pH, redox and photothermal tri-responsive DNA/polyethylenimine conjugated gold nanorods as nanocarriers for specific intracellular co-release of doxorubicin and chemosensitizer pyronaridine to combat multidrug resistant cancer

Advances in stimuli-responsive gold nanorods for drug-delivery and targeted therapy systems

In recent years, the use of gold nanorods (AuNRs) has garnered considerable attention in biomedical applications due to their unique optical and physicochemical properties. They have been considered as potential tools for the advanced treatment of diseases by various stimuli such as magnetic fields, pH, temperature and light in the fields of targeted therapy, imaging and drug delivery. Their biocompatibility and tunable plasmonic properties make them a versatile platform for a range of biomedical applications. While endogenous stimuli have limited cargo delivery control at specific sites, exogenous stimuli are a more favored approach despite their circumscribed penetration depth for releasing the cargo at the specific target. Dual/multi-stimuli responsive AuNTs can be triggered by multiple stimuli for enhanced control and specificity in biomedical applications. This review provides to provide a summary of the biomedical applications of stimuli-responsive AuNRs, including their endogenous and exogenous properties, as well as their dual/multi-functionality and potential for clinical delivery. This review provides a comprehensive review on the improvement of therapeutic efficacy and the effective control of drug release with AuNRs, highlights AuNRs design strategies in recent years, discusses the advantages or challenges so far in the field of AuNRs. Finally, we have addressed the clinical translation bio-integrated nanoassemblies (CTBNs) in this field.

Better together: nanoscale co-delivery systems of therapeutic agents for high-performance cancer therapy

Combination therapies can enhance the sensitivity of cancer to drugs, lower drug doses, and reduce side effects in cancer treatment. However, differences in the physicochemical properties and pharmacokinetics of different therapeutic agents limit their application. To avoid the above dilemma and achieve accurate control of the synergetic ratio, a nanoscale co-delivery system (NCDS) has emerged as a prospective tool for combined therapy in cancer treatment, which is increasingly being used to co-load different therapeutic agents. In this study, we have summarized the mechanisms of therapeutic agents in combination for cancer therapy, nanoscale carriers for co-delivery, drug-loading strategies, and controlled/targeted co-delivery systems, aiming to give a general picture of these powerful approaches for future NCDS research studies.

Progress in Programmable DNA-Aided Self-Assembly of the Master Frame of a Drug Delivery System

Every year cancer causes approximately 10 million deaths globally. Researchers have developed numerous targeted drug delivery systems (DDSs) with nanoparticles, polymers, and liposomes, but these synthetic materials have poor degradability and low biocompatibility. Because DNA nanostructures have good degradability and high biocompatibility, extensive studies have been performed to construct DDSs with DNA nanostructures as the molecular-layer master frame (MF) assembled via programmable DNA-aided self-assembly for targeted drug release. To learn the progressing trend of self-assembly techniques and keep pace with their recent rapid advancements, it is crucial to provide an overview of their past and recent progress. In this review article, we first present the techniques to assemble the MF of a DDS with solely DNA strands; to assemble MFs with one or more additional type of construction materials, e.g., polymers (including RNA and protein), inorganic nanoparticle, or metal ions, in addition to DNA strands; and to assemble the more complex DNA nanocomplexes. It is observed that both the techniques used and the MFs constructed have become increasingly complex and that the DDS constructed has an increasing number of advanced functions. From our focused review, we anticipate that DDSs with the MF of multiple building materials and DNA nanocomplexes will attract an increasing number of researchers' interests. On the basis of knowledge about materials and functional components (e.g., targeting aptamers/peptides/antibodies and stimuli for drug release) obtained from previously performed studies, researchers can combine more materials with DNA strands to assemble more powerful MFs and incorporate more components to endow DDSs with improved or additional properties/functions, thereby subsequently contributing to cancer prevention.

