α-Cyclodextrin and α-Cyclodextrin Polymers as Oxygen Nanocarriers to Limit Hypoxia/Reoxygenation Injury: Implications from an In Vitro Model

Sustained release of gaseous chlorine dioxide from alpha-cyclodextrin: An innovative method for strawberry preservation

The traditional method of generating chlorine dioxide (ClO2) involves reacting sodium chlorite with acid on-site, posing high safety risks of concentrated ClO2. This study encapsulates ClO2 molecules directly in α-cyclodextrin (α-CD) to form inclusion complexes (ClO2@α-CD). This approach enables stable storage and safe handling of gaseous ClO2, while its sustained-release property also provides long-term microbial inhibition. Fumigation with 0.25 g of ClO2@α-CD completely inhibited Aspergillus niger growth on potato dextrose agar (PDA). A 0.5 g dose reduced the 6-day decay incidence of A. niger-inoculated strawberries from 91.67 % (control) to 5.00 % and the severity from 58.75 % (control) to 1.25 %. In commercial storage simulations, 5 g of ClO2@α-CD reduced the natural incidence from 53.33 % (control) to 26.67 %, while preserving the weight, color, firmness, and total soluble solids (TSS)/titratable acidity (TA) ratio of strawberries. These findings suggest that ClO2@α-CD is a viable approach for controlling postharvest diseases and prolonging fruit shelf-life.

Macrophage and cardiomyocyte roles in cardioprotection: Exploiting the NLRP3 Inflammasome inhibitor INF150

BACKGROUND

Cardiovascular diseases remain the leading cause of disability and death in the Western world. Effective cardioprotection involves limiting ischemia/reperfusion injury (IRI), including cell death (pyroptosis) driven by the NLRP3 inflammasome. While various cardiac resident cellular populations contribute to cardioprotection, it remains unclear whether targeting resident macrophages is inherently cardioprotective. Given that INF150, an NLRP3 inhibitor, exhibits varying abilities to penetrate cardiomyocytes and macrophages, we sought to address this question.

METHODS

We studied the cardioprotective potential of INF150, the potent metabolite of the NLRP3 inhibitor INF195, in isolated hearts or cells. In isolated hearts, we measured infarct size, caspase-1 cleavage, and interleukins (IL) release, while in macrophages, naïve H9c2 and differentiated H9c2 cells, we analyzed cell viability, and pyroptosis markers, including IL-1β release and Gasdermin D cleavage, following hypoxia/reoxygenation (H/R).

RESULTS AND CONCLUSION

While INF150 effectively shielded macrophages from LPS/ATP challenges, it failed to penetrate H9c2 and differentiated H9c2, even at high concentrations (no changes in pyroptosis markers induced by H/R). In the isolated mice heart model, INF150 did not demonstrate cardioprotective effects: infarct size, IL-1β, cleaved caspase-1 levels did not change significantly across tested concentrations of INF150. These findings suggest that while INF150 shows promise in macrophage/phagocytic models, its inability to penetrate cardiomyocytes limits its effectiveness in the whole cardiac tissue. Our results underscore the importance of cardiomyocyte uptake for effective cardioprotection, highlighting the need for NLRP3 inhibitors capable of targeting these cells directly. Future research should focus on enhancing the delivery and cardiomyocyte uptake of NLRP3 inhibitors to achieve cardioprotection. Unlike its precursor, INF195, which penetrates H9c2 cells, INF150 does not appear to offer cardioprotection in the whole organ.

Progress on oxygen-releasing bioactive polymeric scaffolds in tissue engineering and biomedical treatment: A review

Tissue engineering presents promising avenues for addressing issues related to tissue defects and regenerative medicine. However, the translational efficacy of tissue engineering in clinical settings remains limited, primarily due to the inadequate survival rates of implanted tissue scaffolds. This is attributed to the grafts' inability to adequately supply oxygen and their dependence on the diffusion of oxygen from surrounding tissues for tissue regeneration. The integration of oxygen-releasing materials in human tissue engineering is anticipated to enhance the hypoxic microenvironment for tissue regeneration. In recent years, a variety of oxygen-producing or oxygen-carrying biomacromolecules, including gelatin, chitosan, and alginate, have been developed, offering innovative strategies for controlled drug release efficacy, regenerative medicine, and biological systems engineering. This review examines applications of these oxygen-releasing biological macromolecules, primarily derived from natural polymeric materials, in diverse facets of human tissue engineering including skin, heart tissue, tumor therapy. We also highlight recent advancements in this field, with an emphasis on current challenges, potential solutions, and future perspectives.

Nanomedicine: A great boon for cardiac regenerative medicine

Cardiovascular disease (CVD) represents a significant global health challenge, remaining the leading cause of illness and mortality worldwide. The adult heart's limited regenerative capacity poses a major obstacle in repairing extensive damage caused by conditions like myocardial infarction. In response to these challenges, nanomedicine has emerged as a promising field aimed at improving treatment outcomes through innovative drug delivery strategies. Nanocarriers, such as nanoparticles (NPs), offer a revolutionary approach by facilitating targeted delivery of therapeutic agents directly to the heart. This precise delivery system holds immense potential for treating various cardiac conditions by addressing underlying mechanisms such as inflammation, oxidative stress, cell death, extracellular matrix remodeling, prosurvival signaling, and angiogenic pathways associated with ischemia-reperfusion injury. In this review, we provide a concise summary of the fundamental mechanisms involved in cardiac remodeling and regeneration. We explore how nanoparticle-based drug delivery systems can effectively target the afore-mentioned mechanisms. Furthermore, we discuss clinical trials that have utilized nanoparticle-based drug delivery systems specifically designed for cardiac applications. These trials demonstrate the potential of nanomedicine in clinical settings, paving the way for future advancements in cardiac therapeutics through precise and efficient drug delivery. Overall, nanomedicine holds promise in revolutionizing the treatment landscape of cardiovascular diseases by offering targeted and effective therapeutic strategies that address the complex pathophysiology of cardiac injuries.

