Oral Delivery of Nucleic Acid Therapies for Local and Systemic Action.

Nucleic acid (NA) therapy has gained importance over the past decade due to its high degree of selectivity and minimal toxic effects over conventional drugs. Currently, intravenous (IV) or intramuscular (IM) formulations constitute majority of the marketed formulations containing nucleic acids. However, oral administration is traditionally preferred due to ease of administration as well as higher patient compliance. To leverage the benefits of oral delivery for NA therapy, the NA of interest must be delivered to the target site avoiding all degrading and inhibiting factors during its transition through the gastrointestinal tract. The oral route presents myriad of challenges to NA delivery, making formulation development challenging. Researchers in the last few decades have formulated various delivery systems to overcome such challenges and several reviews summarize and discuss these strategies in detail. However, there is a need to differentiate between the approaches based on target so that in future, delivery strategies can be developed according to the goal of the study and for efficient delivery to the desired site. The goal of this review is to summarize the mechanisms for target specific delivery, list and discuss the formulation strategies used for oral delivery of NA therapies and delineate the similarities and differences between local and systemic targeting oral delivery systems and current challenges.

Neurodegenerative disorders management: state-of-art and prospects of nano-biotechnology.

Neurodegenerative disorders (NDs) are highly prevalent among the aging population. It affects primarily the central nervous system (CNS) but the effects are also observed in the peripheral nervous system. Neural degeneration is a progressive loss of structure and function of neurons, which may ultimately involve cell death. Such patients suffer from debilitating memory loss and altered motor coordination which bring up non-affordable and unavoidable socio-economic burdens. Due to the unavailability of specific therapeutics and diagnostics, the necessity to control or manage NDs raised the demand to investigate and develop efficient alternative approaches. Keeping trends and advancements in view, this report describes both state-of-the-art and challenges in nano-biotechnology-based approaches to manage NDs, toward personalized healthcare management. Sincere efforts are being made to customize nano-theragnostics to control: therapeutic cargo packaging, delivery to the brain, nanomedicine of higher efficacy, deep brain stimulation, implanted stimulation, and managing brain cell functioning. These advancements are useful to design future therapy based on the severity of the patient's neurodegenerative disease. However, we observe a lack of knowledge shared among scientists of a variety of expertise to explore this multi-disciplinary research field for NDs management. Consequently, this review will provide a guideline platform that will be useful in developing novel smart nano-therapies by considering the aspects and advantages of nano-biotechnology to manage NDs in a personalized manner. Nano-biotechnology-based approaches have been proposed as effective and affordable alternatives at the clinical level due to recent advancements in nanotechnology-assisted theragnostics, targeted delivery, higher efficacy, and minimal side effects.

Polymeric Chloroquine as an Effective Antimigration Agent in the Treatment of Pancreatic Cancer.

Hydroxychloroquine (HCQ) has been the subject of multiple recent preclinical and clinical studies for its beneficial use in the combination treatments of different types of cancers. Polymeric HCQ (PCQ), a macromolecular multivalent version of HCQ, has been shown to be effective in various cancer models both in vitro and in vivo as an inhibitor of cancer cell migration and experimental lung metastasis. Here, we present detailed in vitro studies that show that low concentrations of PCQ can efficiently inhibit cancer cell migration and colony formation orders of magnitude more effectively compared to HCQ. After intraperitoneal administration of PCQ in vivo, high levels of tumor accumulation and penetration are observed, combined with strong antimetastatic activity in an orthotopic pancreatic cancer model. These studies support the idea that PCQ may be effectively used at low doses as an adjuvant in the therapy of pancreatic cancer. In conjunction with previously published literature, these studies further undergird the potential of PCQ as an anticancer agent.

Study of Renal Accumulation of Targeted Polycations in Acute Kidney Injury.

