Overcoming multiple drug resistance in cancer using polymeric micelles

Overcoming P-glycoprotein-mediated multidrug resistance in cancer cells through micelle-forming PHPMA-b-PPO diblock copolymers for doxorubicin delivery

Multidrug resistance (MDR) represents one of the major concerns in cancer therapy as it may cause reduced efficacy of chemotherapeutic drugs due to the overexpression of ABC transporters, particularly P-glycoprotein (P-gp). This study explores the potential of novel amphiphilic diblock (DB) copolymers composed of poly[N-(2-hydroxypropyl)methacrylamide]-based copolymers (PHPMA) and poly(propylene oxide) (PPO) to overcome MDR mechanisms. The DB copolymers and their doxorubicin (Dox) conjugates significantly increased Dox accumulation in P-gp positive cells, markedly sensitizing them to Dox cytotoxic activity. The underlying mechanisms included depletion of intracellular ATP with subsequent inhibition of P-gp mediated drug efflux, an altered mitochondrial membrane potential, and increased ROS production. Moreover, the DB-Dox conjugates inhibited tumor growth in vivo more effectively compared to the corresponding PHPMA-based drug delivery system. Copolymers with additionally loaded PPO in the micelle core demonstrated superior efficacy in terms of P-gp inhibition, ATP depletion, and chemosensitizing effect in vitro, as well as antitumor activity in vivo. DB copolymers effectively depleted ATP levels both in vitro and in vivo using patient-derived xenograft (PDX) models, underscoring their capacity to enhance the effectiveness of standard chemotherapy and translational potential.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

Engineering of a double targeting nanoplatform to elevate ROS generation and DSF anticancer activity

Intracellular oxidative protection mechanisms and adverse systemic toxicity are major obstacles for the success of chemodynamic therapy (CDT)/chemotherapy (CT) synergistic therapy. To tackle the fundamental challenges of current CDT and circumvent the side effects of conventional CT, we developed a copper peroxide (CP) and disulfiram (DSF)-loaded 3-aminotriazole (3-AT) doped ZIF-8 (MAF) with partial sequence-specificity using hyaluronic acid (HA) and triphenylphosphine (TPP) in this study. Upon intravenous administration, CP@MAF-DSF@PEG-TPP@HA (CPMDTH) nanoparticles (NPs) were enriched in tumor tissues through HA-mediated endocytosis, followed by enhanced accumulation in mitochondria by the TPP target. The acidic tumor environment (TME) triggered the decomposition of MAF to release CP, DSF and 3-AT. Cu2+ and H2O2 hydrated from CP NPs produced ˙OH via a Fenton-like reaction. CAT activity inhibition and GSH consumption induced by 3-AT dramatically amplified mitochondrial oxidative stress, thereby promoting the overproduction of ˙OH. In addition, the accumulation of DSF and Cu2+ led to the formation of a cytotoxic bis(N,N-diethyldithiocarbamate) copper(II) complex (Cu(DTC)2) in situ, achieving efficient CT. CPMDTH NPs demonstrated significantly improved antitumor efficiency and excellent biosafety both in vitro and in vivo. This study offers a promising therapeutic strategy for CDT/CT synergistic oncotherapy.

Overcoming colloidal nanoparticle aggregation in biological milieu for cancer therapeutic delivery: Perspectives of materials and particle design

Nanoparticles as cancer therapeutic carrier fail in clinical translation due to complex biological environments in vivo consisting of electrolytes and proteins which render nanoparticle aggregation and unable to reach action site. This review identifies the desirable characteristics of nanoparticles and their constituent materials that prevent aggregation from site of administration (oral, lung, injection) to target site. Oral nanoparticles should ideally be 75-100 nm whereas the size of pulmonary nanoparticles minimally affects their aggregation. Nanoparticles generally should carry excess negative surface charges particularly in fasting state and exert steric hindrance through surface decoration with citrate, anionic surfactants and large polymeric chains (polyethylene glycol and polyvinylpyrrolidone) to prevent aggregation. Anionic as well as cationic nanoparticles are both predisposed to protein corona formation as a function of biological protein isoelectric points. Their nanoparticulate surface composition as such should confer hydrophilicity or steric hindrance to evade protein corona formation or its formation should translate into steric hindrance or surface negative charges to prevent further aggregation. Unexpectedly, smaller and cationic nanoparticles are less prone to aggregation at cancer cell interface favoring endocytosis whereas aggregation is essential to enable nanoparticles retention and subsequent cancer cell uptake in tumor microenvironment. Present studies are largely conducted in vitro with simplified simulated biological media. Future aggregation assessment of nanoparticles in biological fluids that mimic that of patients is imperative to address conflicting materials and designs required as a function of body sites in order to realize the future clinical benefits.

Recent advances in access to overcome cancer drug resistance by nanocarrier drug delivery system

Cancer is currently one of the most intractable diseases causing human death. Although the prognosis of tumor patients has been improved to a certain extent through various modern treatment methods, multidrug resistance (MDR) of tumor cells is still a major problem leading to clinical treatment failure. Chemotherapy resistance refers to the resistance of tumor cells and/or tissues to a drug, usually inherent or developed during treatment. Therefore, an urgent need to research the ideal drug delivery system to overcome the shortcoming of traditional chemotherapy. The rapid development of nanotechnology has brought us new enlightenments to solve this problem. The novel nanocarrier provides a considerably effective treatment to overcome the limitations of chemotherapy or other drugs resulting from systemic side effects such as resistance, high toxicity, lack of targeting, and off-target. Herein, we introduce several tumor MDR mechanisms and discuss novel nanoparticle technology applied to surmount cancer drug resistance. Nanomaterials contain liposomes, polymer conjugates, micelles, dendrimers, carbon-based, metal nanoparticles, and nucleotides which can be used to deliver chemotherapeutic drugs, photosensitizers, and small interfering RNA (siRNA). This review aims to elucidate the advantages of nanomedicine in overcoming cancer drug resistance and discuss the latest developments.

