Magnet-activatable nanoliposomes as intracellular bubble microreactors to enhance drug delivery efficacy and burst cancer cells

Hydrogen Sulfide in Musculoskeletal Diseases: Molecular Mechanisms and Therapeutic Opportunities

Significance: Musculoskeletal diseases seriously affect global health, but their importance is greatly underestimated. These diseases often afflict the elderly, leading to disability, paralysis, and other complications. Hydrogen sulfide (H2S) plays an important role in the occurrence and development of musculoskeletal diseases, which may have potential therapeutic significance for these diseases. Recent Advances: Recently, it has been found that many musculoskeletal diseases, such as osteoporosis, periodontitis, muscle atrophy, muscle ischemia-reperfusion injury, muscle contraction under high fever, arthritis, and disc herniation, can be alleviated by treatment with H2S. H2S may be conducive to the development of multiple myeloma. The mechanism of action of H2S in the musculoskeletal system has been partly elucidated. A variety of H2S donors and nano-delivery systems provide promising prospects for H2S-based therapies. Critical Issues: Related research remains at the level of cell or animal experiments, but clinical research is lacking. The roles of H2S in more musculoskeletal disorders remain largely unknown. The serious consequences of musculoskeletal diseases have not been widely concerned. Targeted delivery of H2S remains a challenging task in musculoskeletal diseases. Future Directions: Develop therapeutic drugs for musculoskeletal diseases based on H2S and test their safety, efficacy, and tolerance. Explore the combination of current drugs for musculoskeletal diseases with H2S-releasing components to improve the therapeutic efficacy and avoid side effects. Carry out relevant clinical trials to verify the possibility of its widespread use. Antioxid. Redox Signal. 42, 321-340.

Role of hydrogen sulfide in health and disease

In the past, hydrogen sulfide (H2S) was recognized as a toxic and dangerous gas; in recent years, with increased research, we have discovered that H2S can act as an endogenous regulatory transmitter. In mammals, H2S-catalyzing enzymes, such as cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, are differentially expressed in a variety of tissues and affect a variety of biological functions, such as transcriptional and posttranslational modification of genes, activation of signaling pathways in the cell, and metabolic processes in tissues, by producing H2S. Various preclinical studies have shown that H2S affects physiological and pathological processes in the body. However, a detailed systematic summary of these roles in health and disease is lacking. Therefore, this review provides a thorough overview of the physiological roles of H2S in different systems and the diseases associated with disorders of H2S metabolism, such as ischemia-reperfusion injury, hypertension, neurodegenerative diseases, inflammatory bowel disease, and cancer. Meanwhile, this paper also introduces H2S donors and novel release modes, as well as the latest preclinical experimental results, aiming to provide researchers with new ideas to discover new diagnostic targets and therapeutic options.

Advances in Cyclodextrins and Their Derivatives in Nano-Delivery Systems

The diversity of cyclodextrins and their derivatives is increasing with continuous research. In addition to monomolecular cyclodextrins with different branched chains, cyclodextrin-based polymers have emerged. The aim of this review is to summarize these innovations, with a special focus on the study of applications of cyclodextrins and their derivatives in nano-delivery systems. The areas covered include nanospheres, nano-sponges, nanogels, cyclodextrin metal-organic frameworks, liposomes, and emulsions, providing a comprehensive and in-depth understanding of the design and development of nano-delivery systems.

