Dual stimuli polysaccharide nanovesicles for conjugated and physically loaded doxorubicin delivery in breast cancer cells

Degradable Polymer-Based Nanoassemblies for Precise Targeting and Drug Delivery to Breast Cancer Cells without Affecting Normal Healthy Cells

Stimuli-responsive amphiphilic polymers are known to be precursors to forming promising nanoarchitectonics with tunable properties for application in biomedical sciences. Currently, self-immolative polymers are widely recognized as an emerging class of responsive materials with excellent degradability, which is one of the crucial criteria for designing a robust drug delivery vehicle. Here, we design an amphiphilic polyurethane endowed with a redox-responsive self-immolative linker and a pH-responsive tertiary amine on the backbone, which forms entropy-driven nanoscale supramolecular assemblies (average hydrodynamic diameter ∼110 nm) and is programmed to disassemble in a redox environment (GSH) due to the degradation of the polymer in a self-immolative fashion. The nanoassembly shows efficient drug sequestration and release in a controlled manner in response to glutathione (10 mM). The tertiary amine residing on the surface of the nanoassembly becomes protonated in the tumor microenvironment (pH ∼ 6.4-6.8) and generates positively charged nanoassembly (ζ-potential = +36 mV), which enhances the cancer cell-selective cellular uptake. The biological evaluation of the drug-loaded nanoassembly revealed triple-negative breast cancer (MDAMB-231) selective internalization and cell death while shielding normal cells (RBCs or PBMCs) from off-targeting toxicity. We envision that polyurethane with a redox-responsive self-immolative linker might open up new opportunities for a completely degradable polyurethane-based nanocarrier for drug delivery and diagnosis applications.

Progress in construction and release of natural polysaccharide-platinum nanomedicines: A review

Natural polysaccharides are natural biomaterials that have become candidate materials for nano-drug delivery systems due to their excellent biodegradability and biocompatibility. Platinum (Pt) drugs have been widely used in the clinical therapy for various solid tumors. However, their extensive systemic toxicity and the drug resistance acquired by cancer cells limit the applications of platinum drugs. Modern nanobiotechnology provides the possibility for targeted delivery of platinum drugs to the tumor site, thereby minimizing toxicity and optimizing the efficacies of the drugs. In recent years, numerous natural polysaccharide-platinum nanomedicine delivery carriers have been developed, such as nanomicelles, nanospheres, nanogels, etc. Herein, we provide an overview on the construction and drug release of natural polysaccharide-Pt nanomedicines in recent years. Current challenges and future prospectives in this field are also put forward. In general, combining with irradiation and tumor microenvironment provides a significant research direction for the construction of natural polysaccharide-platinum nanomedicines and the release of responsive drugs in the future.

Permeable polymersomes from temperature and pH dual stimuli-responsive PVCL-b-PLL block copolymers for enhanced cell internalization and lysosome targeting

A series of dual stimuli-responsive block copolymers comprising temperature-responsive poly(N-vinylcaprolactam) (PVCL) and biodegradable pH-responsive poly(l-lysine) (PLL) of varying chain length were synthesized by a combination of free radical polymerization and ring opening polymerization. The block copolymers formed micelles and vesicles (polymersomes) in response to temperature and pH, respectively, in aqueous solution. The nanoassemblies were characterized by transmission electron microscopy and dynamic light scattering techniques. Encapsulation of both hydrophobic and hydrophilic dyes in the polymersomes was shown. Doxorubicin (DOX) was loaded in the polymersomes and its controlled release in response to the two stimuli, independently and jointly, was studied. The drug was found to be released due to stimuli-induced increased permeability without disassembly of the polymersomes. A significant increase in the cellular uptake of the drug-loaded polymersomes at hyperthermia conditions was demonstrated at 41 °C and release of the drug upon localization in lysosomes was observed. Cellular internalization pathway of the polymersomes was investigated by competitive inhibition assay and a combination of endocytic pathways dominated by caveolae-mediated mechanism was found to be operative.

Glycopolymer Decorated pH-Dependent Ratiometric Fluorescent Probe Based on Förster Resonance Energy Transfer for the Detection of Cancer Cells

Development of fluorescent imaging probes is an important topic of research for the early diagnosis of cancer. Based on the difference between the cellular environment of tumor cells and normal cells, several "smart" fluorescent probes have been developed. In this work, a glycopolymer functionalized Förster resonance energy transfer (FRET) based fluorescent sensor is developed, which can monitor the pH change in cellular system. One-pot sequential reversible addition-fragmentation chain transfer (RAFT)polymerization technique is employed to synthesize fluorescent active triblock glycopolymer that can undergo FRET change on the variation of pH. A FRET pair, fluorescein o-acrylate (FA) and 7-amino-4-methylcoumarin (AMC) is linked via a pH-responsive polymer poly [2-(diisopropylamino)ethyl methacrylate] (PDPAEMA), which can undergo reversible swelling/deswelling under acidic/neutral condition. The presence of glycopolymer segment provides stability, water solubility, and specificity toward cancer cells. The cellular FRET experiments on cancer cells (MDA MB 231) and normal cells (3T3 fibroblast cells) demonstrate that the material is capable of distinguishing cells as a function of pH change.

