Self-assembled micellar nanocomplexes comprising green tea catechin derivatives and protein drugs for cancer therapy

Scalable fabrication of metal-phenolic nanoparticles by coordination-driven flash nanocomplexation for cancer theranostics

Although various nanomaterials have been developed for cancer theranostics, there remains a key challenge for effective integration of therapeutic drugs and diagnostic agents into a single multicomponent nanoparticle via a simple and scalable approach. Moreover, the bottlenecks of nanoformulation in composition controllability, colloidal stability, drug loading capability and batch-to-batch repeatability currently still hinder the clinical translation of nanomedicine. Herein, we report a coordination-driven flash nanocomplexation (cFNC) process to achieve scalable fabrication of doxorubicin-based metal-phenolic nanoparticles (DITH) with a hyaluronic acid surface layer through efficient control of coordination reaction kinetics in a rapid turbulent mixing. The optimized DITH exhibited a small hydrodynamic diameter (84 nm), narrow size distribution, high drug loading capacity (26.6%), high reproducibility and pH-triggered drug release behaviors. The studies indicated that DITH significantly increased cellular endocytosis mediated by CD44+ receptor targeting and accelerated intracellular drug release owing to the sensitivity of DITH to environmental pH stimuli. Furthermore, guided by T1-weighted magnetic resonance (MR) imaging function endowed by ferric ions, DITH exhibited prolonged blood circulation, enhanced tumor accumulation, improved therapeutic performance and decreased toxic side effects after intravenous injection in a MCF-7 tumor-bearing mice model. These results confirmed that the developed DITH is a promising vehicle for cancer theranostic applications, and our work provided a new strategy to promote the development of translational nanomedicine.

Particle toxicology and health - where are we?

BACKGROUND

Particles and fibres affect human health as a function of their properties such as chemical composition, size and shape but also depending on complex interactions in an organism that occur at various levels between particle uptake and target organ responses. While particulate pollution is one of the leading contributors to the global burden of disease, particles are also increasingly used for medical purposes. Over the past decades we have gained considerable experience in how particle properties and particle-bio interactions are linked to human health. This insight is useful for improved risk management in the case of unwanted health effects but also for developing novel medical therapies. The concepts that help us better understand particles' and fibres' risks include the fate of particles in the body; exposure, dosimetry and dose-metrics and the 5 Bs: bioavailability, biopersistence, bioprocessing, biomodification and bioclearance of (nano)particles. This includes the role of the biomolecule corona, immunity and systemic responses, non-specific effects in the lungs and other body parts, particle effects and the developing body, and the link from the natural environment to human health. The importance of these different concepts for the human health risk depends not only on the properties of the particles and fibres, but is also strongly influenced by production, use and disposal scenarios.

CONCLUSIONS

Lessons learned from the past can prove helpful for the future of the field, notably for understanding novel particles and fibres and for defining appropriate risk management and governance approaches.

Phagocyte-Inspired Smart Microcapsules

Phagocytes protect the organism by ingesting harmful foreign particles and cells. We use mesoscale computer simulations to design a phagocyte-inspired active microcapsule that is capable of selectively capturing nanoparticles dispersed in solvent. Our fully synthetic microdevice is actuated by a temperature-sensitive microgel enclosed inside a perforated spherical shell. The shell pores are decorated with a copolymer brush that regulates the transport of solutes into the capsule interior. When exposed to an external stimulus, the microgel swells, expanding through the shell pores to make contact with the nanoparticle-rich solution surrounding the capsule. Upon removal of the external stimulus, the gel retracts back into the shell, bringing along with it captured nanoparticles. We probe how periodic application of the stimulus combined with nanoparticle-microgel adhesion enable selectivity and enhance capturing efficiency of our nature-inspired microdevice.

An energy-blocking nanoparticle decorated with anti-VEGF antibody to reverse chemotherapeutic drug resistance

Multi-drug resistance (MDR) of tumor cells has greatly hindered the therapeutic efficacy of chemotherapeutic drugs, resulting in chemotherapy failure, while overexpression of ATP-binding cassette (ABC) transporters in cell membranes is the leading cause of MDR. In this study, we reported novel self-assembled triphenylphosphine-quercetin-polyethylene glycol-monoclonal antibody nanoparticles (TQ-PEG-mAb NPs) for overcoming MDR primarily through mitochondrial damage to block ATP supply to ABC transporters both in vitro and in vivo. The doxorubicin (DOX)-loaded NPs (TQ/DOX-PEG-mAb) were composed of two drugs (TQ and DOX) and an outer shielding shell of the PEG-mAb conjugate. Besides, the outer shell could be acid-responsively detached to expose the positive charge of TQ inside the NPs to enhance cellular uptake. TQ was proved to effectively induce mitochondrial damage with increased ROS levels and depolarization of mitochondrial membrane potential (MMP), leading to prominently reduced ATP supply to ABC transporters. Moreover, the involvement of the anti-vascular endothelial growth factor (VEGF) mAb was not only for efficient targeting but also for combined therapy. Consequently, TQ/DOX-PEG-mAb showed that the internalized amount of DOX was largely improved while the efflux amount was dramatically inhibited on MCF-7/ADR cells, indicating excellent reversal of DOX resistance. Importantly, the growth of DOX-resistant breast tumors was significantly inhibited with no evident systemic toxicity. Therefore, the employment of TQ-PEG-mAb is believed to be a new approach to improve the efficacy of chemotherapeutic drugs in MDR tumors.