The Novel 5-Fluorouracil Loaded Ruthenium-based Nanocarriers Enhanced Anticancer and Apoptotic Efficiency while Reducing Multidrug Resistance in Colorectal Cancer Cells

Recently, nanocarriers have been made to eliminate the disadvantages of chemotherapeutic agents by nanocarriers. Nanocarriers show their efficacy through their targeted and controlled release. In this study, 5-fluorouracil (5FU) was loaded into ruthenium (Ru)-based nanocarrier (5FU-RuNPs) for the first time to eliminate the disadvantages of 5FU, and its cytotoxic and apoptotic effects on HCT116 colorectal cancer cells were compared with free 5FU. 5FU-RuNPs with a size of approximately 100 nm showed a 2.61-fold higher cytotoxic effect compared to free 5FU. Apoptotic cells were detected by Hoechst/propidium iodide double staining, and the expression levels of BAX/Bcl-2 and p53 proteins, in which apoptosis occurred intrinsically, were revealed. In addition, 5FU-RuNPs was also found to reduce multidrug resistance (MDR) according to BCRP/ABCG2 gene expression levels. When all the results were evaluated, the fact that Ru-based nanocarriers alone did not cause cytotoxicity proved that they were ideal nanocarriers. Moreover, 5FU-RuNPs did not show any significant effect on the cell viability of normal human epithelial cell lines BEAS-2B. Consequently, the 5FU-RuNPs synthesized for the first time may be ideal candidates for cancer treatment because they can minimize the potential drawbacks of free 5FU.

Glioma diagnosis and therapy: Current challenges and nanomaterial-based solutions

Glioma is often referred to as one of the most dreadful central nervous system (CNS)-specific tumors with rapidly-proliferating cancerous glial cells, accounting for nearly half of the brain tumors at an annual incidence rate of 30-80 per a million population. Although glioma treatment remains a significant challenge for researchers and clinicians, the rapid development of nanomedicine provides tremendous opportunities for long-term glioma therapy. However, several obstacles impede the development of novel therapeutics, such as the very tight blood-brain barrier (BBB), undesirable hypoxia, and complex tumor microenvironment (TME). Several efforts have been dedicated to exploring various nanoformulations for improving BBB permeation and precise tumor ablation to address these challenges. Initially, this article briefly introduces glioma classification and various pathogenic factors. Further, currently available therapeutic approaches are illustrated in detail, including traditional chemotherapy, radiotherapy, and surgical practices. Then, different innovative treatment strategies, such as tumor-treating fields, gene therapy, immunotherapy, and phototherapy, are emphasized. In conclusion, we summarize the article with interesting perspectives, providing suggestions for future glioma diagnosis and therapy improvement.

Heparin and Heparin-Based Drug Delivery Systems: Pleiotropic Molecular Effects at Multiple Drug Resistance of Osteosarcoma and Immune Cells

One of the main problems of modern health care is the growing number of oncological diseases both in the elderly and young population. Inadequately effective chemotherapy, which remains the main method of cancer control, is largely associated with the emergence of multidrug resistance in tumor cells. The search for new solutions to overcome the resistance of malignant cells to pharmacological agents is being actively pursued. Another serious problem is immunosuppression caused both by the tumor cells themselves and by antitumor drugs. Of great interest in this context is heparin, a biomolecule belonging to the class of glycosaminoglycans and possessing a broad spectrum of biological activity, including immunomodulatory and antitumor properties. In the context of the rapid development of the new field of “osteoimmunology,” which focuses on the collaboration of bone and immune cells, heparin and delivery systems based on it may be of intriguing importance for the oncotherapy of malignant bone tumors. Osteosarcoma is a rare but highly aggressive, chemoresistant malignant tumor that affects young adults and is characterized by constant recurrence and metastasis. This review describes the direct and immune-mediated regulatory effects of heparin and drug delivery systems based on it on the molecular mechanisms of (multiple) drug resistance in (onco) pathological conditions of bone tissue, especially osteosarcoma.

Applications of Nanotechnology-based Approaches to Overcome Multi-drug Resistance in Cancer

Cancer is one of the leading causes of death worldwide. Chemotherapy and radiation therapy are the major treatments used for the management of cancer. Multidrug resistance (MDR) is a major hindrance faced in the treatment of cancer and is also responsible for cancer relapse. To date, several studies have been carried out on strategies to overcome or reverse MDR in cancer. Unfortunately, the MDR reversing agents have been proven to have minimal clinical benefits, and eventually, no improvement has been made in therapeutic efficacy to date. Thus, several investigational studies have also focused on overcoming drug resistance rather than reversing the MDR. In this review, we focus primarily on nanoformulations regarded as a novel approach to overcome or bypass the MDR in cancer. The nanoformulation systems serve as an attractive strategy as these nanosized materials selectively get accumulated in tumor tissues, thereby improving the clinical outcomes of patients suffering from MDR cancer. In the current work, we present an overview of recent trends in the application of various nano-formulations, belonging to different mechanistic classes and functionalization like carbon nanotubes, carbon nanohorns, carbon nanospheres, liposomes, dendrimers, etc., to overcome MDR in cancer. A detailed overview of these techniques will help researchers in exploring the applicability of nanotechnologybased approaches to treat MDR.

