Multifunctional and multitargeted nanoparticles for drug delivery to overcome barriers of drug resistance in human cancers

Anti-Quenching NIR-II Excitation Phenylboronic Acid Modified Conjugated Polyelectrolyte for Intracellular Peroxynitrite-Enhanced Chemo-Photothermal Therapy

Multidrug resistance to clinical chemotherapeutic drugs severely limits antitumor efficacy and patient survival. The integration of chemotherapy with photothermal therapy (PTT) and reactive nitrogen species has become a major strategy to enhance cancer treatment efficacy. Herein, a multifunctional peroxynitrite (ONOO-) nanogenerator (PBT/NO/Pt) for NIR-II fluorescence (NIR-II FL)/NIR-II photoacoustic (NIR-II PA) imaging-guided chemo/NIR-II PTT/ONOO- combination therapy is reported. The multifunction nanogenerator is developed by co-loading a pH-sensitive nitric oxide donor (DETA NONOate) and nicotinamide adenine dinucleotide phosphate oxidases trigger superoxide (O2 •-) generator chemotherapy drug (CDDP) to an NIR-II excitation-conjugated polyelectrolyte (PNC11BA). PNC11BA has non-conjugated alkyl chain segments in the polymer backbone and abundant positively charged phenylboronic acid in its side chains, which support the anti-quenching of NIR-II FL and the integration of DETA NONOate and CDDP into PBT/NO/Pt. In the acidic tumor microenvironment, the coordination bonds between CDDP and PNC11BA are cleaved, releasing CDDP for chemotherapeutic activity. The simultaneous release of nitric oxide (NO) and O2 •- rapidly leads to the in situ generation of the more cytotoxic reactive physiological nitrogen species ONOO-. In vitro and in vivo results prove that PBT/NO/Pt exhibited a markedly ONOO- enhanced chemo-photothermal synergistic therapy for SKOV3/DDP tumor by downregulating the intracellular glutathione and increasing CDDP-DNA adducts.

Effect of biosynthesized selenium nanoparticles using Nepeta extract against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii

The problems of drug resistance in bacteria have become one of the daily challenges of the clinical treatment of patients, which inevitably forces us to use agents other than common antibiotics. Among these, we can take help from different properties and applications of nanoparticles (NPs). In this work, we evaluate the antibacterial activity of biosynthesized selenium nanoparticles (SeNPs) against standard strains of multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. The production of biosynthesized SeNPs was proved by ultraviolet-visible, Fourier transform infrared, X-ray diffractometer, Field Emission Scanning Electron Microscopy, Dynamic light scattering, and Zeta potential methods. The cytotoxicity effect of SeNPs was investigated by MTT assay. Disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed on the mentioned bacteria using different classes of standard antibiotics and SeNPs separately. The impact of SeNPs combined with the desired antibiotics for better treatment of these infections was evaluated by checkerboard assay to determine the synergism effect. After the confirmation results based on the biosynthesis of SeNPs, both standard bacterial strains were susceptible to SeNPs and had a zone of inhibition using the DDA test. Also, the results of MICs showed that biosynthesized SeNPs in lower concentrations than antibiotics cause no growth of bacteria. On the other hand, according to the checkerboard assay, SeNPs had a synergistic effect with conventional antibiotics. The antibacterial sensitivity tests demonstrated the inhibition of bacterial growth in the presence of lower concentrations of SeNPs than common antibiotics. This property can be exerted in future applications to solve the drug resistance obstacle of microorganisms in bacterial diseases.

Trends in iron oxide nanoparticles: a nano-platform for theranostic application in breast cancer

Breast cancer (BC) is the deadliest malignant disorder globally, with a significant mortality rate. The development of tolerance throughout cancer treatment and non-specific targeting limits the drug's response. Currently, nano therapy provides an interdisciplinary area for imaging, diagnosis, and targeted drug delivery for BC. Several overexpressed biomarkers, proteins, and receptors are identified in BC, which can be potentially targeted by using nanomaterial for drug/gene/immune/photo-responsive therapy and bio-imaging. In recent applications, magnetic iron oxide nanoparticles (IONs) have shown tremendous attention to the researcher because they combine selective drug delivery and imaging functionalities. IONs can be efficaciously functionalised for potential application in BC therapy and diagnosis. In this review, we explored the current application of IONs in chemotherapeutics delivery, gene delivery, immunotherapy, photo-responsive therapy, and bio-imaging for BC based on their molecular mechanism. In addition, we also highlighted the effect of IONs' size, shape, dimension, and functionalization on BC targeting and imaging. To better comprehend the functionalization potential of IONs, this paper provides an outline of BC cellular development. IONs for BC theranostic are also reviewed based on their clinical significance and future aspects.