Metabolomic Signatures in Doxorubicin-Induced Metabolites Characterization, Metabolic Inhibition, and Signaling Pathway Mechanisms in Colon Cancer HCT116 Cells

Doxorubicin (DOX) is a chemotherapeutic agent is used for various cancer cells. To characterize the chemical structural components and metabolic inhibition, we applied a DOX to HCT116 colon cancer cells using an independent metabolites profiling approach. Chemical metabolomics has been involved in the new drug delivery systems. Metabolomics profiling of DOX-applied HCT116 colon cancer cellular metabolisms is rare. We used 1H nuclear magnetic resonance (NMR) spectroscopy in this study to clarify how DOX exposure affected HCT116 colon cancer cells. Metabolomics profiling in HCT116 cells detects 50 metabolites. Tracking metabolites can reveal pathway activities. HCT116 colon cancer cells were evenly treated with different concentrations of DOX for 24 h. The endogenous metabolites were identified by comparison with healthy cells. We found that acetate, glucose, glutamate, glutamine, sn-glycero-3-phosphocholine, valine, methionine, and isoleucine were increased. Metabolic expression of alanine, choline, fumarate, taurine, o-phosphocholine, inosine, lysine, and phenylalanine was decreased in HCT116 cancer cells. The metabolic phenotypic expression is markedly altered during a high dose of DOX. It is the first time that there is a metabolite pool and phenotypic expression in colon cancer cells. Targeting the DOX-metabolite axis may be a novel strategy for improving the curative effect of DOX-based therapy for colon cancer cells. These methods facilitate the routine metabolomic analysis of cancer cells.

Gold Nanoparticle Embedded Stimuli-Responsive Functional Glycopolymer: A Potential Material for Synergistic Chemo-Photodynamic Therapy of Cancer Cells

Photodynamic therapy has emerged as a non-invasive treatment modality for several types of cancers. However, conventional hydrophobic photosensitizers (PS) suffer from low water solubility and poor tumor-targeting ability. Therefore, PS modified with glycopolymers can offer adequate water solubility, biocompatibility and tumor-targeting ability due to the presence of multiple sugar units. In this study, a well-defined block copolymer (BCP) poly(3-O-methacryloyl-D-glucopyranose)-b-poly(2-(4-formylbenzoyloxy)ethylmethacrylate) (PMAG-b-PFBEMA) containing pendant glucose and aldehyde units was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization method. A water-soluble PS (toluidine blue O; TBO) and a potent anti-cancer drug, Doxorubicin (Dox) were introduced to the polymer backbone via acid-labile Schiff-base reaction (PMAG-b-PFBEMA_TBO_Dox). The PMAG-b-PFBEMA_TBO_Dox was then anchored on the surface of AuNP via electrostatic interaction. This hybrid system exhibited excellent reactive oxygen species (ROS) generating ability under exposure of 630 nm LED along with triggered release of Dox under the acidic pH of tumor cells. The in vitro cytotoxicity study on human breast cancer cell line, MDA MB 231, for this hybrid system showed promising results due to the synergistic effect of ROS and Dox released. Thus, this glycopolymer-based dual (chemo-photodynamic) therapy model can work as potential material for future therapeutics. This article is protected by copyright. All rights reserved.

Intelligent design of polymersomes for antibacterial and anticancer applications

Polymersomes (or polymer vesicles) have attracted much attention for biomedical applications in recent years because their lumen can be used for drug delivery and their coronas and membrane can be modified with a variety of functional groups. Thus, polymersomes are very suitable for improved antibacterial and anticancer therapy. This review mainly highlighted recent advances in the synthetic protocols and design principles of intelligent antibacterial and anticancer polymersomes. Antibacterial polymersomes are divided into three categories: polymersomes as antibiotic nanocarriers, intrinsically antibacterial polymersomes, and antibacterial polymersomes with supplementary means including photothermal and photodynamic therapy. Similarly, the anticancer polymersomes are divided into two categories: polymersomes-based delivery systems and anticancer polymersomes with supplementary means. In addition, the bilateral relationship between bacteria and cancer is addressed, since more and more evidences show that bacteria may cause cancer or promote cancer progression. Finally, prospective on next-generation antibacterial and anticancer polymersomes are discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Biology-Inspired Nanomaterials > Lipid-Based Structures.

Self-Reporting Polysaccharide Polymersome for Doxorubicin and Cisplatin Delivery to Live Cancer Cells

We report self-reporting fluorescent polysaccharide polymersome nanoassemblies for enzyme-responsive intracellular delivery of two clinical anticancer drugs doxorubicin (DOX) and cisplatin to study the real-time drug-releasing aspects by fluorescent resonance energy transfer (FRET) bioimaging in live cancer cells. Fluorescent polymersomes were tailor-made by tagging an aggregation-induced emission (AIE) optical chromophore, tetraphenylethylene (TPE), and a plant-based vesicular directing hydrophobic unit through enzyme-biodegradable aliphatic ester chemical linkages in the polysaccharide dextran. The blue-luminescent polymersome self-assembled in water and exhibited excellent encapsulation capability for the red-luminescent anticancer drug DOX. FRET between the AIE polymersome host and DOX guest molecules resulted in a completely turn-off probe. At the intracellular level, the lysosomal enzymatic disassembly of the polymersome restored the dual fluorescent signals from DOX and TPE at the nucleus and the lysosomes, respectively. Live-cell confocal microscopy coupled with selective photoexcitation was employed to study the real-time polymersome disassembly by monitoring the turn-on fluorescent signals in human breast cancer cell lines. Alternatively, carboxylic acid-functionalized AIE polymersomes were also tailor-made for cisplatin stitching to directly monitor Pt drug delivery. The polymersome nanoassemblies exhibited excellent structural tolerance for the chemical conjugation of the Pt drugs, and the fluorescence signals were unaltered. An in vitro drug release study confirmed that the cisplatin-stitched fluorescent polymersomes were very stable under physiological conditions and underwent lysosomal enzymatic degradation to inhibit the cancer cell growth. A lysosomal colocalization experiment using confocal microscopy substantiates the enzyme-responsive degradation of these polymersomes to release both the encapsulated and conjugated drugs at the intracellular level. The present design provides a unique opportunity to deliver more than one anticancer drug from a single polymersome platform in cancer research.