Research Progress on Using Nanoparticles to Enhance the Efficacy of Drug Therapy for Chronic Mountain Sickness

Chronic mountain sickness (CMS) poses a significant health risk to individuals who rapidly ascend to high altitudes, potentially endangering their lives. Nanoparticles (NPs) offer an effective means of transporting and delivering drugs, protecting nucleic acids from nuclease degradation, and mediating the expression of target genes in specific cells. These NPs are almost non-toxic and easy to prepare and store, possess a large surface area, exhibit good biocompatibility and degradability, and maintain good stability. They can be utilized in the treatment of CMS to enhance the therapeutic efficacy of drugs. This paper provides an overview of the impact of NPs on CMS, discussing their roles as nanocarriers and their potential in CMS treatment. It aims to present novel therapeutic strategies for the clinical management of CMS and summarizes the relevant pathways through which NPs contribute to plateau disease treatment, providing a theoretical foundation for future clinical research.

Gasotransmitters and noble gases in cardioprotection: unraveling molecular pathways for future therapeutic strategies

Despite recent progress, ischemic heart disease poses a persistent global challenge, driving significant morbidity and mortality. The pursuit of therapeutic solutions has led to the emergence of strategies such as ischemic preconditioning, postconditioning, and remote conditioning to shield the heart from myocardial ischemia/reperfusion injury (MIRI). These ischemic conditioning approaches, applied before, after, or at a distance from the affected organ, inspire future therapeutic strategies, including pharmacological conditioning. Gasotransmitters, comprising nitric oxide, hydrogen sulfide, sulfur dioxide, and carbon monoxide, play pivotal roles in physiological and pathological processes, exhibiting shared features such as smooth muscle relaxation, antiapoptotic effects, and anti-inflammatory properties. Despite potential risks at high concentrations, physiological levels of gasotransmitters induce vasorelaxation and promote cardioprotective effects. Noble gases, notably argon, helium, and xenon, exhibit organ-protective properties by reducing cell death, minimizing infarct size, and enhancing functional recovery in post-ischemic organs. The protective role of noble gases appears to hinge on their modulation of molecular pathways governing cell survival, leading to both pro- and antiapoptotic effects. Among noble gases, helium and xenon emerge as particularly promising in the field of cardioprotection. This overview synthesizes our current understanding of the roles played by gasotransmitters and noble gases in the context of MIRI and cardioprotection. In addition, we underscore potential future developments involving the utilization of noble gases and gasotransmitter donor molecules in advancing cardioprotective strategies.

Engineering Synthetic Erythrocytes as Next-Generation Blood Substitutes

Blood scarcity is one of the main causes of healthcare disruptions worldwide, with blood shortages occurring at an alarming rate. Over the last decades, blood substitutes has aimed at reinforcing the supply of blood, with several products (e.g., hemoglobin-based oxygen carriers, perfluorocarbons) achieving a limited degree of success. Regardless, there is still no widespread solution to this problem due to persistent challenges in product safety and scalability. In this Review, we describe different advances in the field of blood substitution, particularly in the development of artificial red blood cells, otherwise known as engineered erythrocytes. We categorize the different strategies into natural, synthetic, or hybrid approaches, and discuss their potential in terms of safety and scalability. We identify synthetic engineered erythrocytes as the most powerful approach, and describe erythrocytes from a materials engineering perspective. We review their biological structure and function, as well as explore different methods of assembling a material-based cell. Specifically, we discuss how to recreate size, shape, and deformability through particle fabrication, and how to recreate the functional machinery through synthetic biology and nanotechnology. We conclude by describing the versatile nature of synthetic erythrocytes in medicine and pharmaceuticals and propose specific directions for the field of erythrocyte engineering.

Enhancing Heart Transplantation: Utilizing Gas-Loaded Nanocarriers to Mitigate Cold/Hypoxia Stress

Gas-loaded nanocarriers (G-LN) show promise in improving heart transplantation (HTx) outcomes. Given their success in reducing cell death during normothermic hypoxia/reoxygenation (H/R) in vitro, we tested their integration into cardioplegic solutions and static cold storage (SCS) during simulated HTx. Wistar rat hearts underwent four hours of SCS with four G-LN variants: O2- or N2-cyclic-nigerosyl-nigerose-nanomonomers (CNN), and O2- or N2-cyclic-nigerosyl-nigerose-nanosponges (CNN-NS). We monitored physiological-hemodynamic parameters and molecular markers during reperfusion to assess cell damage/protection. Hearts treated with nanomonomers (N2-CNN or O2-CNN) showed improvements in left ventricular developed pressure (LVDP) and a trend towards faster recovery of the rate pressure product (RPP) compared to controls. However, nanosponges (N2-CNN-NS or O2-CNN-NS) did not show similar improvements. None of the groups exhibited an increase in diastolic left ventricular pressure (contracture index) during reperfusion. Redox markers and apoptosis/autophagy pathways indicated an increase in Beclin 1 for O2-CNN and in p22phox for N2-CNN, suggesting alterations in autophagy and the redox environment during late reperfusion, which might explain the gradual decline in heart performance. The study highlights the potential of nanomonomers to improve early cardiac performance and mitigate cold/H/R-induced stunning in HTx. These early improvements suggest a promising avenue for increasing HTx success. Nevertheless, further research and optimization are needed before clinical application.