Cascaded Nanozyme with In Situ Enhanced Photothermal Capacity for Tumor-Specific and Self-Replenishing Cancer Therapy

Reactive oxygen species (ROS)-involved tumor therapeutic strategy, chemodynamic therapy (CDT), has attracted extensive research interest in the scientific community. However, the therapeutic effect of CDT is insufficient and unsustainable owing to the limited endogenous H2 O2 level in the tumor microenvironment. Here, peroxidase (POD)-like RuTe2 nanozyme with the immobilization of glucose oxidase (GOx) and allochroic 3,3',5,5'-tetramethylbenzidine (TMB) molecule have been synthesized to construct RuTe2 -GOx-TMB nanoreactors (RGT NRs) as cascade reaction systems for tumor-specific and self-replenishing cancer therapy. GOx in sequential nanocatalysts can effectively deplete glucose in tumor cells. Meanwhile, a sustainable supply of H2 O2 for subsequent Fenton-like reactions catalyzed by RuTe2 nanozyme is achieved in response to the mild acidic tumor microenvironment. Through this cascade reaction, highly toxic hydroxyl radicals (·OH) are produced, which can further oxidize TMB to trigger tumor-specific "turn-on" photothermal therapy (PTT). In addition, PTT and massive ROS can stimulate the tumor immune microenvironment and activate the systematic anti-tumor immune responses, exerting a notable effect on hindering tumor recurrence and metastasis. This study paves a promising paradigm for synergistic starvation therapy, PTT, and CDT cancer therapy with high efficiency.

Nanodelivery systems: An efficient and target-specific approach for drug-resistant cancers

BACKGROUND

Cancer treatment is still a global health challenge. Nowadays, chemotherapy is widely applied for treating cancer and reducing its burden. However, its application might be in accordance with various adverse effects by exposing the healthy tissues and multidrug resistance (MDR), leading to disease relapse or metastasis. In addition, due to tumor heterogeneity and the varied pharmacokinetic features of prescribed drugs, combination therapy has only shown modestly improved results in MDR malignancies. Nanotechnology has been explored as a potential tool for cancer treatment, due to the efficiency of nanoparticles to function as a vehicle for drug delivery.

METHODS

With this viewpoint, functionalized nanosystems have been investigated as a potential strategy to overcome drug resistance.

RESULTS

This approach aims to improve the efficacy of anticancer medicines while decreasing their associated side effects through a range of mechanisms, such as bypassing drug efflux, controlling drug release, and disrupting metabolism. This review discusses the MDR mechanisms contributing to therapeutic failure, the most cutting-edge approaches used in nanomedicine to create and assess nanocarriers, and designed nanomedicine to counteract MDR with emphasis on recent developments, their potential, and limitations.

CONCLUSIONS

Studies have shown that nanoparticle-mediated drug delivery confers distinct benefits over traditional pharmaceuticals, including improved biocompatibility, stability, permeability, retention effect, and targeting capabilities.

Nanocarriers overcoming biological barriers induced by multidrug resistance of chemotherapeutics in 2D and 3D cancer models

Multidrug resistance (MDR) is currently a big challenge in cancer therapy and limits its success in several patients. Tumors use the MDR mechanisms to colonize the host and reduce the efficacy of chemotherapeutics that are injected as single agents or combinations. MDR mechanisms are responsible for inactivation of drugs and formbiological barriers in cancer like the drug efflux pumps, aberrant extracellular matrix, hypoxic areas, altered cell death mechanisms, etc. Nanocarriers have some potential to overcome these barriers and improve the efficacy of chemotherapeutics. In fact, they are versatile and can deliver natural and synthetic biomolecules, as well as RNAi/DNAi, thus providing a controlled release of drugs and a synergistic effect in tumor tissues. Biocompatible and safe multifunctional biopolymers, with or without specific targeting molecules, modify the surface and interface properties of nanocarriers. These modifications affect the interaction of nanocarriers with cellular models as well as the selection of suitable models for in vitro experiments. MDR cancer cells, and particularly their 2D and 3D models, in combination with anatomical and physiological structures of tumor tissues, can boost the design and preparation of nanomedicines for anticancer therapy. 2D and 3D cancer cell cultures are suitable models to study the interaction, internalization, and efficacy of nanocarriers, the mechanisms of MDR in cancer cells and tissues, and they are used to tailor a personalized medicine and improve the efficacy of anticancer treatment in patients. The description of molecular mechanisms and physio-pathological pathways of these models further allow the design of nanomedicine that can efficiently overcome biological barriers involved in MDR and test the activity of nanocarriers in 2D and 3D models of MDR cancer cells.

