistry, and its ability to scavenge reactive oxygen species (ROS) and reduce inflammation was tested in H2O2-injured PC12 cells and LPS-stimulated BV2 cells. A C57BL/6 mouse model of transient middle cerebral artery occlusion/reperfusion (tMCAO/R) was established to assess the effect of RS31 on inflammatory factors in ischemic brain tissue. Finally, the potential of combining RS31 with PLGA microparticles (MPs) to further reduce brain edema was investigated.

RESULTS

RS31 effectively scavenged ROS and reduced inflammation. It showed a ~ 4-fold higher concentration in cerebral ischemic regions, significant reducing infarction and improving neurological function. RS31 also effectively reduced inflammatory factors, lowered malondialdehyde (MDA) levels, and increased superoxide dismutase (SOD) activity, showing strong efficacy in treating ischemic stroke.

CONCLUSIONS

In vivo delivery of RS31 is an effective therapeutic strategy for I/R injury, providing a general framework for developing multi-targeted drugs against inflammatory diseases and excessive ROS production.

The role of nanomaterials in revolutionizing ischemic stroke treatment: Current trends and future prospects

Ischemic stroke has a high disability rate, which leads to irreversible neuronal death. The efficacy of conventional stroke treatments, including thrombolytic and neuroprotective therapies, is constrained by a number of factors, including safety concerns and inefficient drug delivery. The advent of nanomaterials has created new avenues for stroke therapy, facilitating enhanced pharmacokinetic behavior of drugs, effective drug accumulation at the target site, augmented therapeutic efficacy, and concomitant reduction in side effects. Therefore, this paper pioneers a research approach that summarized the development trend and clinical value of nanomaterials in the field of ischemic stroke through bibliometric analysis. This review provides an overview of the pathophysiological mechanisms of stroke and examines the current research trends in the use of nanomaterials in stroke management. It encompasses a multitude of domains, including targeted drug delivery systems, biosensors for the sensitive detection of biomarkers, and neuroprotective nanotechnologies capable of traversing the blood-brain barrier. Moreover, we investigate the challenges that nanomaterials encounter in the clinical translation context, including those pertaining to biocompatibility and long-term safety. These results have provided the clinical value and limitations of nanomaterials in the diagnosis and treatment of ischemic stroke from double perspectives, thereby offering new avenues for the further development of innovative nanotherapeutic tools.

Nano revolutions in ischemic stroke: A critical analysis of current options and the potential of nanomedicines in diagnosis and therapeutics

A stroke, also known as cerebrovascular accident, is a medical emergency that occurs when the blood supply to the brain is interrupted. This disruption can happen in two main ways: through a hemorrhagic stroke, where a blood vessel in the brain bursts, or through an ischemic stroke, where a blood clot blocks an artery. Both types of stroke cause damage to brain cells, leading to a range of health complications. Globally, stroke ranks as the second leading cause of death and disability.This review provides an overview of stroke, focusing on its early detection, current treatment options, and emerging therapies. We discuss the complex mechanisms that contribute to stroke development, including the roles of cells, biomolecules, and blood vessels. Additionally, the review explores recent advances in the use of nanoparticles to enhance the efficacy of the pharmacotherapy of stroke, particularly ischemic stroke. Ongoing clinical trials in stroke management are also highlighted. Timely diagnosis and prompt intervention are critical for improving patient outcomes.We aim to increase awareness and understanding of stroke among researchers and healthcare professionals, ultimately improving patient care.