Magnetic nanomaterials mediate precise magnetic therapy

Magnetic nanoparticle (MNP)-mediated precision magnet therapy plays a crucial role in treating various diseases. This therapeutic strategy compensates for the limitations of low spatial resolution and low focusing of magnetic stimulation, and realizes the goal of wireless teletherapy with precise targeting of focal areas. This paper summarizes the preparation methods of magnetic nanomaterials, the properties of magnetic nanoparticles, the biological effects, and the measurement methods for detecting magnetism; discusses the research progress of precision magnetotherapy in the treatment of psychiatric disorders, neurological injuries, metabolic disorders, and bone-related disorders, and looks forward to the future development trend of precision magnet therapy.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

Static Magnetic Field Reduces the Anticancer Effect of Hinokitiol on Melanoma Malignant Cells-Gene Expression and Redox Homeostasis Studies

BACKGROUND

Melanoma malignant is characterized by a high mortality rate, accounting for as much as 65% of deaths caused by skin cancer. A potential strategy in cancer treatment may be the use of natural compounds, which include hinokitiol (β-Thujaplicin), a phenolic component of essential oils extracted from cypress trees. Many studies confirm that a high-induction SMF (static magnetic field) has anticancer effects and can be used as a non-invasive anticancer therapy in combination with or without drugs.

AIM

The aim of this experiment was to evaluate the effect of a static magnetic field on melanoma cell cultures (C32 and COLO 829) treated with hinokitiol.

METHODS AND RESULTS

Melanoma cells were exposed to a static magnetic field of moderate induction and hinokitiol. The research included determining the activity of the antioxidant enzymes (SOD, GPx, and CAT) and MDA concentration as well as the gene expression profile.

CONCLUSION

Hinokitiol disturbs the redox homeostasis of C32 and COLO 829 melanoma malignant cells. Moreover, a static magnetic field has a protective effect on melanoma malignant cells and abolishes the anticancer effect of hinokitiol.

The Story of Ferumoxytol: Synthesis Production, Current Clinical Applications, and Therapeutic Potential

Ferumoxytol, approved by the U.S. Food and Drug Administration in 2009, is one of the intravenous iron oxide nanoparticles authorized for the treatment of iron deficiency in chronic kidney disease and end-stage renal disease. With its exceptional magnetic properties, catalytic activity, and immune activity, as well as good biocompatibility and safety, ferumoxytol has gained significant recognition in various biomedical diagnoses and treatments. Unlike most existing reviews on this topic, this review primarily focuses on the recent clinical and preclinical advances of ferumoxytol in disease treatment, spanning anemia, cancer, infectious inflammatory diseases, regenerative medicine application, magnetic stimulation for neural modulation, etc. Additionally, the newly discovered mechanisms associated with the biological effects of ferumoxytol are discussed, including its magnetic, catalytic, and immunomodulatory properties. Finally, the summary and future prospects concerning the treatment and application of ferumoxytol-based nanotherapeutics are presented.

Magnetic Delivery of Antigen-Loaded Magnetic Liposomes for Active Lymph Node Targeting and Enhanced Anti-Tumor Immunity

Therapeutic cancer vaccines offer the greatest advantage of enhancing antigen-specific immunity against tumors, particularly for immunogenic tumors, such as melanoma. However, clinical responses remain unsatisfactory, primarily due to inadequate T cell priming and the development of acquired immune tolerance. A major obstacle lies in the inefficient uptake of antigen by peripheral dendritic cells (DCs) and their migration to lymph nodes for antigen presentation. In this context, the magnetic delivery of antigen-loaded magnetic liposomes (Ag-MLs) to actively target lymph node, is proposed. These magnetic responsive liposomes contain soluble mouse melanoma lysate and iron oxide nanoparticles in the core, along with the immunostimulatory adjuvant CpG-1826 incorporated into the lipid bilayer. When applied through magnetic targeting in the mouse melanoma model, Ag-MLs accumulate significantly in the target lymph nodes. This accumulation results in increased population of active DCs in lymph nodes and cytotoxic T lymphocytes (CTLs) within tumors, correlating with effective tumor growth inhibition. Overall, this study demonstrates the potential of magnetic targeting as an effective strategy for delivering cancer vaccines and activating the immune response, offering a novel platform for cancer immunotherapies.