Oxygen Nanocarriers for Improving Cardioplegic Solution Performance: Physico-Chemical Characterization

Nanocarriers for oxygen delivery have been the focus of extensive research to ameliorate the therapeutic effects of current anti-cancer treatments and in the organ transplant field. In the latter application, the use of oxygenated cardioplegic solution (CS) during cardiac arrest is certainly beneficial, and fully oxygenated crystalloid solutions may be excellent means of myocardial protection, albeit for a limited time. Therefore, to overcome this drawback, oxygenated nanosponges (NSs) that can store and slowly release oxygen over a controlled period have been chosen as nanocarriers to enhance the functionality of cardioplegic solutions. Different components can be used to prepare nanocarrier formulations for saturated oxygen delivery, and these include native α-cyclodextrin (αCD), αcyclodextrin-based nanosponges (αCD-NSs), native cyclic nigerosyl-nigerose (CNN), and cyclic nigerosyl-nigerose-based nanosponges (CNN-NSs). Oxygen release kinetics varied depending on the nanocarrier used, demonstrating higher oxygen release after 24 h for NSs than the native αCD and CNN. CNN-NSs presented the highest oxygen concentration (8.57 mg/L) in the National Institutes of Health (NIH) CS recorded at 37 °C for 12 h. The NSs retained more oxygen at 1.30 g/L than 0.13 g/L. These nanocarriers have considerable versatility and the ability to store oxygen and prolong the amount of time that the heart remains in hypothermic CS. The physicochemical characterization presents a promising oxygen-carrier formulation that can prolong the release of oxygen at low temperatures. This can make the nanocarriers suitable for the storage of hearts during the explant and transport procedure.

Oxygen-releasing biomaterials for chronic wounds breathing: From theoretical mechanism to application prospect

Chronic wounds have always been considered as "gordian knots" in medicine, in which hypoxia plays a key role in blocking healing. To address this challenge, although tissue reoxygenation therapy based on hyperbaric oxygen therapy (HBOT) has been performed clinically for several years, the bench to bedside still urges the evolution of oxygen-loading and -releasing strategies with explicit benefits and consistent outcome. The combination of various oxygen carriers with biomaterials has gained momentum as an emerging therapeutic strategy in this field, exhibiting considerable application potential. This review gives an overview of the essential relationship between hypoxia and delayed wound healing. Further, detailed characteristics, preparation methods and applications of various oxygen-releasing biomaterials (ORBMs) will be elaborated, including hemoglobin, perfluorocarbon, peroxide, and oxygen-generating microorganisms, those biomaterials are applied to load, release or generate a vast of oxygen to relieve the hypoxemia and bring the subsequent cascade effect. The pioneering papers regarding to the ORBMs practice are presented and trends toward hybrid and more precise manipulation are summarized.

Dexmedetomidine attenuates myocardial ischemia-reperfusion injury via inhibiting ferroptosis by the cAMP/PKA/CREB pathway

This study is to investigate the effects of dexmedetomidine on myocardial ischemia-reperfusion (I/R) injury and its molecular mechanisms. H9c2 cell injury model was constructed by the hypoxia/normoxia (H/R) conditions. Besides, cAMP response element-binding protein (CREB) overexpression and knockdown cell lines were constructed. Cell viability was determined by cell-counting kit 8. Biochemical assays were used to detect oxidative stress-related biomarkers, cell apoptosis, and ferroptosis-related markers. Our results showed that dexmedetomidine's protective effects on H/R-induced cell damage were reversed by the inhibition of protein kinase A (PKA), CREB, and extracellular signal regulated kinase 1/2 (ERK1/2). Treatment of dexmedetomidine ameliorated oxidative stress in the cardiomyocytes induced by H/R, whereas inhibition of PKA, CREB, or ERK1/2 reversed these protective effects. Cell death including cell necrosis, apoptosis, and ferroptosis was found in the cells under H/R insult. Interestingly, targeting CREB ameliorated ferroptosis and oxidative stress in these cells. In conclusion, dexmedetomidine attenuates myocardial I/R injury by suppressing ferroptosis through the cAMP/PKA/CREB signaling pathway.