Advancements in redox-sensitive micelles as nanotheranostics: A new horizon in cancer management

World Health Organisation (WHO) delineated cancer as one of the foremost reasons for mortality with 10 million deaths in the year 2020. Early diagnosis and effective drug delivery are of utmost importance in cancer management. The entrapment of both bio-imaging dyes and drugs will open novel avenues in the area of tumor theranostics. Elevated levels of reactive oxygen species (ROS) and glutathione (GSH) are the characteristic features of the tumor microenvironment (TME). Researchers have taken advantage of these specific TME features in recent years to develop micelle-based theranostic nanosystems. This review focuses on the advantages of redox-sensitive micelles (RSMs) and supramolecular self-assemblies for tumor theranostics. Key chemical linkers employed for the tumor-specific release of the cargo have been discussed. In vitro characterisation techniques used for the characterization of RSMs have been deliberated. Potential bottlenecks that may present themselves in the bench-to-bedside translation of this technology and the regulatory considerations have been deliberated.

A compound formulation of EGF-modified paclitaxel micelles and EGF-modified emodin micelles enhance the therapeutic effect of ovarian cancer

Ovarian cancer is a serious threat to female health, although the incidence of it is relatively low, its mortality rate remains high due to its intense invasion and metastasis. Therefore, it is urgent to explore new treatment strategies for ovarian cancer. In this study, paclitaxel and emodin were encapsulated in different micelles, and loaded on the surface of the micelles with epidermal growth factor (EGF) as the targeting molecule, made compound formulations in proportion. In this study, EGF-modified paclitaxel micelles and EGF-modified emodin micelles were characterized, their inhibitory effects on SKOV3 cell proliferation and invasion were studied in vivo and in vitro, and its targeting ability was confirmed. The results showed that the shape, particle size, zeta potential, release rate, encapsulation rate, polydispersity index, and other physical and chemical properties of EGF-modified paclitaxel micelles plus EGF-modified emodin micelles meet the requirements, and the modification of EGF on the micelle surface could obviously improve the uptake of SKOV3 cells and inhibit the proliferation of SKOV3 cells. The compound formulation can inhibit the invasion and metastasis of ovarian cancer by inhibiting the expression of hypoxia inducible factor-α, MMP-2, MMP-9, and VE-cadherin. The in vivo studies have also showed significant pharmacodynamics results. These results indicated that EGF-modified paclitaxel micelles plus EGF-modified emodin micelles provide a new strategy for the treatment of ovarian cancer.

Natural and Synthetic Micelles for Delivery of Small Molecule Drugs, Imaging Agents and Nucleic Acids

The poor solubility, lack of targetability, quick renal clearance, and degradability of many therapeutic and imaging agents strongly limit their applications inside the human body. Amphiphilic copolymers having self-assembling properties can form core-shell structures called micelles, a promising nanocarrier for hydrophobic drugs, plasmid DNA, oligonucleotides, small interfering RNAs (siRNAs) and imaging agents. Fabrication of micelles loaded with different pharmaceutical agents provides numerous advantages including therapeutic efficacy, diagnostic sensitivity, and controlled release to the desired tissues. Moreover, due to their smaller particle size (10-100 nm) and modified surfaces with different functional groups (such as ligands) help them to accumulate easily in the target location, enhancing cellular uptake and reducing unwanted side effects. Furthermore, the release of the encapsulated agents may also be triggered from stimuli-sensitive micelles at different physiological conditions or by an external stimulus. In this review article, we discuss the recent advancement in formulating and targeting different natural and synthetic micelles including block copolymer micelles, cationic micelles, and dendrimers-, polysaccharide- and protein-based micelles for the delivery of different therapeutic and diagnostic agents. Finally, their applications, outcomes, and future perspectives have been summarized.

Curcuminoid Co-Loading Platinum Heparin-Poloxamer P403 Nanogel Increasing Effectiveness in Antitumor Activity

Nanosized multi-drug delivery systems provide synergistic effects between drugs and bioactive compounds, resulting in increased overall efficiency and restricted side effects compared to conventional single-drug chemotherapy. In this study, we develop an amphiphilic heparin-poloxamer P403 (HP403) nanogel that could effectively co-load curcuminoid (Cur) and cisplatin hydrate (CisOH) (HP403@CisOH@Cur) via two loading mechanisms. The HP403 nanogels and HP403@CisOH@Cur nanogels were closely analyzed with 1H-NMR spectroscopy, FT-IR spectroscopy, TEM, and DLS, exhibiting high stability in spherical forms. In drug release profiles, accelerated behavior of Cur and CisOH at pH 5.5 compared with neutral pH was observed, suggesting effective delivery of the compounds in tumor sites. In vitro studies showed high antitumor activity of HP403@CisOH@Cur nanogels, while in vivo assays showed that the dual-drug platform prolonged the survival time of mice and prevented tail necrosis. In summary, HP403@CisOH@Cur offers an intriguing strategy to achieve the cisplatin and curcumin synergistic effect in a well-designed delivery platform that increases antitumor effectiveness and overcomes undesired consequences caused by cisplatin in breast cancer treatment.

