Recent progress in nitric oxide-generating nanomedicine for cancer therapy

Nitric oxide-based multi-synergistic nanomedicine: an emerging therapeutic for anticancer

Gas therapy has emerged as a promising approach for treating cancer, with gases like NO, H2S, and CO showing positive effects. Among these, NO is considered a key gas molecule with significant potential in stopping cancer progression. However, due to its high reactivity and short half-life, delivering NO directly to tumors is crucial for enhancing cancer treatment. NO-driven nanomedicines (NONs) have been developed to effectively deliver NO donors to tumors, showing great progress in recent years. This review provides an overview of the latest advancements in NO-based cancer nanotherapeutics. It discusses the types of NO donors used in current research, the mechanisms of action behind NO therapy for cancer, and the different delivery systems for NO donors in nanotherapeutics. It also explores the potential of combining NO donors with other treatments for enhanced cancer therapy. Finally, it examines the future prospects and challenges of using NONs in clinical settings for cancer treatment.

A water-soluble mycelium polysaccharide from Monascus pilosus: Extraction, structural characterization, immunomodulatory effect and yield enhanced by overexpression of UGE gene

Mycelium polysaccharide (MPP) from Monascus pilosus with the compositions of glucose, galactose, mannose, glucosamine hydrochloride, rhamnose and arabinose, was obtained using alkaline extracting, and subsequently three purified components (MPP-0, MPP-0.1 and MPP-0.3) were separated. The purity and extraction volume of the MPP-0.1 fraction surpassed those of the other two groups, thus warranting its selection for subsequent experimental investigations. The sample MPP-0.1, with an average molecular weight of 3.7776 × 104 Da, exhibited exceptional thermal stability up to 170 °C. The main glycosidic linkage pattern of MPP-0.1 was structured as→[4)-α-D-Glcp-(1]6 → 4)-α-D-Glcp-(1 → [2)-α-D-Manp-(1]5 → 2)-α-D-Manp-(1 → 5)-β-D-Galf-(1 → 3)-β-D-Galf (1 → 3)-β-D-Galf-(1 → 3)-β-D-Galf-(1→, and branched Glcp, Manp, Galf fragments were connected with the main chain through →4, 6)-α-D-Glcp-(1→, →2, 6)-α-D-Manp-(1 → and →3, 6)-β-D-Galf-(1→. Besides, the up-regulated levels of Nitric oxide (NO), Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β) and other pro-inflammatory cytokines along with increased phagocytic activity revealed that MPP-0.1 has significant immunomodulatory effect, and can significantly enhance the proliferation and activation of RAW264.7 cells. Finally, the gene UGE (UDP-glucose 4-epimerase) was overexpressed in M. pilosus to increase the MPP production. Results showed that the biomass of the recombinant strain exhibited a remarkable increase of approximately 62.56 ± 1.50 % compared to that of the parental strain, and the extraction yield of MPP increased significantly by 83.19 ± 4.56 %.

Light-Armed Nitric Oxide-Releasing Micromotor In Vivo

The delivery of NO at a high spatiotemporal precision is important but still challenging for existing NO-releasing platforms due to the lack of precise motion control and limited biomedical functions. In this work, we propose an alternative strategy for developing the light-armed nitric oxide-releasing micromotor (LaNorM), in which a main light beam was employed to navigate the microparticle and stimulate NO release and an auxiliary light beam was used to cooperate with the released NO to act as a remotely controlled scalpel for cell separation. Benefiting from the advantages of fully controlled locomotion, photostimulated NO release, and microsurgery ability at the single-cell level, the proposed LaNorM could enable a series of biomedical applications in vivo, including the separation of flowing emboli, selective removal of a specific thrombus, and inhibition of thrombus growth, which may provide new insight into the precise delivery of NO and the treatment of cardiovascular diseases.