Emerging near-infrared targeting diagnostic and therapeutic strategies for ischemic cardiovascular and cerebrovascular diseases

Ischemic cardiovascular and cerebrovascular diseases (ICCDs), including thrombosis, ischemic stroke and atherosclerosis, represent a significant threat to human health, and there is an urgent requirement for the implementation of emerging diagnostic and therapeutic approaches to improve symptoms and prognosis. As a promising noninvasive modality offering high spatial and temporal resolution with favorable biocompatible properties, near-infrared (NIR) light has demonstrated a vast and profound potential in the biomedical field in recent years. Meanwhile, nanomedicine carriers are undergoing rapid development due to their high specific surface area, elevated drug loading capacity, and unique physicochemical properties. The combination of NIR light with targeted nanoprobes modified with different functional components not only maintains the high penetration depth of NIR irradiation in biological tissues but also significantly enhances the targeting specificity at the lesion site. This strategy allows for the realization of on-demand drug release and photothermal effects, thus inspiring promising avenues for the diagnosis and treatment of ICCDs. However, the clinical translation of NIR imaging and therapy is still hindered by significant obstacles. The existing literature has provided a comprehensive overview of the advancements in NIR-based nanomedicine research. However, there is a notable absence of reviews that summarize the NIR-mediated targeting strategies against ICCDs in imaging and therapy. Therefore, this review concludes the application of the emerging targeting probes combined with NIR radiation for ICCDs classified by molecular targets, analyzes the current challenges, and provides improvement strategies and prospects for further clinical translation. STATEMENT OF SIGNIFICANCE: Ischemic cardiovascular and cerebrovascular diseases (ICCDs) represent a significant threat to human health. Recently, near-infrared (NIR) light combined with targeting probes have been employed for the diagnosis and treatment of ICCDs, offering exceptional advantages including rapid feedback, high penetration depth, on-demand drug release, and favorable biocompatibility. However, there is a notable absence of reviews that summarize the NIR light-mediated targeting strategies for the imaging and therapy of ICCDs. Therefore, this review summarizes the emerging targeting probes combined with NIR light classified by molecular targets, and the proposes potential improvement strategies for clinical translation. This review elucidates the potential and current status of NIR-based techniques in ICCDs, while also serving as a reference point for additional targeted therapeutic strategies for ICCDs.

Blood-Brain Barrier-Penetrating Metal-Organic Framework Antioxidant Nanozymes for Targeted Ischemic Stroke Therapy

Overproduction of reactive oxygen species (ROS) during reperfusion in ischemic stroke (IS) severely impedes neuronal survival and results in high rates of morbidity and disability. The effective blood-brain barrier (BBB) penetration and brain delivery of antioxidative agents remain the biggest challenge in treating ischemic reperfusion-induced cerebrovascular and neural injury. In this study, a metal-organic framework (MOF) nanozyme (MIL-101-NH2(Fe/Cu)) with ROS scavenging activities to encapsulate neuroprotective agent rapamycin is fabricated and decorating the exterior with BBB-targeting protein ligands (transferrin), thereby realizing enhanced drug retention and controlled release within ischemic lesions for the synergistic treatment of IS. Through the receptor-mediated transcellular pathway, the transferrin-coated MOF nanoparticles achieved efficient transport across the BBB and targeted accumulation at the cerebral ischemic injury site of mice with middle cerebral artery occlusion/reperfusion (MCAO/R), wherein the nanocarrier exhibited catalytic activities of ROS decomposition into O2 and H2O2-responsive rapamycin release. By its BBB-targeting, antioxidative, anti-inflammatory, and antiapoptotic properties, the MOF nanosystem addressed multiple pathological factors of IS and realized remarkable neuroprotective effects, leading to the substantial reduction of cerebral infarction volume and accelerated recovery of nerve functions in the MCAO/R mouse model. This MOF-based nanomedicine provides valuable design principles for effective IS therapy with multi-mechanism synergies.

In Situ Gelation Strategy for Efficient Drug Delivery in a Gastrointestinal System

Developing a microenvironment-responsive drug delivery system (DDS) for the gastrointestinal system is of great interest to enhance drug efficiency and minimize side effects. Unfortunately, the rapid-flowing digestive juice in the gastrointestinal tract and the continuous contraction and peristalsis of the gastrointestinal tract muscle accelerate the elimination of drug carriers. In this study, a boric hydroxyl-modified mesoporous Mg(OH)2 drug carrier is prepared to prolong the drug retention time. Results show that the newly designed DDS presents high biocompatibility and can immediately turn the free polyhydric alcohol molecules into a gelation form. The in situ-formed gelation network presents high viscosity and can prevent the drug carriers from being washed away by the digestive juice in the gastrointestinal tract.