Repurposing Antimalarial Pyronaridine as a DNA Repair Inhibitor to Exploit the Full Potential of Gold-Nanoparticle-Mediated Radiation Response

Radiation therapy (RT) is frequently used to locally treat tumors. One of the major issues in RT is normal tissue toxicity; thus, it is necessary to limit dose escalation for enhanced local control in patients that have locally advanced tumors. Integrating radiosensitizing agents such as gold nanoparticles (GNPs) into RT has been shown to greatly increase the cure rate of solid tumors. The objective of this study was to explore the repurposing of an antimalarial drug, pyronaridine (PYD), as a DNA repair inhibitor to further enhance RT/GNP-induced DNA damage in cancerous cell lines. We were able to achieve inhibitory effects of DNA repair due to PYD at 500 nM concentration. Our results show a significant enhancement in DNA double-strand breaks of 42% in HeLa cells treated with PYD/GNP/RT in comparison to GNP/RT alone when irradiated with a dose of 2 Gy. Furthermore, there was a significant reduction in cellular proliferation for both HeLa and HCT-116 irradiated cells with the combined treatment of PYD/GNP/RT. Therefore, the emergence of promising novel concepts introduced in this study could lay the foundation for the transition of this treatment modality into clinical environments.

Hypoxia-Activatable Nanovesicles as In Situ Bombers for Combined Hydrogen-Sulfide-Mediated Respiration Inhibition and Photothermal Therapy

Photothermal therapy (PTT) has emerged as a promising alternative or supplement to cancer treatments. While PTT induces the ablation of solid tumors, its efficiency is hampered by self-recovery within impaired cancer cells through glycolysis and respiration metabolism. Based on this, the introduction of hydrogen sulfide (H₂S)-mediated respiration inhibition is a good choice to make up for the PTT limitation. Herein, nanovesicles (NP1) are integrated by a hypoxia-responsive conjugated polymer (P1), polymetric H₂S donor (P2), and near-infrared (NIR) light-harvesting aza-BODIPY dye (B1) for the delivery of H₂S and synergistic H₂S gas therapy/PTT. The scaffold of NP1 undergoes disassembly in the hypoxic environments, thus triggering the hydrolysis of P2 to continuously long-term release H₂S. Dependent on the superior photothermal ability of B1, NP1 elicits high photothermal conversion efficiency (η = 19.9%) under NIR light irradiation for PTT. Moreover, NP1 serves as in situ H₂S bombers in the hypoxic tumor environment and suppresses the mitochondrial respiration through inhibiting expression of cytochrome c oxidase (COX IV) and cutting off the adenosine triphosphate (ATP) generation. Both in vitro and in vivo results demonstrate good antitumor efficacy of H₂S gas therapy/PTT, which will be recommended as an advanced strategy for cancer therapeutics.

NIR-II bioimaging of small molecule fluorophores: From basic research to clinical applications

Due to the low autofluorescence and deep-photo penetration, the second near-infrared region fluorescence imaging technology (NIR-II, 1000-2000 nm) has been widely utilized in basic scientific research and preclinical practice throughout the past decade. The most attractive candidates for clinical translation are organic NIR-II fluorophores with a small-molecule framework, owing to their low toxicity, high synthetic repeatability, and simplicity of chemical modification. In order to enhance the translation of small molecule applications in NIR-II bioimaging, NIR-II fluorescence imaging technology has evolved from its usage in cells to the diagnosis of diseases in large animals and even humans. Although several examples of NIR-II fluorescence imaging have been used in preclinical studies, there are still many challenges that need to be addressed before they can finally be used in clinical settings. In this paper, we reviewed the evolution of the chemical structures and photophysical properties of small-molecule fluorophores, with an emphasis on their biomedical applications ranging from small animals to humans. We also explored the potential of small-molecule fluorophores.