A photothermal responsive system accelerating nitric oxide release to enhance bone repair by promoting osteogenesis and angiogenesis

Managing bone defects remains a formidable clinical hurdle, primarily attributed to the inadequate orchestration of vascular reconstruction and osteogenic differentiation in both spatial and temporal dimensions. This challenge persists due to the constrained availability of autogenous grafts and the limited regenerative capacity of allogeneic or synthetic bone substitutes, thus necessitating continual exploration and innovation in the realm of functional and bioactive bone graft materials. While synthetic scaffolds have emerged as promising carriers for bone grafts, their efficacy is curtailed by deficiencies in vascularization and osteoinductive potential. Nitric oxide (NO) plays a key role in revascularization and bone tissue regeneration, yet studies related to the use of NO for the treatment of bone defects remain scarce. Herein, we present a pioneering approach leveraging a photothermal-responsive system to augment NO release. This system comprises macromolecular mPEG-P nanoparticles encapsulating indocyanine green (ICG) (NO-NPs@ICG) and a mPEG-PA-PP injectable thermosensitive hydrogel carrier. By harnessing the synergistic photothermal effects of near-infrared radiation and ICG, the system achieves sustained NO release, thereby activating the soluble guanylate cyclase (SGC)-cyclic guanosine monophosphate (cGMP) signaling pathway both in vitro and in vivo. This orchestrated cascade culminates in the facilitation of angiogenesis and osteogenesis, thus expediting the reparative processes in bone defects. In a nutshell, the NO release-responsive system elucidated in this study presents a pioneering avenue for refining the bone tissue microenvironment and fostering enhanced bone regeneration.

Novel 131-iodine labeled and ultrasound-responsive nitric oxide and reactive oxygen species controlled released nanoplatform for synergistic sonodynamic/nitric oxide/chemodynamic/radionuclide therapy

Nitric oxide (NO) and reactive oxygen species (ROS) embody excellent potential in cancer therapy. However, as a small molecule, their targeted delivery and precise, controllable release are urgently needed to achieve accurate cancer therapy. In this paper, a novel US-responsive bifunctional molecule (SD) and hyaluronic acid-modified MnO2 nanocarrier was developed, and a US-responsive NO and ROS controlled released nanoplatform was constructed. US can trigger SD to release ROS and NO simultaneously at the tumor site. Thus, SD served as acoustic sensitizer for sonodynamic therapy and NO donor for gas therapy. In the tumor microenvironment, the MnO2 nanocarrier can effectively deplete the highly expressed GSH, and the released Mn2+ can make H2O2 to produce .OH by Fenton-like reaction, which exhibited a strong chemodynamic effect. The high concentration of ROS and NO in cancer cell can induce cancer cell apoptosis ultimately. In addition, toxic ONOO-, which was generated by the reaction of NO and ROS, can effectively cause mitochondrial dysfunction, which induced the apoptosis of tumor cells. The 131I was labeled on the nanoplatform, which exhibited internal radiation therapy for tumor therapy. In -vitro and -vivo experiments showed that the nanoplatform has enhanced biocompatibility, and efficient anti-tumor potential, and it achieves synergistic sonodynamic/NO/chemodynamic/radionuclide therapy for cancer.

Tumor-Specific Nano-Herb Delivery System with High L-Arginine Loading for Synergistic Chemo and Gas Therapy against Cervical Cancer

Cancer metastasis poses significant challenges in current clinical therapy. Osthole (OST) has demonstrated efficacy in treating cervical cancer and inhibiting metastasis. Despite these positive results, its limited solubility, poor oral absorption, low bioavailability, and photosensitivity hinder its clinical application. To address this limitation, a glutathione (GSH)-responded nano-herb delivery system (HA/MOS@OST&L-Arg nanoparticles, HMOA NPs) is devised for the targeted delivery of OST with cascade-activatable nitric oxide (NO) release. The HMOA NPs system is engineered utilizing enhanced permeability and retention (EPR) effects and active targeting mediated by hyaluronic acid (HA) binding to glycoprotein CD44. The cargoes, including OST and L-Arginine (L-Arg), are released rapidly due to the degradation of GSH-responsive mesoporous organic silica (MOS). Then abundant reactive oxygen species (ROS) are produced from OST in the presence of high concentrations of NAD(P)H quinone oxidoreductase 1 (NQO1), resulting in the generation of NO and subsequently highly toxic peroxynitrite (ONOO-) by catalyzing guanidine groups of L-Arg. These ROS, NO, and ONOO- molecules have a direct impact on mitochondrial function by reducing mitochondrial membrane potential and inhibiting adenosine triphosphate (ATP) production, thereby promoting increased apoptosis and inhibiting metastasis. Overall, the results indicated that HMOA NPs has great potential as a promising alternative for the clinical treatment of cervical cancer.