Effects and mechanisms of tea for the prevention and management of cancers: An updated review

Tea is a traditional and popular beverage worldwide, and the consumption of tea has been demonstrated to possess many health benefits, such as cardiovascular protection, anti-obesity, anti-diabetes, and anticancer. Epidemiological studies have shown that the consumption of tea is inversely associated with the risk of several cancers. In addition, experimental studies have revealed that the anticancer actions of tea are mainly attributed to tea polyphenols, such as epigallocatechin-3-gallate and theaflavins. Both in vitro and in vivo studies have demonstrated that the possible anticancer mechanisms are the inhibition on proliferation, anti-angiogenesis, induction of apoptosis, suppression on metastasis, inhibition on cancer stem cells, and modulation on gut microbiota. Its synergetic anticancer effects with drugs or other compounds could promote anticancer therapies. Furthermore, clinical trials have elucidated that intervention of tea phytochemicals is effective in the prevention of several cancers. This paper is an updated review for the prevention and management of cancers by tea based on the findings from epidemiological, experimental and clinical studies, and special attention is paid on the mechanisms of action.

Nanochemoprevention with therapeutic benefits: An updated review focused on epigallocatechin gallate delivery

Epigallocatechin gallate (EGCG) is a natural phenolic compound found in many plants, especially in green tea, which is a popular and restorative beverage with many claimed health benefits such as antioxidant, anti-cancer, anti-microbial, anti-diabetic, and anti-obesity activities. Despite its great curative potential, the poor bioavailability of EGCG restricts its clinical applcation. However, nanoformulations of EGCG are emerging as new alternatives to traditional formulations. This review focuses on the nanochemopreventive applications of various EGCG nanoparticles such as lipid-based, polymer-based, carbohydrate-based, protein-based, and metal-based nanoparticles. EGCG hybridized with these nanocarriers is capable of achieving advanced functions such as targeted release, active targeting, and enhanced penetration, ultimately increasing the bioavailability of EGCG. In addition, this review also summarizes the challenges for the use of EGCG in therapeutic applications, and suggests future directions for progress.

Self-Assembled Reduced Albumin and Glycol Chitosan Nanoparticles for Paclitaxel Delivery

Cancer continues to pose health problems for people all over the world. Nanoparticles (NPs) have emerged as a promising platform for effective cancer chemotherapy. NPs formed by the assembly of proteins and chitosan (CH) through noncovalent interactions are attracting a great deal of interest. However, the poor water solubility of CH and low stability of this kind of NP limit its practical application. Herein, the formation of reduced bovine serum albumin (rBSA) and glycol chitosan (GC) nanoparticles (rBG-NPs) stabilized by hydrophobic interactions and disulfide bonds was demonstrated for paclitaxel (PTX) delivery. The effects of the rBSA:GC mass ratio and pH on the particle size, polydispersity index (PDI), number of particles, and surface charge were evaluated. The formation mechanism and stability of the NPs were determined by compositional analysis and dynamic light scattering. Hydrophobic and electrostatic interactions were the driving forces for the formation of the rBG-NPs, and the NPs were stable under physiological conditions. PTX was successfully encapsulated into rBG-NPs with a high encapsulation efficiency (∼90%). PTX-loaded rBG-NPs had a particle size of ∼400 nm with a low PDI (0.2) and positive charge. rBG-NPs could be internalized by HeLa cells, possibly via endocytosis. An in vitro cytotoxicity study revealed that PTX-loaded rBG-NPs had anticancer activity that was lower than that of a Taxol-like formulation at 24 h but had similar activity at 48 h, possibly because of the slow release of PTX into the cells. Our study suggests that rBG-NPs could be used as a potential nanocarrier for hydrophobic drugs.

Green Mass Production of Pure Nanodrugs via an Ice-Template-Assisted Strategy

To make nanomedicine potentially applicable in a clinical setting, several methods have been developed to synthesize pure nanodrugs (PNDs) without using any additional inert carriers. In this work, we report a novel green, low-cost, and scalable ice-template-assisted approach which shows several unique characteristics. First, the whole process only requires adding a drug solution into an ice template and subsequent melting (or freeze-drying), allowing easy industrial mass production with low capital investment. Second, the production yield is much higher than that of the traditional reprecipitation approach. The yield of Curcumin (Cur) PNDs is over two orders (∼140 times) magnitude higher than that obtained in a typical reprecipitation preparation. By adjusting simple processing parameters, PNDs with different sizes (∼20-200 nm) can be controllably obtained. Finally, the present approach can be easily applicable for a wide range of hydrophobic therapeutic drugs without any structural modification.

Advanced nanotechnology: An arsenal to enhance immunotherapy in fighting cancer

Cancer remains a major disease process with considerable healthcare and socioeconomic impact worldwide. Unfortunately, standard treatments using chemotherapy often do not effectively control cancer progression or prevent relapse. Over the past decades, the development of targeted therapies has substantially improved outcomes. Recently, immunotherapy has emerged as a new alternative for more effective cancer treatment and may even bring hope of a cure. Cancer immunotherapy functions by reinforcing a patient's immune defense system to fight the disease. Clinically, promising immunotherapy approaches have, however, been limited by unpredictable response and strong adverse effects. A drug delivery system (DDS) that effectively targets tumor and reduces drug exposure to normal tissue would mitigate these limitations. In this regard, nanotechnology has been intensively studied as a DDS for targeting tumors with various oncologic drugs. Several have resulted in improved treatment and outcome. Research has shown that nanoparticle drug delivery technologies can also be applied to immunotherapy. In this review, the current state of nanotechnology will be discussed. Because most cancer immunotherapies approved in recent years are protein drugs, this article will focus on a micellar nanocomplex (MNC) technology, a DDS platform especially suited for targeted delivery of these therapeutics to solid tumors.