Designing Smart Iron Oxide Nanoparticles for MR Imaging of Tumors

Iron oxide nanoparticles (IONPs) possess unique magnetism and good biocompatibility, and they have been widely applied as contrast agents (CAs) for magnetic resonance imaging (MRI). Traditional CAs typically show a fixed enhanced signal, thus exhibiting the limitations of low sensitivity and a lack of specificity. Nowadays, the progress of stimulus-responsive IONPs allows alteration of the relaxation signal in response to internal stimuli of the tumor, or external stimuli, thus providing an opportunity to overcome those limitations. This review summarizes the current status of smart IONPs as tumor imaging MRI CAs that exhibit responsiveness to endogenous stimuli, such as pH, hypoxia, glutathione, and enzymes, or exogenous stimuli, such as magnets, light, and so on. We discuss the challenges and future opportunities for IONPs as MRI CAs and comprehensively illustrate the applications of these stimuli-responsive IONPs. This review will help provide guidance for designing IONPs as MRI CAs and further promote the reasonable design of magnetic nanoparticles and achieve early and accurate tumor detection.

Nanotherapy based on magneto-mechanochemical modulation of tumor redox state

Magnetic nanoparticles (MNs) are typically used as contrast agents for magnetic resonance imaging or as drug carriers with a remotely controlled delivery to the tumor. However, they can also potentiate the action of anticancer drugs under the influence of applied constant magnetic (CMFs) and electromagnetic fields (EMFs). This review demonstrates the role of magneto-mechanochemical effects produced by MNs alone and loaded with anticancer agents (MNCs) in response to CMFs and EMFs for modulation of tumor redox state. The combined treatment is suggested to act by two mechanisms: spin-dependent electron transport propagates free radical chain reactions, while magnetomechanical interactions cause conformational changes in drug molecules loaded onto MNs and generate reactive oxygen species (ROS). By adjusting the parameters of CMFs and EMFs during the magneto-mechanochemical synthesis and subsequent treatment, it is possible to modulate ROS production and switch redox signaling involved in ERK1/2 and NF-κB pathways from initiation of tumor growth to inhibition. Observations of tumor volume in different animal models and treatment combinations reported a 6%-70% reduction as compared with conventional drugs. Despite these results, there is a general lack of research in magnetic nanotheranostics that link redox changes across multiple levels of organization in the tumor-bearing host. Further multidisciplinary studies with more focus on the relationship between the electron transport processes in biomolecules and their effects on the tumor-host interaction should accelerate the clinical translation of magnetic nanotheranostics. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Intelligent polymeric hydrogen sulfide delivery systems for therapeutic applications

Hydrogen sulfide (H₂S) plays an important role in regulating various pathological processes such as protecting mammalian cell from harmful injuries, promoting tissue regeneration, and regulating the process of various diseases caused by physiological disorders. Studies have revealed that the physiological effects of H₂S are highly associated with its concentrations. At relatively low concentration, H₂S shows beneficial functions. However, long-time and high-dose donation of H₂S would inhibit regular biological process, resulting in cell dysfunction and apoptosis. To regulate the dosage of H₂S delivery for precision medicine, H₂S delivery systems with intelligent characteristics were developed and a variety of biocompatibility polymers have been utilized to establish intelligent polymeric H₂S delivery systems, with the abilities to specifically target the lesions, smartly respond to pathological microenvironments, as well as real-timely monitor H₂S delivery and lesion conditions by incorporating imaging-capable moieties. In this review, we focus on the design, preparation, and therapeutic applications of intelligent polymeric H₂S delivery systems in cardiovascular therapy, inflammatory therapy, tissue regenerative therapy, cancer therapy and bacteria-associated therapy. Strategies for precise H₂S therapies especially imaging-guided H₂S theranostics are highlighted. Since H₂S donors with stimuli-responsive characters are vital components for establishing intelligent H₂S delivery systems, the development of H₂S donors is also briefly introduced.

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H₂S is an endogenous gasotransmitter that plays important role in regulating various physiological and pathological pathways.

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Controlled H₂S delivery is vital since the therapeutic effects of H₂S are highly associated with its concentrations.