Gas Therapy: Generating, Delivery, and Biomedical Applications

Oxygen (O2), nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2) with direct effects, and carbon dioxide (CO2) with complementary effects on the condition of various diseases are known as therapeutic gases. The targeted delivery and in situ generation of these therapeutic gases with controllable release at the site of disease has attracted attention to avoid the risk of gas poisoning and improve their performance in treating various diseases such as cancer therapy, cardiovascular therapy, bone tissue engineering, and wound healing. Stimuli-responsive gas-generating sources and delivery systems based on biomaterials that enable on-demand and controllable release are promising approaches for precise gas therapy. This work highlights current advances in the design and development of new approaches and systems to generate and deliver therapeutic gases at the site of disease with on-demand release behavior. The performance of the delivered gases in various biomedical applications is then discussed.

Melatonin Protects Against Colistin-Induced Intestinal Inflammation and Microbiota Dysbiosis

Colistin is renowned as a last-resort antibiotic due to the emergence of multidrug-resistant pathogens. However, its potential toxicity significantly hampers its clinical utilization. Melatonin, chemically known as N-acetyl-5-hydroxytryptamine, is an endogenous hormone produced by the pineal gland and possesses diverse biological functions. However, the protective role of melatonin in alleviating antibiotic-induced intestinal inflammation remains unknown. Herein, we reveal that colistin stimulation markedly elevates intestinal inflammatory levels and compromises the gut barrier. In contrast, pretreatment with melatonin safeguards mice against intestinal inflammation and mucosal damage. Microbial diversity analysis indicates that melatonin supplementation prevents a reduction in the abundance of Erysipelotrichales and Bifidobacteriales, as well as an increase in Desulfovibrionales abundance, following colistin exposure. Remarkably, short-chain fatty acids (SCFAs) analysis shows that propanoic acid contributes to the protective effect of melatonin on colistin-induced intestinal inflammation. Furthermore, the protection effects of melatonin and propanoic acid on LPS-induced cellular inflammation in RAW 264.7 cells are confirmed. Mechanistic investigations suggest that intervention with melatonin and propanoic acid can repress the activation of the TLR4 signal and its downstream NF-κB and MAPK signaling pathways, thereby mitigating the toxic effects of colistin. Our work highlights the unappreciated role of melatonin in preventing the potential detrimental effects of colistin on intestinal health and suggests a combined therapeutic strategy to effectively manage intestinal infectious diseases.

Application of Non-Pharmacologic Therapy in Hair Loss Treatment and Hair Regrowth

Purpose

Alopecia significantly affects the appearance and psychology of patients, and pharmacological therapies and hair transplantation are the main treatments for alopecia, but both have limitations. This review aimed to summarize the non-pharmacological therapies that promote hair growth and regeneration.

Patients and Methods

This is a non-systematic review. Multiple databases was searched with relevant data published between 1997 and 2024. Searching and screening followed the PRISMA guidelines.

Results

Novel therapeutic modalities, such as gas molecules, platelet-rich plasma, laser, and microneedling, can change the microenvironment of hair follicles, activate hair follicle stem cells, and promote hair growth and regeneration.

Conclusion

This paper reviews research on the application of non-pharmacological therapies in alopecia treatment and hair regeneration, with a view to providing an important basis for future research on alopecia treatment and the postoperative treatment of patients after hair transplantation.