Prostate Apoptosis Response-4 (Par-4): A Novel Target in Pyronaridine-Induced Apoptosis in Glioblastoma (GBM) Cells

Simple Summary

GBM treatment is an area of high unmet need due to the heterogeneous and anaplastic character of this cancer in turn leading to an extremely poor prognosis. Finding new molecular entities by traditional or de novo approaches to drug discovery is lengthy and expensive. Repurposing existing drugs can be attractive as the process is often less risky, more cost, and time-effective. Amongst potential drug-repurposing candidates, Pyronaridine (PYR), an antimalarial drug has shown anti-cancer effects against several cancers, however, its potential for the treatment of GBM has not been explored. In this study, we have identified a unique mechanism of action of PYR against GBM by upregulating a tumor suppressor protein, Par-4 along with the elucidation of the complex network of pathways mediated through Par-4 leading to GBM cell death.

Abstract

Glioblastoma (GBM) is an aggressive form of brain tumor with a median survival of approximately 12 months. With no new drugs in the last few decades and limited success in clinics for known therapies, drug repurposing is an attractive choice for its treatment. Here, we examined the efficacy of pyronaridine (PYR), an anti-malarial drug in GBM cells. PYR induced anti-proliferative activity in GBM cells with IC₅₀ ranging from 1.16 to 6.82 µM. Synergistic activity was observed when PYR was combined with Doxorubicin and Ritonavir. Mechanistically, PYR triggered mitochondrial membrane depolarization and enhanced the ROS levels causing caspase-3 mediated apoptosis. PYR significantly decreased markers associated with proliferation, EMT, hypoxia, and stemness and upregulated the expression of E-cadherin. Interestingly, PYR induced the expression of intracellular as well as secretory Par-4, a tumor suppressor in GBM cells, which was confirmed using siRNA. Notably, Par-4 levels in plasma samples of GBM patients were significantly lower than normal healthy volunteers. Thus, our study demonstrates for the first time that PYR can be repurposed against GBM with a novel mechanism of action involving Par-4. Herewith, we discuss the role of upregulated Par-4 in a highly interconnected signaling network thereby advocating its importance as a therapeutic target.

Synchronous conjugation of i-motif DNA and therapeutic siRNA on the vertexes of tetrahedral DNA nanocages for efficient gene silence

The functionality of DNA biomacromolecules has been widely excavated, as therapeutic drugs, carriers, and functionalized modification derivatives. In this study, we developed a series of DNA tetrahedron nanocages (Td), via synchronous conjugating different numbers of i-(X) and therapeutic siRNA on four vertexes of tetrahedral DNA nanocage (aX-Td@bsiRNA, a+b = 4). This i-motif-conjugated Td exhibited good endosomal escape behaviours in A549 tumor cells, and the escape efficiency was affected by the number of i-motif. Furthermore, the downregulating mRNA and protein expression level of epidermal growth factor receptor (EGFR) caused by this siRNA embedded Td were verified in A549 cells. The tumor growth inhibition efficiency of the 2X-Td@2siRNA treated group in tumor-bearing mice was significantly higher than that of non-i-motif-conjugated Td@2siRNA (3.14-fold) and free siRNA (3.63-fold). These results demonstrate a general strategy for endowing DNA nanostructures with endosomal escape behaviours to achieve effective in vivo gene delivery and therapy.

I, Six JL, Ferji K, Jaafar J, Boer JC, Plebanski M, Uskoković V, Mohamud R. Nanoparticles and Gut Microbiota in Colorectal Cancer

Recent years have witnessed an unprecedented growth in the research area of nanomedicine. There is an increasing optimism that nanotechnology applied to medicine will bring significant advances in the diagnosis and treatment of various diseases, including colorectal cancer (CRC), a type of neoplasm affecting cells in the colon or the rectum. Recent findings suggest that the role of microbiota is crucial in the development of CRC and its progression. Dysbiosis is a condition that disturbs the normal microbial environment in the gut and is often observed in CRC patients. In order to detect and treat precancerous lesions, new tools such as nanotechnology-based theranostics, provide a promising option for targeted marker detection or therapy for CRC. Because the presence of gut microbiota influences the route of biomarker detection and the route of the interaction of nanoparticle/drug complexes with target cells, the development of nanoparticles with appropriate sizes, morphologies, chemical compositions and concentrations might overcome this fundamental barrier. Metallic particles are good candidates for nanoparticle-induced intestinal dysbiosis, but this aspect has been poorly explored to date. Herein, we focus on reviewing and discussing nanotechnologies with potential applications in CRC through the involvement of gut microbiota and highlight the clinical areas that would benefit from these new medical technologies.