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Intelligent polymeric H₂S delivery systems possess specific targeting, stimuli responsive and imaging guided capabilities, representing a strategic option for next generation of therapies.

A Water-Soluble Hydrogen Sulfide Donor Suppresses the Growth of Hepatocellular Carcinoma via Inhibiting the AKT/GSK-3β/β-Catenin and TGF-β/Smad2/3 Signaling Pathways

Hepatocellular carcinoma (HCC) is a disease with high morbidity, high mortality, and low cure rate. Hyaluronic acid (HA) is widely adopted in tissue engineering and drug delivery. 5-(4-Hydroxyphenyl)-3H-1, 2-dithiol-3-thione (ADT-OH) is one of commonly used H₂S donors. In our previous study, HA-ADT was designed and synthesized via coupling of HA and ADT-OH. In this study, compared with sodium hydrosulfide (NaHS, a fast H₂S-releasing donor) and morpholin-4-ium (4-methoxyphenyl)-morpholin-4-ylsulfanylidenesulfido-λ5-phosphane (GYY4137, a slow H₂S-releasing donor), HA-ADT showed stronger inhibitory effect on the proliferation, migration, invasion, and cell cycle of human HCC cells. HA-ADT promoted apoptosis by suppressing the expressions of phospho (p)-protein kinase B (PKB/AKT), p-glycogen synthase kinase-3β (GSK-3β), p-β-catenin, and also inhibited autophagy via the downregulation of the protein levels of p-Smad2, p-Smad3, and transforming growth factor-β (TGF-β) in human HCC cells. Moreover, HA-ADT inhibited HCC xenograft tumor growth more effectively than both NaHS and GYY4137. Therefore, HA-ADT can suppress the growth of HCC cells by blocking the AKT/GSK-3β/β-catenin and TGF-β/Smad2/3 signaling pathways. HA-ADT and its derivatives may be developed as promising antitumor drugs.

The cytological and electrophysiological effects of silver nanoparticles on neuron-like PC12 cells

The aim of this study was to investigate the toxic effects and mechanism of silver nanoparticles (SNPs) on the cytological and electrophysiological properties of rat adrenal pheochromocytoma (PC12) cells. Different concentrations of SNPs (20 nm) were prepared, and the effects of different application durations on the cell viability and electrical excitability of PC12 quasi-neuronal networks were investigated. The effects of 200 μM SNPs on the neurite length, cell membrane potential (CMP) difference, intracellular Ca2+ content, mitochondrial membrane potential (MMP) difference, adenosine triphosphate (ATP) content, and reactive oxygen species (ROS) content of networks were then investigated. The results showed that 200 μM SNPs produced grade 1 cytotoxicity at 48 h of interaction, and the other concentrations of SNPs were noncytotoxic. Noncytotoxic 5 μM SNPs significantly increased electrical excitability, and noncytotoxic 100 μM SNPs led to an initial increase followed by a significant decrease in electrical excitability. Cytotoxic SNPs (200 μM) significantly decreased electrical excitability. SNPs (200 μM) led to decreases in neurite length, MMP difference and ATP content and increases in CMP difference and intracellular Ca2+ and ROS levels. The results revealed that not only cell viability but also electrophysiological properties should be considered when evaluating nanoparticle-induced neurotoxicity. The SNP-induced cytotoxicity mainly originated from its effects on ATP content, cytoskeletal structure and ROS content. The decrease in electrical excitability was mainly due to the decrease in ATP content. ATP content may thus be an important indicator of both cell viability and electrical excitability in PC12 quasi-neuronal networks.