A Cascade-Amplified Pyroptosis Inducer: Optimizing Oxidative Stress Microenvironment by Self-Supplying Reactive Nitrogen Species Enables Potent Cancer Immunotherapy

Selective generation of sufficient pyroptosis inducers at the tumor site without external stimulation holds immense significance for a longer duration of immunotherapy. Here, we report a cascade-amplified pyroptosis inducer CSCCPT/SNAP that utilizes reactive nitrogen species (RNS), self-supplied from the diffusion-controlled reaction between reactive oxygen species (ROS) and nitric oxide (NO) to potentiate pyroptosis and immunotherapy, while both endogenous mitochondrial ROS stimulated by released camptothecin and released NO initiate pyroptosis. Mechanistically, cascade amplification of the antitumor immune response is prompted by the cooperation of ROS and NO and enhanced by RNS with a long lifetime, which could be used as a pyroptosis trigger to effectively compensate for the inherent drawbacks of ROS, resulting in long-lasting pyroptosis for favoring immunotherapy. Tumor growth is efficiently inhibited in mouse melanoma tumors through the facilitation of reactive oxygen/nitrogen species (RONS)-NO synergy. In summary, our therapeutic approach utilizes supramolecular engineering and nanotechnology to integrate ROS producers and NO donors of tumor-specific stimulus responses into a system that guarantees synchronous generation of these two reactive species to elicit pyroptosis-evoked immune response, while using self-supplied RNS as a pyroptosis amplifier. RONS-NO synergy achieves enhanced and sustained pyroptosis and antitumor immune responses for robust cancer immunotherapy.

Photothermal-controlled NO-releasing Nanogels reverse epithelial-mesenchymal transition and restore immune surveillance against cancer metastasis

Metastasis leads to high mortality among cancer patients. It is a complex, multi-step biological process that involves the dissemination of cancer cells from the primary tumor and their systemic spread throughout the body, primarily through the epithelial-mesenchymal transition (EMT) program and immune evasion mechanisms. It presents a challenge in how to comprehensively treat metastatic cancer cells throughout the entire stage of the metastatic cascade using a simple system. Here, we fabricate a nanogel (HNO-NG) by covalently crosslinking a macromolecular nitric oxide (NO) donor with a photothermal IR780 iodide-containing hyaluronic acid derivative via a click reaction. This enables stable storage and tumor-targeted, photothermia-triggered release of NO to combat tumor metastasis throughout all stages. Upon laser irradiation (HNO-NG+L), the surge in NO production within tumor cells impairs the NF-κB/Snail/RKIP signaling loop that promotes the EMT program through S-nitrosylation, thus inhibiting cell dissemination from the primary tumor. On the other hand, it induces immunogenic cell death (ICD) and thereby augments anti-tumor immunity, which is crucial for killing both the primary tumor and systemically distributed tumor cells. Therefore, HNO-NG+L, by fully leveraging EMT reversal, ICD induction, and the lethal effect of NO, achieved impressive eradication of the primary tumor and significant prevention of lung metastasis in a mouse model of orthotropic 4T1 breast tumor that spontaneously metastasizes to the lungs, extending the NO-based therapeutic approach against tumor metastasis.

Coumarin-Furoxan Hybrid Suppressed the Proliferation and Metastasis of Triple-Negative Breast Cancer by Activating Mitochondrial Stress and Cell Apoptosis

Triple-negative breast cancer (TNBC) typically manifests as higher invasive carcinoma correlated with a worse prognosis that primarily relies on chemotherapy. There is growing evidence that nitric oxide (NO) donor drugs have the potential for anticancer therapy. On this basis, we constructed and evaluated a novel coumarin-furoxan hybrid 4A93 as an effective antitumor candidate drug. 4A93 exhibits low IC50 values in three TNBC cell lines and inhibits colony formation and DNA synthesis, probably due to the release of high concentrations of NO in mitochondria, which induces oxidative stress, mitochondrial dysfunction, and apoptosis. Further research suggests that 4A93 might destroy mitochondria by opening the mitochondrial permeability transition pore (mPTP), depolarizing the mitochondrial membrane potential (MMP), and promoting the release of cytochrome c into the cytoplasm. Intrinsic apoptosis is induced finally, along with Akt/Erk signaling suppression. Additionally, 4A93 underregulates the Epithelial-mesenchymal transition process to inhibit cell migration and invasion. In 4T1 subcutaneous and hematogenous models of mice, 4A93 therapy suppresses the tumor growth and prevented lung metastasis with favorable biosafety. Our results provide insights into 4A93 in TNBC treatment and validate the contribution of NO donors in tumor therapy.