Janus, or the Inevitable Battle Between Too Much and Too Little Oxygen

Significance: Oxygen levels are key regulators of virtually every living mammalian cell, under both physiological and pathological conditions. Starting from embryonic and fetal development, through the growth, onset, and progression of diseases, oxygen is a subtle, although pivotal, mediator of key processes such as differentiation, proliferation, autophagy, necrosis, and apoptosis. Hypoxia-driven modifications of cellular physiology are investigated in depth or for their clinical and translational relevance, especially in the ischemic scenario. Recent Advances: The mild or severe lack of oxygen is, undoubtedly, related to cell death, although abundant evidence points at oscillating oxygen levels, instead of permanent low pO₂, as the most detrimental factor. Different cell types can consume oxygen at different rates and, most interestingly, some cells can shift from low to high consumption according to the metabolic demand. Hence, we can assume that, in the intracellular compartment, oxygen tension varies from low to high levels depending on both supply and consumption. Critical Issues: The positive balance between supply and consumption leads to a pro-oxidative environment, with some cell types facing hypoxia/hyperoxia cycles, whereas some others are under fairly constant oxygen tension. Future Directions: Within this frame, the alterations of oxygen levels (dysoxia) are critical in two paradigmatic organs, the heart and brain, under physiological and pathological conditions and the interactions of oxygen with other physiologically relevant gases, such as nitric oxide, can alternatively contribute to the worsening or protection of ischemic organs. Further, the effects of dysoxia are of pivotal importance for iron metabolism. Antioxid. Redox Signal. 37, 972-989.

Nanoparticle-based drug delivery systems for the treatment of cardiovascular diseases

Cardiovascular disease is the most common health problem worldwide and remains the leading cause of morbidity and mortality. Despite recent advances in the management of cardiovascular diseases, pharmaceutical treatment remains suboptimal because of poor pharmacokinetics and high toxicity. However, since being harnessed in the cancer field for the delivery of safer and more effective chemotherapeutics, nanoparticle-based drug delivery systems have offered multiple significant therapeutic effects in treating cardiovascular diseases. Nanoparticle-based drug delivery systems alter the biodistribution of therapeutic agents through site-specific, target-oriented delivery and controlled drug release of precise medicines. Metal-, lipid-, and polymer-based nanoparticles represent ideal materials for use in cardiovascular therapeutics. New developments in the therapeutic potential of drug delivery using nanoparticles and the application of nanomedicine to cardiovascular diseases are described in this review. Furthermore, this review discusses our current understanding of the potential role of nanoparticles in metabolism and toxicity after therapeutic action, with a view to providing a safer and more effective strategy for the treatment of cardiovascular disease.

Identification of a βCD-Based Hyper-Branched Negatively Charged Polymer as HSV-2 and RSV Inhibitor

Cyclodextrins and cyclodextrin derivatives were demonstrated to improve the antiviral potency of numerous drugs, but also to be endowed with intrinsic antiviral action. They are suitable building blocks for the synthesis of functionalized polymer structures with potential antiviral activity. Accordingly, four water-soluble hyper-branched beta cyclodextrin (βCD)-based anionic polymers were screened against herpes simplex virus (HSV-2), respiratory syncytial virus (RSV), rotavirus (HRoV), and influenza virus (FluVA). They were characterized by FTIR-ATR, TGA, elemental analyses, zeta-potential measurements, and potentiometric titrations, while the antiviral activity was investigated with specific in vitro assays. The polymer with the highest negative charge, pyromellitic dianhydride-linked polymer (P_PMDA), showed significant antiviral action against RSV and HSV-2, by inactivating RSV free particles and by altering HSV-2 binding to the cell. The polymer fraction with the highest molecular weight showed the strongest antiviral activity and both P_PMDA and its active fractions were not toxic for cells. Our results suggest that the polymer virucidal activity against RSV can be exploited to produce new antiviral materials to counteract the virus dissemination through the air or direct contact. Additionally, the strong HSV-2 binding inhibition along with the water solubility of P_PMDA and the acyclovir complexation potential of βCD are attractive features for developing new therapeutic topical options against genital HSV-2 infection.

Implementation of Water-Soluble Cyclodextrin-Based Polymers in Biomedical Applications: How Far are we?

Cyclodextrin-based polymers can be prepared starting from the naturally occurring monomers following green and low-cost procedures. They can be selectively derivatized pre- or post-polymerization allowing to fine-tune functionalities of ad hoc customized polymers. Preparation nowadays has reached the 100 g scale thanks also to the interest of industries in these extremely versatile compounds. During the last 15 years these macromolecules have been the object of intense investigations in view of possible biomedical applications as the ultimate goal and large amounts of scientific data are now available. Compared to their monomeric models, already used in the formulation of various therapeutic agents, they display superior behavior in terms of their solubility in water and solubilizing power towards drugs incompatible with biological fluids. Moreover, they allow the combination of more than one type of therapeutic agent in the polymeric system. In this review we provide a complete state-of-the-art on the knowledge and potentialities of water-soluble cyclodextrin-based polymers as therapeutic agents as well as carrier systems for different types of therapeutics to implement combination therapy. Finally, we give a perspective on their assets for innovation in disease treatment as well as their limits that still need to be addressed. This article is protected by copyright. All rights reserved.

Nanocarriers Loaded with Oxygen to Improve the Protection of the Heart to be Transplanted

In the case of serious cardiovascular diseases, such as refractory heart failure, heart transplantation is the only possible intervention. Currently, the modes of organ transport in hypothermic cardioplegic solution do not allow the implantation of the heart beyond 4-5 hours from the explant. The heart being an organ with a greater consumption of oxygen and high metabolism than the brain, its transport in hypothermic cardioplegic solutions presents critical issues in terms of time and conservation. An ambitious goal of many researchers and clinicians is to minimize the hypoxia of the explanted heart and extend the permanence time in cardioplegic solution without damage from hypoxia. Adequately oxygenating the explanted organs may extend the usability time of the explanted organ. This challenge has been pursued for years with approaches that are often expensive, risky, and/or difficult to use. We propose to consider oxygenated nanocarriers realizing oxygen for a long time. In this way, it will also be possible to use organs from distant countries with respect to the recipient, thus exceeding the canonical 4-5 hours tolerated up to now. In addition to the lack of oxygen, the transplanted organ can undergo the accumulation of catabolites due to the lack of perfusion during transport. Therefore, nanocarriers can also be perfused in adequate solution during organ transportation. A better oxygenation improving the postoperative recovery of the transplanted heart will improve the recipient's quality of life.