Biofunctionalized Chrysin-conjugated gold nanoparticles neutralize Leishmania parasites with high efficacy

Current treatments for leishmaniasis involve various drugs, including miltefosine and amphotericin B, which are associated with several side effects and high costs. Long-term use of these drugs may lead to the development of resistance, thereby reducing their efficiency. Chrysin (CHY) is a well-known, non-toxic flavonoid with antioxidant, antiviral, anti-inflammatory, anti-cancer, hepatoprotective, and neuroprotective properties. Recently we have shown that CHY targets the MAP kinase 3 enzyme of Leishmania and neutralizes the parasite rapidly. However, CHY is associated with low bioavailability, poor absorption, and rapid excretion issues, limiting its usage. In this study, we developed and tested a novel CHY-gold nanoformulation with improved efficacy against the parasites. The reducing power of CHY was utilized to reduce and conjugate with gold nanoparticles. Gold nanoparticles, which are already known for their anti-leishmanial properties, along with conjugated CHY, exhibited a decreased parasite burden in mammalian macrophages. Our findings showed that this biofunctionalized nanoformulation could be used as a potential therapeutic tool against leishmaniasis.

Nanobiosystems for Antimicrobial Drug-Resistant Infections

The worldwide increased bacterial resistance toward antimicrobial therapeutics has led investigators to search for new therapeutic options. Some of the options currently exploited to treat drug-resistant infections include drug-associated nanosystems. Additionally, the use of bacteriophages alone or in combination with drugs has been recently revisited; some studies utilizing nanosystems for bacteriophage delivery have been already reported. In this review article, we focus on nine pathogens that are the leading antimicrobial drug-resistant organisms, causing difficult-to-treat infections. For each organism, the bacteriophages and nanosystems developed or used in the last 20 years as potential treatments of pathogen-related infections are discussed. Summarizing conclusions and future perspectives related with the potential of such nano-antimicrobials for the treatment of persistent infections are finally highlighted.

Gold nanoparticle-conjugated nanomedicine: design, construction, and structure-efficacy relationship studies

In comparison with conventional therapies, nanomedicine shows prominent clinical performance, with better therapeutic efficacy and less off-target toxicity. As an important component of nanomedicine, gold nanoparticle (GNP)-based nanodrugs have attracted considerable interest because of their excellent performance given by the unique structure. Although no pharmaceutical formulations of GNP-associated nanodrugs have been officially marketed yet, a substantial amount of research on this aspect is being carried out, producing numerous GNP-based drug delivery systems with potential clinical applications. In this review, we present an overview of our progress on GNP-based nanodrugs combined with other achievements in biomedical applications, including drug-conjugated GNPs prepared for disease treatments and specific tumour targeting, structure-efficacy relationship (SER) studies on GNP-conjugated nanodrugs, and therapeutic hybrid nanosystems composed of GNPs. In addition, we also put forward some proposals to guide future work in developing GNP-based nanomedicine. We hope that this review will offer some useful experience for our peers and GNP-based nanodrugs will be utilized in the clinic with further persistent efforts.

Supramolecular nanofibers increase the efficacy of 10-hydroxycamptothecin by enhancing nuclear accumulation and depleting cellular ATP

Poor nuclear delivery and accumulation are the main reasons for the reduced drug efficacy of many anticancer drugs that target DNA or enzymes in the nucleus, and it is a major obstacle to successful cancer therapy. To address this problem, developing practical drug delivery systems for nuclear delivery is urgently needed. Here we develop a supramolecular hydrogel by conjugating the anticancer agent 10-hydroxycamptothecine (HCPT) and macrocyclic polyamine cyclen to a self-assembling peptide. The cyclen fragment possesses nuclear localization and ATP hydrolysis properties, which can provide a synergistic therapeutic effect for cancer treatment. The HCPT-FFFK-cyclen nanofibers showed improved nuclear accumulation and inhibition capacity in cancer cells including drug-resistant cancer cells in vitro. The nanofibers also exhibited favorable ATP consuming ability in vitro. Moreover, the obtained nanomedicine showed enhanced anticancer efficiency and favorable biocompatibility in vivo when administered to mice via tail vein injection. This constructed self-delivery drug system significantly improved the delivery efficiency of the small molecule agents into the nucleus and showed favorable ATP consuming ability, offering new strategies for developing nanomedicines for cancer combination therapy.