Trinitroglycerin-loaded chitosan nanogels: Shedding light on cytotoxicity, antioxidativity, and antibacterial activities

AIM AND BACKGROUND

Trinitroglycerin (TNG) is a remarkable NO-releasing agent. Here, we synthesized TNG based on chitosan Nanogels (Ngs) for ameliorating complications associated with high-dose TNG administration.

METHOD

TNG-Ngs fabricated through ionic-gelation technique. Fourier-transformed infrared (FT-IR), zeta-potential, dynamic light scattering (DLS), and electron microscopy techniques evaluated the physicochemical properties of TNG-Ngs. MTT was used to assess the biocompatibility of TNG-Ngs, as the antioxidative properties were determined via lactate dehydrogenase (LDH), reactive oxygen species (ROS), and lipid peroxide (LPO) assays. The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE).

RESULTS

Physicochemical characterization reveals that TNG-Ngs with size diameter (96.2 ± 29 nm), polydispersity index (PDI, 0.732), and negative zeta potential (-1.1 mv) were fabricated. The encapsulation efficacy (EE) and loading capacity (LC) were obtained at 71.1 % and 2.3 %, respectively, with no considerable effect on particle size and morphology. The cytotoxicity assay demonstrated that HepG2 cells exposed to TNG-Ngs showed relative cell viability (RCV) of >80 % for 70 μg/ml compared to the TNG-free drug at the same concentration (P < 0.05). TNG-Ngs showed significant differences with the TNG-free drug for LDH, LPO, and ROS formation at the same concentration (P < 0.001). The antibacterial activity of the TNG-Ngs against S. aureus, E. coli, VRE, and MRSA was higher than the TNG-free drug and Ngs (P < 0.05).

CONCLUSION

TNG-Ngs with enhanced antibacterial and antioxidative activity and no obvious cytotoxicity might be afforded as novel nanoformulation for promoting NO-dependent diseases.

"Targeted plus controlled" - Composite nano delivery system opens the tumor vascular and microenvironment normalization window for anti-tumor therapy

The bottleneck of traditional anti-tumor therapy is mainly limited by the abnormal microenvironment of tumors. Leaky vessels are difficult for drugs or immune cells to penetrate deep into tumors, but tumor cells can easily escape through which and metastasize to other organs. Reprogramming the tumor microenvironment is one of the main directions for anti-cancer research, among which, tumor vascular normalization has received increasing attention. However, how to control the dose and time of anti-angiogenic drugs for stable vascular normalizing effect limits it for further research. We developed a composite nano delivery system, P-V@MG, with double delivery function of pH-responsibility and sustained drug release. The PHMEMA shell improves amphiphilicity of nano delivery system and prolongs in vivo retention, and releases V@MG in the weakly acidic tumor microenvironment, which slowly release anti-angiogenic drugs, Vandetanib. We found that P-V@MG not only prolonged the normalization window of tumor vascular but also reprogram tumor microenvironment with increased perfusion, immune cells infiltration and relieved hypoxia, which further opened the pathway for other anti-cancer therapeutics. This synergy was proved by the improving anti-tumor efficiency by combination of P-V@MG with the doxorubicin hydrochloride in 4 T1 breast cancer model suggesting the desirable value of pro-vascular normalization nano delivery systems in the field of anti-tumor combination therapy.