Pharmaceutical Formulations with P-Glycoprotein Inhibitory Effect as Promising Approaches for Enhancing Oral Drug Absorption and Bioavailability

P-glycoprotein (P-gp) is crucial in the active transport of various substrates with diverse structures out of cells, resulting in poor intestinal permeation and limited bioavailability following oral administration. P-gp inhibitors, including small molecule drugs, natural constituents, and pharmaceutically inert excipients, have been exploited to overcome P-gp efflux and enhance the oral absorption and bioavailability of many P-gp substrates. The co-administration of small molecule P-gp inhibitors with P-gp substrates can result in drug–drug interactions and increased side effects due to the pharmacological activity of these molecules. On the other hand, pharmaceutically inert excipients, including polymers, surfactants, and lipid-based excipients, are safe, pharmaceutically acceptable, and are not absorbed from the gut. Notably, they can be incorporated in pharmaceutical formulations to enhance drug solubility, absorption, and bioavailability due to the formulation itself and the P-gp inhibitory effects of the excipients. Different formulations with inherent P-gp inhibitory activity have been developed. These include micelles, emulsions, liposomes, solid lipid nanoparticles, polymeric nanoparticles, microspheres, dendrimers, and solid dispersions. They can bypass P-gp by different mechanisms related to their properties. In this review, we briefly introduce P-gp and P-gp inhibitors, and we extensively summarize the current development of oral drug delivery systems that can bypass and inhibit P-gp to improve the oral absorption and bioavailability of P-gp substrates. Since many drugs are limited by P-gp-mediated efflux, this review is helpful for designing suitable formulations of P-gp substrates to enhance their oral absorption and bioavailability.

Dual-Targeting Polymeric Nanocarriers to Deliver ROS-Responsive Prodrugs and Combat Multidrug Resistance of Cancer Cells

Targeting delivery of anticancer drugs that can interact with DNA into mitochondria of cancer cells has been demonstrated to be an effective method to combat drug resistance. In this report, a cancer cell and mitochondria dual-targeting drug delivery system (DT-NP) is presented based on nanoparticles self-assembled from amphiphilic block copolymers with pH-responsive release of cinnamaldehyde (CA), which is used to encapsulate reactive oxygen species (ROS)-activable prodrug, phenylboronic pinacol ester-caged doxorubicin (BDOX). The surfaces of nanoparticles are conjugated by cancer cell-targeting folic acid (FA) and mitochondria-targeting triphenyl phosphonium (TPP) for dual targeting delivery. After incubation of DT-NP with multidrug-resistant breast cancer cells MCF-7/ADR, CA release under acidic conditions in endosomes from DT-NP can effectively induce intracellular oxidative stress improvement, especially in mitochondria. After targeting drug delivery into mitochondria, high level of ROS in mitochondria can in situ activate BDOX to interact with mitochondrial DNA and induce cell apoptosis. DT-NP displays a remarkably higher cancer cell killing effect on MCF-7/ADR as compared with DOX. Accordingly, DT-NP shows great potentials toward multidrug-resistant cancers as dual-targeting drug delivery systems with intracellular oxidative stress improvement and ROS-responsive prodrug activation in mitochondria.

Albumin nanoformulations as an innovative solution to overcome doxorubicin chemoresistance

Aim: Resistance to chemotherapy is a major limiting factor that hamper the effectiveness of anticancer therapies. Doxorubicin is an antineoplastic agent used in the treatment of a wide range of cancers. However, it presents several limitations such as dose-dependent cardiotoxicity, lack of selectivity for tumor cells, and induced cell resistance. Nanotechnology represents a promising strategy to avoid these drawbacks. In this work, new albumin-based nanoparticles were formulated for the intracellular delivery of doxorubicin with the aim to overcome cancer drug resistance.

Methods: Glycol chitosan-coated and uncoated albumin nanoparticles were prepared with a tuned coacervation method. The nanoformulations were in vitro characterized evaluating the physicochemical parameters, morphology, and in vitro release kinetics. Biological assays were performed on A2780res and EMT6 cells from human ovarian carcinoma and mouse mammary cell lines resistant for doxorubicin, respectively.

Results: Cell viability assays showed that nanoparticles have higher cytotoxicity than the free drug. Moreover, at low concentrations, both doxorubicin-loaded nanoparticles inhibited the cell colony formation in a greater extent than drug solution. In addition, the cell uptake of the different formulations was investigated by confocal microscopy and by the HPLC determination of doxorubicin intracellular accumulation. The nanoparticles were rapidly internalized in greater extent compared to the free drug.

Conclusion: Based on these results, doxorubicin-loaded albumin nanoparticles might represent a novel platform to overcome the mechanism of drug resistance in cancer cell lines and improve the drug efficacy.

Polymeric Micelles in Cancer Immunotherapy

Cancer immunotherapies have generated some miracles in the clinic by orchestrating our immune system to combat cancer cells. However, the safety and efficacy concerns of the systemic delivery of these immunostimulatory agents has limited their application. Nanomedicine-based delivery strategies (e.g., liposomes, polymeric nanoparticles, silico, etc.) play an essential role in improving cancer immunotherapies, either by enhancing the anti-tumor immune response, or reducing their systemic adverse effects. The versatility of working with biocompatible polymers helps these polymeric nanoparticles stand out as a key carrier to improve bioavailability and achieve specific delivery at the site of action. This review provides a summary of the latest advancements in the use of polymeric micelles for cancer immunotherapy, including their application in delivering immunological checkpoint inhibitors, immunostimulatory molecules, engineered T cells, and cancer vaccines.

Doxorubicin and Edelfosine Combo-Loaded Lipid-Polymer Hybrid Nanoparticles for Synergistic Anticancer Effect Against Drug-Resistant Osteosarcoma

Introduction

The failure of chemotherapy in osteosarcoma results in drug resistance and acute side effects in the body.