Acute kidney injury (AKI) is a global healthcare burden characterized by rapid loss of renal function and high morbidity and mortality. Chemokine receptor CXCR4 participates in the renal infiltration of immune cells following injury and in local inflammatory enhancement. Injured renal tubule cells overexpress CXCR4, which could be used as a target for improved drug delivery in AKI. Plerixafor is a small-molecule CXCR4 antagonist that has shown beneficial effects against AKI and has been previously developed into a polymeric analog (polymeric plerixafor, PP). With the goal of gaining a better understanding of how overall charge and hydrophilicity affect renal accumulation of PP, we have synthesized PP copolymers containing hydroxyl, carboxyl, primary amine, and alkyl moieties using Michael-type addition copolymerization. All synthesized copolymers showed excellent CXCR4-binding and inhibiting ability in vitro and improved cellular uptake in hypoxia-reoxygenation stimulated mouse tubule cells. Analysis of serum protein binding revealed that polymers with hydroxyl group modification showed the least amount of protein binding. Biodistribution of the polymers was tested in a unilateral ischemia reperfusion-induced AKI mouse model. The results showed significant differences in accumulation in the injured kidneys depending on the net charge and hydrophilicity of the polymers. The findings of this study will guide the development of polymeric drug carriers for targeted delivery to injured kidneys for better AKI therapy.

Self-Assembled Alkylated Polyamine Analogs as Supramolecular Anticancer Agents.

Conformationally restrained polyamine analog PG11047 is a well-known drug candidate that modulates polyamine metabolism and inhibits cancer cell growth in a broad spectrum of cancers. Here, we report a structure-activity relationship study of the PG11047 analogs (HPGs) containing alkyl chains of varying length, while keeping the unsaturated spermine backbone unchanged. Synthesis of higher symmetrical homologues was achieved through a synthetic route with fewer steps than the previous route to PG11047. The amphiphilic HPG analogs underwent self-assembly and formed spherically shaped nanoparticles whose size increased with the hydrophobic alkyl group's increasing chain length. Assessment of the in vitro anticancer activity showed more than an eight-fold increase in the cancer cell inhibition activity of the analogs with longer alkyl chains compared to PG11047 in human colon cancer cell line HCT116, and a more than ten-fold increase in human lung cancer cell line A549. Evaluation of the inhibition of spermine oxidase (SMOX) showed no activity for PG11047, but activity was observed for its higher symmetrical homologues. Comparison with a reference SMOX inhibitor MDL72527 showed nine-fold better activity for the best performing HPG analog.

Intraperitoneal siRNA Nanoparticles for Augmentation of Gemcitabine Efficacy in the Treatment of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma is a deadly disease with limited treatment options due to late diagnosis and resistance to conventional chemotherapy. Among emerging therapeutic targets, the CXCR4 chemokine receptor and polo-like kinase 1 (PLK1) play critical roles in the progression, metastasis, and chemoresistance of pancreatic cancer. Here, we tested the hypothesis that combining CXCR4 inhibition by a polymeric CXCR4 antagonist PAMD-CHOL with PLK1 knockdown by siRNA will enhance the therapeutic effect of gemcitabine (GEM) in the orthotopic model of metastatic pancreatic cancer. We formulated nanoparticles with cholesterol-modified PAMD and siPLK1 and found strong synergism when combined with GEM treatment in vitro in both murine and human pancreatic cancer cell lines. The biodistribution of the nanoparticles in orthotopic pancreatic cancer models revealed strong accumulation in primary and metastatic tumors, with limited hepatic disposition. The cholesterol-containing nanoparticles showed not only increased tumor accumulation than the cholesterol-lacking control but also deeper penetration into the tumors. In a therapeutic study in vivo, the triple combination of PAMD-CHOL/siPLK1 and GEM showed superior anticancer activity when compared with single and dual combination controls. In conclusion, PAMD-CHOL/siPLK1 nanoparticles synergistically enhance anticancer activity of GEM in pancreatic cancer and represent a promising addition to the treatment arsenal.

Proximal tubule cyclophilin D regulates fatty acid oxidation in cisplatin-induced acute kidney injury.