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Nitric oxide-driven nanotherapeutics for cancer treatment

Nitric oxide (NO) is a gaseous molecule endowed with diverse biological functions, offering vast potential in the realm of cancer treatment. Considerable efforts have been dedicated to NO-based cancer therapy owing to its good biosafety and high antitumor activity, as well as its efficient synergistic therapy with other antitumor modalities. However, delivering this gaseous molecule effectively into tumor tissues poses a significant challenge. To this end, nano drug delivery systems (nano-DDSs) have emerged as promising platforms for in vivo efficient NO delivery, with remarkable achievements in recent years. This review aims to provide a summary of the emerging NO-driven antitumor nanotherapeutics. Firstly, the antitumor mechanism and related clinical trials of NO therapy are detailed. Secondly, the latest research developments in the stimulation of endogenous NO synthesis are presented, including the regulation of nitric oxide synthases (NOS) and activation of endogenous NO precursors. Moreover, the emerging nanotherapeutics that rely on tumor-specific delivery of NO donors are outlined. Additionally, NO-driven combined nanotherapeutics for multimodal cancer theranostics are discussed. Finally, the future directions, application prospects, and challenges of NO-driven nanotherapeutics in clinical translation are highlighted.

Can Nitric Oxide-Based Therapy Be Improved for the Treatment of Cancers? A Perspective

Since the early observations that nitric oxide (•NO) at high concentrations is cytotoxic to cancer cells and that it may play an important role in the treatment of human cancers, a significant number of compounds (NO-donors) have been prepared to deliver •NO to tumors. •NO also sensitizes various clinically active anticancer drugs and has been shown to induce the reversal of multi-drug resistance in tumor cells expressing ATP-binding cassette-transporter proteins. For the successful treatment of cancers, •NO needs to be delivered precisely to tumors, and its adverse toxicity must be limited. Like other chemotherapeutics, the precise delivery of drugs has been a problem and various attempts have been made, such as the encapsulation of drugs in lipid polymers, to overcome this. This prospective study examines the use of various strategies for delivering •NO (using NO-donors) for the treatment of cancers. Finding and utilizing such a delivery system is an important step in delivering cytotoxic concentrations of •NO to tumors without adverse reactions, leading to a successful clinical outcome for patient management.

Tailored Beta-Lapachone Nanomedicines for Cancer-Specific Therapy

Nanotechnology shows the power to improve efficacy and reduce the adverse effects of anticancer agents. As a quinone-containing compound, beta-lapachone (LAP) is widely employed for targeted anticancer therapy under hypoxia. The principal mechanism of LAP-mediated cytotoxicity is believed due to the continuous generation of reactive oxygen species with the aid of NAD(P)H: quinone oxidoreductase 1 (NQO1). The cancer selectivity of LAP relies on the difference between NQO1 expression in tumors and that in healthy organs. Despite this, the clinical translation of LAP faces the problem of narrow therapeutic window that is challenging for dose regimen design. Herein, the multifaceted anticancer mechanism of LAP is briefly introduced, the advance of nanocarriers for LAP delivery is reviewed, and the combinational delivery approaches to enhance LAP potency in recent years are summarized. The mechanisms by which nanosystems boost LAP efficacy, including tumor targeting, cellular uptake enhancement, controlled cargo release, enhanced Fenton or Fenton-like reaction, and multidrug synergism, are also presented. The problems of LAP anticancer nanomedicines and the prospective solutions are discussed. The current review may help to unlock the potential of cancer-specific LAP therapy and speed up its clinical translation.