Nanotechnological approaches for counteracting multidrug resistance in cancer

Every year, cancer accounts for a vast portion of deaths worldwide. Established clinical protocols are based on chemotherapy, which, however, is not tumor-selective and produces a series of unbearable side effects in healthy tissues. As a consequence, multidrug resistance (MDR) can arise causing metastatic progression and disease relapse. Combination therapy has demonstrated limited responses in the treatment of MDR, mainly due to the different pharmacokinetic properties of administered drugs and to tumor heterogeneity, challenges that still need to be solved in a significant percentage of cancer patients. In this perspective, we briefly discuss the most relevant MDR mechanisms leading to therapy failure and we report the most advanced strategies adopted in the nanomedicine field for the design and evaluation of ad hoc nanocarriers. We present some emerging classes of nanocarriers developed to reverse MDR and discuss recent progress evidencing their limits and promises.

Pyronaridine: An update of its pharmacological activities and mechanisms of action

Pyronaridine (PYR) is an erythrocytic schizonticide with a potent antimalarial activity against multidrug-resistant Plasmodium. The drug is used in combination with artesunate for the treatment of uncomplicated P. falciparum malaria, in adults and children. The present review briefly retraces the discovery of PYR and recent antimalarial studies which has led to the approval of PYR/artesunate combination (Pyramax) by the European Medicines Agency to treat uncomplicated malaria worldwide. PYR also presents a marked antitumor activity and has revealed efficacy for the treatment of other parasitic diseases (notably Babesia and Trypanosoma infections) and to mitigate the Ebola virus propagation. On the one hand, PYR functions has an inhibitor of hemozoin (biomineral malaria pigment, by-product of hemoglobin digestion) formation, blocking the biopolymerization of β-hematin and thus facilitating the accumulation of toxic hematin into the digestive vacuole of the parasite. On the other hand, PYR is a bona fide DNA-intercalating agent and an inhibitor of DNA topoisomerase 2, leading to DNA damages and cell death. Inhibition of hematin polymerization represents the prime mechanism at the origin of the antimalarial activity, whereas anticancer effects relies essentially on the interference with DNA metabolism, as with structurally related anticancer drugs like amsacrine and quinacrine. In addition, recent studies point to an immune modulatory activity of PYR and the implication of a mitochondrial oxidative pathway. An analogy with the mechanism of action of artemisinin drugs is underlined. In brief, the biological actions of pyronaridine are recapitulated to shed light on the diverse health benefits of this unsung drug.

A multi-functionalized nanocomposite constructed by gold nanorod core with triple-layer coating to combat multidrug resistant colorectal cancer

Multi-drug resistance (MDR) remains the main culprit for the low survival rate of advanced colorectal cancer (CRC). Photothermal-therapy (PPT) is effective to kill MDR tumor cells, but fails to completely eradicate tumors. In this study, we prepared a nanocomposite based on gold nanorod core with triple layer coating (GNRs/mSiO₂/PHIS/TPGS/DOX) to combat multidrug resistant (MDR) colorectal cancer via multi-strategies. We first synthesized the mesoporous silica-coated gold nanorods (GNRs/mSiO₂), and loaded with antitumor drug doxorubicin (DOX) to realize a combination of chemo- and photothermal-therapy. To reverse DOX resistance, pH responsive poly-histidine (PHIS) was conjugated on GNRs/mSiO₂ to increase drug intracellular accumulation via efficient endo/lysosome escape; d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was then assembled on the surface of the particles to realize drug intracellular retention by inhibition P-glycoprotein. The results showed that the nanocomposite exhibited a highly efficient photothermal conversion in the NIR region, a pH and NIR triggered drug release profile and an increment of DOX intracellular accumulation and cytotoxicity on MDR SW620/Ad300 cells. Most importantly, the nanocomposite showed the most potent antitumor efficacy without obvious systemic toxicity comparing to other control groups with either chemo- or photothermal therapy alone on SW620/Ad300 tumor bearing mice. Altogether, the successful preparation of the nanocomposite and its potent efficacy might provide evidence for the future design and develop of nano-therapeutic system in the treatment of MDR colorectal cancer.