Stimuli-responsive linkers and their application in molecular imaging

Molecular imaging is a non-invasive imaging method that is widely used for visualization and detection of biological events at cellular or molecular levels. Stimuli-responsive linkers that can be selectively cleaved by specific biomarkers at desired sites to release or activate imaging agents are appealing tools to improve the specificity, sensitivity, and efficacy of molecular imaging. This review summarizes the recent advances of stimuli-responsive linkers and their application in molecular imaging, highlighting the potential of these linkers in the design of activatable molecular imaging probes. It is hoped that this review could inspire more research interests in the development of responsive linkers and associated imaging applications.

Biomedical applications of stimuli-responsive nanomaterials

Nanomaterials have aroused great interests in drug delivery due to their nanoscale structure, facile modifiability, and multifunctional physicochemical properties. Currently, stimuli-responsive nanomaterials that can respond to endogenous or exogenous stimulus display strong potentials in biomedical applications. In comparison with conventional nanomaterials, stimuli-responsive nanomaterials can improve therapeutic efficiency and reduce the toxicity of drugs toward normal tissues through specific targeting and on-demand drug release at pathological sites. In this review, we summarize the responsive mechanism of a variety of stimulus, including pH, redox, and enzymes within pathological microenvironment, as well as exogenous stimulus such as thermal effect, magnetic field, light, and ultrasound. After that, biomedical applications (e.g., drug delivery, imaging, and theranostics) of stimuli-responsive nanomaterials in a diverse array of common diseases, including cardiovascular diseases, cancer, neurological disorders, inflammation, and bacterial infection, are presented and discussed. Finally, the remaining challenges and outlooks of future research directions for the biomedical applications of stimuli-responsive nanomaterials are also discussed. We hope that this review can provide valuable guidance for developing stimuli-responsive nanomaterials and accelerate their biomedical applications in diseases diagnosis and treatment.

REVIEW: "ISCHEMIC STROKE: From Fibrinolysis to Functional Recovery" Nanomedicine: emerging approaches to treat ischemic stroke

Stroke is responsible for 11% of all deaths worldwide, the majority of which are caused by ischemic strokes, thus making the need to urgently find safe and effective therapies. Today, these can be cured either by mechanical thrombectomy when the thrombus is accessible, or by intravenous injection of fibrinolytics. However, the latter present several limitations, such as potential severe side effects, few eligible patients and low rate of partial and full recovery. To design safer and more effective treatments, nanomedicine appeared in this medical field a few decades ago. This review will explain why nanoparticle-based therapies and imaging techniques are relevant for ischemic stroke management. Then, it will present the different nanoparticle types that have been recently developed to treat this pathology. It will also study the various targeting strategies used to bring nanoparticles to the stroke site, thereby limiting side effects and improving the therapeutic efficacy. Finally, this review will present the few clinical studies testing nanomedicine on stroke and discuss potential causes for their scarcity.

Advanced Nano-Drug Delivery Systems in the Treatment of Ischemic Stroke

In recent years, the frequency of strokes has been on the rise year by year and has become the second leading cause of death around the world, which is characterized by a high mortality rate, high recurrence rate, and high disability rate. Ischemic strokes account for a large percentage of strokes. A reperfusion injury in ischemic strokes is a complex cascade of oxidative stress, neuroinflammation, immune infiltration, and mitochondrial damage. Conventional treatments are ineffective, and the presence of the blood-brain barrier (BBB) leads to inefficient drug delivery utilization, so researchers are turning their attention to nano-drug delivery systems. Functionalized nano-drug delivery systems have been widely studied and applied to the study of cerebral ischemic diseases due to their favorable biocompatibility, high efficiency, strong specificity, and specific targeting ability. In this paper, we briefly describe the pathological process of reperfusion injuries in strokes and focus on the therapeutic research progress of nano-drug delivery systems in ischemic strokes, aiming to provide certain references to understand the progress of research on nano-drug delivery systems (NDDSs).

