ROS and GSH-responsive S-nitrosoglutathione functionalized polymeric nanoparticles to overcome multidrug resistance in cancer

Nanomedicines for combating multidrug resistance of cancer

Chemotherapy typically involves the use of specific chemodrugs to inhibit the proliferation of cancer cells, but the frequent emergence of a variety of multidrug-resistant cancer cells poses a tremendous threat to our combat against cancer. The fundamental causes of multidrug resistance (MDR) have been studied for decades, and can be generally classified into two types: one is associated with the activation of diverse drug efflux pumps, which are responsible for translocating intracellular drug molecules out of the cells; the other is linked with some non-efflux pump-related mechanisms, such as antiapoptotic defense, enhanced DNA repair ability, and powerful antioxidant systems. To overcome MDR, intense efforts have been made to develop synergistic therapeutic strategies by introducing MDR inhibitors or combining chemotherapy with other therapeutic modalities, such as phototherapy, gene therapy, and gas therapy, in the hope that the drug-resistant cells can be sensitized toward chemotherapeutics. In particular, nanotechnology-based drug delivery platforms have shown the potential to integrate multiple therapeutic agents into one system. In this review, the focus was on the recent development of nanostrategies aiming to enhance the efficiency of chemotherapy and overcome the MDR of cancer in a synergistic manner. Different combinatorial strategies are introduced in detail and the advantages as well as underlying mechanisms of why these strategies can counteract MDR are discussed. This review is expected to shed new light on the design of advanced nanomedicines from the angle of materials and to deepen our understanding of MDR for the development of more effective anticancer strategies. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Nuclear-targeted nanocarriers based on pH-sensitive amphiphiles for enhanced GNA002 delivery and chemotherapy

GNA002, a novel EZH2 inhibitor, exhibits significant anticancer efficiency in solid malignant tumor therapy; however, its poor water solubility and low enrichment at tumor sites limit its clinical application and translation. In this study, an original pH-sensitive nanocarrier (cyclo (RGDyCSH) (cRGD)-poly (ethylene glycol) (PEG)-hydrazine (Hyd)-hexa-arginine (R6)-stearic acid (SA)) was designed to precisely deliver GNA002 into the nuclei of cancer cells. The PEG-modified hydrophilic shell of the spherical GNA002-loaded nanoparticles with a mean size of 143.13 ± 0.20 nm effectively facilitated the passive target of tumor tissues and prolonged the blood circulation time. Meanwhile, cRGD was used as the active targeting ligand, which promoted the accumulation of the nanoparticles in cancer cells via ανβ3-receptor-mediated endocytosis. Furthermore, the acidic environment of lysosomes triggered the rupture of the pH-sensitive hydrazine bond and the rapid formation of penetrating peptide R6-shelled secondary nanoparticles, thus enabling the lysosomal escape of the nanoparticles and the ultimate R6-mediated nuclear-targeted delivery of GNA002. Consequently, the nuclear-enriched GNA002 effectively enhanced the cytotoxicity against cancer cells both in vitro and in vivo, thus providing an original and promising drug delivery system for the targeted delivery of GNA002.

Effects of nanocapsules of poly-ε-caprolactone containing artemisinin on zebrafish early-life stages and adults

Artemisinin extracted from Artemisia annua L. plants has a range of properties that qualifies it to treat several diseases, such as malaria and cancer. However, it has short half-life, which requires making continuous use of it, which has motivated the association of artemisinin (ART) with polymeric nanoparticles to increase its therapeutic efficiency. However, the ecotoxicological safety of this association has been questioned, given the scarcity of studies in this area. Thus, in this work the toxicity of Poly (ε-Caprolactone) nanocapsules added with ART (ART-NANO) in zebrafish (Danio rerio), embryos and adults was studied. Different endpoints were analyzed in organisms exposed to ART-NANO, including those predictive of embryotoxicity and histopatoxicity. Embryotoxicity was analyzed based on Organization for Economic Co-operation and Development (OECD) test guideline (236) for fish embryo acute toxicity applied to zebrafish (Danio rerio) at 96 hpf under five nominal logarithmic concentrations (0.125 to 2.0 mg/ L). Our results demonstrate, mainly, that fertilized eggs presented increased coagulation, lack of heart rate, vitelline sac displacement and lack of somite formation. On the other hand, adult individuals (exposed to the same concentrations and evaluated after 24 and 96 h of exposure) have shown increased pericarditis. Therefore, the treatment based on ART, poly (ε-caprolactone) nanocapsules and on their combination at different concentrations have shown toxic effects on zebrafish embryos and adult individuals.