Redox Nano-Architectures: Perspectives and Implications in Diagnosis and Treatment of Human Diseases

SIGNIFICANCE

Efficient targeted therapy with minimal side-effects is the need of the hour. Locally altered redox state is observed in several human ailments, such as inflammation, sepsis, and cancer. This has been taken advantage of in designing redox-responsive nanodrug carriers. Redox-responsive nanosystems open a door to a multitude of possibilities for the control of diseases over other drug delivery systems. Recent Advances: The first-generation nanotherapy relies on novel properties of nanomaterials to shield the drug and deliver it to the diseased tissue or organ. The second generation is based on targeting the drug or diagnostic material to the diseased cell-specific receptors, or to a particular organ to improve the efficacy of the drug. The third and the latest generation of nanocarriers, the stimuli-responsive nanocarriers exploit the disease condition or environment to specifically deliver the drug or diagnostic probe for the best diagnosis and treatment. Several different kinds of stimuli such as temperature, magnetic field, pH, and altered redox state-responsive nanosystems have educed immense promise in the field of nanomedicine and therapy.

CRITICAL ISSUES

We describe the evolution of nanomaterial since its inception with an emphasis on stimuli-responsive nanocarriers, especially redox-sensitive nanocarriers. Importantly, we discuss the future perspectives of redox-responsive nanocarriers and their implications.

FUTURE DIRECTIONS

Redox-responsive nanocarriers achieve a near-to-zero premature release of the drug, thus avoiding off-site toxicity associated with the free drug. This bears great potential for the development of more effective drug delivery with better pharmacokinetics and pharmacodynamics.

Pyronaridine exerts potent cytotoxicity on human breast and hematological cancer cells through induction of apoptosis

The potent antimalarial drug pyronaridine (PND) was tested for its potential as an anticancer drug. After exposing cancerous (17) and non-cancerous (2) cells to PND for 72 hr, PND was found to exhibit consistent and potent cytotoxic activity at low micromolar (μM) concentrations that ranged from 1.6 μM to 9.4 μM. Moreover, PND exerted a significant selective cytotoxicity index (SCI) on five out of seven breast cancer cell lines tested, with favorable values of 2.5 to 4.4, as compared with the non-cancerous breast MCF-10A cell line. By using the same comparison, PND exhibited a significant SCI on three out of four leukemia/lymphoma cell lines with promising values of 3.3 to 3.5. One breast cancer and one leukemia cell line were tested further in order to determine the likely mode of action of PND. PND was found to consistently elicit phosphatidylserine externalization, mitochondrial depolarization, and DNA fragmentation, in both the triple negative MDA-MB-231 breast cancer and HL-60 leukemia cell lines. In addition, PND treatment altered cell cycle progression in both cancer cells. Subsequent DNA mobility-shift assays, UV-Visible spectroscopic titrations, and circular dichroism (CD) experiments revealed that PND intercalates with DNA. The findings presented in this study indicates that PND induces apoptosis and interfered with cell cycle progression of cancer cell lines and these results indicate that this drug has the potential as a repurposed drug for cancer therapy.

Glutathione detonated and pH responsive nano-clusters of Au nanorods with a high dose of DOX for treatment of multidrug resistant cancer

Effects of nanosized drug delivery systems on cancer are often compromised due to their low drug loadings, premature drug release and multi-drug resistance (MDR). Herein, we reported a glutathione detonated and pH responsive nano-cluster of Au nanorods (AuNRs) with chemotherapeutic doxorubicin (DOX) and pre-chemosensitizer polycurcumin to treat MCF-7/ADR cells. The nano-cluster was prepared by self-assembling of AuNRs conjugated with DOX and amphiphilic poly(curcumin-co-dithiodipropionic acid)-b-biotinylated poly(ethylene glycol) via an emulsion/solvent evaporation technique, termed AuNR Cluster. The AuNR Cluster had a high drug loading (31.5% DOX), presenting much better aqueous solubility and stability at physiological pH than their individual AuNRs. The AuNR Cluster could be detonated to be their individual AuNRs at an intracellular concentration level of glutathione (GSH) (5 mM) and triggered to release DOX at an acidic pH (pH 6.8 or 5.0), which effectively facilitated cellular uptake of DOX (607 vs 356 a.u. for AuNRs at 12 h) and inhibited DOX efflux (471.33 vs 39.17 a.u. for free DOX at 24 h). The IC₅₀ value of DOX against MCF-7/ADR cells for AuNR Cluster was 4.15 µg/mL, much lower than that for free DOX (90.97 µg/mL). The AuNR Cluster took much more photothermal effects than their corresponding AuNRs and presented enhanced anti-tumor effect (IC₅₀: 2.61 µg/mL) under 808 nm laser irradiation.