Recent advances in mechanical force-responsive drug delivery systems

Mechanical force responsive drug delivery systems (in terms of mechanical force induced chemical bond breakage or physical structure destabilization) have been recently explored to exhibit a controllable pharmaceutical release behaviour at a molecular level. In comparison with chemical or biological stimulus triggers, mechanical force is not only an external but also an internal stimulus which is closely related to the physiological status of patients. However, although this mechanical force stimulus might be one of the most promising and feasible sources to achieve on-demand pharmaceutical release, current research in this field is still limited. Hence, this tutorial review aims to comprehensively evaluate the recent advances in mechanical force-responsive drug delivery systems based on different types of mechanical force, in terms of direct stimulation by compressive, tensile, and shear force, or indirect/remote stimulation by ultrasound and a magnetic field. Furthermore, the exciting developments and current challenges in this field will also be discussed to provide a blueprint for potential clinical translational research of mechanical force-responsive drug delivery systems.

Stimuli-responsive liposomal nanoformulations in cancer therapy: Pre-clinical & clinical approaches

The site-specific delivery of antitumor agents is of importance for providing effective cancer suppression. Poor bioavailability of anticancer compounds and the presence of biological barriers prevent their accumulation in tumor sites. These obstacles can be overcome using liposomal nanostructures. The challenges in cancer chemotherapy and stimuli-responsive nanocarriers are first described in the current review. Then, stimuli-responsive liposomes including pH-, redox-, enzyme-, light-, thermo- and magneto-sensitive nanoparticles are discussed and their potential for delivery of anticancer drugs is emphasized. The pH- or redox-sensitive liposomes are based on internal stimulus and release drug in response to a mildly acidic pH and GSH, respectively. The pH-sensitive liposomes can mediate endosomal escape via proton sponge. The multifunctional liposomes responsive to both redox and pH have more capacity in drug release at tumor site compared to pH- or redox-sensitive alone. The magnetic field and NIR irradiation can be exploited for external stimulation of liposomes. The light-responsive liposomes release drugs when they are exposed to irradiation; thermosensitive-liposomes release drugs at a temperature of >40 °C when there is hyperthermia; magneto-responsive liposomes release drugs in presence of magnetic field. These smart nanoliposomes also mediate co-delivery of drugs and genes in synergistic cancer therapy. Due to lack of long-term toxicity of liposomes, they can be utilized in near future for treatment of cancer patients.

US/MR Bimodal Imaging-Guided Bio-Targeting Synergistic Agent for Tumor Therapy

Purpose

Breast cancer is detrimental to the health of women due to the difficulty of early diagnosis and unsatisfactory therapeutic efficacy of available breast cancer therapies. High intensity focused ultrasound (HIFU) ablation is a new method for the treatment of breast tumors, but there is a problem of low ablation efficiency. Therefore, the improvement of HIFU efficiency to combat breast cancer is immediately needed. This study aimed to describe a novel anaerobic bacteria-mediated nanoplatform, comprising synergistic HIFU therapy for breast cancer under guidance of ultrasound (US) and magnetic resonance (MR) bimodal imaging.

Methods

The PFH@CL/Fe₃O₄ nanoparticles (NPs) (Perfluorohexane (PFH) and superparamagnetic iron oxides (SPIO, Fe₃O₄) with cationic lipid (CL) NPs) were synthesized using the thin membrane hydration method. The novel nanoplatform Bifidobacterium bifidum-mediated PFH@CL/Fe₃O₄ NPs were constructed by electrostatic adsorption. Thereafter, US and MR bimodal imaging ability of B. bifidum-mediated PFH@CL/Fe₃O₄ NPs was evaluated in vitro and in vivo. Finally, the efficacy of HIFU ablation based on B. bifidum-PFH@CL/Fe₃O₄ NPs was studied.

Results

B. bifidum combined with PFH@CL/Fe₃O₄ NPs by electrostatic adsorption and enhanced the tumor targeting ability of PFH@CL/Fe₃O₄ NPs. US and MR bimodal imaging clearly displayed the distribution of the bio-targeting nanoplatform in vivo. It was conducive for accurate and effective guidance of HIFU synergistic treatment of tumors. Furthermore, PFH@CL/Fe₃O₄ NPs could form microbubbles by acoustic droplet evaporation and promote efficiency of HIFU ablation under guidance of bimodal imaging.