Reactive oxygen species and glutathione dual responsive nanoparticles for enhanced prostate cancer therapy

Docetaxel (DTX)-based chemotherapy of prostate cancer is still confronted with significant challenges due to insufficient drug accumulation at the tumor sites and the systemic side effects on normal cells and organs. Tumor microenvironment-responsive nanosized drug delivery systems have shown enormous potential to improve the anticancer efficacy and minimize the systemic side effects of chemotherapeutics. However, most of the currently redox-responsive nanoparticles respond only to single stimuli, which compromise the treatment effect. Hence, inspired by the abundance of reactive oxygen species (ROS) and intracellular glutathione (GSH) in cancer cells, we proposed a unique ROS and GSH dual responsive nanocarrier (PCL-SS) for DTX delivery. The DTX-loaded PCL-SS nanoparticles (PCL-SS@DTX NPs) were not only stable in a normal physiological environment but also rapidly triggered DTX release in prostate cancer cells. In vitro experiments showed that PCL-SS@DTX NPs had robust prostate cancer cell cytotoxicity, induced cell apoptosis, inhibited cell migration and invasion and exhibited satisfactory biocompatibility. In mice bearing orthotopic prostate cancer, PCL-SS@DTX NPs could accumulate in orthotopic tumor sites and then significantly weaken tumor growth by inhibiting prostate cancer cell proliferation and inducing cell apoptosis, without obvious damages to major organs. Overall, this dual responsive nanosized drug delivery system may act as a promising therapeutic option for prostate cancer chemotherapy.

Polymeric Nitric Oxide Delivery Nanoplatforms for Treating Cancer, Cardiovascular Diseases, and Infection

The shortened Abstract is as follows: Therapeutic gas nitric oxide (NO) has demonstrated the unique advances in biomedical applications due to its prominent role in regulating physiological/pathophysiological activities in terms of vasodilation, angiogenesis, chemosensitizing effect, and bactericidal effect. However, it is challenging to deliver NO, due to its short half-life (<5 s) and short diffusion distances (20-160 µm). To address these, various polymeric NO delivery nanoplatforms (PNODNPs) have been developed for cancer therapy, antimicrobial and cardiovascular therapeutics, because of the important advantages of polymeric delivery nanoplatforms in terms of controlled release of therapeutics and the extremely versatile nature. This reviews highlights the recent significant advances made in PNODNPs for NO storing and targeting delivery. The ideal and unique criteria that are required for PNODNPs for treating cancer, cardiovascular diseases and infection, respectively, are summarized. Hopefully, effective storage and targeted delivery of NO in a controlled manner using PNODNPs could pave the way for NO-sensitized synergistic therapy in clinical practice for treating the leading death-causing diseases.

H2S- and NO-releasing gasotransmitter platform: A crosstalk signaling pathway in the treatment of acute kidney injury

Acute kidney injury (AKI) is a syndrome affecting most patients hospitalized due to kidney disease; it accounts for 15 % of patients hospitalized in intensive care units worldwide. AKI is mainly caused by ischemia and reperfusion (IR) injury, which temporarily obstructs the blood flow, increases inflammation processes and induces oxidative stress. AKI treatments available nowadays present notable disadvantages, mostly for patients with other comorbidities. Thus, it is important to investigate different approaches to help minimizing side effects such as the ones observed in patients subjected to the aforementioned treatments. Therefore, the aim of the current review is to highlight the potential of two endogenous gasotransmitters - hydrogen sulfide (H₂S) and nitric oxide (NO) - and their crosstalk in AKI treatment. Both H₂S and NO are endogenous signalling molecules involved in several physiological and pathophysiological processes, such as the ones taking place in the renal system. Overall, these molecules act by decreasing inflammation, controlling reactive oxygen species (ROS) concentrations, activating/inactivating pro-inflammatory cytokines, as well as promoting vasodilation and decreasing apoptosis, hypertrophy and autophagy. Since these gasotransmitters are found in gaseous state at environmental conditions, they can be directly applied by inhalation, or in combination with H₂S and NO donors, which are compounds capable of releasing these molecules at biological conditions, thus enabling higher stability and slow release of NO and H₂S. Moreover, the combination between these donor compounds and nanomaterials has the potential to enable targeted treatments, reduce side effects and increase the potential of H₂S and NO. Finally, it is essential highlighting challenges to, and perspectives in, pharmacological applications of H₂S and NO to treat AKI, mainly in combination with nanoparticulated delivery platforms.