STATEMENT OF SIGNIFICANCE

Nano-sized drug delivery systems for anti-MDR cancer is still a challenging task. Herein, AuNR Cluster was self-assembled by individual AuNRs via emulsion/solvent evaporation technique, having a structure consisting of hydrophobic DOX/PCDA-AuNR core and hydrophilic biotin-PEG chain shell. AuNR Cluster is detonated to disintegrate and yield its individual AuNRs at an intracellular concentration level of glutathione (5 mM) and triggered to release DOX at an acidic pH (6.8 or 5.0). In comparison with its individual AuNRs, AuNR Cluster has better water solubility and stability, greater photothermal effects under NIR irradiation, bigger cytotoxicity against MCF-7/ADR cells. AuNR Cluster is expected to be a potential nanomedicine for treatment of MDR cancer.

Nanocarrier-Mediated Photochemotherapy and Photoradiotherapy

Photothermal therapy (PTT) and photodynamic therapy (PDT) both utilize light to induce a therapeutic effect. These therapies are rapidly gaining importance due to the noninvasiveness of light and the limited adverse effect associated with these treatments. However, most preclinical studies show that complete elimination of tumors is rarely observed. Combining PDT and PTT with chemotherapy or radiotherapy can improve the therapeutic outcome and simultaneously decrease side effects of these conventional treatments. Nanocarriers can help to facilitate such a combined treatment. Here, the most recent advancements in the field of photochemotherapy and photoradiotherapy, in which nanocarriers are employed, are reviewed.

Polymer-Based Nanocarriers for Co-Delivery and Combination of Diverse Therapies against Cancers

Cancer gives rise to an enormous number of deaths worldwide nowadays. Therefore, it is in urgent need to develop new therapies, among which combined therapies including photothermal therapy (PTT) and chemotherapy (CHT) using polymer-based nanocarriers have attracted enormous interest due to the significantly enhanced efficacy and great progress has been made so far. The preparation of such nanocarriers is a comprehensive task involving the cooperation of nanomaterial science and biomedicine science. In this review, we try to introduce and analyze the structure, preparation and synergistic therapeutic effect of various polymer-based nanocarriers composed of anti-tumor drugs, nano-sized photothermal materials and other possible parts. Our effort may bring benefit to future exploration and potential applications of similar nanocarriers.

Stimuli-Responsive Nanomedicines for Overcoming Cancer Multidrug Resistance

Chemotherapy is still a main option for cancer therapy, but its efficacy is often unsatisfying due to multidrug resistance (MDR). The tumor microenvironment is considered a dominant factor causing MDR. Stimuli-responsive nanomedicines exhibit many superiorities for reversal of MDR. As smart systems, stimuli-responsive nanomedicines are desirable for achieving site-specific accumulation and triggered drug release in response to slight changes in physicochemical properties in pathological conditions or to exogenous stimuli. In this review, we highlight the current progress of various nanomedicines with different stimuli-responsive capabilities for overcoming MDR. The materials, design, construction as well as efficacy in overcoming MDR of these nanomedicines are discussed. Eventually, we look forward to forthcoming intelligent nanoparticle systems with new mechanisms to deliver drugs for practical applications in conquering cancer MDR.

Nanodiamond mediated co-delivery of doxorubicin and malaridine to maximize synergistic anti-tumor effects on multi-drug resistant MCF-7/ADR cells

Novel nanodiamond based nanoparticle co-loading of doxorubicin and malaridine with pH-responsive co-release properties was developed for maximizing synergistic anti-tumor effects on multi-drug resistant MCF-7/ADR cells.