Therapeutic strategies to overcome taxane resistance in cancer

One of the primary causes of attenuated or loss of efficacy of cancer chemotherapy is the emergence of multidrug resistance (MDR). Numerous studies have been published regarding potential approaches to reverse resistance to taxanes, including paclitaxel (PTX) and docetaxel, which represent one of the most important classes of anticancer drugs. Since 1984, following the FDA approval of paclitaxel for the treatment of advanced ovarian carcinoma, taxanes have been extensively used as drugs that target tumor microtubules. Taxanes, have been shown to affect an array of oncogenic signaling pathways and have potent cytotoxic efficacy. However, the clinical success of these drugs has been restricted by the emergence of cancer cell resistance, primarily caused by the overexpression of MDR efflux transporters or by microtubule alterations. In vitro and in vivo studies indicate that the mechanisms underlying the resistance to PTX and docetaxel are primarily due to alterations in α-tubulin and β-tubulin. Moreover, resistance to PTX and docetaxel results from: 1) alterations in microtubule-protein interactions, including microtubule-associated protein 4, stathmin, centriole, cilia, spindle-associated protein, and kinesins; 2) alterations in the expression and activity of multidrug efflux transporters of the ABC superfamily including P-glycoprotein (P-gp/ABCB1); 3) overexpression of anti-apoptotic proteins or inhibition of apoptotic proteins and tumor-suppressor proteins, as well as 4) modulation of signal transduction pathways associated with the activity of several cytokines, chemokines and transcription factors. In this review, we discuss the abovementioned molecular mechanisms and their role in mediating cancer chemoresistance to PTX and docetaxel. We provide a detailed analysis of both in vitro and in vivo experimental data and describe the application of these findings to therapeutic practice. The current review also discusses the efficacy of different pharmacological modulations to achieve reversal of PTX resistance. The therapeutic roles of several novel compounds, as well as herbal formulations, are also discussed. Among them, many structural derivatives had efficacy against the MDR phenotype by either suppressing MDR or increasing the cytotoxic efficacy compared to the parental drugs, or both. Natural products functioning as MDR chemosensitizers offer novel treatment strategies in patients with chemoresistant cancers by attenuating MDR and increasing chemotherapy efficacy. We broadly discuss the roles of inhibitors of P-gp and other efflux pumps, in the reversal of PTX and docetaxel resistance in cancer cells and the significance of using a nanomedicine delivery system in this context. Thus, a better understanding of the molecular mechanisms mediating the reversal of drug resistance, combined with drug efficacy and the application of target-based inhibition or specific drug delivery, could signal a new era in modern medicine that would limit the pathological consequences of MDR in cancer patients.

Homing Peptides for Cancer Therapy

Tumor-homing peptides are widely used for improving tumor selectivity of anticancer drugs and imaging agents. The goal is to increase tumor uptake and reduce accumulation at nontarget sites. Here, we describe current approaches for tumor-homing peptide identification and validation, and provide comprehensive overview of classes of tumor-homing peptides undergoing preclinical and clinical development. We focus on unique mechanistic features and applications of a recently discovered class of tumor-homing peptides, tumor-penetrating C-end Rule (CendR) peptides, that can be used for tissue penetrative targeting of extravascular tumor tissue. Finally, we discuss unanswered questions and future directions in the field of development of peptide-guided smart drugs and imaging agents.

Polymeric Nanoparticles and Their Novel Modifications for Targeted Delivery of Bortezomib

Bortezomib (BTZ) as a specific proteasome inhibitor is used to inhibit proliferation and migration of tumor cell in variety of cancers. Targeted delivery of this drug not only would minimize its unwanted side effects but also might improve its efficacy. This purpose could be gotten through different pathways but using efficient carriers may be the best one without using any additional ingredients/ materials. Some polymer based nanoparticles with specific functional groups have the ability to interact with boronic acid moiety in BTZ. This reaction might play an important role not only in cancer targeting therapy but also in loading and release properties of this drug. Novel modification such as making multifunctional or pH-sensitive nanocarriers, may also improve anticancer effect of BTZ. This review might have remarkable effect on researchers’ consideration about other possible interactions between BTZ and polymeric nanocarriers that might have great effect on its remedy pathway. It has the ability to brought bright ideas to their minds for novel amendments about other drugs and delivery systems.

Synergistic Anticancer Therapy by Ovalbumin Encapsulation-Enabled Tandem Reactive Oxygen Species Generation

The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2.- produced by the PDT is converted to H2 O2 by superoxide dismutase, followed by the transformation of H2 O2 to the highly toxic . OH via Fenton reactions by Fe2+ originating from the dissolution of co-loaded Fe3 O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular delivery to the nucleus-even for drug-resistant cells. Cisplatin generates O2.- in the presence of nicotinamide adenine dinucleotide phosphate oxidase and thereby improves the treatment efficiency by serving as an additional O2.- source for production of . OH radicals. Improved anticancer efficiency is achieved under both hypoxic and normoxic conditions.

Co-delivery of a RanGTP inhibitory peptide and doxorubicin using dual-loaded liposomal carriers to combat chemotherapeutic resistance in breast cancer cells

BACKGROUND

Multidrug resistance (MDR) limits the beneficial outcomes of conventional breast cancer chemotherapy. Ras-related nuclear protein (Ran-GTP) plays a key role in these resistance mechanisms, assisting cancer cells to repair damage to DNA. Herein, we investigate the co-delivery of Ran-RCC1 inhibitory peptide (RAN-IP) and doxorubicin (DOX) to breast cancer cells using liposomal nanocarriers.

RESEARCH DESIGN

A liposomal delivery system, co-encapsulating DOX, and RAN-IP, was prepared using a thin-film rehydration technique. Dual-loaded liposomes were optimized by systematic modification of formulation variables. Real-Time-Polymerase Chain Reaction was used to determine Ran-GTP mRNA expression. In vitro cell lines were used to evaluate the effect of loaded liposomes on the viability of breast and lung cancer cell lines. In vivo testing was performed on a murine Solid Ehrlich Carcinoma model.