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

An Ultrasmall Cu/Cu2O Nanoparticle-Based Diselenide-Bridged Nanoplatform Mediating Reactive Oxygen Species Scavenging and Neuronal Membrane Enhancement for Targeted Therapy of Ischemic Stroke

Ischemic stroke is one of the major causes of death and disability worldwide, and an effective and timely treatment of ischemic stroke has been a challenge because of the narrow therapeutic window and the poor affinity with thrombus of the thrombolytic agent. In this study, rPZDCu, a multifunctional nanoparticle (NP) with the effects of thrombolysis, reactive oxygen species (ROS) scavenging, and neuroprotection, was synthesized based on an ultrasmall Cu4.6O NP, the thrombolytic agent rt-PA, and docosahexaenoic acid (DHA), which is a major component of the neuronal membrane. rPZDCu showed strong thrombus-targeting ability, which was achieved by the platelet cell membrane coating on the NP surface, and a good thrombolytic effect in both the common carotid artery clot model and embolic middle cerebral artery occlusion (MCAO) model of rats. Furthermore, rPZDCu exhibited a good escape from the phagocytosis of macrophages, effective promotion of the polarization of microglia, and efficient recovery of neurobiological and behavioral functions in the embolic MCAO model of rats. This is a heuristic report of (1) the Cu0/Cu+ NP for the treatments of brain diseases, (2) the integration of DHA and ROS scavengers for central nervous system therapies, and (3) diselenide-based ROS-responsive NPs for ischemic stroke treatments. This study also offers an example of cell membrane-camouflaged stimuli-responsive nanomedicine for brain-targeting drug delivery.

Application of stimuli-responsive nanomedicines for the treatment of ischemic stroke

Ischemic stroke (IS) refers to local brain tissue necrosis which is caused by impaired blood supply to the carotid artery or vertebrobasilar artery system. As the second leading cause of death in the world, IS has a high incidence and brings a heavy economic burden to all countries and regions because of its high disability rate. In order to effectively treat IS, a large number of drugs have been designed and developed. However, most drugs with good therapeutic effects confirmed in preclinical experiments have not been successfully applied to clinical treatment due to the low accumulation efficiency of drugs in IS areas after systematic administration. As an emerging strategy for the treatment of IS, stimuli-responsive nanomedicines have made great progress by precisely delivering drugs to the local site of IS. By response to the specific signals, stimuli-responsive nanomedicines change their particle size, shape, surface charge or structural integrity, which enables the enhanced drug delivery and controlled drug release within the IS tissue. This breakthrough approach not only enhances therapeutic efficiency but also mitigates the side effects commonly associated with thrombolytic and neuroprotective drugs. This review aims to comprehensively summarize the recent progress of stimuli-responsive nanomedicines for the treatment of IS. Furthermore, prospect is provided to look forward for the better development of this field.

Nanomaterial-Based Drug Delivery Systems for Ischemic Stroke

Ischemic stroke is a leading cause of death and disability in the world. At present, reperfusion therapy and neuroprotective therapy, as guidelines for identifying effective and adjuvant treatment methods, are limited by treatment time windows, drug bioavailability, and side effects. Nanomaterial-based drug delivery systems have the characteristics of extending half-life, increasing bioavailability, targeting drug delivery, controllable drug release, and low toxicity, thus being used in the treatment of ischemic stroke to increase the therapeutic effects of drugs. Therefore, this review provides a comprehensive overview of nanomaterial-based drug delivery systems from nanocarriers, targeting ligands and stimulus factors of drug release, aiming to find the best combination of nanomaterial-based drug delivery systems for ischemic stroke. Finally, future research areas on nanomaterial-based drug delivery systems in ischemic stroke and the implications of the current knowledge for the development of novel treatment for ischemic stroke were identified.