Efficient Design to Monitor the Site-specific Sustained Release of a Non-Emissive Anticancer Drug

A pH-responsive smart nanocarrier with significant components was synthesized by conjugating the non-emissive anticancer drug methyl orange and polyethylene glycol derived folate moiety to the backbone of polynorbornene. Complete synthesis procedure and characterization methods of three monomers included in the work: norbornene-derived Chlorambucil (Monomer 1), norbornene grafted with polyethylene glycol, and folic acid (Monomer 2) and norbornene attached methyl orange (Monomer 3) connected to the norbornene backbone through ester linkage were clearly discussed. Finally, the random copolymer CHO PEG FOL METH was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' second-generation catalyst. Advanced polymer chromatography (APC) was used to find the final polymer's molecular weight and polydispersity index (PDI). Dynamic light scattering, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to explore the prodrug's size and morphology. Release experiments of the anticancer drug, Chlorambucil and the coloring agent, methyl orange, were performed at different pH and time. Cell viability assay was carried out for determining the rate of survived cells, followed by the treatment of our final polymer named CHO PEG FOL METH.

Glycomacromolecules: Addressing challenges in drug delivery and therapeutic development

Carbohydrate-based materials offer exciting opportunities for drug delivery. They present readily available, biocompatible components for the construction of macromolecular systems which can be loaded with cargo, and can enable targeting of a payload to particular cell types through carbohydrate recognition events established in biological systems. These systems can additionally be engineered to respond to environmental stimuli, enabling triggered release of payload, to encompass multiple modes of therapeutic action, or to simultaneously fulfil a secondary function such as enabling imaging of target tissue. Here, we will explore the use of glycomacromolecules to deliver therapeutic benefits to address key health challenges, and suggest future directions for development of next-generation systems.

Out-of-the-Box Nanocapsules Packed with On-Demand Hydrophobic Anticancer Drugs for Lung Targeting, Esterase Triggering, and Synergy Therapy

Most anticancer drugs, particularly paclitaxel (PTX), are suffering the challenges of cancer chemotherapy due to their poor water-solubility, high toxicity under effective therapeutic dosages, and multi-drug resistance. Currently, nanoscale drug delivery systems (DDSs) represent an efficient platform to overcome the above challenges. However, those DDSs generally need a careful design of conjugation, complexation, or co-self-assembly. Herein, a facile out-of-the-box nanocapsule is developed not only to be easily packed with on-demand hydrophobic anticancer drugs (up to 76% of loading efficiency for PTX), but also to be loaded with other concomitant drugs for synergy therapy (Itraconazole (ITA) here as P-glycoprotein inhibitor for drug resistance and antiangiogenic agent for combination therapy with PTX). Three kinds of biocompatible poly(ethylene glycol) dimethacrylates (PEGDM) derivatives usually as cross-linking agents are selected and successfully constructed adequate nanocapsules with single monomer as shell materials. More importantly, as-prepared nanocapsules have abilities of esterase triggering and lung targeting. Both in vitro and in vivo studies showed that the drug-loaded nanocapsules can effectively inhibit tumor growth and vascular proliferation in PTX-resistant tumor models without apparent systemic toxicity. The above results demonstrate that the nanocapsule system provides an effective and universal strategy for lung targeting, esterase triggering, and synergy therapy.

An AIE-driven fluorescent polysaccharide polymersome as an enzyme-responsive FRET nanoprobe to study the real-time delivery aspects in live cells

An enzyme-responsive FRET nanoprobe was designed and developed based on AIE-driven fluorescent polysaccharide polymersomes to study the real-time delivery aspects in the intracellular compartments in live cancer cells.

Overcoming Biological Barriers With Block Copolymers-Based Self-Assembled Nanocarriers. Recent Advances in Delivery of Anticancer Therapeutics

Cancer is one of the most common life-threatening illness and it is the world's second largest cause of death. Chemotherapeutic anticancer drugs have many disadvantages, which led to the need to develop novel strategies to overcome these shortcomings. Moreover, tumors are heterogenous in nature and there are various biological barriers that assist in treatment reisistance. In this sense, nanotechnology has provided new strategies for delivery of anticancer therapeutics. Recently, delivery platforms for overcoming biological barriers raised by tumor cells and tumor-bearing hosts have been reported. Among them, amphiphilic block copolymers (ABC)-based self-assembled nanocarriers have attracted researchers worldwide owing to their unique properties. In this work, we addressed different biological barriers for effective cancer treatment along with several strategies to overcome them by using ABC-based self-assembled nanostructures, with special emphasis in those that have the ability to act as responsive nanocarriers to internal or external environmental clues to trigger release of the payload. These nanocarriers have shown promising properties to revolutionize cancer treatment and diagnosis, but there are still challenges for their successful translation to clinical applications.

Cascade-Targeting of Charge-Reversal and Disulfide Bonds Shielding for Efficient DOX Delivery of Multistage Sensitive MSNs-COS-SS-CMC

BACKGROUND

Although pH and redox sensitiveness have been extensively investigated to improve therapeutic efficiency, the effect of disulfide bonds location and pH-triggered charge-reversal on cascade-targeting still need to be further evaluated in cancer treatment with multi-responsive nanoparticles.

PURPOSE

The aim of this study was to design multi-responsive DOX@MSNs-COS-NN-CMC, DOX@MSNs-COS-SS-CMC and DOX@MSNs-COS-CMC-SS and systematically investigate the effects of disulfide bonds location and charge-reversal on the cancer cell specificity, endocytosis mechanisms and antitumor efficiency.