Intraoperative biophotonic imaging systems for image-guided interventions

Biophotonic imaging has revolutionized the operation room by providing surgeons intraoperative image-guidance to diagnose tumors more efficiently and to resect tumors with real-time image navigation. Among many medical imaging modalities, near-infrared (NIR) light is ideal for image-guided surgery because it penetrates relatively deeply into living tissue, while nuclear imaging provides quantitative and unlimited depth information. It is therefore ideal to develop an integrated imaging system by combining NIR fluorescence and gamma-positron imaging to provide surgeons with highly sensitive and quantitative detection of diseases, such as cancer, in real-time without changing the look of the surgical field. The focus of this review is to provide recent progress in intraoperative biophotonic imaging systems, NIR fluorescence imaging and intraoperative nuclear imaging devices, and their future perspectives for image-guided interventions.

Protective Effects of Epigallocatechin-3-Gallate from Green Tea in Various Kidney Diseases

Kidney diseases are common health problems worldwide. Various etiologies (e.g., diabetes, hypertension, drug-induced nephrotoxicity, infection, cancers) can affect renal function and ultimately lead to development of chronic kidney disease (CKD) and end-stage renal disease (ESRD). The global rise in number of CKD/ESRD patients during recent years has led to tremendous concern to look for effective strategies to prevent or slow progression of CKD and ESRD. Natural compounds derived from herbs or medicinal plants have gained wide attention for scientific scrutiny to achieve such goals. One of such natural compounds that has been extensively investigated is epigallocatechin-3-gallate (EGCG), a major polyphenol found in the tea plant (Camellia sinensis). A growing body of recent evidence has shown that EGCG may be a promising therapeutic or protective agent in various kidney diseases. This article thus highlights recent progress in medical research on beneficial effects of EGCG against a broad spectrum of kidney diseases, including acute kidney injury, cisplatin-induced nephrotoxicity, kidney stone disease, glomerulonephritis, lupus nephritis, renal cell carcinoma, diabetic nephropathy, CKD, and renal fibrosis. The renoprotective mechanisms are also detailed. Finally, future perspectives of medical research on EGCG and its potential use in clinical practice for treatment and prevention of kidney diseases are discussed.

Carrier-free nanodrugs for in vivo NIR bioimaging and chemo-photothermal synergistic therapy

The combination of chemotherapy and photothermal therapy displays improved anti-cancer effects and lower systematic toxicity of a free drug compared with monotherapy.

DOX-assisted functionalization of green tea polyphenol nanoparticles for effective chemo-photothermal cancer therapy

Green tea polyphenol nanoparticles with chemotherapeutic and photothermal performance exhibited effective anti-tumor effects in vivo with intravenous injection.

Fabrication and Characterization of Oleogel Stabilized by Gelatin-Polyphenol-Polysaccharides Nanocomplexes

The development of oleogel has attracted growing attention because of its health benefits and promising potential to substitute saturated or trans-fat. The present work reports a type of oleogel using the emulsion stabilized by gelatin (GLT), tannic acid (TA), and flaxseed gum (FG) complexes (GLT-TA-FG) through freeze-drying and oven-drying. Results showed that the incorporation of TA and FG promoted the formation of nanoparticles, resulting in increased charge quantity and reduced oil-water surface tension. The structural integrity of oleogel largely depends on the drying method, FG incorporation, and TA concentration. It was demonstrated that with oven drying, stable oleogel without oil leakage could only be fabricated in the presence of FG. The GLT-0.075 wt % TA-FG complexes formed a particle shell around the oil droplet, leading to the enhanced gel strength of the oleogel. In addition, the oleogel stabilized by GLT-TA-FG complexes had high thixotropic recovery degree and rehydration ability, implying the stabilizing effect of TA and FG. Therefore, the interfacially adsorbed particles and the polymer gel network in bulk together contributed to the compact structure of oleogel. We believe that the oleogel based on GLT-TA-FG complexes has potential applications in food products with tunable rheological and textural properties.

Hydrogen-Bonded Tannic Acid-Based Anticancer Nanoparticle for Enhancement of Oral Chemotherapy

Oral chemotherapy has been emerging as a hopeful therapeutic regimen for the treatment of various cancers because of its high safety and convenience, lower costs, and high patient compliance. Currently, nanoparticulate drug delivery systems (NDDS) exhibit many unique advantages in mediating oral drug delivery; however, many anticancer drugs that were susceptible in hostile gastrointestinal (GI) environment showed poor permeability across intestinal epithelium, and most materials used as drug carriers are nonactive excipients and displayed no therapeutically relevant function, which leads to low oral bioavailability and therapeutic efficacy of anticancer drugs (e.g., paclitaxel). Inspired by these, in this study, paclitaxel (PTX) was used as a model drug, depending on intermolecular hydrogen-bonded interactions, PTX-loaded tannic acid/poly( N-vinylpyrrolidone) nanoparticles (PTX-NP) were produced by a flash nanoprecipitation (FNP) process. The optimized PTX-NP showed an average diameter of 54 nm with a drug encapsulation efficiency of 80% and loading capacity of 14.5%. Molecular dynamics simulations were carried out to illuminate the assembling mechanism of hydrogen-bonded PTX-NP. In vitro and in vivo results confirmed that PTX-NP showed pH-dependent intestinal site-specific drug release, P-gp inhibitory function by tannic acid (TA), prolonged intestinal retention, and improved trans-epithelial transport properties. Oral administration of PTX-NP generated a high oral delivery efficiency and relative oral bioavailability of 25.6% in rats, and further displayed a significant tumor-inhibition effect in a xenograft breast tumor model. These findings confirmed that our PTX-NP might be a promising oral drug formulation for chemotherapy.