Methods

In this study, we have prepared a novel folate receptor-targeted doxorubicin (DOX) and edelfosine (EDL)-loaded lipid-polymer hybrid nanoparticle (DE-FPLN) to enhance the anticancer efficacy in osteosarcoma. The nanoparticles were thoroughly characterized for in vitro biological assays followed by detailed antitumor efficacy analysis and toxicity analysis in a xenograft model.

Results

The dual drug-loaded nanoparticles showed a nanosized morphology and physiological stability. The targeted nanoparticles showed enhanced cellular internalization and subcellular distribution in MG63 cancer cells compared to that of non-targeted nanoparticles. Among many ratios of DOX and EDL, 1:1 ratiometric combinations of drugs were observed to be highly synergistic in killing the cancer cells. MTT assay and caspase-3/7 activity assay clearly showed the superior anticancer efficacy of DE-FPLN formulations in inducing the cancer cell death. In vitro results indicate that the co-administration of two drugs in a folic acid-targeted nanoparticle could potentially induce the apoptosis and cell death. In vivo results displayed the potency of tumor cell killing and significant suppression of tumor growth without any detectable side effects.

Conclusion

The lipid-polymer hybrid nanocarriers with multiple properties of high drug loading, sequential and ratiometric drug release, improved physiological stability, prolonged blood circulation, and tumor-specific targeting are promising for the delivery of multiple drugs in the treatment of osteosarcoma.

Nanoparticles in Colorectal Cancer Therapy: Latest In Vivo Assays, Clinical Trials, and Patents

Colorectal cancer (CRC) is the third most common cancer worldwide. Its poor response to current treatment options in advanced stages and the need for efficient diagnosis in early stages call for the development of new therapeutic and diagnostic strategies. Some of them are based on the use of nanometric materials as carriers and releasers of therapeutic agents and fluorescent molecules, or even on the utilization of magnetic materials that provide very interesting properties. These nanoformulations present several advantages compared with the free molecular cargo, including increased drug solubility, bioavailability, stability, and tumor specificity. Moreover, tumor multidrug resistance has been decreased in some cases, leading to improved treatment effectiveness by reducing drug dose and potential side effects. Here, we present an updated overview of the latest advances in clinical research, in vivo studies, and patents regarding the application of nanoformulations in the treatment of CRC. Based on the information gathered, a wide variety of nanomaterials are being investigated in clinical research, even in advanced phases, i.e., close to reaching the market. In sum, these novel materials can offer remarkable advantages with respect to current therapies, which could be complemented or even replaced by these nanosystems in the near future.

Epigallocatechin-3-gallate sensitises multidrug-resistant oral carcinoma xenografts to vincristine sulfate

Oral squamous cell carcinoma (OSCC) is a very aggressive malignancy, and 50% of patients who receive curative treatment die from the disease or related complications within 5 years. Epigallocatechin‐3‐gallate (EGCG) is the most abundant bioactive ingredient of tea polyphenols in green tea and has anticancer properties. Here, we evaluated the preclinical efficacy of EGCG combined with vincristine sulfate (VCR) on the growth, angiogenic activity and vascular endothelial growth factor (VEGF) expression in xenograft nude mice inoculated with KBV200 cells. Compared with VCR alone, the combined use of EGCG and VCR strongly inhibited tumour growth and angiogenesis (P < 0.01). VEGF mRNA and protein levels were lower in the KBV200 xenograft group treated with the combined regime (P < 0.01) than those in the VCR alone group. EGCG sensitises multidrug‐resistant OSCC to VCR, and this may occur through the inhibition of angiogenesis via VEGF down‐regulation.

Alpha-1 Antitrypsin Induces Epithelial-to-Mesenchymal Transition, Endothelial-to-Mesenchymal Transition, and Drug Resistance in Lung Cancer Cells

Purpose

Alpha-1 antitrypsin (A1AT) is a secreted protein that plays an important role in various diseases. However, the role of A1AT in non-small cell lung cancer is obscure.

Materials and Methods

A1AT expression in non-small cell lung cancer was analyzed using quantitative reverse transcription PCR, Western blotting (WB), immunohistochemistry (IHC), and ELISA. WB and IF were used to analyze markers of epithelial-to-mesenchymal transition (EMT), EndoMT, and cancer stem cell (CSC). Transwell and cell wound healing assays were used to analyze migration and invasion abilities. Colony formation and CCK-8 assays were used to analyze cell proliferation following cisplatin treatment.

Results

A1AT expression was higher in lung cancer samples than in normal tissues and the increased expression was correlated with poor overall survival of patients. In vitro experiments showed that A1AT overexpressed by plasmid transfection significantly promoted migration, invasion, EMT, EndoMT, stemness, and colony formation in lung cancer cell lines, as opposed to A1AT downregulation by siRNA transfection, which significantly inhibited all these variables.

Conclusion

A1AT is a novel therapeutic target and might be associated with tumor metastasis in lung carcinoma.

Enhanced Percutaneous Delivery of Methotrexate Using Micelles Prepared with Novel Cationic Amphipathic Material

BACKGROUND

Methotrexate (MTX) is an antiproliferative drug widely used to treat inflammatory diseases and autoimmune diseases. The application of percutaneous administration is hindered due to its poor transdermal penetration. To reduce side effects and enhanced percutaneous delivery of MTX, novel methotrexate (MTX)-loaded micelles prepared with a amphiphilic cationic material, N,N-dimethyl-(N',N'-di-stearoyl-1-ethyl)1,3-diaminopropane (DMSAP), was designed.