Oxygen-Releasing Biomaterials: Current Challenges and Future Applications

Oxygen is essential for the survival, function, and fate of mammalian cells. Oxygen tension controls cellular behaviour via metabolic programming, which in turn controls tissue regeneration, stem cell differentiation, drug metabolism, and numerous pathologies. Thus, oxygen-releasing biomaterials represent a novel and unique strategy to gain control over a variety of in vivo processes. Consequently, numerous oxygen-generating or carrying materials have been developed in recent years, which offer innovative solutions in the field of drug efficiency, regenerative medicine, and engineered living systems. In this review, we discuss the latest trends, highlight current challenges and solutions, and provide a future perspective on the field of oxygen-releasing materials.

Percutaneous Coronary Intervention (PCI) Reprograms Circulating Extracellular Vesicles from ACS Patients Impairing Their Cardio-Protective Properties

Extracellular vesicles (EVs) are promising therapeutic tools in the treatment of cardiovascular disorders. We have recently shown that EVs from patients with Acute Coronary Syndrome (ACS) undergoing sham pre-conditioning, before percutaneous coronary intervention (PCI) were cardio-protective, while EVs from patients experiencing remote ischemic pre-conditioning (RIPC) failed to induce protection against ischemia/reperfusion Injury (IRI). No data on EVs from ACS patients recovered after PCI are currently available. Therefore, we herein investigated the cardio-protective properties of EVs, collected after PCI from the same patients. EVs recovered from 30 patients randomly assigned (1:1) to RIPC (EV-RIPC) or sham procedures (EV-naive) (NCT02195726) were characterized by TEM, FACS and Western blot analysis and evaluated for their mRNA content. The impact of EVs on hypoxia/reoxygenation damage and IRI, as well as the cardio-protective signaling pathways, were investigated in vitro (HMEC-1 + H9c2 co-culture) and ex vivo (isolated rat heart). Both EV-naive and EV-RIPC failed to drive cardio-protection both in vitro and ex vivo. Consistently, EV treatment failed to activate the canonical cardio-protective pathways. Specifically, PCI reduced the EV-naive Dusp6 mRNA content, found to be crucial for their cardio-protective action, and upregulated some stress- and cell-cycle-related genes in EV-RIPC. We provide the first evidence that in ACS patients, PCI reprograms the EV cargo, impairing EV-naive cardio-protective properties without improving EV-RIPC functional capability.

Characteristic of Cyclodextrins: Their Role and Use in the Pharmaceutical Technology

About 40% of newly-discovered entities are poorly soluble in water, and this may be an obstacle in the creation of new drugs. To address this problem, the present review article examines the structure and properties of cyclodextrins and the formation and potential uses of drug - cyclodextrin inclusion complexes. Cyclodextrins are cyclic oligosaccharides containing six or more D-(+)- glucopyranose units linked by α-1,4-glycosidic bonds, which are characterized by a favourable toxicological profile, low local toxicity and low mucous and eye irritability; they are virtually non-toxic when administered orally. They can be incorporated in the formulation of new drugs in their natural form (α-, β-, γ-cyclodextrin) or as chemically-modified derivatives. They may also be used as an excipient in drugs delivered by oral, ocular, dermal, nasal and rectal routes, as described in the present paper. Cyclodextrins are promising compounds with many beneficial properties, and their use may be increasingly profitable for pharmaceutical scientists.

Oxygen in Metabolic Dysfunction and Its Therapeutic Relevance

Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease, and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at a high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Further, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction to find appropriate therapeutic targets. Future Directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and its related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders. Antioxid. Redox Signal. 35, 642-687.

Extracellular vesicles from patients with Acute Coronary Syndrome impact on ischemia-reperfusion injury

The relevance of extracellular vesicles (EV) as mediators of cardiac damage or recovery upon Ischemia Reperfusion Injury (IRI) and Remote Ischemic PreConditioning (RIPC) is controversial. This study aimed to investigate whether serum-derived EV, recovered from patients with Acute Coronary Syndrome (ACS) and subjected to the RIPC or sham procedures, may be a suitable therapeutic approach to prevent IRI during Percutaneous-Coronary-Intervention (PCI). A double-blind, randomized, sham-controlled study (NCT02195726) has been extended, and EV were recovered from 30 patients who were randomly assigned (1:1) to undergo the RIPC- (EV-RIPC) or sham-procedures (EV-naive) before PCI. Patient-derived EV were analyzed by TEM, FACS and western blot. We found that troponin (TnT) was enriched in EV, compared to healthy subjects, regardless of diagnosis. EV-naive induced protection against IRI, both in-vitro and in the rat heart, unlike EV-RIPC. We noticed that EV-naive led to STAT-3 phosphorylation, while EV-RIPC to Erk-1/2 activation in the rat heart. Pre-treatment of the rat heart with specific STAT-3 and Erk-1/2 inhibitors led us to demonstrate that STAT-3 is crucial for EV-naive-mediated protection. In the same model, Erk-1/2 inhibition rescued STAT-3 activation and protection upon EV-RIPC treatment. 84 Human Cardiovascular Disease mRNAs were screened and DUSP6 mRNA was found enriched in patient-derived EV-naive. Indeed, DUSP6 silencing in EV-naive prevented STAT-3 phosphorylation and cardio-protection in the rat heart. This analysis of ACS-patients' EV proved: (i) EV-naive cardio-protective activity and mechanism of action; (ii) the lack of EV-RIPC-mediated cardio-protection; (iii) the properness of the in-vitro assay to predict EV effectiveness in-vivo.