The Effectiveness of L-arginine in Clinical Conditions Associated with Hypoxia

The review summarises the data of the last 50 years on the effectiveness of the amino acid L-arginine in therapeutic practice in conditions accompanied by different-origin hypoxia. The aim of this review was to analyse the literature and our research data on the role of nitric oxide in the modulation of individual physiological reactivity to hypoxia. The review considers the possibility of eliminating methodological conflicts in the case of L-arginine, which can be solved by taking into account individual physiological reactivity (or the hypoxia resistance factor). Considerable attention is paid to genetic and epigenetic mechanisms of adaptation to hypoxia and conditions of adaptation in different models. The article presents data on the clinical effectiveness of L-arginine in cardiovascular system diseases (hypertension, atherosclerosis, coronary heart disease, etc.) and stress disorders associated with these diseases. The review presents a generalised analysis of techniques, data on L-arginine use by athletes, and the ambiguous role of NO in the physiology and pathology of hypoxic states shown via nitric oxide synthesis. Data on the protective effects of adaptation in the formation of individual high reactivity in sportsmen are demonstrated. The review demonstrates a favourable effect of supplementation with L-arginine and its application depending on mitochondrial oxidative phosphorylation processes and biochemical indices in groups of individuals with low and high capacity of adaptation to hypoxia. In individuals with high initial anti-hypoxic reserves, these favourable effects are achieved by the blockade of NO-dependent biosynthesis pathways. Therefore, the methodological tasks of physiological experiments and the therapeutic consequences of treatment should include a component depending on the basic level of physiological reactivity.

Nitric Oxide-Loaded Bioinspired Lipoprotein Normalizes Tumor Vessels To Improve Intratumor Delivery and Chemotherapy of Albumin-Bound Paclitaxel Nanoparticles

The disorganized vasculatures in tumors represent a substantial challenge of intratumor nanomedicine delivery to exert the anticancer effects. Herein, we rationally designed a glutathione (GSH)-activated nitric oxide (NO) donor loaded bioinspired lipoprotein system (NO-BLP) to normalize tumor vessels and then promote the delivery efficiency of sequential albumin-bound paclitaxel nanoparticles (PAN) in tumors. NO-BLP exhibited higher tumor accumulation and deeper penetration versus the counterpart liposomal formulation (NO-Lipo) in 4T1 breast cancer tumors, thus producing notable vascular normalization efficacy and causing a 2.33-fold increase of PAN accumulation. The sequential strategy of NO-BLP plus PAN resulted in an 81.03% inhibition of tumor growth in 4T1 tumors, which was better than the NO-BLP monotherapy, PAN monotherapy, and the counterpart NO-Lipo plus PAN treatment. Therefore, the bioinspired lipoprotein of NO-BLP provides an encouraging platform to normalize tumor vessels and promote intratumor delivery of nanomedicines for effective cancer treatment.

Ultrasound targeted microbubble destruction-triggered nitric oxide release via nanoscale ultrasound contrast agent for sensitizing chemoimmunotherapy

Immunotherapy had demonstrated inspiring effects in tumor treatment, but only a minority of people could benefit owing to the hypoxic and immune-suppressed tumor microenvironment (TME). Therefore, there was an urgent need for a strategy that could relieve hypoxia and increase infiltration of tumor lymphocytes simultaneously. In this study, a novel acidity-responsive nanoscale ultrasound contrast agent (L-Arg@PTX nanodroplets) was constructed to co-deliver paclitaxel (PTX) and L-arginine (L-Arg) using the homogenization/emulsification method. The L-Arg@PTX nanodroplets with uniform size of about 300 nm and high drug loading efficiency displayed good ultrasound diagnostic imaging capability, improved tumor aggregation and achieved ultrasound-triggered drug release, which could prevent the premature leakage of drugs and thus improve biosafety. More critically, L-Arg@PTX nanodroplets in combination with ultrasound targeted microbubble destruction (UTMD) could increase cellular reactive oxygen species (ROS), which exerted an oxidizing effect that converted L-Arg into nitric oxide (NO), thus alleviating hypoxia, sensitizing chemotherapy and increasing the CD8 + cytotoxic T lymphocytes (CTLs) infiltration. Combined with the chemotherapeutic drug PTX-induced immunogenic cell death (ICD), this promising strategy could enhance immunotherapy synergistically and realize powerful tumor treatment effect. Taken together, L-Arg@PTX nanodroplets was a very hopeful vehicle that integrated drug delivery, diagnostic imaging, and chemoimmunotherapy.