MATERIALS AND METHODS

DMSAP was synthesized via three steps using simple chemical agents. H nuclear magnetic resonance and mass spectroscopy were used to confirm the successful synthesis of DMSAP. A safe and non-toxic phosphatidylcholine, soybean phosphatidylcholine (SPC), was added to DMSAP at different ratios to form P/D-micelles. Then, MTX-entrapped micelles (M/P/D-micelles) were prepared by electrostatic adsorption. The physicochemical properties and blood stability of micelles were examined thoroughly. In addition, the transdermal potential of the micelles was evaluated by permeation experiments.

RESULTS

In aqueous environments, DMSAP conjugates could self-assemble spontaneously into micelles with a low critical micelle concentration (CMC) of 0.056 mg/mL. Stable, spherical MTX-entrapped micelles (M/P/D-micelles) with a size of 100-120 nm and high zeta potential of +36.26 mV were prepared. In vitro permeation studies showed that M/P/D-micelles exhibited superior skin permeability and deposition of MTX in the epidermis and dermis compared with that of free MTX.

CONCLUSION

These special novel cationic M/P/D-micelles can enhance the permeability of MTX and are expected to be a promising percutaneous delivery system for therapy skin diseases.

Enhancing Drug Delivery for Overcoming Angiogenesis and Improving the Phototherapy Efficacy of Glioblastoma by ICG-Loaded Glycolipid-Like Micelles

Background

Phototherapy is a potential new candidate for glioblastoma (GBM) treatment. However inadequate phototherapy due to stability of the photosensitizer and low target specificity induces the proliferation of neovascular endothelial cells for angiogenesis and causes poor prognosis.

Methods

In this study, we constructed c(RGDfk)-modified glycolipid-like micelles (cRGD-CSOSA) encapsulating indocyanine green (ICG) for dual-targeting neovascular endothelial cells and tumor cells, and cRGD-CSOSA/ICG mediated dual effect of PDT/PTT with NIR irradiation.

Results

In vitro, cRGD-CSOSA/ICG inhibited cell proliferation and blocked angiogenesis with NIR irradiation. In vivo, cRGD-CSOSA/ICG exhibited increased accumulation in neovascular endothelial cells and tumor cells. Compared with that of CSOSA, the accumulation of cRGD-CSOSA in tumor tissue was further improved after dual-targeted phototherapy pretreatment. With NIR irradiation, the tumor-inhibition rate of cRGD-CSOSA/ICG was 80.00%, significantly higher than that of ICG (9.08%) and CSOSA/ICG (42.42%). Histological evaluation showed that the tumor vessels were reduced and that the apoptosis of tumor cells increased in the cRGD-CSOSA/ICG group with NIR irradiation.

Conclusion

The cRGD-CSOSA/ICG nanoparticle-mediated dual-targeting phototherapy could enhance drug delivery to neovascular endothelial cells and tumor cells for anti-angiogenesis and improve the phototherapy effect of glioblastoma, providing a new strategy for glioblastoma treatment.

The potential of micelleplexes as a therapeutic strategy for osteosarcoma disease

Osteosarcoma (OS) is a rare aggressive bone, presenting low patient survival rate, high metastasis and relapse occurrence, mostly due to multi-drug resistant cells. To surpass that, the use of nanomedicine for the targeted delivery of genetic material, drugs or both have been extensively researched. In this review, we address the current situation of the disorder and some gene therapy options in the nanomedicine field that have been investigated. Among them, polymeric micelles (PM) are an advantageous therapeutic alternative highly explored for OS, as they allow for the targeted transportation of poorly water-soluble drugs to cancer cells. In addition, micelleplexes are PMs with cationic properties with promising features, such as the possibility for a dual therapy, which have made them an attractive research subject. The aim of this review article is to elucidate the application of a micelleplex formulation encapsulating the underexpressed miRNA145 to achieve an active targeting to OS cells and overcome multi-drug resistance, as a new and viable therapeutic strategy.

Liver-Targeting and pH-Sensitive Sulfated Hyaluronic Acid Mixed Micelles for Hepatoma Therapy

Background

The tumor-targeting ability and pH-sensitive properties of intelligent drug delivery systems are crucial for effective drug delivery and anti-tumor therapy.

Methods

In this study, sHA-DOX/HA-GA mixed micelles were designed with the following properties: sulfated hyaluronic acid (sHA) was synthesized to block cell migration by inhibiting HAase; sHA-DOX conjugates were synthesized via pH-sensitive hydrazone bond to realize DOX-sensitive release. The introduction of HA-GA conjugate could improve active-targeting ability and cellular uptake.

Results

The results showed that the mixed micelles possessed a nearly spherical shape, nanoscale particle size (217.70±0.89 nm), narrow size distribution (PDI=0.07±0.04), negative zeta potential (-31.87±0.61 mV) and pH-dependent DOX release. In addition, the sHA-DOX/HA-GA micelles exhibited concentration-dependent cytotoxicities against liver carcinoma cells (HepG2) and HeLa cells, and were shown to be effectively taken up by HepG2 cells by confocal microscopy analysis. Furthermore, the in vivo anti-tumor study showed that mixed micelles had a superior anti-tumor effect compared to that of free DOX. Further evidence obtained from the hematoxylin-eosin staining and immunohistochemistry analysis also demonstrated that sHA-DOX/HA-GA exhibited stronger tumor inhibition and lower systemic toxicity than free DOX.

Conclusion

The sHA-DOX/HA-GA mixed micelles could be a potential drug delivery system for anti-hepatoma therapy.

Co-Delivery of Curcumin and Paclitaxel by "Core-Shell" Targeting Amphiphilic Copolymer to Reverse Resistance in the Treatment of Ovarian Cancer

Background

Ovarian cancer is a common malignancy in the female reproductive system with a high mortality rate. The most important reason is multidrug resistance (MDR) of cancer chemotherapy. To reduce side effects, reverse resistance and improve efficacy for the treatment of ovarian cancer, a “core-shell” polymeric nanoparticle-mediated curcumin and paclitaxel co-delivery platform was designed.