RESULTS

RAN-IP reversed the Ran-expression-mediated MDR by inhibiting the Ran DNA damage repair function. Co-administration of RAN-IP enhanced sensitivity of DOX in breast cancer cell lines. Finally, liposome-mediated co-delivery with RAN-IP improved the anti-tumor effect of DOX in tumor-bearing mice when compared to single therapy.

CONCLUSIONS

This study is the first to show the simultaneous delivery of RAN-IP and DOX using liposomes can be synergistic with DOX and lead to tumor regression in vitro and in vivo.

Sensitizing activities of nitric oxide donors for cancer resistance to anticancer therapeutic drugs

Cancer is not a single disease but it constitutes a large variety of different types that are also different from each other phenotypically and molecularly. Although the standard treatments have resulted in clinical responses in a subset of patients, though, many patients relapse and no longer respond to further treatments. Hence, both the innate and adaptive resistance to treatments are the main challenges in today's treatment strategies. Noteworthy, several novel treatment strategies, particularly immunotherapies, used alone or in combination, have been developed and that have significantly improved the therapeutic response of many unresponsive cancer patients. Nevertheless, even with the latest new developments of therapeutics that were effective in a larger subset of patients, there is still an urgent need to treat the remaining unresponsive subset of patients. This requires the development of new targeting agents of superior antitumor activities that will lead to overcoming the unaffected resistance by current treatments. There has been accumulating evidence suggesting nitric oxide donors as such targeting agents and considering their pleiotropic antitumor activities, including both the reversal of chemo and immuno-resistance of various unresponsive resistant cancers. The in vitro and in vivo preclinical findings corroborate the sensitizing antitumor activities of nitric oxide donors. In addition, a few clinical findings with NO donors that have been applied in patients have corroborated their antitumor and sensitizing activities in combination with standard therapies. In this review, the role and underlying mechanisms by which nitric oxide donors sensitize cancer resistant cells to both chemotherapy and immunotherapy are briefly described.

Targeting Approaches of Nanomedicines in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a hematological malignancy, which is commonly associated with high incidence and mortality among adult patients. The standard induction regimen for AML has been substantially unchanged over the past 40 years, for which novel nanomedicines have represented a promising strategy in AML therapies. Despite developments of multiple nanoparticles formulated with drugs or genes, less there is not much information available about approaches in AML is available. This review presents an overview of nanomedicines currently being evaluated in AML. First, it briefly summarized conventional chemotherapies in use. Second, nanomedicines presently ongoing in clinical trials or preclinical researches were classified and described, with illustrative examples from recent literatures. Finally, limitations and potential safety issues concerns in clinical translation of AML treatment were discussed as well.

An oxygen self-sufficient NIR-responsive nanosystem for enhanced PDT and chemotherapy against hypoxic tumors

The efficacy of photodynamic therapy and chemotherapy is largely limited by oxygen deficiency in the hypoxic tumor microenvironment. To solve these problems, we fabricated a novel NIR-responsive nanosystem which could co-deliver oxygen and anticancer drug DOX. An oxygen self-sufficient amphiphile (F-IR780-PEG) was first synthesized and subsequently utilized to load anticancer drug DOX to form nanoparticles (F/DOX nanoparticles). Due to the high oxygen capacity of such nanoparticles, the hypoxic tumor microenvironment was greatly modulated after these nanoparticles reached the tumor region, and the results revealed that hypoxia-inducible factor α (HIF-1α) was down-regulated and the expression of P-glycoprotein (P-gp) was then reduced, which were in favor of chemotherapy. Under light irradiation at 808 nm, IR780 could efficiently produce singlet oxygen to damage cancer cells by photodynamic therapy (PDT). Simultaneously, the IR780 linkage could be cleaved by singlet oxygen generated by itself and resulted in DOX release, which further caused cell damage by chemotherapy. With the combination of PDT and chemotherapy, F/DOX nanoparticles showed remarkable therapeutic efficacy under in vitro and in vivo conditions. Furthermore, the F/DOX nanoparticles are favorable for imaging-guided tumor therapy due to the inherent fluorescence properties of IR780. We thus believe that the synergistic treatment described here leads to an ideal therapeutic approach to hypoxic tumors.

Gas Therapy: An Emerging “Green” Strategy for Anticancer Therapeutics

As an emerging area, gas therapy has attracted more and more attention in treating many diseases including cancer. The fabrication of stimuli‐responsive delivery systems with on‐demand release behavior is very promising for precision gas therapy, which can obtain optimal therapeutic performance without gas poisoning risks. In this review, the authors introduce the recent progress in the preparation of different kinds of gas carriers for efficient delivery of gaseous molecules (NO, H2S, CO, O2). Particularly, in order to achieve targeted accumulation of gaseous molecules in tumor tissues, gaseous molecules–integrated nanoparticles were constructed. Most importantly, by combination of gas therapy with other therapeutic modalities such as chemotherapy, photodynamic therapy (PDT), and radiotherapy, various multifunctional nanocarriers have been designed for synergistic cancer therapy. Especially, the recent developments of multifunctional gas‐carrying nanocarriers for synergistic cancer therapy are discussed in detail.