Regardless of the etiology, acute kidney injury involves aspects of mitochondrial dysfunction and ATP depletion. Fatty acid oxidation is the preferred energy source of the kidney and is inhibited during acute kidney injury. A pivotal role for the mitochondrial matrix protein, cyclophilin D in regulating overall cell metabolism is being unraveled. We hypothesize that mitochondrial interaction of proximal tubule cyclophilin D and the transcription factor PPARα modulate fatty acid beta-oxidation in cisplatin-induced acute kidney injury. Cisplatin injury resulted in histological and functional damage in the kidney with downregulation of fatty acid oxidation genes and increase of intrarenal lipid accumulation. However, proximal tubule-specific deletion of cyclophilin D protected the kidneys from the aforementioned effects. Mitochondrial translocation of PPARα, its binding to cyclophilin D, and sequestration led to inhibition of its nuclear translocation and transcription of PPARα-regulated fatty acid oxidation genes during cisplatin-induced acute kidney injury. Genetic or pharmacological inhibition of cyclophilin D preserved nuclear expression and transcriptional activity of PPARα and prevented the impairment of fatty acid oxidation and intracellular lipid accumulation. Docking analysis identified potential binding sites between PPARα and cyclophilin D. Thus, our results indicate that proximal tubule cyclophilin D elicits impaired mitochondrial fatty acid oxidation via mitochondrial interaction between cyclophilin D and PPARα. Hence, targeting their interaction may be a potential therapeutic strategy to prevent energy depletion, lipotoxicity and cell death in cisplatin-induced acute kidney injury.

Combined Hydrophobization of Polyethylenimine with Cholesterol and Perfluorobutyrate Improves siRNA Delivery.

Polyethylenimine (PEI) is a promising delivery vector of nucleic acids, but cytotoxicity and only moderate transfection efficacy with small RNAs limit its applications. Here we hypothesized that hydrophobization of PEI by combined modification with perfluorinated moieties (F) and cholesterol (Ch) will help in addressing both the cytotoxicity and siRNA delivery efficacy. To test the hypothesis, we synthesized a series of copolymers (F-PEI-Ch) by modifying PEI by reaction with heptafluorobutyric anhydride and cholesteryl chloroformate. We investigated and compared the effect of the modifications on siRNA delivery in vitro and in vivo. We found that the F-PEI-Ch copolymers assembled into micellar structures and that the copolymer with the highest Ch content exhibited the best siRNA delivery performance, including lower cytotoxicity, enhanced cell uptake, improved endosomal escape, and the best siRNA silencing efficacy in vitro and in vivo when compared with control PEI, F-PEI, and PEI-Ch. Overall, hydrophobization of PEI with a combination of cholesterol and superhydrophobic perfluorinated moieties represents a promising approach to the design of siRNA delivery vectors with decreased toxicity and enhanced transfection efficacy.

Increased Survival by Pulmonary Treatment of Established Lung Metastases with Dual STAT3/CXCR4 Inhibition by siRNA Nanoemulsions.

Lung metastasis is a common and deadly occurrence in many types of solid tumors. Chemokine receptor CXCR4 and transcription factor signal transducer and activator of transcription 3 (STAT3) are among potential therapeutic targets in lung metastatic cancer. Both CXCR4 and STAT3 play important roles in the proliferation, angiogenesis, and metastasis of cancer cells. Here, we report on the development of a pulmonary delivery (p.d.) system based on perfluorocarbon (PFC) nanoemulsions for combined delivery of a partially fluorinated polymeric CXCR4 antagonist (FM) and anti-STAT3 small interfering RNA (siRNA). We have prepared FM-stabilized PFC (FM@PFC) as a delivery system of therapeutic siRNA adsorbed on the surface of the emulsion. These FM@PFC/siRNA nanoemulsions inhibited both CXCR4 and STAT3, as demonstrated by effective anti-invasive ability in vitro and related antimetastatic activity in vivo. The combined nanoemulsions provided a comprehensive anticancer effect in the model of established lung metastasis of breast carcinoma, which was dependent on induction of cancer cell apoptosis, anti-angiogenic effect, anti-invasive activity, and overcoming of the immunosuppressive tumor microenvironment. Direct comparison with intravenous (i.v.) injection showed superior activity of pulmonary administration as indicated by significantly increased animal survival. Overall, this work established the suitability of the PFC nanoemulsions for p.d. of combination anticancer treatments and as a promising method to treat lung metastasis.