RESULTS

In vitro drug release rate of DOX@MSNs-COS-SS-CMC in tumor environments was 7-fold higher than that under normal physiological conditions after 200 h. Furthermore, the fluorescence intensity of DOX@MSNs-COS-SS-CMC and DOX@MSNs-COS-CMC-SS was 1.9-fold and 1.3-fold higher than free DOX at pH 6.5 and 10 mM GSH. In addition, vesicular transport might be a factor that affects the uptake efficiency of DOX@MSNs-COS-SS-CMC and DOX@MSNs-COS-CMC-SS. The clathrin-mediated endocytosis and endosomal escape of DOX@MSNs-COS-SS-CMC enhanced cellular internalization and preserved highly controllable drug release into the perinuclear of HeLa cells. DOX@MSNs-COS-SS-CMC exhibited a synergistic chemotherapy in preeminent tumor inhibition and less side effects of cardiotoxicity.

CONCLUSION

The cascade-targeting of charge-reversal and disulfide bonds shielding would be a highly personalized strategy for cervical cancer treatment.

Focal drug administration via heparin-containing cryogel microcarriers reduces cancer growth and metastasis

Developing drug delivery systems that release anticancer drugs in a controlled and sustained manner remains challenging. We hypothesized that highly sulfated heparin-based microcarriers would allow electrostatic drug binding and controlled release. In silico modelling showed that the anticancer drug doxorubicin has affinity for the heparin component of the microcarriers. Experimental results showed that the strong electrostatic interaction was reversible, allowing both doxorubicin loading and a subsequent slow release over 42 days without an initial burst release. The drug-loaded microcarriers were able to reduce cancer cell viability in vitro in both hormone-dependent and highly aggressive triple-negative human breast cancer cells. Focal drug treatment, of an in vivo orthotopic triple-negative breast cancer model significantly decreased tumor burden and reduced cancer metastasis, whereas systemic administration of an equivalent drug dose was ineffective. This study proves that heparin-based microcarriers can be used as drug delivery platforms, for focal delivery and sustained long-term drug release.

Glycopolymer decorated multiwalled carbon nanotubes for dual targeted breast cancer therapy

Carbon-based nanomaterials (CNMs) have attracted great attention in biomedical applications such as cancer imaging and therapy. CNMs, which are currently used in a wide range of applications, suffer from drawbacks of toxicity and low biocompatibility. Either noncovalent or covalent functionalization of CNMs with hydrophilic and biocompatible polymers which help to block hydrophobic interactivity between CNMs and cells can greatly increase their biocompatibility by eliminating their probable toxicity towards living organisms. In this report, we present a comparison of both noncovalent and covalent functionalization approaches in order to introduce a biocompatible glycoblock copolymer onto multi-walled carbon nanotubes (CNTs) in order to enhance their potential in therapies. An anticancer drug (doxorubicin, Dox) was conjugated with two different end functionalized poly(1-O-methacryloyl-β-d-fructopyranose-b-(2-methacryloxyethoxy))benzaldehyde glycoblock copolymers, which were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, by either noncovalent or covalent tethering. CNTs were coated separately with the synthesized drug-conjugated glycoblock copolymers and folic acid (FA) to obtain an efficient drug delivery platform for dual-targeting of glucose transporter protein (GLUT5) and folic acid receptors (FR) in breast cancer. A library of synthesized monomers, polymers and prepared glycoblock copolymer coated CNTs (hybrid-CNTs) using both approaches were comprehensively characterized by various techniques. Transmission electron microscopy measurements showed the homogeneous, smooth morphology of the prepared Dox-conjugated glycoblock copolymer coating of CNTs and confocal laser scanning microscopy images displayed successful cellular internalization of hybrid-CNTs in the MCF-7 and MDA-MB-231 human breast cancer cell lines. This research demonstrates the potential of hybrid-CNTs as a biocompatible drug delivery system as well as in vitro use of Dox-conjugated vehicles for dual receptor mediated breast cancer therapy.

Development and disassembly of single and multiple acid-cleavable block copolymer nanoassemblies for drug delivery

Acid-degradable block copolymer-based nanoassemblies are promising intracellular candidates for tumor-targeting drug delivery as they exhibit the enhanced release of encapsulated drugs through their dissociation.

Flexible, sticky, and biodegradable wireless device for drug delivery to brain tumors

Implantation of biodegradable wafers near the brain surgery site to deliver anti-cancer agents which target residual tumor cells by bypassing the blood-brain barrier has been a promising method for brain tumor treatment. However, further improvement in the prognosis is still necessary. We herein present novel materials and device technologies for drug delivery to brain tumors, i.e., a flexible, sticky, and biodegradable drug-loaded patch integrated with wireless electronics for controlled intracranial drug delivery through mild-thermic actuation. The flexible and bifacially-designed sticky/hydrophobic device allows conformal adhesion on the brain surgery site and provides spatially-controlled and temporarily-extended drug delivery to brain tumors while minimizing unintended drug leakage to the cerebrospinal fluid. Biodegradation of the entire device minimizes potential neurological side-effects. Application of the device to the mouse model confirms tumor volume suppression and improved survival rate. Demonstration in a large animal model (canine model) exhibited its potential for human application.

There is a need to further improve the efficacy of biodegradable wafers used in surgically treated brain tumors. Here, the authors report a flexible, biodegradable wireless device capable of adhesion to surgical site for optimal drug delivery upon mild-thermic actuation and report therapeutic efficacy in mouse and canine tumor models.

Doxorubicin/cisplatin co-loaded hyaluronic acid/chitosan-based nanoparticles for in vitro synergistic combination chemotherapy of breast cancer

Combination chemotherapy has attracted more and more attention in the field of anticancer treatment. Herein, a synergetic targeted combination chemotherapy of doxorubicin (DOX) and cisplatin in breast cancer was realized by HER2 antibody-decorated nanoparticles assembled from aldehyde hyaluronic acid (AHA) and hydroxyethyl chitosan (HECS). Cisplatin and DOX were successively conjugated onto AHA through chelation and Schiff's base reaction, respectively, forming DOX/cisplatin-loaded AHA inner core. The core was sequentially complexed with HECS and targeting HER2 antibody-conjugated AHA. The formed near-spherical nanoplatform had an average size of ∼160 nm and a zeta potential of -28 mV and displayed pH-responsive surface charge reversal and drug release behaviors. HER2 receptor-mediated active targeting significantly enhanced the cellular uptake of nanoplatform. Importantly, DOX and cisplatin exhibited a synergistic cell-killing effect in human breast cancer MCF-7 cells. These results clearly indicate that the novel nanoplatform is promising for synergistic combination chemotherapy of breast cancer.