Synergetic Photodynamic-Photothermal-Chemotherapy Dual Targeting Nanoplatform Effective Against Breast Cancer in-Mice Model

Introduction

Combined multimodal therapy for breast cancer is a promising therapeutic approach to increase treatment efficacy and reduce systemic toxicity. The present study aimed to develop a novel multifunctional drug release nanoplatform based on RGD-conjugated hyaluronic acid (HA)-functionalized copper sulfide (CuS) for activatable dual-targeted synergetic therapy against cancer.

Methods

The pH and NIR-responsive dual-targeting nanoplatform CuS:Ce6@HA:DOX@RGD was prepared, characterized, and evaluated for its stability and photodynamic and photothermal properties. The loading and release of the drug were measured at different pH values with or without laser radiation using the dialysis method. The cellular uptake of the platform specifically by the tumor cells treated with different formulations was investigated through fluorescence imaging. The in vitro and in vivo biosafety levels were assessed systematically. Finally, the antitumor efficiencies against breast cancer were assessed via in vitro and in vivo experiments.

Results

The spheroid CuS:Ce6@HA:DOX@RGD exhibited remarkable stability and monodispersity in solution. The photosensitive CuS and Ce6 could simultaneously absorb the near-infrared light efficiently to convert NIR light to fatal heat and to generate reactive oxygen species. The CuS:Ce6@HA:DOX@RGD dissociated under an acid environment, causing the release of DOX into the tumor to accelerate upon laser irradiation. The CuS:Ce6@HA:DOX@RGD exhibited target-specific and strong binding ability via a synergic CD44/αvβ3 receptor-mediated bimodal targeting, which led to improved therapeutic efficacy. The tumor growth was effectively inhibited using synergetic photodynamic/photothermal/chemo therapy. No evident systemic toxicity was noted during treatment.

Conclusion

The newly prepared CuS:Ce6@HA:DOX@RGD has great potential as an activatable theranostic nanoplatform for efficient dual-targeted synergistic therapy against breast cancer.

Copolymer Micelles: A Focus on Recent Advances for Stimulus-Responsive Delivery of Proteins and Peptides

Historically used for the delivery of hydrophobic drugs through core encapsulation, amphiphilic copolymer micelles have also more recently appeared as potent nano-systems to deliver protein and peptide therapeutics. In addition to ease and reproducibility of preparation, micelles are chemically versatile as hydrophobic/hydrophilic segments can be tuned to afford protein immobilization through different approaches, including non-covalent interactions (e.g., electrostatic, hydrophobic) and covalent conjugation, while generally maintaining protein biological activity. Similar to many other drugs, protein/peptide delivery is increasingly focused on stimuli-responsive nano-systems able to afford triggered and controlled release in time and space, thereby improving therapeutic efficacy and limiting side effects. This short review discusses advances in the design of such micelles over the past decade, with an emphasis on stimuli-responsive properties for optimized protein/peptide delivery.

Near-Infrared Afterglow ONOO--Triggered Nanoparticles for Real-Time Monitoring and Treatment of Early Ischemic Stroke

Early detection and drug intervention with the appropriate timing and dosage are the main clinical challenges for ischemic stroke (IS) treatment. The conventional therapeutic agents relay fluorescent signals, which require real-time external light excitation, thereby leading to inevitable autofluorescence and poor tissue penetration. Herein, we report endogenous peroxynitrite (ONOO-)-activated BDP-4/Cur-CL NPs that release NIR afterglow signals (λmax 697 nm) for real-time monitoring of the progression of ischemia reperfusion (I/R) brain injury while releasing curcumin for the safe treatment of IS. The BDP-4/Cur-CL NPs exhibited bright NIR afterglow luminescence (maximum 732-fold increase), superb sensitivity (LOD = 82.67 nM), high energy-transfer efficiency (94.6%), deep tissue penetration (20 mm), outstanding antiapoptosis, and anti-inflammatory effects. The activated NIR afterglow signal obtained in mice with middle cerebral artery occlusion (MCAO) showed three functions: (i) the BDP-4/Cur-CL NPs are rapidly activated by endogenous ONOO-, instantly illuminating the lesion area, distinguishing I/R damage from normal areas, which can be successfully used for endogenous ONOO- detection in the early stage of IS; (ii) real-time reporting of in situ generation and dynamic fluctuations of endogenous ONOO- levels in the lesion area, which is of great value in monitoring the evolutionary mechanisms of IS; and (iii) dynamic monitoring of the release of curcumin drug for safe treatment. Indeed, the released curcumin effectively decreased apoptosis, enhanced survival, alleviated neuroinflammation, reduced brain tissue loss, and improved the cognition of MCAO stroke mice. This work is the first example of afterglow luminescence for early diagnosis, real-time reporting, drug tracing, and treatment for IS.