Stereotactic Body Radiation Therapy Versus Nonradiotherapeutic Ablative Procedures (Laser/Cryoablation and Electrocautery) for Early-Stage Non-Small Cell Lung Cancer.

BACKGROUND: Despite the fact that stereotactic body radiation therapy (SBRT) is the only recommended first-line therapy for inoperable early-stage non-small cell lung cancer (NSCLC), several thermal ablative procedures (TAPs; defined herein as laser/cryoablation and electrocautery) are available. Studies showing outcomes of these procedures and how they compare with SBRT are scarce. We sought to evaluate the comparative efficacy of SBRT versus TAPs using the National Cancer Database (NCDB). METHODS: The NCDB was queried for patients with early-stage NSCLC who did not undergo surgical resection. Treatment-specific inclusion criteria were applied to select for patients receiving either TAPs or SBRT. Univariate logistic regression and Cox proportional hazards modeling were performed, and Kaplan-Meier curves were generated. Serial propensity matches were performed using a modified greedy 8→n matching 1:1 algorithm. RESULTS: A total of 27,734 patients were analyzed; 26,725 underwent SBRT and 1,009 underwent TAPs. Patients who received SBRT were older and more likely to have clinical stage IB (vs IA) disease. Despite this, SBRT was associated with longer median overall survival (mOS; 37.7 vs 33.5 months; P=.001) and 1-, 2-, and 5-year OS rates compared with the TAPs cohort (86.7% vs 83.1%, 67.5% vs 62.7%, and 30.6% vs 26.9%, respectively; P=.001). Upon propensity matching, improved OS with SBRT remained, with a mOS of 40.4 versus 33.4 months and 1-, 2-, and 5-year OS rates of 89.0% versus 82.9%, 69.7% versus 62.7%, and 34.4% versus 26.4%, respectively (P=.003). CONCLUSIONS: Despite being associated with more higher-risk factors, SBRT was associated with higher OS compared with TAPs for treatment of nonoperative patients diagnosed with early-stage NSCLC. However, causation cannot be implied owing to the inherent limitations of large heterogeneous datasets such as the NCDB.

Conjugate Polyplexes with Anti-Invasive Properties and Improved siRNA Delivery In Vivo.

This study reports on a simple method to prepare siRNA-polycation conjugate polyplexes by in situ thiol-disulfide exchange reaction. The conjugate polyplexes are prepared using thiol-terminated siRNA and a bioreducible branched polycationic inhibitor of the CXCR4 chemokine receptor (rPAMD). The rPAMD-SS-siRNA conjugate polyplexes exhibit improved colloidal stability and resistance against disassembly with heparin, serum, and physiological salt concentrations when compared with control conventional rPAMD/siRNA polyplexes. Coating the polyplexes with human serum albumin masks the positive surface charge and contributes to the enhanced in vitro gene silencing and improved safety in vivo. The conjugate polyplexes display improved in vivo reporter gene silencing following intravenous injection in tumor-bearing mice. Because the conjugate polyplexes retained the ability of rPAMD to inhibit CXCR4 and restrict cancer cell invasion, the developed systems show promise for future combination anti-metastatic siRNA therapies of cancer.

Polymeric Prodrugs Targeting Polyamine Metabolism Inhibit Zika Virus Replication.