Cyclodextrin Monomers and Polymers for Drug Activity Enhancement

Cyclodextrins (CDs) and cyclodextrin (CD)-based polymers are well-known complexing agents. One of their distinctive features is to increase the quantity of a drug in a solution or improve its delivery. However, in certain instances, the activity of the solutions is increased not only due to the increase of the drug dose but also due to the drug complexation. Based on numerous studies reviewed, the drug appeared more active in a complex form. This review aims to summarize the performance of CDs and CD-based polymers as activity enhancers. Accordingly, the review is divided into two parts, i.e., the effect of CDs as active drugs and as enhancers in antimicrobials, antivirals, cardiovascular diseases, cancer, neuroprotective agents, and antioxidants.

Cyclic Nigerosyl-Nigerose as Oxygen Nanocarrier to Protect Cellular Models from Hypoxia/Reoxygenation Injury: Implications from an In Vitro Model

Heart failure (HF) prevalence is increasing among the aging population, and the mortality rate remains unacceptably high despite improvements in therapy. Myocardial ischemia (MI) and, consequently, ischemia/reperfusion injury (IRI), are frequently the basis of HF development. Therefore, cardioprotective strategies to limit IRI are mandatory. Nanocarriers have been proposed as alternative therapy for cardiovascular disease. Controlled reoxygenation may be a promising strategy. Novel nanocarriers, such as cyclic nigerosyl-nigerose (CNN), can be innovative tools for oxygen delivery in a controlled manner. In this study we analyzed new CNN-based formulations as oxygen nanocarriers (O₂-CNN), and compared them with nitrogen CNN (N₂-CNN). These different CNN-based formulations were tested using two cellular models, namely, cardiomyoblasts (H9c2), and endothelial (HMEC) cell lines, at different concentrations. The effects on the growth curve during normoxia (21% O₂, 5% CO₂ and 74% N₂) and their protective effects during hypoxia (1% O₂, 5% CO₂ and 94% N₂) and reoxygenation (21% O₂, 5% CO₂ and 74% N₂) were studied. Neither O₂-CNN nor N₂-CNN has any effect on the growth curve during normoxia. However, O₂-CNN applied before hypoxia induces a 15–30% reduction in cell mortality after hypoxia/re-oxygenation when compared to N₂-CNN. O₂-CNN showed a marked efficacy in controlled oxygenation, which suggests an interesting potential for the future medical application of soluble nanocarrier systems for MI treatment.

Drug-Encapsulated Cyclodextrin Nanosponges

To date, a number of nanocarriers, either inorganic or organic, have been developed to improve the delivery and therapeutic efficacy of various drugs. Drug delivery systems have attempted to overcome the undesirable pharmacokinetic problems encountered. Among the various nanomaterials that have been designed as potential nanocarriers, cyclodextrin-based polymers are of particular interest in this review.Cyclodextrins (CD) are a class of cyclic glucopyranose oligomers, obtained from starch by enzymatic action, with a characteristic toroidal shape that forms a truncated cone-shaped lipophilic cavity. The main common native cyclodextrins are named α, β, and γ which comprise six, seven, and eight glucopyranose units, respectively. Cyclodextrins have the capability to include compounds whose size and polarity are compatible with those of their cavity.Cyclodextrin-based cross-linked polymers, often referred to as "cyclodextrin nanosponges" (CDNSs), attract great attention from researchers for solving major bioavailability problems such as inadequate solubility, poor dissolution rate, and limited stability of some agents, as well as increasing their effectiveness and decreasing unwanted side effects.Registered patents about this novel system in various fields, different pharmaceutical applications, and classes of drugs encapsulated by CDNSs are detailed. The features outlined make CDNSs a promising platform for the development of innovative and advanced delivery systems.

Comparative Evaluation of Different Chitosan Species and Derivatives as Candidate Biomaterials for Oxygen-Loaded Nanodroplet Formulations to Treat Chronic Wounds

Persistent hypoxia is a main clinical feature of chronic wounds. Intriguingly, oxygen-loaded nanodroplets (OLNDs), filled with oxygen-solving 2H,3H-decafluoropentane and shelled with polysaccharides, have been proposed as a promising tool to counteract hypoxia by releasing a clinically relevant oxygen amount in a time-sustained manner. Here, four different types of chitosan (low or medium weight (LW or MW), glycol-(G-), and methylglycol-(MG-) chitosan) were compared as candidate biopolymers for shell manufacturing. The aim of the work was to design OLND formulations with optimized physico-chemical characteristics, efficacy in oxygen release, and biocompatibility. All OLND formulations displayed spherical morphology, cationic surfaces, ≤500 nm diameters (with LW chitosan-shelled OLNDs being the smallest), high stability, good oxygen encapsulation efficiency, and prolonged oxygen release kinetics. Upon cellular internalization, LW, MW, and G-chitosan-shelled nanodroplets did not significantly affect the viability, health, or metabolic activity of human keratinocytes (HaCaT cell line). On the contrary, MG-chitosan-shelled nanodroplets showed very poor biocompatibility. Combining the physico-chemical and the biological results obtained, LW chitosan emerges as the best candidate biopolymer for future OLND application as a skin device to treat chronic wounds.