Nanoformulations to Enhance the Bioavailability and Physiological Functions of Polyphenols

Polyphenols are micronutrients that are widely present in human daily diets. Numerous studies have demonstrated their potential as antioxidants and anti-inflammatory agents, and for cancer prevention, heart protection and the treatment of neurodegenerative diseases. However, due to their vulnerability to environmental conditions and low bioavailability, their application in the food and medical fields is greatly limited. Nanoformulations, as excellent drug delivery systems, can overcome these limitations and maximize the pharmacological effects of polyphenols. In this review, we summarize the biological activities of polyphenols, together with systems for their delivery, including phospholipid complexes, lipid-based nanoparticles, protein-based nanoparticles, niosomes, polymers, micelles, emulsions and metal nanoparticles. The application of polyphenol nanoparticles in food and medicine is also discussed. Although loading into nanoparticles solves the main limitation to application of polyphenolic compounds, there are some concerns about their toxicological safety after entry into the human body. It is therefore necessary to conduct toxicity studies and residue analysis on the carrier.

Photodynamic Nanophotosensitizers: Promising Materials for Tumor Theranostics

Photodynamic theranostics/therapy (PDT) is a potential strategy for selectively imaging malignant sites and treating cancer via a non-invasive therapeutic method. Photosensitizers, the crucial components of PDT, enable colocalization of photons and light, and photon/light therapy in the therapeutic window of 400-900 nm exhibits photocytotoxicity to tumor cells. Due to their high biostability and photocytotoxicity, nanophotosensitizers (NPSs) are of much interest for malignant tumor theranostics at present. NPS-activated photons transfer energy through the absorption of a photon and convert molecular oxygen to the singlet reactive oxygen species, which leads to apoptosis and necrosis. Moreover, NPSs modified by polymers, including PLGA, PEG-PLA, PDLLA, PVCL-g-PLA, and P(VCL-co-VIM)-g-PLA, exhibit excellent biocompatibility, and a tumor-targeting molecule linked on the nanoparticle surface can precisely deliver NPSs into the tumor region. The development of NPSs will accelerate the progress in tumor theranostics through the photon/light pathway.

Functionalization of Polymers and Nanomaterials for Biomedical Applications: Antimicrobial Platforms and Drug Carriers

The use of polymers and nanomaterials has vastly grown for industrial and biomedical sectors during last years. Before any designation or selection of polymers and their nanocomposites, it is vital to recognize the targeted applications which require these platforms to be modified. Surface functionalization to introduce the desired type and quantity of reactive functional groups to target a cell or tissue in human body is a pivotal approach to improve the physicochemical and biological properties of these materials. Herein, advances in the functionalized polymer and nanomaterials surfaces are highlighted along with their applications in biomedical fields, e.g., antimicrobial therapy and drug delivery.

Nano Encapsulated Curcumin: And Its Potential for Biomedical Applications

Curcumin, a yellow-colored polyphenol extracted from the rhizome of turmeric root, is commonly used as a spice and nutritional supplement. It exhibits many pharmacological activities such as anti-inflammatory, anti-bacterial, anti-cancer, anti-Alzheimer, and anti-fungal. However, the therapeutic application of curcumin is limited by its extremely low solubility in aqueous buffer, instability in body fluids, and rapid metabolism. Nano delivery system has shown excellent potential to improve the solubility, biocompatibility and therapeutic effect of curcumin. In this review, we focus on the recent development of nano encapsulated curcumin and its potential for biomedical applications.