Green Tea Catechin Dramatically Promotes RNAi Mediated by Low-Molecular-Weight Polymers

Cytosolic delivery is the major challenge that limits the clinical translation of siRNA-based therapeutics. Although thousands of polymers have been developed for siRNA delivery, the efficiency-toxicity correlation is unsatisfactory. Here, we report a facile strategy to fabricate core-shell-structured nanoparticles with robust siRNA delivery efficiency. The nanoparticle is prepared by entropy-driven complexation of siRNA with a green tea catechin to yield a negatively charged core, followed by coating low-molecular-weight polymers to form the shell. This supramolecular strategy facilitates the polymers condensing siRNA into uniform nanoparticles. The nanoparticle specifically down-regulates target genes in vitro and in vivo, and efficiently attenuates chronic intestinal inflammation in an inflammatory bowel disease model. Notably, the highly efficient nanoparticles are applicable for various polymers with different topologies and chemical compositions, providing a versatile technique to break down the efficiency-toxicity correlation of cationic polymers. The proposed strategy in this study permits the development of a promising platform for polymer-mediated siRNA delivery.

The environmental pollutant, polychlorinated biphenyls, and cardiovascular disease: a potential target for antioxidant nanotherapeutics

Despite production having stopped in the 1970s, polychlorinated biphenyls (PCBs) represent persistent organic pollutants that continue to pose a serious human health risk. Exposure to PCBs has been linked to chronic inflammatory diseases, such as cardiovascular disease, type 2 diabetes, obesity, as well as hepatic disorders, endocrine dysfunction, neurological deficits, and many others. This is further complicated by the PCB's strong hydrophobicity, resulting in their ability to accumulate up the food chain and to be stored in fat deposits. This means that completely avoiding exposure is not possible, thus requiring the need to develop intervention strategies that can mitigate disease risks associated with exposure to PCBs. Currently, there is excitement in the use of nutritional compounds as a way of inhibiting the inflammation associated with PCBs, yet the suboptimal delivery and pharmacology of these compounds may not be sufficient in more acute exposures. In this review, we discuss the current state of knowledge of PCB toxicity and some of the antioxidant and anti-inflammatory nanocarrier systems that may be useful as an enhanced treatment modality for reducing PCB toxicity.

Granzyme B-loaded, cell-selective penetrating and reduction-responsive polymersomes effectively inhibit progression of orthotopic human lung tumor in vivo

The clinical use of protein therapeutics with intracellular targets is hampered by its in vivo fragility and low cell permeability. Here, we report that cell-selective penetrating and reduction-responsive polymersomes (CPRPs) mediate high-efficiency targeted delivery of granzyme B (GrB) to orthotopic human lung tumor in vivo. Model protein studies using FITC-labeled cytochrome C (FITC-CC) revealed efficient and high protein loading up to 17.2 wt% for CPRPs. FITC-CC-loaded CPRPs exhibited a small size of 82-90 nm, reduction-responsive protein release, as well as greatly enhanced internalization and cytoplasmic protein release in A549 lung cancer cells compared with the non-targeted FITC-CC-loaded RPs control. GrB-loaded CPRPs showed a high potency toward A549 lung cancer cells with a half maximal inhibitory concentration (IC₅₀) of 20.7 nM. Under the same condition, free GrB was essentially non-toxic. Importantly, installing cell-selective penetrating peptide did not alter the circulation time but did enhance tumor accumulation of RPs. Orthotopic A549-Luc lung tumor-bearing nude mice administered with GrB-loaded CPRPs at a dosage of 2.88 nmol GrB equiv./kg showed complete tumor growth inhibition with little body weight loss throughout the treatment period, resulting in significantly improved survival rate over the non-targeted and non-treated controls. These cell-selective penetrating and reduction-responsive polymersomes provide a targeted protein therapy for cancers.

Protein Nanotherapeutics as an Emerging Modality for Cancer Therapy

Protein drugs are a unique and versatile class of biotherapeutics that have not only high biological activity but also superb specificity. This rapidly evolving biotechnology has rendered it possible to produce various proteins in a large scale and reproducible way. Many proteins have demonstrated striking anticancer activities and have emerged as advanced alternatives to cytotoxic chemotherapeutic agents for cancer therapy. The clinical translation of anticancer proteins with intracellular targets is, nevertheless, severely hindered by their fast degradation in vivo, poor cell penetration, and inefficient intracellular transportation. The past few years have witnessed tremendous effort and progress in developing polymeric protein delivery nanosystems, ranging from nanoparticles, nanocapsules, nanogels, micelles, to polymersomes, for the treatment of different tumors such as lung tumors, breast tumors, ovarian cancers, and glioblastoma. These proof-of-concept studies point out that protein nanotherapeutics, with rationally designed nanovehicles, are able to overcome the extracellular barriers, cell membrane barriers, and intracellular barriers, and systemically deliver proteins into targeted cancer cells, resulting in effective cancer protein therapy. Protein nanotherapeutics appear to be a novel modality for safe and efficient cancer treatment.

Tannin-Titanium Oxide Multilayer as a Photochemically Suppressed Ultraviolet Filter

UV filters can initiate redox reactions of oxygen and water when exposed to sunlight, generating reactive oxygen species (ROS) that deteriorate the products containing them and cause biological damages. This photochemical reactivity originates from the high chemical potential of UV filters, which also determines the optical properties desirable for sunscreen applications. We hypothesize that this dilemma can be alleviated if the photochemical pathway of UV filters is altered to coupling with redox active molecules. Here, we employ tannic acid (TA) as a key molecule for controlling the photochemical properties of titanium dioxide nanoparticles (TiO₂ NPs). TA provides an unusual way for layer-by-layer assembly of TiO₂ NPs by the formation of a ligand-to-metal charge transfer complex that alters the nature of UV absorption of TiO₂ NPs. The galloyl moieties of TA efficiently scavenge ROS due to the stabilization of ROS by intramolecular hydrogen bonding while facilitating UV screening through direct charge injection from TA to the conduction band of TiO₂. The TiO₂-TA multilayers assembled in open porous polymer microspheres substantially increased sun protection while dramatically reducing ROS under UV exposure. The assembled structure exhibits excellent in vivo anti-UV skin protection against epidermal hyperplasia, inflammation, and keratinocyte apoptosis without long-term toxicity.