Methods

Nuclear magnetic resonance confirmed the successful grafting of polyethylenimine (PEI) and stearic acid (SA) (PEI-SA), which is designed as a mother core for transport carrier. Then, PEI-SA was modified with hyaluronic acid (HA) and physicochemical properties were examined. To understand the regulatory mechanism of resistance and measure the anti-tumor efficacy of the treatments, cytotoxicity assay, cellular uptake, P-glycoprotein (P-gp) expression and migration experiment of ovarian cancer cells were performed. In addition, adverse reactions of nanoformulation to the reproductive system were examined.

Results

HA-modified drug-loaded PEI-SA had a narrow size of about 189 nm in diameters, and the particle size was suitable for endocytosis. The nanocarrier could target specifically to CD44 receptor on the ovarian cancer cell membrane. Co-delivery of curcumin and paclitaxel by the nanocarriers exerts synergistic anti-ovarian cancer effects on chemosensitive human ovarian cancer cells (SKOV3) and multi-drug resistant variant (SKOV3-TR30) in vitro, and it also shows a good anti-tumor effect in ovarian tumor-bearing nude mice. The mechanism of reversing drug resistance may be that the nanoparticles inhibit the efflux of P-gp, inhibit the migration of tumor cells, and curcumin synergistically reverses the resistance of PTX to increase antitumor activity. It is worth noting that the treatment did not cause significant toxicity to the uterus and ovaries with the observation of macroscopic and microscopic.

Conclusion

This special structure of targeting nanoparticles co-delivery with the curcumin and paclitaxel can increase the anti-tumor efficacy without increasing the adverse reactions as a promising strategy for therapy ovarian cancer.

A carbohydrate mimetic peptide modified size-shrinkable micelle nanocluster for anti-tumor targeting and penetrating drug delivery

Purpose

To deliver the chemotherapeutics through the nanoparticles, the delivery system should accumulate at the tumor site first and then penetrate through the interstitium into the interior. The specific tumor-targeting pathway mediated via the receptor-ligand binding could achieve the desirable accumulation of nanoparticles, and the nanoparticles with smaller sizes were required for penetration.

Methods and materials

We constructed a size-shrinkable nanocluster modified with a tumor-targeting motif IF-7 (IF-7-MNC) based on a pH-sensitive framework which could be disintegrated in an acid environment to release the micelles aggregated inside. The micelles were constructed by amphiphilic block copolymers PEG−PLA to encapsulate paclitaxel (PTX), while the cross-linked framework consisting of TPGS-PEI was used as a net to gather and release micelles. This nanoplatform could specifically bind with the tumor receptor Annexin A1 through the ligand IF-7 and then shrunk into small micelles with a desirable size for penetration.

Conclusion

IF-7-MNC of 112.27±6.81 nm could shrink into micelles in PBS (0.01 M, pH 5.0) with sizes of 14.89±0.32 nm. The cellular-uptake results showed that IF-7-MNC could be significantly internalized by A549 cells and HUVEC cells, while the penetration of IF-7-MNC could be more prominent into the 3D-tumor spheroids compared with that of MNC. The biodistribution results displayed that the fluorescence of IF-7-MNC in the tumor site at 24 hrs was 4.5-fold stronger than that of MNC. The results of anti-tumor growth demonstrated that IF-7-MNC was more favorable for the tumor therapy than MNC, where the inhibitory rate of tumor growth was 88.29% in the PTX-loaded IF-7-MNC (IF-7-PMNC) treated group, significantly greater than PMNC treatment group (p<0.05).

Nobiletin-loaded micelles reduce ovariectomy-induced bone loss by suppressing osteoclastogenesis

Background

Nobiletin (NOB), a polymethoxy flavonoid, possesses anti-cancer and anti-inflammatory activities, has been reported that it played role in anti-osteoporosis treatment. However, previous research did not focus on practical use due to lack of hydrophilicity and cytotoxicity at high concentrations. The aim of this study was to develop a therapeutic formulation for osteoporosis based on the utilization of NOB.

Methods

In this study, NOB-loaded poly(ethylene glycol)-block-poly(e-caprolactone) (NOB-PEG-PCL) was prepared by dialysis method. The effects on osteoclasts and anti-osteoporosis functions were investigated in a RANKL-induced cell model and ovariectomized (OVX) mice.

Results

Dynamic light scattering and transmission electron microscopy examination results revealed that the NOB-PEG-PCL had a round shape, with a mean diameter around 124 nm. The encapsulation efficiency and drug loading were 76.34±3.25% and 7.60±0.48%, respectively. The in vitro release of NOB from NOB-PEG-PCL showed a remarkably sustained releasing characteristic and could be retained at least 48 hrs in pH 7.4 PBS. Anti-osteoclasts effects demonstrated that the NOB-PEG-PCL significantly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells stimulated by RANKL. Furthermore, the NOB-PEG-PCL did not produce cytotoxicity on bone marrow-derived macrophages (BMMs). The mRNA expressions of genetic markers of osteoclasts including TRAP and cathepsin K were significantly decreased in the presence of NOB-PEG-PCL. In addition, the NOB-PEG-PCL inhibited OC differentiation of BMMs through RANKL-induced MAPK signal pathway. After administration of the NOB-PEG-PCL, NOB-PEG-PCL prevented bone loss and improved bone density in OVX mice. These findings suggest that NOB-PEG-PCL might have great potential in the treatment of osteoporosis.