Stimulus-responsive vesicular polymer nano-integrators for drug and gene delivery

Over the past two decades, nano-sized biosystems have increasingly been utilized to deliver various pharmaceutical agents to a specific region, organ or tissue for controllable precision therapy. Whether solid nanohydrogel, nanosphere, nanoparticle, nanosheet, micelles and lipoproteins, or "hollow" nanobubble, liposome, nanocapsule, and nanovesicle, all of them can exhibit outstanding loading and releasing capability as a drug vehicle - in particular polymeric nanovesicle, a microscopic hollow sphere that encloses a water core with a thin polymer membrane. Besides excellent stability, toughness and liposome-like compatibility, polymeric nanovesicles offer considerable scope for tailoring properties by changing their chemical structure, block lengths, stimulus-responsiveness and even conjugation with biomolecules. In this review, we summarize the latest advances in stimulus-responsive polymeric nanovesicles for biomedical applications. Different functionalized polymers are in development to construct more complex multiple responsive nanovesicles in delivery systems, medical imaging, biosensors and so on.

A green method for the production of an efficient bioimaging nanotool

The possibility of exploring basic biological phenomena requires the development of new and efficient bio-imaging tools. These should ideally combine the feasibility of production (potentially through the use of green chemistry) together with high targeting efficiency, low cytotoxicity, and optimal contrast characteristics. In this work, we developed nanovesicles based on cardanol, a natural and renewable byproduct of the cashew industry, and a fluorescent reporter was encapsulated in them through an environment-friendly synthesis method. In vitro investigations demonstrated that the cardanol nanovesicles are efficiently taken-up by both professional and non-professional phagocytic cells, which have been modeled in our approach by macrophages and HeLa cells, respectively. Co-localization studies show high affinity of the nanovesicles towards the cell plasma membrane. Moreover, metabolic assays confirmed that these nanostructures are biocompatible in a specific concentration range, and do not promote inflammation response in human macrophages. Stability studies carried out at different temperatures showed that the nanovesicles are stable at both 37 °C and 20 °C, while the formation of aggregates occurs when the nanodispersion is incubated at 4 °C. The results demonstrate the high potential of fluorescent cardanol nanovesicles as a green bioimaging tool, especially for investigating cell membrane dynamics.

Design and synthesis of a dual imageable theranostic platinum prodrug for efficient cancer therapy

Platinum-based chemotherapeutic agents are considered first-line treatments for various cancers but their application is limited by the lack of site specificity and severe side effects.

Inflammation-Responsive Drug-Conjugated Dextran Nanoparticles Enhance Anti-Inflammatory Drug Efficacy

Stimuli-responsive nanoparticles (NPs) are especially interesting to enhance the drug delivery specificity for biomedical applications. With the aim to achieve a highly stable and inflammation-specific drug release, we designed a reactive oxygen species (ROS)-responsive dextran-drug conjugate (Nap-Dex). By blending Nap-Dex with the acid-sensitive acetalated dextran polymer, we achieved a dual-responsive NP with high specificity toward the inflammatory environment. The inflammatory environment not only has elevated ROS levels but also has a lower pH than healthy tissues, making pH and ROS highly suitable triggers to target inflammatory diseases. The anti-inflammatory cyclooxygenase inhibitor naproxen was modified with an ROS-responsive phenylboronic acid (PBA) and conjugated onto dextran. The dextran units were functionalized with up to 87% modified naproxen. This resulted in a complete drug release from the polymer within 20 min at 10 mM H2O2. The dual-responsive NPs reduced the levels of the proinflammatory cytokine IL-6 120 times more efficiently and TNFα 6 times more efficiently than free naproxen from lipopolysaccharide (LPS)-activated macrophages. These additional anti-inflammatory effects were found to be mainly attributed to ROS-scavenging effects. In addition, the model cargo fluorescein diacetate was released in an LPS-induced inflammatory response in vitro. We believe that drug conjugation using PBA can be applied to various drugs and dextran-based materials for enhanced drug efficacy, where this work demonstrates the significance of functionalized carbohydrates polymer-drug conjugates.

Enhanced Melanoma-Targeted Therapy by "Fru-Blocked" Phenyboronic Acid-Modified Multiphase Antimetastatic Micellar Nanoparticles

Metastasis remains the main driver of mortality in patients suffering from cancer because of the refractoriness resulting from the multi-phase metastatic cascade. Herein, a multifunctional self-delivering PBA-LMWH-TOS nanoparticle (PLT NP) is established that acts as both nanocarrier and anti-metastatic agent with effects on most hematogenous metastases of cancers. The hydrophilic segment (low molecular weight heparin, LMWH) inhibits the interactions between tumor cells and platelets. The hydrophobic segment (d-α-tocopheryl succinate, TOS) could inhibit the expression of matrix metalloproteinase-9 (MMP-9) in B16F10 cells which is first reported in this article. Surprisingly, even the blank NPs showed excellent anti-metastatic capacity in three mouse models by acting on different phases of the metastatic cascade. Moreover, the overexpression of sialic acid (SA) residues on tumor cells is implicated in the malignant and metastatic phenotypes of cancers. Thus, these 3-aminophenylboronic acid (PBA)-modified doxorubicin (DOX)-loaded NPs offer an efficient approach for the treatment of both solid melanomas and metastases. Furthermore, a simple pH-sensitive "Fructose (Fru)-blocking" coping strategy is established to reduce the NP distribution in normal tissues and distinctly increases the accumulation in melanoma tumors. These micellar NPs consisting of biocompatible materials offer a promising approach for the clinical therapy of highly invasive solid tumors and metastases.