Conclusion

A bio-targeting nanoplatform with high stability and good physicochemical properties was constructed. The HIFU synergistic agent achieved early precision imaging of tumors and promoted therapeutic effect, monitored by US and MR bimodal imaging during the treatment process.

The Advancement of Gas-Generating Nanoplatforms in Biomedical Fields: Current Frontiers and Future Perspectives

Diverse gases (NO, CO, H₂ S, H₂ , etc.) have been widely applied in the medical intervention of various diseases, including cancer, cardiovascular disease, ischemia-reperfusion injury, bacterial infection, etc., attributing to their inherent biomedical activities. Although many gases have many biomedical activities, their clinical use is still limited due to the rapid and free diffusion behavior of these gases molecules, which may cause potential side effects and/or ineffective treatment. Gas-generating nanoplatforms (GGNs) are effective strategies to address the aforementioned challenges of gas therapy by preventing gas production or release at nonspecific sites, enhancing GGNs accumulation at targeted sites, and controlling gas release in response to exogenous (UV, NIR, US, etc.) or endogenous (H₂ O₂ , GSH, pH, etc.) stimuli at the lesion site, further maintaining gas concentration within the effective range and achieving the purpose of disease treatment. This review comprehensively summarizes the advancements of "state-of-the-art" GGNs in the recent three years, with emphasis on the composition, structure, preparation process, and gas release mechanism of the nanocarriers. Furthermore, the therapeutic effects and limitations of GGNs in preclinical studies using cell/animal models are discussed. Overall, this review enlightens the further development of this field and promotes the clinical transformation of gas therapy.

Photoprotective Mechanism of Fucoxanthin in Ultraviolet B Irradiation-Induced Retinal Müller Cells Based on Lipidomics Analysis

Long-term exposure to sunlight and/or blue light causes vision damage to people of all ages. Dietary pigments and polyphenols have been shown to have photoprotective potential for eyes; however, many unknowns regarding the protective mechanism remain. In this study, we used ultraviolet B (UVB) irradiation-induced retinal Müller cells (RMCs) to screen for dietary polyphenols and pigment compounds with effective photoprotective activity. Fucoxanthin (FX) was shown to have the best therapeutic effect, and the mechanism was evaluated via lipidomics analysis. Both intra- and extracellular ROS, mitochondrial depolarization, and DNA damage induced by UVB irradiation were inhibited by FX. Meanwhile, FX modulated the MAPK signaling pathway, which is correlated with apoptosis and inflammation. Our lipidomics data revealed that FX regulated lipid metabolism disorder and protected the membrane structure. These results confirm the effective photoprotective effects of FX, which may lead to new insights into FX-functionalized photoprotective foods.

Gas and gas-generating nanoplatforms in cancer therapy

Gas therapy is the usage of certain gases with special therapeutic effects for the treatment of diseases. Hydrogen (H₂), nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H₂S) acting as gas signalling molecules are representative gases in cancer therapy. They act directly on mitochondria or nuclei to lead to cell apoptosis. They can also alleviate immuno-suppression in the tumour microenvironment and promote phenotype conversion of tumour-associated macrophages. Moreover, the combination of gas therapy and other traditional therapy methods can reduce side effects and improve therapeutic efficacy. Here, we discuss the roles of NO, CO, H₂S and H₂ in cancer biology. Considering the rapidly developing nanotechnology, gas-generating nanoplatforms which can achieve targeted delivery and controlled release were also discussed. Finally, we highlight the current challenges and future opportunities of gas-based cancer therapy.

Synergistic Therapy Using Doxorubicin-Loading and Nitric Oxide-Generating Hollow Prussian Blue Nanoparticles with Photoacoustic Imaging Potential Against Breast Cancer

Introduction

Traditional antitumor chemotherapy faces great challenges, such as multi-drug resistance (MDR) and poor penetration into tumor tissues. The newly emerging nitric oxide (NO)-based gas therapy has been recognized to reduce MDR and has improved permeation into tumor tissue.