Combination of nitric oxide and drug delivery systems: tools for overcoming drug resistance in chemotherapy

Chemotherapeutic drugs have made significant contributions to anticancer therapy, along with other therapeutic methods including surgery and radiotherapy over the past century. However, multidrug resistance (MDR) of cancer cells has remained as a significant obstacle in the achievement of efficient chemotherapy. Recently, there has been increasing evidence for the potential function of nitric oxide (NO) to overcome MDR. NO is an endogenous and biocompatible molecule, contrasting with other potentially toxic chemosensitizing agents that reverse MDR effects, which has raised expectations in the development of efficient therapeutics with low side effects. In particular, nanoparticle-based drug delivery systems not only facilitate the delivery of multiple therapeutic agents, but also help bypass MDR pathways, which are conducive for the efficient delivery of NO and anticancer drugs, simultaneously. Therefore, this review will discuss the mechanism of NO in overcoming MDR and recent progress of combined NO and drug delivery systems.

Co-delivery of oxygen and erlotinib by aptamer-modified liposomal complexes to reverse hypoxia-induced drug resistance in lung cancer

Tumor hypoxia is a common feature of the tumor microenvironment and has been regarded as one of the key factors in driving the emergence of drug resistance in solid tumors. To surmount the hypoxia-associated drug resistance, we fabricated the novel multifunctional liposomal complexes (ACLEP) that could co-deliver oxygen and molecular targeted drug to overcome the hypoxia-induced drug resistance in lung cancer. The ACLEP were fabricated with liposomes anchored with anti-EGFR aptamer-conjugated chitosan to co-administrate erlotinib and PFOB to EGFR-overexpressing non-small-cell lung cancer. Our results showed that the ACLEP possessed desired physicochemistry, good biostability and controlled drug release. The entrapped PFOB in nanoparticle facilitated the uptake of ACLEP in either normoxia or hypoxic condition. Comparing to those nanoparticles loading erlotinib alone, our innovative oxygen/therapeutic co-delivery system showed a promising outcome in fighting against hypoxia-evoked erotinib resistance both in vitro and in vivo. Hence, this work presents a potent drug delivery platform to overcome hypoxia-induced chemotherapy resistance.

d-α-Tocopheryl Succinate/Phosphatidyl Ethanolamine Conjugated Amphiphilic Polymer-Based Nanomicellar System for the Efficient Delivery of Curcumin and To Overcome Multiple Drug Resistance in Cancer

Nanomedicines have emerged as a promising treatment strategy for cancer. Multiple drug resistance due to overexpression of various drug efflux transporters and upregulation of apoptotic inhibitory pathways in cancer cells are major barriers that limit the success of chemotherapy. Here, we developed a d-α-tocopherol (α-TOS)/lipid-based copolymeric nanomicellar system (VPM) by conjugating phosphatidyl ethanolamine (PE) and α-TOS with poly(ethylene glycol) (PEG) via an amino acid linkage. The synthesized polymers were characterized by Fourier transform IR, gas-phase chromatography, and ¹H and ¹³C NMR spectroscopy. VPM exhibited mean hydrodynamic diameter of 141.0 ± 0.94 nm with low critical micelles concentrations (CMC) of 15 μM compared to plain PEG-PE micelles (PPM) with size of 23.9 ± 0.34 nm and CMC 20 μM. The bigger hydrophobic compartment in VPM resulted in improved loading of a potent chemotherapeutic drug, curcumin (Cur), and increased encapsulation efficiency (EE) (% drug loading 98.3 ± 1.92, and 85.3 ± 3.29; EE 14.8 ± 0.16 and 12.8 ± 0.09 for VPM and PPM, respectively). Curcumin loaded Vitamin E based micelles exhibited higher cytotoxicity compared to Curcumin loaded PEG-PE micelles in tested cancer cell lines. C-VPM demonstrated ∼3.2 and ∼2.7-fold higher ability to reverse multiple drug resistance compared to PPM and verapamil (concentration used 30 μM), respectively. In the in vivo study by using B16F10 implanted C57Bl6/J mice, C-VPM reduced the tumor volume and weight more efficiently than C-PPM by inducing apoptosis as analyzed by TUNEL assay on tumor cryosections. The newly developed polymeric micelles, VPM with improved drug loadability and ability to reverse the drug resistance could successfully be utilized as a nanocarrier system for hydrophobic chemotherapeutic agents for the treatment of drug-resistant solid tumors.