The Inflammatory Cytokine IL-3 Hampers Cardioprotection Mediated by Endothelial Cell-Derived Extracellular Vesicles Possibly via Their Protein Cargo

The biological relevance of extracellular vesicles (EV) released in an ischemia/reperfusion setting is still unclear. We hypothesized that the inflammatory microenvironment prevents cardioprotection mediated by endothelial cell (EC)-derived extracellular vesicles. The effects of naïve EC-derived EV (eEV) or eEV released in response to interleukin-3 (IL-3) (eEV-IL-3) were evaluated in cardiomyoblasts (H9c2) and rat hearts. In transwell assay, eEV protected the H9c2 exposed to hypoxia/reoxygenation (H/R) more efficiently than eEV-IL-3. Conversely, only eEV directly protected H9c2 cells to H/R-induced damage. Consistent with this latter observation, eEV, but not eEV-IL-3, exerted beneficial effects in the whole heart. Protein profiles of eEV and eEV-IL-3, established using label-free mass spectrometry, demonstrated that IL-3 drives changes in eEV-IL-3 protein cargo. Gene ontology analysis revealed that both eEV and eEV-IL-3 were equipped with full cardioprotective machinery, including the Nitric Oxide Signaling in the Cardiovascular System. eEV-IL-3 were also enriched in the endothelial-nitric oxide-synthase (eNOS)-antagonist caveolin-1 and proteins related to the inflammatory response. In vitro and ex vivo experiments demonstrated that a functional Mitogen-Activated Protein Kinase Kinase (MEK1/2)/eNOS/guanylyl-cyclase (GC) pathway is required for eEV-mediated cardioprotection. Consistently, eEV were found enriched in MEK1/2 and able to induce the expression of B-cell-lymphoma-2 (Bcl-2) and the phosphorylation of eNOS in vitro. We conclude that an inflammatory microenvironment containing IL-3 changes the eEV cargo and impairs eEV cardioprotective action.

Biomedical Application of Cyclodextrin Polymers Cross-Linked via Dianhydrides of Carboxylic Acids

Cyclodextrin-based nanosponges (CD-NS) are a novel class of polymers cross-linked with a three-dimensional network and can be obtained from cyclodextrins (CD) and pyromellitic dianhydride. Their properties, such as their ability to form an inclusion complex with drugs, can be used in biomedical science, as nanosponges influence stability, toxicity, selectivity, and controlled release. Most pharmaceutical research use CD-NS for the delivery of drugs in cancer treatment. Application of molecular targeting techniques result in increased selectivity of CD-NS; for example, the addition of disulfide bridges to the polymer structure makes the nanosponge sensitive to the presence of glutathione, as it can reduce such disulfide bonds to thiol moieties. Other delivery applications include dermal transport of pain killers or photosensitizers and delivery of oxygen to heart cells. This gives rise to the opportunity to transition to medical scaffolds, but more, in modern times, to create an ultrasensitive biosensor, which employs the techniques of surface-modified nanoparticles and molecularly imprinted polymers (MIP). The following review focuses on the biomedical research of cyclodextrin polymers cross-linked via dianhydrides of carboxylic acids.

An ultrasound activated oxygen generation nanosystem specifically alleviates myocardial hypoxemia and promotes cell survival following acute myocardial infarction

Hypoxemia after acute myocardial infarction (AMI) causes severe damage to cardiac cells and induces cardiac dysfunction. Protection of cardiac cells and reconstruction of cardiac functions by re-introducing oxygen into the infarcted myocardium represents an efficient approach for the treatment of AMI. However, the established methods for oxygen supplementation mainly focus on systemic oxygen delivery, which always results in inevitable oxidative stress on normal tissues. In this work, an ultrasound (US) activated oxygen generation nanosystem has been developed, which specifically releases oxygen in the infarcted myocardium and alleviates the hypoxemic myocardial microenvironment to protect cardiac cells after AMI. The nanosystem was constructed through the formation of calcium peroxide in the mesopores of biocompatible mesoporous silica nanoplatforms, followed by the assembly of the thermosensitive material heneicosane and polyethyleneglycol. The mild hyperthermia induced by US irradiation triggered the phase change of heneicosane, thus achieving US responsive diffusion of water and release of oxygen. The US-activated oxygen release significantly alleviated the hypoxia and facilitated the mitigation of oxidative stress after AMI. Consequently, the survival of cardiac cells under hypoxic conditions was substantially improved and the damage in the infarcted myocardial tissue was minimized. This US-activated oxygen generation nanosystem may provide an efficient modality for the treatment of AMI.