Anticancer Effects of Green Tea and the Underlying Molecular Mechanisms in Bladder Cancer

Green tea and green tea polyphenols (GTPs) are reported to inhibit carcinogenesis and malignant behavior in several diseases. Various in vivo and in vitro studies have shown that GTPs suppress the incidence and development of bladder cancer. However, at present, opinions concerning the anticancer effects and preventive role of green tea are conflicting. In addition, the detailed molecular mechanisms underlying the anticancer effects of green tea in bladder cancer remain unclear, as these effects are regulated by several cancer-related factors. A detailed understanding of the pathological roles and regulatory mechanisms at the molecular level is necessary for advancing treatment strategies based on green tea consumption for patients with bladder cancer. In this review, we discuss the anticancer effects of GTPs on the basis of data presented in in vitro studies in bladder cancer cell lines and in vivo studies using animal models, as well as new treatment strategies for patients with bladder cancer, based on green tea consumption. Finally, on the basis of the accumulated data and the main findings, we discuss the potential usefulness of green tea as an antibladder cancer agent and the future direction of green tea-based treatment strategies for these patients.

Combination of fucoidan-based magnetic nanoparticles and immunomodulators enhances tumour-localized immunotherapy

Checkpoint immunotherapy that inhibits tumour immune evasion has demonstrated significant clinical success. However, the therapeutic response is limited to certain patient populations, and immunotoxicity as well as autoimmunity have compromised the therapeutic benefits. Here, we report on an inherently therapeutic fucoidan-dextran-based magnetic nanomedicine (IO@FuDex³) conjugated with a checkpoint inhibitor (anti-PD-L1) and T-cell activators (anti-CD3 and anti-CD28). IO@FuDex³ can repair the immunosuppressive tumour microenvironment by reinvigorating tumour-infiltrating lymphocytes, while targeting the nanomedicine via magnetic navigation to the tumour to minimize off-target effects. Treatment that combines IO@FuDex³ and magnetic navigation reduces the occurrence of adverse events and extends the median survival from 32 to 63 days with less than 1 per cent dose compared with soluble anti-PD-L1. Thus, we demonstrate the potential of integrating anti-PD-L1 and T-cell activators as a form of inherently therapeutic nanomedicine to augment the therapeutic index of combination checkpoint immunotherapy.

Nucleoside Analogue-Based Supramolecular Nanodrugs Driven by Molecular Recognition for Synergistic Cancer Therapy

The utilization of nanotechnology for the delivery of a wide range of anticancer drugs has the potential to reduce adverse effects of free drugs and improve the anticancer efficacy. However, carrier materials and/or chemical modifications associated with drug delivery make it difficult for nanodrugs to achieve clinical translation and final Food and Drug Administration (FDA) approvals. We have discovered a molecular recognition strategy to directly assemble two FDA-approved small-molecule hydrophobic and hydrophilic anticancer drugs into well-defined, stable nanostructures with high and quantitative drug loading. Molecular dynamics simulations demonstrate that purine nucleoside analogue clofarabine and folate analogue raltitrexed can self-assemble into stable nanoparticles through molecular recognition. In vitro studies exemplify how the clofarabine:raltitrexed nanoparticles could greatly improve synergistic combination effects by arresting more G1 phase of the cell cycle and reducing intracellular deoxynucleotide pools. More importantly, the nanodrugs increase the blood retention half-life of the free drugs, improve accumulation of drugs in tumor sites, and promote the synergistic tumor suppression property in vivo.

Dual Intratumoral Redox/Enzyme-Responsive NO-Releasing Nanomedicine for the Specific, High-Efficacy, and Low-Toxic Cancer Therapy

Chemotherapy suffers numbers of limitations including poor drug solubility, nonspecific biodistribution, and inevitable adverse effects on normal tissues. Tumor-targeted delivery and intratumoral stimuli-responsive release of drugs by nanomedicines are considered to be highly promising in solving these problems. Compared with traditional chemotherapeutic drugs, high concentration of nitric oxide (NO) exhibits unique anticancer effects. The development of tumor-targeting and intratumoral microenvironment-responsive NO-releasing nanomedicines is highly desired. Here a novel kind of organic-inorganic composite nanomedicine (QM-NPQ@PDHNs) is presented by encapsulating a glutathione S-transferases π (GSTπ)-responsive drug O² -(2,4-dinitro-5-{[2-(β-d-galactopyranosyl olean-12-en-28-oate-3-yl)-oxy-2-oxoethyl] piperazine-1-yl} phenyl) 1-(methylethanolamino)diazen-1-ium-1,2-dilate (NPQ) as NO donor and an aggregation-induced-emission (AIE) red fluorogen QM-2 into the cores of the hybrid nanomicelles (PEGylated disulfide-doped hybrid nanocarriers (PDHNs)) with glutathione (GSH)-responsive shells. The QM-NPQ@PDHN nanomedicine is able to respond to the intratumoral over-expressed GSH and GSTπ, resulting in the responsive biodegradation of the protective organosilica shell and NPQ release, and subsequent NO release within the tumor, respectively, and thus normal organs remain unaffected. This work demonstrates a paradigm of dual intratumoral redox/enzyme-responsive NO-release nanomedicine for tumor-specific and high-efficacy cancer therapy.