Transferrin receptor-targeted pH-sensitive micellar system for diminution of drug resistance and targetable delivery in multidrug-resistant breast cancer

The emergence of drug resistance is partially associated with overproduction of transferrin receptor (TfR). To overcome multidrug resistance (MDR) and achieve tumor target delivery, we designed a novel biodegradable pH-sensitive micellar system modified with HAIYPRH, a TfR ligand (7pep). First, the polymers poly(l-histidine)-coupled polyethylene glycol-2000 (PHIS-PEG₂₀₀₀) and 7pep-modified 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (7pep-DSPE-PEG₂₀₀₀) were synthesized, and the mixed micelles were prepared by blending of PHIS-PEG₂₀₀₀ and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (DSPE-PEG₂₀₀₀) or 7pep-DSPE-PEG₂₀₀₀ (7-pep HD micelles). The micelles exhibited good size uniformity, high encapsulation efficiency, and a low critical micelle concentration. By changing the polymer ratio in the micellar formulation, the pH response range was specially tailored to pH ~6.0. When loaded with antitumor drug doxorubicin (DOX), the micelle showed an acid pH-triggering drug release profile. The cellular uptake and cytotoxicity study demonstrated that 7-pep HD micelles could significantly enhance the intracellular level and antitumor efficacy of DOX in multidrug-resistant cells (MCF-7/Adr), which attributed to the synergistic effect of poly(l-histidine)-triggered endolysosom escape and TfR-mediated endocytosis. Most importantly, the in vivo imaging study confirmed the target-ability of 7-pep HD micelles to MDR tumor. These findings indicated that 7-pep HD micelles would be a promising drug delivery system in the treatment of drug-resistant tumors.

Synergistic effects of negative-charged nanoparticles assisted by ultrasound on the reversal multidrug resistance phenotype in breast cancer cells

We have fabricated a negative-charged nanoparticle (Heparin-Folate-Tat-Taxol NP, H-F-Tat-T NP) with dual ligands, tumor targeting ligand folate and cell-penetrating peptide Tat, to deliver taxol presenting great anticancer activity for sensitive cancer cells, while it fails to overcome multidrug resistance (MDR) in MCF-7/T cells (taxol-resistant breast cancer cells). Ultrasound (US) can increase the sensitivity of positive-charged NPs thereby making it possible to reverse MDR through inducing NPs' drug release. However, compared with the negative-charged NPs, positive-charged NPs may cause higher toxic effect. Hence, the combination of negative-charged NPs and US may be an efficient strategy for overcoming MDR. The conventional procedure to treat with NPs followed by US exposure possibly destruct multifunctional NPs resulting in its bioactivity inhibition. Herein, we have further improved the operating approach to eliminate US mechanical damage and keep the integrity of negative-charged NPs: cells are exposed to US with microbubbles (MBs) prior to the treatment of H-F-Tat-T NPs. Superior to the conventional method, US sonoporation affects the physiological property of cancer cells while preventing direct promotion of drug release from NPs. The results of the present study displayed that US in condition (1MHz, 10% duty cycle, duration of 80s, US intensity of 0.6W/cm² and volume ratio of medium to MBs 20:1) combined with H-F-T-Tat-T NPs can achieve optimal reversal MDR effect in MCF-7/T cells. Mechanism study further disclosed that the individual effect of US was responsible for the enhancement of cell membrane permeability, inhibition of cell proliferation rate and down-regulation of MDR-related genes and proteins. Simultaneously, US sonoporation on resistant cancer cells indirectly increased the accumulation of NPs by inducing endosomal escape of negative-charged NPs. Taken together, the overcoming MDR ability for the combined strategy was achieved by the synergistic effect from individual function of NPs, physiological changes of resistant cancer cells and behavior changes of NPs caused by US.

Doxorubicin-Incorporated Nanotherapeutic Delivery System Based on Gelatin-Coated Gold Nanoparticles: Formulation, Drug Release, and Multimodal Imaging of Cellular Internalization

In this work, we developed a new pH- and temperature-responsive nanochemotherapeutic system based on Doxorubicin (DOX) noncovalently bound to biosynthesized gelatin-coated gold nanoparticles (DOX-AuNPs@gelatin). The real-time release profile of DOX was evaluated at different pH values (7.4, 5.3, and 4.6) and temperatures (22-45 °C) in aqueous solutions, and its therapeutic performance was examined in vitro against MCF-7 breast cancer cells. TEM, dark-field scattering, and wide-field fluorescence microscopy indicated the effective uptake of nanochemotherapeutics with the subsequent release and progressive accumulation of DOX in cell nuclei. MTT assays clearly showed the effectiveness of the treatment by inhibiting the growth of MCF-7 breast cancer cells for a loaded drug concentration of 5 μg/mL. The most informative data about the dynamic release and localization were provided by scanning confocal microscopy using time-resolved fluorescence and surface-enhanced Raman scattering (SERS) techniques. In particular, fluorescence-lifetime imaging (FLIM) recorded under 485 nm pulsed diode laser excitation revealed the bimodal distribution of DOX in cells. The shorter fluorescence lifetime of DOX localized in nuclei (1.52 ns) than in the cytoplasm (2.4 ns) is consistent with the cytotoxic mechanism induced by DOX-DNA intercalation. Remarkably, the few DOX molecules captured between nanoparticles ("electromagnetic hotspots") after most drug is released act as SERS reporters for the localization of plasmonic nanocarriers in MCF-7 cells. The high drug loading capacity and effective drug release under pH control combined with the advantage of multimodal visualization inside cells clearly indicate the high potential of our DOX-AuNPs@gelatin delivery system for implementation in nanomedicine.