Hydrogen-Bonded Organic Frameworks Chelated Manganese for Precise Magnetic Resonance Imaging Diagnosis of Cancers

Magnetic resonance imaging (MRI) is an important tool in the diagnosis of many cancers. However, clinical gadolinium (Gd)-based MRI contrast agents have limitations, such as large doses and potential side effects. To address these issues, we developed a hydrogen-bonded organic framework-based MRI contrast agent (PFC-73-Mn). Due to the hydrogen-bonded interaction of water molecules and the restricted rotation of manganese ions, PFC-73-Mn exhibits high longitudinal relaxation r1 (5.03 mM-1 s-1) under a 3.0 T clinical MRI scanner. A smaller intravenous dose (8 μmol of Mn/kg) of PFC-73-Mn can provide strong contrast and accurate diagnosis in multiple kinds of cancers, including breast tumor and ultrasmall orthotopic glioma. PFC-73-Mn represents a prospective new approach in tumor imaging, especially in early-stage cancer.

Structural and functional imaging of brains

Analyzing the complex structures and functions of brain is the key issue to understanding the physiological and pathological processes. Although neuronal morphology and local distribution of neurons/blood vessels in the brain have been known, the subcellular structures of cells remain challenging, especially in the live brain. In addition, the complicated brain functions involve numerous functional molecules, but the concentrations, distributions and interactions of these molecules in the brain are still poorly understood. In this review, frontier techniques available for multiscale structure imaging from organelles to the whole brain are first overviewed, including magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), serial-section electron microscopy (ssEM), light microscopy (LM) and synchrotron-based X-ray microscopy (XRM). Specially, XRM for three-dimensional (3D) imaging of large-scale brain tissue with high resolution and fast imaging speed is highlighted. Additionally, the development of elegant methods for acquisition of brain functions from electrical/chemical signals in the brain is outlined. In particular, the new electrophysiology technologies for neural recordings at the single-neuron level and in the brain are also summarized. We also focus on the construction of electrochemical probes based on dual-recognition strategy and surface/interface chemistry for determination of chemical species in the brain with high selectivity and long-term stability, as well as electrochemophysiological microarray for simultaneously recording of electrochemical and electrophysiological signals in the brain. Moreover, the recent development of brain MRI probes with high contrast-to-noise ratio (CNR) and sensitivity based on hyperpolarized techniques and multi-nuclear chemistry is introduced. Furthermore, multiple optical probes and instruments, especially the optophysiological Raman probes and fiber Raman photometry, for imaging and biosensing in live brain are emphasized. Finally, a brief perspective on existing challenges and further research development is provided.

Multifunctional nanomedicine strategies to manage brain diseases

Brain diseases represent a substantial social and economic burden, currently affecting one in six individuals worldwide. Brain research has been focus of great attention in order to unravel the pathogenesis and complexity of brain diseases at the cellular, molecular, and microenvironmental levels. Due to the intrinsic nature of the brain, the presence of the highly restrictive blood-brain barrier (BBB), and the pathophysiology of most diseases, therapies can hardly be considered successful purely by the administration of one drug to a patient. Apart from improving pharmacokinetic parameters, tailoring biodistribution, and reducing the number of side effects, nanomedicines are able to actively co-target the therapeutics to the brain parenchyma and brain lesions, as well as to achieve the delivery of multiple cargos with therapeutic, diagnostic, and theranostic properties. Among other multivalent effects that can be personalized according to the disease needs, this represents a promising class of novel nanosystems, termed multifunctional nanomedicines. Herein, we review the principal mechanisms of therapeutic resistance of the most prevalent brain diseases, how to overcome this therapeutic resistance through the use of multifunctional nanomedicines that tackle multiple fronts of the disease microenvironment, and the promising therapeutic responses achieved by some of the most cutting-edge multifunctional nanomedicines reported in literature.