Protein Toxin Chaperoned by LRP-1-Targeted Virus-Mimicking Vesicles Induces High-Efficiency Glioblastoma Therapy In Vivo

Glioblastoma is a most intractable and high-mortality malignancy because of its extremely low drug accessibility resulting from the blood-brain barrier (BBB). Here, it is reported that angiopep-2-directed and redox-responsive virus-mimicking polymersomes (ANG-PS) (angiopep-2 is a peptide targeting to low-density lipoprotein receptor-related protein-1 (LRP-1)) can efficiently and selectively chaperone saporin (SAP), a highly potent natural protein toxin, to orthotopic human glioblastoma xenografts in nude mice. Unlike chemotherapeutics, free SAP has a low cytotoxicity. SAP-loaded ANG-PS displays, however, a striking antitumor activity (half-maximal inhibitory concentration, IC₅₀  = 30.2 × 10^-9 m) toward U-87 MG human glioblastoma cells in vitro as well as high BBB transcytosis and glioblastoma accumulation in vivo. The systemic administration of SAP-loaded ANG-PS to U-87 MG orthotopic human-glioblastoma-bearing mice brings about little side effects, effective tumor inhibition, and significantly improved survival rate. The protein toxins chaperoned by LRP-1-targeted virus-mimicking vesicles emerge as a novel and highly promising treatment modality for glioblastoma.

Carrier-Free, Pure Nanodrug Formed by the Self-Assembly of an Anticancer Drug for Cancer Immune Therapy

Ursolic acid (UA) is a food-plant-derived natural product which has good anticancer activities and low toxicity. However, the poor water solubility of UA limits its application in clinic. To address this issue, we developed a carrier-free nanodrug by self-assembly of UA. Here, we showed that UA nanoparticles (NPs) have a near-spherical shape with a diameter of ∼150 nm. UA NPs exhibited higher antiproliferative activity; significantly caused apoptosis; decreased the expression of COX-2/VEGFR2/VEGFA; and increased the immunostimulatory activity of TNF-α, IL-6, and IFN-β and decreased the activity of STAT-3 in A549 cells in vitro. Furthermore, UA NPs could inhibit tumor growth and have the ability of liver protection in vivo. More importantly, UA NPs could significantly improve the activation of CD4+ T-cells, which indicated that UA NPs have the potential for immunotherapy. Overall, a carrier-free UA nanodrug may be a promising drug to further enhance their anticancer efficacy and immune function.

Multivalent Mannose-Decorated NIR Nanoprobes for Targeting Pan Lymph Nodes

Lymphadenectomy is a prerequisite for most malignancies to define the precise staging of cancer, as well as resect the possible metastases completely. While it improves prognosis, lymphadenectomy often causes postoperative edema or bleeding because of unclear surgical margins. In this study, we synthesized near-infrared (NIR) fluorescent nanoprobes with conjugating various mannose moieties on the surface to target macrophages in the lymph node. Armed with these NIR nanoprobes, we demonstrated the feasibility of intraoperative pan lymph nodes (PLN) mapping and real-time optical imaging under the NIR fluorescence imaging system. We found that even single mannose-conjugated ZW800-1 showed specific uptake in lymph nodes within 4 h, and multiple mannose-employed polyrotaxanes highlighted PLN efficiently with low background signals in major organs. This technology can help surgeons perform lymphadenectomy with ease and safety by identifying all regional lymph nodes proficiently after a single intravenous injection of NIR nanoprobes.

Highly Augmented Drug Loading and Stability of Micellar Nanocomplexes Composed of Doxorubicin and Poly(ethylene glycol)-Green Tea Catechin Conjugate for Cancer Therapy

Low drug loading and instability in blood circulation are two key challenges that impede the successful clinical translation of nanomedicine, as they result in only marginal therapeutic efficacy and toxic side effects associated with premature drug leakage, respectively. Herein, highly stable and ultrahigh drug loading micellar nanocomplexes (MNCs) based on the self-assembly of the anticancer drug doxorubicin (DOX) and a poly(ethylene glycol)-epigallocatechin-3-O-gallate (EGCG) conjugate are developed. The formation of these MNCs is facilitated by strong favorable intermolecular interactions between the structurally similar aromatic EGCG and DOX molecules, which impart exceptionally high drug-loading capability of up to 88% and excellent thermodynamic and kinetic stability. Unlike two clinical formulations of DOX-free DOX and liposomal DOX, which are not effective below their lethal dosages, these DOX-loaded MNCs demonstrate significant tumor growth inhibition in vivo on a human liver cancer xenograft mouse model with minimal unwanted toxicity. Overall, these MNCs can represent a safe and effective strategy to deliver DOX for cancer therapy.