The Zika virus (ZIKV) is primarily transmitted via an infected mosquito bite, during sexual intercourse, or in utero mother to child transmission. When a fetus is infected, both neurological malformations and deficits in brain development are frequently manifested. As such, there is a need for vaccines or drugs that may be used to cure ZIKV infections. Metabolic pathways play a crucial role in cell differentiation and development. More importantly, polyamines play a key role in replication and translation of several RNA viruses, including ZIKV, Dengue virus, and Chikungunya virus. Here, we present polyamine analogues (BENSpm and PG11047) and their corresponding polymer prodrug derivatives for inhibiting ZIKV infection by intersecting with polyamine catabolism pathways. We tested the compounds against ZIKV African (MR766) and Asian (PRVABC59) strains in human kidney epithelial (Vero) and glioblastoma derived (SNB-19) cell lines. Our results demonstrate potent inhibition of ZIKV viral replication in both cell lines tested. This antiviral effect was mediated by the upregulation of two polyamine catabolic enzymes, spermine oxidase, and spermidine (SMOX)/spermine N1-acetyltransferase (SAT1) as apparent reduction of the ZIKV infection following heterologous expression of SMOX and SAT1. On the basis of these observations, we infer potential use of these polyamine analogues to treat ZIKV infections.

Reversible Covalent Cross-Linked Polycations with Enhanced Stability and ATP-Responsive Behavior for Improved siRNA Delivery.

Cationic polyplex as commonly used nucleic acid carriers faced several shortcomings, such as high cytotoxicity, low serum stability, and slow cargo release at the target site. The traditional solution is covering a negative charged layer (e.g., hyaluronic acid, HA) via electrostatic interaction. However, it was far from satisfactory for the deshielding by physiological anions in circulation (e.g., serum proteins, phosphate). In this study, we proposed a new strategy of reversible covalent cross-linking to enhance stability in circulation and enable stimuli-disassembly of polyplexes in tumor cells. Here, 25k polyethylenimine (PEI) was chosen as model polycations for veriying the hypothesis. HA-PEI conjugation was formed by the cross-linking of adenosine triphosphate grafted HA (HA-ATP) with phenylboronic acid grafted PEI (PEI-PBA) via the chemical reaction between PBA and ATP. Compared with noncovalent polyplex by electrostatic interaction (HA/PEI), HA-PEI exhibited much better colloidal stability and serum stability. The covered HA-ATP layer on PEI-PBA could maintain stable in the absence of physiological anions, while HA layer on PEI in HA/PEI group showed obvious detachment after anion's competition. More importantly, the covalent cross-linking polyplex could selectively release siRNA in the ATP rich environment of cytosol and significantly improve siRNA silence. Besides, the covalent cross-linking with HA-ATP could effectively reduce the cytotoxicity of cationic polyplex, improve the uptake by B61F10 cells and promote the endosomal escape. Consequently, this strategy of HA-PEI conjugation significantly enhanced the siRNA transfection in the absence or presence of FBS (fetal bovine serum) on B16F10 cells and CHO cells. Taken together, the reversible covalent cross-linking approach shows obvious superiority compared with the noncovalent absorption strategy. It held great potential to be developed to polish up the performance of cationic polyplex on reducing the toxicity, enhancing the serum tolerance and achieving controlled release of siRNA at target site.

Cyclam-Modified PEI for Combined VEGF siRNA Silencing and CXCR4 Inhibition To Treat Metastatic Breast Cancer.

Chemokine receptor CXCR4 plays an important role in cancer cell invasion and metastasis. Recent findings suggest that anti-VEGF therapies upregulate CXCR4 expression, which contributes to resistance to antiangiogenic therapies. Here, we report the development of novel derivatives of polyethylenimine (PEI) that effectively inhibit CXCR4 while delivering anti-VEGF siRNA. PEI was alkylated with different amounts of a CXCR4-binding cyclam derivative to prepare PEI-C. Modification with the cyclam derivatives resulted in a considerable decrease in cytotoxicity when compared with unmodified PEI. All the PEI-C showed significant CXCR4 antagonism and the ability to inhibit cancer cell invasion. Polyplexes of PEI-C prepared with siVEGF showed effective silencing of the VEGF expression in vitro. In vivo testing in a syngeneic breast cancer model showed promising antitumor and antimetastatic activity of the PEI-C/siVEGF polyplexes. Our data demonstrate the feasibility of using PEI-C as a carrier for simultaneous VEGF silencing and CXCR4 inhibition for enhanced antiangiogenic cancer therapies.

Histone Deacetylase Inhibitor (HDACi) Conjugated Polycaprolactone for Combination Cancer Therapy.