History of Cyclodextrin Nanosponges

Nowadays, research in the field of nanotechnology and nanomedicine has become increasingly predominant, focusing on the manipulation and development of materials on a nanometer scale. Polysaccharides have often been used as they are safe, non-toxic, hydrophilic, biodegradable and are low cost. Among them, starch derivatives and, in particular, cyclodextrin-based nanosponges (CD NSs) have recently emerged due to the outstanding properties attributable to their peculiar structure. In fact, alongside the common polysaccharide features, such as the presence of tunable functional groups and their ability to interact with biological tissues, thus giving rise to bioadhesion, which is particularly useful in drug delivery, what makes CD NSs unique is their three-dimensional network made up of crosslinked cyclodextrin units. The name “nanosponge” appeared for the first time in the 1990s due to their nanoporous, sponge-like structure and responded to the need to overcome the limitations of native cyclodextrins (CDs), particularly their water solubility and inability to encapsulate charged and large molecules efficiently. Since CD NSs were introduced, efforts have been made over the years to understand their mechanism of action and their capability to host molecules with low or high molecular weight, charged, hydrophobic or hydrophilic by changing the type of cyclodextrin, crosslinker and degree of crosslinking used. They enabled great advances to be made in various fields such as agroscience, pharmaceutical, biomedical and biotechnological sectors, and NS research is far from reaching its conclusion. This review gives an overview of CD NS research, focusing on the origin and key points of the historical development in the last 50 years, progressing from relatively simple crosslinked networks in the 1960s to today’s multifunctional polymers. The approach adopted in writing the present study consisted in exploring the historical evolution of NSs in order to understand their role today, and imagine their future.

Nanoparticle delivery of cardioprotective therapies

Acute myocardial infarction (AMI), and the heart failure (HF) that often follows, are leading causes of death and disability worldwide. Crucially, there are currently no effective treatments, other than myocardial reperfusion, for reducing myocardial infarct (MI) size and preventing HF following AMI. Thus, there is an unmet need to discover novel cardioprotective therapies to reduce MI size, and prevent HF in AMI patients. Although a large number of therapies have been shown to reduce MI size in experimental studies, the majority have failed to benefit AMI patients. Failure to deliver cardioprotective therapy to the ischemic heart in sufficient concentrations following AMI is a major factor for the lack of success observed in previous clinical cardioprotection studies. Therefore, new strategies are needed to improve the delivery of cardioprotective therapies to the ischemic heart following AMI. In this regard, nanoparticles have emerged as drug delivery systems for improving the bioavailability, delivery, and release of cardioprotective therapies, and should result in improved efficacy in terms of reducing MI size and preventing HF. In this article, we provide a review of currently available nanoparticles, some of which have been FDA-approved, in terms of their use as drug delivery systems in cardiovascular disease and cardioprotection.

Retracted Article: Long noncoding RNA ANRIL protects cardiomyocytes against hypoxia/reoxygenation injury by sponging miR-195-5p and upregulating Bcl-2

Long noncoding RNAs have been widely accepted to play important roles in acute myocardial infarction (AMI). The dysregulation of cyclin-dependent kinase inhibitor 2B antisense RNA 1 (ANRIL) was discovered in AMI patients. Nevertheless, the detailed role and molecular mechanisms of ANRIL in AMI remain indistinct. The levels of ANRIL, miR-195-5p and Bcl-2 mRNA were determined by qRT-PCR. western blot was performed to assess the expression of Bcl-2, Bax, Cyclin D1 and p21. Cell proliferation was detected by CCK-8 assay, and cell apoptosis was measured by flow cytometry. The targeted correlation between ANRIL and miR-195-5p was confirmed by the dual-luciferase reporter and RNA pull-down assays. Our data revealed that ANRIL was downregulated and miR-195-5p was upregulated in the serum of AMI patients and hypoxia/reoxygenation (H/R)-induced myocardial cells. ANRIL upregulation or miR-195-5p knockdown alleviated H/R-induced myocardial cell injury. Moreover, ANRIL sequestered miR-195-5p by acting as a sponge of miR-195-5p. ANRIL upregulated Bcl-2 expression by sponging miR-195-5p. Additionally, ANRIL overexpression alleviated H/R-induced myocardial cell injury by upregulating Bcl-2. In conclusion, our study indicated that ANRIL upregulation alleviated H/R-induced myocardial cell injury partially through sponging miR-195-5p and upregulating Bcl-2, highlighting its role as a promising mediator for new therapies for AMI treatment.

Overcoming the Limits of Flash Nanoprecipitation: Effective Loading of Hydrophilic Drug into Polymeric Nanoparticles with Controlled Structure

Flash nanoprecipitation (FNP) is a widely used technique to prepare particulate carriers based on various polymers, and it was proven to be a promising technology for the industrial production of drug loaded nanoparticles. However, up to now, only its application to hydrophobic compounds has been deeply studied and the encapsulation of some strongly hydrophilic compounds, such as caffeine, remains a challenge. Caffeine loaded poly-ε-caprolactone (PCL) nanoparticles were produced in a confined impinging jet mixer using acetone as the solvent and water as the antisolvent. Caffeine was dissolved either in acetone or in water to assess the effects of two different process conditions. Nanoparticles properties were assessed in terms of loading capacity (LC%), encapsulation efficiency (EE%), and in vitro release kinetics. Samples were further characterized by dynamic light scattering, scanning electron microscopy, X-ray photo electron spectroscopy, and infrared spectroscopy to determine the size, morphology, and structure of nanoparticles. FNP was proved an effective technique for entrapping caffeine in PCL and to control its release behavior. The solvent used to solubilize caffeine influences the final structure of the obtained particles. It was observed that the active principle was preferentially adsorbed at the surface when using acetone, while with water, it was embedded in the matrix structure. The present research highlights the possibility of extending the range of applications of FNP to hydrophilic molecules.

Host⁻Guest Polymer Complexes

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