Self-assembled nanomicelles of amphiphilic clotrimazole glycyl-glycine analogue augmented drug delivery, apoptosis and restrained melanoma tumour progression

In present investigation, self-assembled nanomicelles of amphiphilic clotrimazole glycyl-glycine (CLT-GG-SANMs) analogue were customized for augmenting drug delivery, permeability and apoptosis in B16F1 mouse melanoma cancer cells both in vitro and in vivo following intratumoral (i.t.) route of administration. The mean particle size of CLT-GG-SANMs was measured to be 35.9 ± 3.4 nm in addition to zeta-potential of -17.1 ± 3.5 mV. The shape of CLT-GG-SANMs was visualized to be smooth and spherical as like nanoparticles. The critical micellar concentration (CMC) of CLT-GG-SANMs was estimated to be 17 μg/ml using DPH (1,6-diphenyl-1,3,5-hexatriene) as a UV probe. Modification of CLT to CLT-GG-SANMs induced the amorphization in therapeutic moiety. Next, CLT suspension released only 9.7% of the drug within 1 h under dissolution testing and further analysis up to 48 h did not display any remarkable effect on the drug release. On the other hand, CLT-GG-SANMs released 46.2% of the drug significantly (P < 0.01) higher than CLT suspension at 4 h. The IC₅₀ of CLT-GG-SANMs was measured to be 15.1-μM significantly (P < 0.05) lower than CLT suspension (IC₅₀ > 20 μM) in B16F1 cells. Western blotting and histopathological analysis also supported the superior therapeutic efficacy of CLT-GG-SANMs in terms of higher extent of apoptosis, tumour regression and exhibition of strong antioxidant potential against B16F1 cells induced tumour in C57BL6J mice. In conclusion, in vitro and in vivo therapeutic efficacy analysis indicated that CLT-GG-SANMs may be a potential candidate for translating in to a clinically viable product.

Nanostructured Peptidotoxins as Natural Pro-Oxidants Induced Cancer Cell Death via Amplification of Oxidative Stress

Melittin (Mel), one of the host defense peptides derived from the venom of honeybees, demonstrates substantial anticancer properties, which is attributed to augmenting reactive oxygen species (ROS) generation. However, little has been reported on its pro-oxidation capacity in cancer oxidation therapy. In this study, an ROS amplifying nanodevice was fabricated through direct complexation of two natural pro-oxidants, Mel and condensed epigallocatechin gallate (pEGCG). The obtained nanocomplex (NC) was further covered with phenylboronic acid derivatized hyaluronic acid (pHA) through the ROS-responsive boronate ester coordination bond to produce pHA-NC. Upon undergoing receptor-mediated endocytosis into cancer cells, the inner cores of pHA-NC will be partially uncovered once pHA corona is degraded by hyaluronidase and will then escape from the lysosome by virtue of cytolytic Mel. The elevated ROS level in the tumor cytoplasm can disrupt the boronate ester bond to facilitate drug release. Both Mel and pEGCG could synergistically amplify oxidative stress and prolong ROS retention in cancer cells, leading to enhanced anticancer efficacy. This ROS cascade amplifier based on selective coordination bond and inherent pro-oxidation properties of natural ingredients could detect and elevate intracellular ROS signals, potentiating to move the tumor away from its homeostasis and make the tumor vulnerable. Compared to previously reported chemosynthetic pro-oxidants, the ROS self-sufficient system, fully composed of natural medicine, from this study provides a new insight in developing cancer oxidation therapy.

Self-assembling toxin-based nanoparticles as self-delivered antitumoral drugs

Loading capacity and drug leakage from vehicles during circulation in blood is a major concern when developing nanoparticle-based cell-targeted cytotoxics. To circumvent this potential issue it would be convenient the engineering of drugs as self-delivered nanoscale entities, devoid of any heterologous carriers. In this context, we have here engineered potent protein toxins, namely segments of the diphtheria toxin and the Pseudomonas aeruginosa exotoxin as self-assembling, self-delivered therapeutic materials targeted to CXCR4⁺ cancer stem cells. The systemic administration of both nanostructured drugs in a colorectal cancer xenograft mouse model promotes efficient and specific local destruction of target tumor tissues and a significant reduction of the tumor volume. This observation strongly supports the concept of intrinsically functional protein nanoparticles, which having a dual role as drug and carrier, are designed to be administered without the assistance of heterologous vehicles.

Size-controlled, colloidally stable and functional nanoparticles based on the molecular assembly of green tea polyphenols and keratins for cancer therapy

Molecular assembly of green tea polyphenols and keratins into size-controlled, colloidally stable and functional nanoparticles for enhanced cancer therapy was achieved.

Biologically inspired, catechol-coordinated, hierarchical organization of raspberry-like calcium phosphate nanospheres with high specific surface area

Catechol directs the assembly of mesoporous CaP spheres with a hierarchically reticulated architecture and excellent interconnectivity.

A novel design of a polynuclear co-delivery system for safe and efficient cancer therapy

A polynuclear nanoparticle fabricated through a sequential hydrophobic and electrostatic interaction mechanism can circumvent the contradictory problem of siRNA binding capacity and toxicities of cationic vectors.

ROS-responsive capsules engineered from green tea polyphenol–metal networks for anticancer drug delivery

Reactive oxygen species (ROS)-responsive nanocapsules for cancer drug delivery were engineered from green tea polyphenol–metal networks.

Cellulose/keratin–catechin nanocomposite hydrogel for wound hemostasis

Rapid wound hemostatic was achieved by a composite hydrogel based on human hair keratin–catechin nanoparticles and cellulose.

A Small Molecule Nanodrug by Self-Assembly of Dual Anticancer Drugs and Photosensitizer for Synergistic near-Infrared Cancer Theranostics

Phototherapy including photodynamic therapy (PDT) and photothermal therapy (PTT) has attracted great attention. However, applications of some photosensitizers remain an obstacle by their poor photostability. To enhance the treatment efficiency of photosensitizers and tumor theranostic effect, herein, we reported a novel carrier-free, theranostic nanodrug by self-assembly of small molecule dual anticancer drugs and photosensitizer for tumor targeting. The developed carrier-free small molecule nanodrug delivery system was formed by hydrophobic ursolic acid, paclitaxel, and amphipathic indocyanine green (ICG) associated with electrostatic, π-π stacking, and hydrophobic interactions exhibiting water stability. The self-assembling of ICG on the dual anticancer nanodrug significantly enhanced water solubility of hydrophobic anticancer drugs and ICG photostability contributing to long-term near-infrared (NIR) fluorescence imaging and effective chemophototherapy of tumor. The in vivo NIR fluorescence imaging showed that the theranostic nanodrug could be targeted to the tumor site via a potential enhanced permeability and retention effect proving the efficient accumulation of nanoparticles in the tumor site. Dramatically, chemophototherapy of tumor-bearing mice in vivo almost completely suppressed tumor growth and no tumor recurrence was observed. Encouraged by its carrier-free, prominent imaging and effective therapy, the small molecule nanodrug via self-assembly will provide a promising strategy for synergistic cancer theranostics.