Nano-based strategies to overcome p-glycoprotein-mediated drug resistance

INTRODUCTION

The discussion about cancer treatment has a long history. Chemotherapy, one of the promising approaches in cancer therapy, is limited in the clinic as plenty of factors evolve and prevent appropriate therapeutic response to drugs. Multi-drug resistance (MDR), which is mostly P-glycoprotein-mediated, is described as the most well-known impediment in this contribution. It extrudes several agents out of cells, arising MDR and decreasing the bioavailability of drugs. Hence, cancer cells become insensitive to chemotherapy.

AREAS COVERED

Many agents have been developed to reverse MDR, but it is difficult to deliver them into cancer sites and cancer cells. The emerging nano-based drug delivery systems have been more effective to overcome P-glycoprotein-mediated MDR by increasing the intracellular delivery of these agents. Here, we represent systems including siRNA-targeted inhibition of P-gp, monoclonal antibodies, natural extracts, conventional inhibitors, hard nanoparticles and soft nanoparticles as delivery systems in addition to a novel approach applying cell penetrating peptides.

EXPERT OPINION

Overcoming cancer drug resistance using innovative nanotechnology is being increasingly used and developed. Among resistance mechanisms, drug efflux transporter inhibitors and MDR gene expression silencing are among the those being investigated. In the near future, it seems some of these nanomedical approaches might become the mainstay of effective treatment of important human conditions like cancer.

Endostatin combined with platinum-based chemo-radiotherapy for advanced non-small cell lung cancer

This retrospective study was conducted to determine whether endostatin improves the efficacy and safety of platinum-based chemotherapy administered via both intravenous and arterial infusions for stage III/IV non-small-cell lung cancer (NSCLC). Seventy one patients with confirmed pathological or cytological diagnosis of NSCLC from January 2008 to March 2013 were enrolled for the study. Patients received three different therapeutic regimens until disease progression or an intolerable toxicity was evidenced. Group C received chemotherapy administered by intravenous injection and subsequent radiotherapy. Group IC received chemotherapy by intravenous injection and arterial infusion plus radiotherapy. Group IC + E patients were treated with chemotherapy plus Endostatin injected arterially and intravenously and subsequent radiotherapy. Group IC + E showed a progression-free survival (PFS) of 12 months as compared to 7 months of group C, a significant increase indeed (p = 0.037). Likewise, the overall survival time higher in Group IC + E and Group IC was compared to Group C (p = 0.001; p = 0.004, respectively). The adverse or toxic side effects exhibited by Group IC + E were not significantly different from either Group IC or Group C. Endostatin administered in combination with chemotherapeutic agents via both intravenous injection and arterial infusion enhanced the PFS and OS in advanced NSCLC without increasing the risk of toxicity.

Engineered Nanoparticles Against MDR in Cancer: The State of the Art and its Prospective

Cancer is a highly heterogeneous disease at intra/inter patient levels and known as the leading cause of death worldwide. A variety of mono and combinational therapies including chemotherapy have been evolved over the years for its effective treatment. However, advent of chemotherapeutic resistance or multidrug resistance (MDR) in cancer is a major challenge researchers are facing in cancer chemotherapy. MDR is a complex process having multifaceted non-cellular or cellular-based mechanisms. Research in the area of cancer nanotechnology over the past two decade has now proven that the smartly designed nanoparticles help in successful chemotherapy by overcoming the MDR and preferentially accumulate in the tumor region by means of active and passive targeting therefore reducing the offtarget accumulation of payload. Many of such nanoparticles are in different stages of clinical trials as nanomedicines showing promising result in cancer therapy including the resistant cases. Nanoparticles as chemotherapeutics carriers offer the opportunity to have multiple payload of drug and or imaging agents for combinational and theranostics therapy. Moreover, nanotechnology further bring in notice the new treatment strategies such as combining the NIR, MRI and HIFU in cancer chemotherapy and imaging. Here, we discussed the cellular/non-cellular factors constituting the MDR in cancer and the role of nanomedicines in effective chemotherapy of MDR cases of cancers. Moreover, recent advancements like combinational payload delivery and combined physical approach with nanotechnology in cancer therapy have also been discussed.

Dietary flavone chrysin (5,7-dihydroxyflavone ChR) functionalized highly-stable metal nanoformulations for improved anticancer applications

A new approach to formulate biofunctionalized metallic silver (ChR–AgNPs) and gold (ChR–AuNPs) nanoparticles using ChR as a direct bioreductant and capping agent as a combinational drug-nano platform for breast cancer therapy.