The short chain fatty acid, 4-phenylbutyric acid (PBA), is used for the treatment of urea cycle disorders and sickle cell disease as an endoplasmic reticulum stress inhibitor. PBA is also known as a histone deacetylase inhibitor (HDACi). We report here the effect of combination therapy on HeLa cancer cells using PBA as the HDACi together with the anticancer drug, doxorubicin (DOX). We synthesized γ-4-phenylbutyrate-ε-caprolactone monomer which was polymerized to form poly(γ-4-phenylbutyrate-ε-caprolactone) (PPBCL) homopolymer using NdCl3·3TEP/TIBA (TEP = triethyl phosphate, TIBA = triisobutylaluminum) catalytic system. DOX-loaded nanoparticles were prepared from the PPBCL homopolymer using poly(ethylene glycol) as a surfactant. An encapsulation efficiency as high as 88% was obtained for these nanoparticles. The DOX-loaded nanoparticles showed a cumulative release of >95% of DOX at pH 5 and 37 °C within 12 h, and PBA release was monitored by 1H NMR spectroscopy. The efficiency of the combination therapy can notably be seen in the cytotoxicity study carried out on HeLa cells, where only ∼20% of cell viability was observed after treatment with the DOX-loaded nanoparticles. This drastic cytotoxic effect on HeLa cells is the result of the dual action of DOX and PBA on the DNA strands and the HDAC enzymes, respectively. Overall, this study shows the potential of combination treatment with HDACi and DOX anticancer drug as compared to the treatment with an anticancer drug alone.

Near-infrared light-activated IR780-loaded liposomes for anti-tumor angiogenesis and Photothermal therapy.

Tumor angiogenesis is a key step in the process of tumor development, and antitumor angiogenesis has a profound influence on tumor growth. Herein we report a dual-function drug delivery system comprising a Near-infrared (NIR) dye and an anti-angiogenic drug within liposomes (Lip-IR780-Sunitinib) for enhanced antitumor therapy. The hydrophobic NIR dye IR780 was loaded into the liposome phospholipid bilayer, and the bilayer would be disrupted by laser irradiation so that anti-angiogenic drug sunitinib release would be activated remotely at the tumor site. The released hydrophilic sunitinib could potentially target multiple VEGF receptors on the tumor endothelial cell surface to inhibit angiogenesis. Meanwhile, IR780-loaded liposomes kill the cancer cells by photothermal therapy. Lip-IR780-Sunitinib exhibited enhanced anti-tumor and anti-angiogenic effects in vitro and in vivo. This system facilitates easy and controlled release of cargos to achieve anti-tumor angiogenesis and photothermal therapy.

Pulmonary delivery of polyplexes for combined PAI-1 gene silencing and CXCR4 inhibition to treat lung fibrosis.

This report describes the development of polyplexes based on CXCR4-inhibiting poly(ethylenimine) derivative (PEI-C) for pulmonary delivery of siRNA to silence plasminogen activator inhibitor-1 (siPAI-1) as a new combination treatment of pulmonary fibrosis (PF). Safety and delivery efficacy of the PEI-C/siPAI-1 polyplexes was investigated in vitro in primary lung fibroblasts isolated from mice with bleomycin-induced PF. Biodistribution analysis following intratracheal administration of fluorescently labeled polyplexes showed prolonged retention in the lungs. Treatment of mice with bleomycin-induced PF using the PEI-C/siPAI-1 polyplexes resulted in a significant down-regulation of the PAI-1 expression and decreased collagen deposition in the lung. The results of this study provide first evidence of the potential benefits of combined inhibition of CXCR4 and PAI-1 in the pulmonary treatment of PF.

Dual-Function Polymeric HPMA Prodrugs for the Delivery of miRNA.