Methods

In this study, NO-generating prodrug sodium nitroprusside (SNP) was doped to hollow mesoporous Prussian blue (PB) nanoparticles to fabricate NO-generating nanoparticles (NO-PB), which was further loaded with doxorubicin (DOX).

Results

DOX loaded NO-PB (DOX-NO-PB) was released quicker at pH 6 compared with neutral pH, suggesting NO-PB may facilitate the release of loaded drug in acidic tumor tissue. The capacity of NO production by NO-PB was measured, and the results showed the presence of NO in the culture medium from 4T1 cells incubated with NO-PB and inside the cells. NP-PB could be detected by photoacoustic imaging (PAI) in tumor tissue in 4T1 tumor bearing mice, suggesting this nanoparticle may serve as contrast agent for the noninvasive diagnosis of tumor tissues. NO-PB suppressed the growth of tissues in 4T1 tumor bearing mice. DOX-NO-PB showed more potent anti-tumor effects in 4T1 cells and tumor bearing mice compared with free DOX and NO-PB alone, indicating that the combination of DOX and NO-PB exhibited synergistic effects on tumor suppression.

Conclusion

This study provides a novel nanocarrier for gas therapy with additional PAI imaging capacity. This nanocarrier can be utilized for combination therapy of NO and chemotherapeutics which may serve as theranostic agents.

Construction of a pH-responsive, ultralow-dose triptolide nanomedicine for safe rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronicautoimmune disease, marked by joint swelling and pain, articular synovial hyperplasia, as well as cartilage and bone destruction. Triptolide (TP) is an anti-inflammatory molecule but its use to treat RA is limited due to poor solubility and extremely high toxicity. In this study, by encapsulating TP into a star-shaped amphiphilic block copolymer, POSS-PCL-b-PDMAEMA, we engineered a pH-sensitive TP-loaded nanomedicine (TP@NPs) to simultaneously reduce the toxicity of TP and improve its therapeutic efficacy. TP@NPs shows a uniform spherical structure with a hydrodynamic diameter of ~92 nm and notable pH-responsiveness. In vitro TP@NPs showed reduced cytotoxicity and cell apoptosis of treated RAW264.7 cells compared to free TP. And in vivo intravenous injection of indocyanine green-labeled NPs into a collagen-induced arthritis model in mice showed that the engineered compound had potent pharmacokinetic and pharmacodynamic profiles, while exhibiting significant cartilage-protective and anti-inflammatory effects with a better efficacy and neglible systemic toxicity even at an ultralow dose compared to free TP. These results suggest that TP@NPs may be a safe and effective therapy for RA and other autoimmune diseases.

Chitosan derived glycolipid nanoparticles for magnetic resonance imaging guided photodynamic therapy of cancer

Currently, the development of polysaccharide, especially chitosan (CS), based drug delivery system to afford magnetic resonance imaging (MRI) guided theranostic cancer therapy remains largely unexplored. Herein, we successfully developed a CS derived polymer (Gd-CS-OA) through chemical conjugation of CS, octadecanoic acid (OA) and gadopentetic acid (GA). After self-assemble into glycolipid nanoparticles to loaded chlorin e6 (Ce6), the resulted Gd-CS-OA/Ce6 was able to realize MRI guided photodynamic therapy (PDT) of cancer. Our results revealed that Gd-CS-OA was able to increase the MRI sensitivity as compared to Gd-DTPA with decent residence time and preferable excretion behavior in vivo. Moreover, the Gd-CS-OA/Ce6 showed negligible hemolysis, satisfactory ROS generation and stability in physiological environments with preferable cellular uptake and enhanced in vitro cytotoxicity (through elevated ROS generation) on 4T1 cells. Most importantly, Gd-CS-OA/Ce6 demonstrated promising in vivo tumor targetability (enhanced penetration and retention effect) and powerful MRI guided tumor ablation through PDT on in situ 4T1 tumor model.