Biotin-Tagged Polysaccharide Vesicular Nanocarriers for Receptor-Mediated Anticancer Drug Delivery in Cancer Cells

Biotin-conjugated multistimuli-responsive polysaccharide vesicular nanocarriers are designed and developed, for the first time, to accomplish receptor-mediated endocytosis in cancer cells and to deliver anticancer drugs to intracellular compartments. For this purpose, a new renewable hydrophobic unit was custom designed with redox-degradable disulfide and enzyme-biodegradable aliphatic ester chemical linkages, and it was conjugated along with biotin on the dextran backbone. The dextran derivative self-assembled into nanovesicles of <200 nm in size, which were characterized by dynamic and static light scattering, electron, and atomic force microscopes. Avidin-HABA assay established the high affinity of biotin-tagged dextran vesicles toward membrane-receptors up to 25 nM concentration. Doxorubicin-hydrochloride (DOX.HCl)-loaded dextran vesicles exhibited stable formulation in phosphate-buffered saline (PBS) and fetal bovine serum (FBS). Redox-degradation by glutathione (GSH) showed 60% drug release, whereas lysosomal esterase enzyme enabled >98% drug release in 12 h. Confocal microscope and flow cytometry-assisted time-dependent cellular uptake studies revealed that the biotin-receptors overexpressed in cervical cancer cells (HeLa) exhibited larger drug accumulation through the receptor-assisted endocytosis process. This process enabled the delivery of higher amount of DOX and significantly enhanced the killing in cancer cells (HeLa) compared to wild-type mouse embryonic fibroblast cells (WT-MEF, normal cells). Control experiments such as biotin pretreatment in cancer cells and energy-suppressed cellular uptake at 4 °C further supported the occurrence of receptor-mediated endocytosis by the biotin-tagged polymer vesicles. This report provides first insights into the targeted polysaccharide vesicle platform, and the proof-of-concept is successfully demonstrated in biotin receptor-overexpressed cervical cancer cells.

Polymer Nanovesicle-Mediated Delivery of MLN8237 Preferentially Inhibits Aurora Kinase A To Target RalA and Anchorage-Independent Growth in Breast Cancer Cells

The small GTPase RalA is a known mediator of anchorage-independent growth in cancers and is differentially regulated by adhesion and aurora kinase A (AURKA). Hence, inhibiting AURKA offers a means of specifically targeting RalA (over RalB) in cancer cells. MLN8237 (alisertib) is a known inhibitor of aurora kinases; its specificity for AURKA, however, is compromised by its poor solubility and transport across the cell membrane. A polymer nanovesicle platform is used for the first time to deliver and differentially inhibit AURKA in cancer cells. For this purpose, polysaccharide nanovesicles made from amphiphilic dextran were used as nanocarriers to successfully administer MLN8237 (V_MLN) in cancer cells in 2D and 3D microenvironments. These nanovesicles (<200 nm) carry the drug in their intermembrane space with up to 85% of it released by the action of esterase enzyme(s). Lysotracker experiments reveal the polymer nanovesicles localize in the lysosomal compartment of the cell, where they are enzymatically targeted and MLN released in a controlled manner. Rhodamine B fluorophore trapped in the nanovesicles hydrophilic core (V_MLN+RhB) allows us to visualize its uptake and localization in cells in a 2D and 3D microenvironment. In breast cancer, MCF-7 cells V_MLN inhibits AURKA significantly better than the free drug at low concentrations (0.02-0.04 μM). This ensures that the drug in V_MLN at these concentrations can specifically inhibit up to 94% of endogenous AURKA without affecting AURKB. This targeting of AURKA causes the downstream differential inhibition of active RalA (but not RalB). Free MLN8237 at similar concentrations and conditions failed to affect RalA activation. V_MLN-mediated inhibition of RalA, in turn, disrupts the anchorage-independent growth of MCF-7 cells supporting a role for the AURKA-RalA crosstalk in mediating the same. These studies not only identify the polysaccharide nanovesicle to be an improved way to efficiently deliver low concentrations of MLN8237 to inhibit AURKA but, in doing so, also help reveal a role for AURKA and its crosstalk with RalA in anchorage-independent growth of MCF-7 cells.

Self-Stabilized Hyaluronate Nanogel for Intracellular Codelivery of Doxorubicin and Cisplatin to Osteosarcoma

Osteosarcoma is one of the most serious bone malignancies with rapid speed of deterioration and low survival rate in children and teenagers. Chemotherapy is an important treatment for osteosarcoma, while the conventional small-molecule therapeutics exhibit low efficacies and severe side effects in the clinic. Drug-delivery platforms based on nanotechnology, particularly for self-stabilized delivery platforms with prolonged blood circulation, enhanced intratumoral accumulation, improved antitumor efficacy, and diminished side effects, may break the deadlock on osteosarcoma chemotherapy. Here, a cisplatin (CDDP)-crosslinked hyaluronic acid (HA) nanogel (CDDPHANG) is prepared for effective delivery of doxorubicin (DOX) to treat osteosarcoma. Importantly, both DOX and CDDP have led clinically used antitumor drugs, and CDDP acts as a crosslinker and ancillary anticarcinogen to prevent the premature release of DOX and to achieve synergistic therapeutic performance. Because of the enhanced stability of the nanogel, this CDDP-crosslinked DOX-loaded nanomedicine (CDDPHANG/DOX) exhibits an obviously prolonged circulation time compared to free drugs. Moreover, after valid tumor accumulation, DOX and CDDP are synergistically delivered into the tumor cells and synchronously released into the intracellular acidic environment. Based on the synergistic apoptosis-inducing effects of DOX and CDDP, CDDPHANG/DOX reveals an evidently enhanced antitumor efficacy compared to free drugs and their combination, indicating its great prospects for the chemotherapy of osteosarcoma.