Cube-shaped theranostic paclitaxel prodrug nanocrystals with surface functionalization of SPC and MPEG-DSPE for imaging and chemotherapy

As one of nanomedicine delivery systems (NDSs), drug nanocrystals exhibited an excellent anticancer effect. Recently, differences of internalization mechanisms and subcellular localization of both drug nanocrystals and small molecular free drug have drawn much attention. In this paper, paclitaxel (PTX) as a model anticancer drug was directly labeled with 4-chloro-7-nitro-1, 2, 3-benzoxadiazole (NBD-Cl) (a drug-fluorophore conjugate Ma et al. (2016) and Wang et al. (2016) [1,2] (PTX-NBD)). PTX-NBD was synthesized by nucleophilic substitution reaction of PTX with NBD-Cl in high yield and characterized by fluorescence, XRD, ESI-MS, and FT-IR analysis. Subsequently, the cube-shaped PTX-NBD nanocrystals were prepared with an antisolvent method followed by surface functionalization of SPC and MPEG-DSPE. The obtained specific shaped PTX-NBD@PC-PEG NCs had a hydrodynamic particle size of ∼50nm, excellent colloidal stability, and a high drug-loading content of ∼64%. Moreover, in comparison with free PTX-NBD and the sphere-shaped PTX-NBD nanocrystals with surface functionalization of SPC and MPEG-DSPE (PTX-NBD@PC-PEG NSs), PTX-NBD@PC-PEG NCs remarkably reduced burst release and improved cellular uptake efficiency and in vitro cancer cell killing ability. In a word, the work highlights the potential of theranostic prodrug nanocrystals based on the drug-fluorophore conjugates for cell imaging and chemotherapy.

Programmed Nanococktail Based on pH-Responsive Function Switch for Self-Synergistic Tumor-Targeting Therapy

Tumor-targeting combination chemotherapy is an important way to improve the therapeutic index and reduce the side effects as compared to traditional cancer treatments. However, one of the major challenges in surface functionalization of nanoparticle (NP) is accomplishing multiple purposes through one single ligand. Upon such consideration, methotrexate (MTX), an anticancer drug with a targeting moiety inspired by the similar structure of folate, could be used to covalently link with lipid-polymer conjugate (DSPE-PEG) via a pH-sensitive dynamic covalent imine (CH═N) bond to synthesize the acid-induced function "targeting-anticancer" switching DSPE-PEG-CH═N-MTX. We hypothesize that using this kind of MTX prodrug to functionalize NP's surface would be conductive to combine the early phase active targeting function and the late-phase anticancer function in one nanosystem. Herein, a nanococktail is programmed for codelivery of epirubicin (EPI) and MTX by co-self-assembly of acid-dissociated EPI-phospholipid (PC) complex and acid-cleavable DSPE-PEG-CH═N-MTX conjugate. The obtained nanococktail (MTX-PEG-EPI-PC NPs) could not only actively target folate receptors-overexpressing tumor cells but also respond to acidic endo/lysosomes for triggering the on-demand release of pharmaceutically active EPI/MTX. The intracellular drug distribution also demonstrated that the system could codeliver two drugs to individual target sites of action, inducing the significant synergistic anticancer efficiency based on different anticancer mechanisms. More importantly, the in vivo tumor accumulation and anticancer efficacy of MTX-PEG-EPI-PC NPs (via cleavable imine bond) were significantly enhanced as compared to the individual free drug, both free drugs, PEG-EPI-PC NPs, and MTX-PEG-EPI-PC NPs (via the uncleavable amide bond). This self-synergistic tumor-targeting therapy might represent a promising strategy for cancer treatment.

Phenolic compounds based conjugates from dextran aldehyde and BSA: Preparation, characterization and evaluation of their anti-cancer efficacy for therapeutic applications

Here, we have synthesized phenolic compounds (pc) based on conjugates from dextran aldehyde (dex-ald) and bovine serum albumin (BSA) and screening their potential activity as therapeutic agents in cancer disease. The synthesized conjugates were analyzed by UV-vis, FT-IR, XRD and SEM analysis. UV-vis spectra of conjugates showed the shifting of spectral peak at UV to visible region revealed the enhanced conjugation due to formation of linkage. The XRD peaks of conjugates found broader and indicating the amorphous phase of conjugating materials in compared to free components. The SEM images showed that the conjugated materials having numerous pores on its surface, which proved its porous nature. The amount of phenolic compounds conjugated with (dex-ald-pc) and (BSA-pc) were found to be 65.4 and 73.91mg/g of conjugates, respectively. Cells viability was significantly decreased approximately 80-85% at concentration of 100μg conjugates whereas the free polymers or phenolics did not affect the viability of cancer cells. Generation of high quantity of reactive oxygen species (ROS) in cells treated with conjugate materials, which may caused cell apoptosis in cancer cell line. The results clearly showed that conjugation of phenolic compounds were an effective method to improve the functional properties for therapeutic applications.