Conclusion

The results suggested that NOB-PEG-PCL micelles could effectively prevent NOB fast release from micelles and extend circulation time. The NOB-PEG-PCL delivery system may be a promising way to prevent and treat osteoporosis.

Analysis of toxicity and anticancer activity of micelles of sodium alginate-curcumin

Background

Curcumin is a natural polyphenol with anti-inflammatory, chemopreventive and anticancer activity. However, its high hydrophobicity and poor bioavailability limit its medical application. The development of nanocarriers for curcumin delivery is an attractive approach to overcome its low bioavailability and fast metabolism in the liver. We synthesized a blood compatible alginate-curcumin conjugate, AA-Cur, which formed colloidally stable micelles of approximately 200 nm and, as previously shown, exerted strong cytotoxicity against mouse cancer cell lines. Here we analyze in vivo toxicity and antitumor activity of AA-Cur in two different mouse tumor models.

Method

Potential toxicity of intravenously injected AA-Cur was evaluated by: i) analyses of blood parameters (morphology and biochemistry), ii) histology, iii) DNA integrity (comet assay), and iv) cytokine profiling (flow cytometry). Antitumor activity of AA-Cur was evaluated by measuring the growth of subcutaneously inoculated colon MC38-CEA- or orthotopically injected breast 4T1 tumor cells in control mice vs mice treated with AA-Cur.

Results

Injections of four doses of AA-Cur did not reveal any toxicity of the conjugate, thus indicating the safety of its use. AA-Cur elicited moderate anti-tumor activity toward colon MC38-CEA or breast 4T1 carcinomas.

Conclusion

The tested conjugate of alginate and curcumin, AA-Cur, is non-toxic and safe, but exhibits limited anticancer activity.

A Danshensu-Tetramethylpyrazine Conjugate DT-010 Overcomes Multidrug Resistance in Human Breast Cancer

Background: We previously demonstrated that a Danshensu-Tetramethylpyrazine conjugate DT-010 enhanced anticancer effect of doxorubicin (Dox) in Dox-sensitive human breast cancer cells, and protected against Dox-induced cardiotoxicity. This work was designed to see whether DT-010 overcomes Dox resistance in resistant human breast cancer cells.

Methods: The effects of DT-010, Dox or their combination on cell viability of Dox-resistant human breast cancer MCF-7/ADR cells were conducted using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was examined by flow cytometry after Annexin V-FITC/PI co-staining. Dox accumulation in MCF-7/ADR cells was detected by flow cytometry and fluorescence microscopy. A fluorometric multidrug resistance (MDR) assay kit was used to evaluate the effect of DT-010 on MDR transporter activity. P-glycoprotein (P-gp) expression and activity were analyzed by Western blot and rhodamine 123 (Rh123) efflux assay, respectively. The effects of DT-010 on glycolysis and mitochondrial stress were detected using an Extracellular Flux Analyzer. A Succinate Dehydrogenase Activity Assay kit was used to measure mitochondrial complex II activity.

Results: At non-cytotoxic concentrations, DT-010 in combination with Dox led to a significant growth inhibition of MCF-7/ADR cells, suggesting a synergy between DT-010 and Dox to reverse Dox resistance. DT-010 restored Dox-mediated apoptosis and p53 induction in MCF-7/ADR cells. DT-010 increased Dox accumulation in MCF-7/ADR cells via inhibiting P-gp activity, but without changing P-gp expression. Further studies showed that DT-010 significantly inhibited glycolysis and mitochondrial function of MCF-7/ADR cells. Mitochondrial complex II activity was inhibited by DT-010 or DT-010/Dox combination, but not by Dox. The DT-010-mediated suppression of metabolic process may render cells more vulnerable to Dox treatment and thus result in enhanced efficacy.

Conclusions: The results indicate that DT-010 overcomes Dox resistance in human breast cancer cells through a dual action via simultaneously inhibiting P-gp-mediated drug efflux and influencing metabolic process.

Co-Delivery of Eugenol and Dacarbazine by Hyaluronic Acid-Coated Liposomes for Targeted Inhibition of Survivin in Treatment of Resistant Metastatic Melanoma

While melanoma remains a challenge for oncologists, possibilities are being continuously explored to fight resistant metastatic melanoma more effectively. Eugenol is reported to inhibit survivin protein in breast cancer cells. Survivin is also overexpressed by melanoma cells, and is known to impart resistance to them against chemotherapy-induced apoptosis. To be able to fight resistant melanoma, we formulated hyaluronic acid (HA)-coated liposomes loaded with an effective combination of anti-melanoma agents (Dacarbazine and Eugenol), using a solvent injection method. Quality-by-Design (QbD) was applied to optimize and obtain a final formulation with the desired quality attributes, and within an acceptable size range. The optimized formulation was then subjected to performance analysis in cell lines. Coated-Dacarbazine Eugenol Liposomes were found to possess 95.08% cytotoxicity at a dacarbazine concentration of 0.5 µg/mL, while Dacarbazine Solution showed only 10.20% cytotoxicity at the same concentration. The number of late apoptotic cells was also found to be much higher (45.16% vs. 8.43%). Furthermore, migration assay and proliferation study also revealed significantly higher inhibition of cell migration and proliferation by Coated-Dacarbazine Eugenol Liposomes, signifying its potential against metastasis. Thus, surface-functionalized dacarbazine- and eugenol-loaded liposomes hold great promise against resistant and aggressive metastatic melanoma, with much less unwanted cytotoxicity and reduced doses of the chemotherapeutic agent.