Polypeptide self-assemblies: nanostructures and bioapplications

Polypeptide copolymers can self-assemble into diverse aggregates. The morphology and structure of aggregates can be varied by changing molecular architectures, self-assembling conditions, and introducing secondary components such as polymers and nanoparticles. Polypeptide self-assemblies have gained significant attention because of their potential applications as delivery vehicles for therapeutic payloads and as additives in the biomimetic mineralization of inorganics. This review article provides an overview of recent advances in nanostructures and bioapplications related to polypeptide self-assemblies. We highlight recent contributions to developing strategies for the construction of polypeptide assemblies with increasing complexity and novel functionality that are suitable for bioapplications. The relationship between the structure and properties of the polypeptide aggregates is emphasized. Finally, we briefly outline our perspectives and discuss the challenges in the field.

Reduction responsive and surface charge switchable polyurethane micelles with acid cleavable crosslinks for intracellular drug delivery

Previously we synthesized redox sensitive polyurethane micelles, core crosslinked by diisocyanates (PU-CCL).

Biodegradable polyurethane micelles with pH and reduction responsive properties for intracellular drug delivery

Polyurethane micelles with disulfide linkage located at the interface of hydrophilic shell and hydrophobic core (PU-SS-I) have been shown enhanced drug release profiles. However, the payloads could not be released completely. The occurrence of aggregation of hydrophobic cores upon shedding hydrophilic PEG coronas was considered as the reason for the incomplete release. To verify the above hypothesis and to develop a new polyurethane based micelles with dual stimuli respond properties and controllable location of pH and reduction responsive groups in the PU main chains, a tertiary amine was incorporated into the hydrophobic core PU-SS-I, which resulted polyurethane with both reduction and pH sensitive properties (PU-SS-N). Biodegradable polyurethane with only disulfide linkages located between the hydrophilic PEG segment and the hydrophobic PCL segments (PU-SS-I) and polyurethane with only pH sensitive tertiary amine at the hydrophobic core (PU-N-C) were used as comparisons. Paclitaxel (PTX) was chosen as mode hydrophobic drug to evaluate the loading and redox triggered release profiles of the PU micelles. It was demonstrated that PU-SS-N micelles disassembled instantly at the presence of 10mM GSH and at an acidic environment (pH=5.5), which resulted the nearly complete release (~90%) of the payloads within 48h, while about ~70% PTX was released from PU-SS-I and PU-SS-N micelles at neutral environment (pH=7.4) with the presence of 10mM GSH. The rapid and complete redox and pH stimuli release properties of the PU-SS-N nanocarrier will be a promising anticancer drug delivery system to ensure sufficient drug concentration to kill the cancer cells and to prevent the emergency of MDR. The in vitro cytotoxicity and cell uptake of the PTX-loaded micelles was also assessed in H460 and HepG2 cells.

Synergistic chemotherapeutic effect of sorafenib-loaded pullulan-Dox conjugate nanoparticles against murine breast carcinoma

pH-Sensitive pullulan-doxorubicin conjugates encapsulating sorafenib (P-Dox/S) nanoparticles were developed as a synergistic combinatorial delivery system against murine breast carcinoma. The nanoparticles can encapsulate Dox and sorafenib with ultra-high loading capacity (65.34 wt%) through chemical conjugation and physical loading, whereas can remain stable under physiological conditions and gradually release Dox and sorafenib with the decreasing pH. These conjugates can be effectively internalized and clearly suppress 4T1 cell growth in vitro. Furthermore, research data of in vivo animal models revealed that the synergistic combinatorial P-Dox/S nanoparticles heavily accumulated in solid tumor tissue sites to maximize therapeutic efficacy; they also significantly inhibited solid tumor growth, even remarkably reduced solid tumor volume in comparison to the initial volume, and obviously diminished adverse effects. The anti-tumor therapeutic effect obviously outperformed the delivery of combinational chemotherapy of free drugs or single drug-loaded P-Dox nanoparticles at the same concentration. These promising results indicate the high-efficiency synergistic chemotherapeutic effects of these nanoparticles. Combinational chemotherapy using P-Dox/S nanoparticles has important potential in the clinical treatment of malignancy for overcoming drug resistance and heterogeneity.

Surface charge switchable and core cross-linked polyurethane micelles as a reduction-triggered drug delivery system for cancer therapy

The core cross-linked polyurethane micelles with redox sensitive and pH-responsive surface charge switchable properties were prepared by using diisocyanates as crosslinkers and studied as anticancer drug carriers.

Triple Block Nanocarrier Platform for Synergistic Cancer Therapy of Antagonistic Drugs

A unique biodegradable triple block nanocarrier (TBN) is designed and developed for synergistic combination therapy of antagonistic drugs for cancer treatment. The TBN was built with hydrophilic polyethylene glycol (PEG) outer shell; a middle hydrophobic and biodegradable polycaprolactone (PCL) block for encapsulating anthracycline anticancer drug like doxorubicin (DOX), and an inner carboxylic-functionalized polycaprolactone (CPCL) core for cisplatin (CP) drug conjugation. TBN-cisplatin drug conjugate self-assembled as stable nanoparticles in saline (also in PBS) wherein the hydrophobic PCL block functions as a shield for Pt-drug stability against GSH detoxification. Enzymatic-biodegradation of TBN exclusively occurred at the intracellular environment to deliver both cisplatin (CP) and doxorubicin (DOX) simultaneously to the nucleus. As a result, the TBN-cisplatin conjugate and its DOX-loaded nanoparticles accomplished 100% cell growth inhibition in GSH overexpressed breast cancer cells. Combination therapy revealed that free drugs were antagonistic to each other, whereas the dual drug-loaded TBN exhibited excellent synergistic cell killing at much lower drug concentrations in breast cancer cells. Confocal microscopic analysis confirmed the localization of drugs in the cytoplasm and at peri-nuclear site. Flow cytometry analysis revealed that the drugs were taken up 4-fold better while delivering them from TBN platform compared to free form. The TBNs approach is a perfect platform to overcome the GSH detoxification in Pt-drugs and enable the codelivery of antagonistic drugs like cisplatin and DOX from single polymer dose to accomplish synergistic killing in breast cancer cells.