PEGylated solid lipid nanoparticles: design, methotrexate loading and biological evaluation in animal models

The design of pegylated SLNs for efficient entrapment and delivery of methotrexate at tumour sites in order to overcome its bioavailability and blood retention issues.

Drug-targeting methodologies with applications: A review

Targeted drug delivery to solid tumors is a very active research area, focusing mainly on improved drug formulation and associated best delivery methods/devices. Drug-targeting has the potential to greatly improve drug-delivery efficacy, reduce side effects, and lower the treatment costs. However, the vast majority of drug-targeting studies assume that the drug-particles are already at the target site or at least in its direct vicinity. In this review, drug-delivery methodologies, drug types and drug-delivery devices are discussed with examples in two major application areas: (1) inhaled drug-aerosol delivery into human lung-airways; and (2) intravascular drug-delivery for solid tumor targeting. The major problem addressed is how to deliver efficiently the drug-particles from the entry/infusion point to the target site. So far, most experimental results are based on animal studies. Concerning pulmonary drug delivery, the focus is on the pros and cons of three inhaler types, i.e., pressurized metered dose inhaler, dry powder inhaler and nebulizer, in addition to drug-aerosol formulations. Computational fluid-particle dynamics techniques and the underlying methodology for a smart inhaler system are discussed as well. Concerning intravascular drug-delivery for solid tumor targeting, passive and active targeting are reviewed as well as direct drug-targeting, using optimal delivery of radioactive microspheres to liver tumors as an example. The review concludes with suggestions for future work, considereing both pulmonary drug targeting and direct drug delivery to solid tumors in the vascular system.

‘Green’ biocompatible organic–inorganic hybrid electrospun nanofibers for potential biomedical applications

Gold nanoparticles were prepared by green route using Couroupita guianensis leaves extract. The green synthesized gold nanoparticles exhibited maximum absorbance at 526 nm in the ultraviolet spectrum. By incorporating the green synthesized gold nanoparticles in poly(vinyl alcohol) matrix, unique green organic–inorganic hybrid nanofibers (poly (vinyl alcohol)–gold nanoparticles) were developed by electrospinning. Contact angle measurements showed that the prepared poly (vinyl alcohol)–gold nanoparticles were found to be highly hydrophilic. The crystallinity of gold nanoparticles was analyzed using XRD. The synthesized gold nanoparticles and poly (vinyl alcohol)–gold nanoparticles were characterized using high-resolution transmission electron microscope, Fourier transform-infrared spectroscopy and energy-dispersive analysis of X-ray. The ultimate aim of the present work is to achieve optimum antibacterial, antifungal, biocompatibility and antiproliferative activities at a very low loading of gold nanoparticles. Vero cell lines showed a maximum of 90% cell viability on incubation with the prepared poly (vinyl alcohol)–gold nanoparticles. MCF 7 and HeLa cell lines proliferated only to 8% and 9%, respectively, on incubation with the poly (vinyl alcohol)–gold nanoparticles, and also exhibited good antibacterial and antifungal activities against test pathogenic bacterial and fungal strains. Thus, the poly (vinyl alcohol)–gold nanoparticles could be used for dual applications such as antimicrobial, anticancer treatment besides being highly biocompatible.

Enhanced in vivo targeting of murine nonparenchymal liver cells with monophosphoryl lipid A functionalized microcapsules

A broad spectrum of infectious liver diseases emphasizes the need of microparticles for targeted delivery of immunomodulatory substances to the liver. Microcapsules (MCs) are particularly attractive for innovative drug and vaccine formulations, enabling the combination of antigen, drugs, and adjuvants. The present study aimed to develop microcapsules characterized by an enhanced liver deposition and accelerated uptake by nonparenchymal liver cells (NPCs). Initially, two formulations of biodegradable microcapsules were synthesized from either hydroxyethyl starch (HES) or mannose. Notably, HES-MCs accumulated primarily in the liver, while mannose particles displayed a lung preference. Functionalization of HES-MCs with anti-CD40, anti-DEC205, and/or monophosphoryl lipid A (MPLA) enhanced uptake of MCs by nonparenchymal liver cells in vitro. In contrast, only MPLA-coated HES-MCs promoted significantly the in vivo uptake by NPCs. Finally, HES-MCs equipped with MPLA, anti-CD40, and anti-DEC205 induced the secretion of TNF-α, IL-6 by Kupffer cells (KCs), and IFN-γ and IL-12p70 by liver dendritic cells (DCs). The enhanced uptake and activation of KCs by MPLA-HES-MCs is a promising approach to prevent or treat infection, since KCs are exploited as an entry gate in various infectious diseases, such as malaria. In parallel, loading and activating liver DCs, usually prone to tolerance, bears the potential to induce antigen specific, intrahepatic immune responses necessary to prevent and treat infections affecting the liver.