Recent Advances in Targeted Nanotherapies for Ischemic Stroke

Ischemic stroke (IS) is a severe neurological disease caused by the narrowing or occlusion of cerebral blood vessels and is known for high morbidity, disability, and mortality rates. Clinically available treatments of stroke include the surgical removal of the thrombus and thrombolysis with tissue fibrinogen activator. Pharmaceuticals targeting IS are uncommon, and the development of new therapies is hindered by the low bioavailability and stability of many drugs. Nanomedicine provides new opportunities for the development of novel neuroprotective and thrombolytic strategies for the diagnosis and treatment of IS. Numerous nanotherapeutics with different physicochemical properties are currently being developed to facilitate drug delivery by accumulation and controlled release and to improve their restorative properties. In this review, we discuss recent developments in IS therapy, including assisted drug delivery and targeting, neuroprotection through regulation of the neuron environment, and sources of endogenous biomimetic specific targeting. In addition, we discuss the role and neurotoxic effects of inorganic metal nanoparticles in IS therapy. This study provides a theoretical basis for the utilization of nano-IS therapies that may contribute to the development of new strategies for a range of embolic diseases.

A noise-immune reinforcement learning method for early diagnosis of neuropsychiatric systemic lupus erythematosus

The neuropsychiatric systemic lupus erythematosus (NPSLE), a severe disease that can damage the heart, liver, kidney, and other vital organs, often involves the central nervous system and even leads to death. Magnetic resonance spectroscopy (MRS) is a brain functional imaging technology that can detect the concentration of metabolites in organs and tissues non-invasively. However, the performance of early diagnosis of NPSLE through conventional MRS analysis is still unsatisfactory. In this paper, we propose a novel method based on genetic algorithm (GA) and multi-agent reinforcement learning (MARL) to improve the performance of the NPSLE diagnosis model. Firstly, the proton magnetic resonance spectroscopy (1H-MRS) data from 23 NPSLE patients and 16 age-matched healthy controls (HC) were standardized before training. Secondly, we adopt MARL by assigning an agent to each feature to select the optimal feature subset. Thirdly, the parameter of SVM is optimized by GA. Our experiment shows that the SVM classifier optimized by feature selection and parameter optimization achieves 94.9% accuracy, 91.3% sensitivity, 100% specificity and 0.87 cross-validation score, which is the best score compared with other state-of-the-art machine learning algorithms. Furthermore, our method is even better than other dimension reduction ones, such as SVM based on principal component analysis (PCA) and variational autoencoder (VAE). By analyzing the metabolites obtained by MRS, we believe that this method can provide a reliable classification result for doctors and can be effectively used for the early diagnosis of this disease.

Advances in the research of nano delivery systems in ischemic stroke

Ischemic stroke is the most common type of cerebrovascular disease with high disability rate and mortality. The blood-brain barrier (BBB) protects the homeostasis of the brain's microenvironment and impedes the penetration of 98% of drugs. Therefore, effective treatment requires the better drug transport across membranes and increased drug distribution. Nanoparticles are a good choice for drugs to cross BBB. The main pathways of nano delivery systems through BBB include passive diffusion, adsorption-mediated endocytosis, receptor-mediated transport, carrier-mediated transport, etc. At present, the materials used in brain-targeted delivery can be divided into natural polymer, synthetic polymers, inorganic materials and phospholipid. In this review, we first introduced several ways of nano delivery systems crossing the BBB, and then summarized their applications in ischemic stroke. Based on their potential and challenges in the treatment of ischemic stroke, new ideas and prospects are proposed for designing feasible and effective nano delivery systems.