An HPMA-based polymeric prodrug of a CXCR4 antagonist, AMD3465 (P-SS-AMD), was developed as a dual-function carrier of therapeutic miRNA. P-SS-AMD was synthesized by a copolymerization of HPMA with a methacrylamide monomer in which the AMD3465 was attached via a self-immolative disulfide linker. P-SS-AMD showed effective release of the parent AMD3465 drug following treatment with intracellular levels of glutathione (GSH). The AMD3465 was released in the cells and exhibited functional CXCR4 antagonism, demonstrated by inhibition of the CXCR4-mediated cancer cell invasion. Due to its cationic character, P-SS-AMD could form polyplexes with miRNA and mediate efficient transfection of miR-200c mimics to downregulate expression of a downstream target ZEB-1 in cancer cells. The combined P-SS-AMD/miR-200c polyplexes showed improved ability to inhibit cancer cell migration when compared with individual treatments. The reported findings validate P-SS-AMD as a dual-function delivery vector that can simultaneously deliver a therapeutic miRNA and function as a polymeric prodrug of CXCR4 antagonist.

Chloroquine-Modified Hydroxyethyl Starch as a Polymeric Drug for Cancer Therapy.

Hydroxyethyl starch (HES) is a clinically used polysaccharide colloidal plasma volume expander. The goal of this study was to synthesize HES modified with hydroxychloroquine (HCQ) as a novel polymeric drug with the ability to inhibit the invasive character of pancreatic cancer (PC) cells. HES was conjugated with HCQ using a simple carbonyldiimidazole coupling to prepare Chloroquine-modified HES (CQ-HES). CQ-HES with various degrees of HCQ substitution were synthesized and characterized. Atomic force microscopy was used to demonstrate a pH-dependent assembly of CQ-HES into well-defined nanoparticles. In vitro studies in multiple PC cell lines showed CQ-HES to have a similar toxicity profile as HCQ. Confocal microscopy revealed the propensity of CQ-HES to localize to lysosomes and mechanistic studies confirmed the ability of CQ-HES to inhibit autophagy in PC cells. Further studies demonstrated a greatly enhanced ability of CQ-HES to inhibit the migration and invasion of PC cells when compared with HCQ. The enhanced inhibitory actions of CQ-HES compared to HCQ appeared to arise in part from the increased inhibition of ERK and Akt phosphorylation. We found no significant HCQ release from CQ-HES, which confirmed that the observed activity was due to the action of CQ-HES as a polymeric drug. Due to its promising ability to block cancer cell invasion and the ability to form nanoparticles, CQ-HES has the potential as a drug delivery platform suitable for future development with chemotherapeutics to establish novel antimetastatic treatments.

CXCR4-Targeted and Redox Responsive Dextrin Nanogel for Metastatic Breast Cancer Therapy.

The unsatisfied results of cancer therapy are caused by many issues and metastasis of cancer cells is one of the major challenge. It has been reported that inhibiting the SDF1/CXCR4 interaction can significantly reduce the metastasis of breast cancer cells to regional lymph nodes and lung. Herein, a nanogel system equipped with the FDA-approved CXCR4 antagonist AMD3100 was developed and evaluated for its combined antimetastatic and tumor targeting effects. Briefly, a bioreducible cross-linked dextrin nanogel (DNG) coated with AMD3100 was designed to possess multiple functions, including CXCR4 chemokine targeting, inhibition of tumor metastasis, and reduction-responsive intracellular release of doxorubicin (DOX) to reduce the cells proliferation. The in vitro results confirmed that the DOX-loaded AMD3100-coated dextrin nanogel (DOX-AMD-DNG) was more effectively taken up by 4T1 breast cancer cells than DOX-DNG and was significantly more cytotoxic to 4T1 cells than DOX-DNG. In biodistribution studies, the stronger fluorescence intensity of Cy7-AMD-DNG than Cy7-DNG further confirmed that AMD3100 mediated tumor targeting in vivo. AMD3100-coated DOX-DNG also exhibited a distinct antimetastatic effect and CXCR4 antagonistic activity by inhibiting CXCR4-mediated cell invasion in 4T1 and U2OS cells. Moreover, DOX-AMD-DNG displayed superior anticancer activity and antimetastatic effects in orthotopic breast cancer-bearing Balb/C mice. In summary, the multifunctional DOX-AMD-DNG can effectively target the tumor site and dually impede cancer progression and metastasis.