A review of solute encapsulating nanoparticles used as delivery systems with emphasis on branched amphipathic peptide capsules

Various strategies are being developed to improve delivery and increase the biological half-lives of pharmacological agents. To address these issues, drug delivery technologies rely on different nano-sized molecules including: lipid vesicles, viral capsids and nano-particles. Peptides are a constituent of many of these nanomaterials and overcome some limitations associated with lipid-based or viral delivery systems, such as tune-ability, stability, specificity, inflammation, and antigenicity. This review focuses on the evolution of bio-based drug delivery nanomaterials that self-assemble forming vesicles/capsules. While lipid vesicles are preeminent among the structures; peptide-based constructs are emerging, in particular peptide bilayer delimited capsules. The novel biomaterial-Branched Amphiphilic Peptide Capsules (BAPCs) display many desirable properties. These nano-spheres are comprised of two branched peptides-bis(FLIVI)-K-KKKK and bis(FLIVIGSII)-K-KKKK, designed to mimic diacyl-phosphoglycerides in molecular architecture. They undergo supramolecular self-assembly and form solvent-filled, bilayer delineated capsules with sizes ranging from 20 nm to 2 μm depending on annealing temperatures and time. They are able to encapsulate different fluorescent dyes, therapeutic drugs, radionuclides and even small proteins. While sharing many properties with lipid vesicles, the BAPCs are much more robust. They have been analyzed for stability, size, cellular uptake and localization, intra-cellular retention and, bio-distribution both in culture and in vivo.

In Vitro Evaluation of Doxorubicin Conjugates Based on Sugar Core Nonlinear Polymethacrylates toward Anticancer Drug Delivery

V-shaped and star-shaped hydroxylamine-functionalized polymethacrylates designed as nanosized conjugates (<120 nm) with anticancer agent, namely, doxorubicin (DOX), were evaluated in vitro toward their potential usage as drug delivery systems in breast cancer (MCF-7) treatment. Statistical analysis of MTS assay results showed that the 4-arm conjugate (n(DOX) = 16) was the most effective polymeric system against MCF-7/W (wild type) and MCF-7/R (DOX resistant) cell lines. Apoptosis assay analysis showed that MCF-7/R cells cultured with nonlinear copolymers died due to necrosis and late apoptotis, whereas MCF-7/W cells were in early and late apoptosis. Among all tested conjugates, the most promising results with induction of apoptosis without inducing necrosis in both MCF-7 cell lines were obtained for conjugate based on 4-arm stars with low content of DOX. The cell cycle assay revealed that increase of MMA units in 4-arm copolymers induced MCF-7/R cell arrest in the SubG1 phase. In the same cell line, the corresponding conjugates triggered S and G2/M arrest. Gradual internalization of the chosen conjugate by MCF-7/R cells was monitored via fluorescence microscopy showing its main localization in the cytoplasm.

Reduction-Degradable Polymeric Micelles Decorated with PArg for Improving Anticancer Drug Delivery Efficacy

In this study, five kinds of reduction-degradable polyamide amine-g-polyethylene glycol/polyarginine (PAA-g-PEG/PArg) micelles with different proportions of hydrophilic and hydrophobic segments were synthesized as novel drug delivery vehicles. Polyarginine not only acted as a hydrophilic segment but also possessed a cell-penetrating function to carry out a rapid transduction into target cells. Polyamide amine-g-polyethylene glycol (PAA-g-PEG) was prepared for comparison. The characterization and antitumor effect of the DOX-incorporated PAA-g-PEG/PArg cationic polymeric micelles were investigated in vitro and in vivo. The cytotoxicity experiments demonstrated that the PAA-g-PEG/PArg micelles have good biocompatibility. Compared with DOX-incorporated PAA-g-PEG micelles, the DOX-incorporated PAA-g-PEG/PArg micelles were more efficiently internalized into human hepatocellular carcinoma (HepG2) cells and more rapidly released DOX into the cytoplasm to inhibit cell proliferation. In the 4T1-bearing nude mouse tumor models, the DOX-incorporated PAA-g-PEG/PArg micelles could efficiently accumulate in the tumor site and had a longer accumulation time and more significant aggregation concentration than those of PAA-g-PEG micelles. Meanwhile, it excellently inhibited the solid tumor growth and extended the survival period of the tumor-bearing Balb/c mice. These results could be attributed to their appropriate nanosize and the cell-penetrating peculiarity of polyarginine as a surface layer. The PAA-g-PEG/PArg polymeric micelles as a safe and high efficiency drug delivery system were expected to be a promising delivery carrier that targeted hydrophobic chemotherapy drugs to tumors and significantly enhanced antitumor effects.

Polymeric prodrugs conjugated with reduction-sensitive dextran–camptothecin and pH-responsive dextran–doxorubicin: an effective combinatorial drug delivery platform for cancer therapy

Two types of stimuli-sensitive polymeric prodrugs for combinatorial cancer therapy have been prepared and found to exhibit favorable anticancer activity in vitro and in vivo.