Antiangiogenic and anticancer effect of an orally active low molecular weight heparin conjugates and its application to lung cancer chemoprevention

Preparation of chitosan nanoparticles for simultaneous drug delivery of dacarbazine and enoxaparin in melanoma

The aim of this study was to investigate the anti-melanoma and anti-angiogenic effects of enoxaparin surface-coated dacarbazine-loaded chitosan nanoparticles (Enox-Dac-Chi NPs). The prepared Enox-Dac-Chi NPs had a particle size of 367.95 ± 1.84 nm, zeta potential of -7.12 ± 0.25 mV, efficiency of drug loading (DL%) of 73.90 ± 3.84 %, and attached enoxaparin percentage of 98.53 ± 0.96 %. Both drugs had extended-release profiles and approximately 96 % of enoxaparin and 67 % dacarbazine were released within 8 h. The Enox-Dac-Chi NPs with IC₅₀ of 59.60 ± 1.25 μg/ml were the most cytotoxic against melanoma cancer cells compared with chitosan nanoparticles containing only dacarbazine (Dac-Chi NPs) and free dacarbazine. There was no significant difference between the cellular uptake of Chi NPs and enoxaparin coated Chi NPs (Enox-Chi NPs) in B16F10 cells. Enox-Chi NPs with an average anti-angiogenic score of 1.75 ± 0.125 had more anti-angiogenic effect than enoxaparin. The results showed that simultaneous delivery of dacarbazine and enoxaparin by chitosan nanoparticles can enhance the anti-melanoma effect of dacarbazine. Additionally, enoxaparin can prevent the melanoma metastasis by its anti-angiogenic activity. Thus, the designed nanoparticles can be introduced as effective drug delivery vehicles for the treatment and prevention of metastatic melanoma.

Direct thrombin inhibitors as alternatives to heparin to preserve lung growth and function in a murine model of compensatory lung growth

Infants with congenital diaphragmatic hernia (CDH) may require cardiopulmonary bypass and systemic anticoagulation. Expeditious lung growth while on bypass is essential for survival. Previously, we demonstrated that heparin impairs lung growth and function in a murine model of compensatory lung growth (CLG). We investigated the effects of the direct thrombin inhibitors (DTIs) bivalirudin and argatroban. In vitro assays of lung endothelial cell proliferation and apoptosis were performed. C57BL/6 J mice underwent left pneumonectomy and subcutaneous implantation of osmotic pumps. Pumps were pre-loaded with normal saline (control), bivalirudin, argatroban, or heparin and outcomes were assessed on postoperative day 8. Heparin administration inhibited endothelial cell proliferation in vitro and significantly decreased lung volume in vivo, while bivalirudin and argatroban preserved lung growth. These findings correlated with changes in alveolarization on morphometric analysis. Treadmill exercise tolerance testing demonstrated impaired exercise performance in heparinized mice; bivalirudin/argatroban did not affect exercise tolerance. On lung protein analysis, heparin decreased angiogenic signaling which was not impacted by bivalirudin or argatroban. Together, this data supports the use of DTIs as alternatives to heparin for systemic anticoagulation in CDH patients on bypass. Based on this work, clinical studies on the impact of heparin and DTIs on CDH outcomes are warranted.

An Overview of Antitumour Activity of Polysaccharides

Cancer incidence and mortality are rapidly increasing worldwide; therefore, effective therapies are required in the current scenario of increasing cancer cases. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, and they have become the focus of current antitumour drug research owing to their significant antitumour effects. In addition to the direct antitumour activity of some natural polysaccharides, their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in natural polysaccharides and polysaccharide-based nanomedicines for cancer therapy.

Development of Alectinib-Suspended SNEDDS for Enhanced Solubility and Dissolution

Alectinib hydrochloride (ALH), a tyrosine kinase inhibitor, is a practically water-insoluble drug classified as BCS class IV. The present study aimed to develop novel suspended self-nanoemulsifying drug delivery system (Su-SNEDDS) to enhance the solubility and dissolution rate. The Su-SNEDDS was prepared by saturation and suspension of ALH in SNEDDS with ultrasonication energy. According to evaluation by the dispersion test and the results of particle size analysis, the selected SNEDDS composed of Kolliphor HS 15 and Capmul MCM C8 as surfactant and oil, respectively, showed a complete dissolution within 30 min. However, the SNEDDS loaded and solubilized only small amount of ALH (<0.6%, w/w). On the other hand, 10% ALH-loaded Su-SNEDDS containing small and micronized ALH particles of <5 μm had about 20-fold higher ALH-loading% than the SNEDDS and reached a 100% dissolution rate within 30 min in 1% sodium lauryl sulfate (SLS) pH 1.2 buffer. In the dispersion test and microscopic observation, micronized ALH particles in the Su-SNEDDS were readily dispersed in the dissolution medium with spontaneous nanoemulsion formation and instantly solubilized with the aid of SLS. Taken together, our results suggest that the Su-SNEDDS would be a potent oral dosage form to enhance the solubilization and dissolution rate of ALH in a new technological way.

Platycodin D Inhibits Vascular Endothelial Growth Factor-Induced Angiogenesis by Blocking the Activation of Mitogen-Activated Protein Kinases and the Production of Interleukin-8

Platycodin D is a major constituent in the root of Platycodon grandiflorum and has diverse pharmacologic activities, including anti-inflammatory, anti-allergic, and antitumor activities. Vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) are potent angiogenic factors and contribute to tumor angiogenesis by directly and indirectly promoting angiogenic processes, including the proliferation, adhesion, migration, and tube formation of endothelial cells. Here, we found that platycodin D at noncytotoxic concentrations inhibited VEGF-induced proliferation, adhesion to the extracellular matrix proteins fibronectin and vitronectin, chemotactic motility, and tube formation of human umbilical vein endothelial cells (HUVECs). Platycodin D reduced the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) and the secretion of IL-8 in VEGF-stimulated HUVECs. Moreover, platycodin D inhibited tube formation and the phosphorylation of ERK and p38 in IL-8-stimulated HUVECs. The in vitro anti-angiogenic activity of platycodin D was confirmed by in vivo experimental models. Platycodin D inhibited the formation of new blood vessels into mouse Matrigel plugs with VEGF or IL-8. In mice injected with MDA-MB-231 human breast cancer cells, orally administered platycodin D inhibited tumor growth, the number of CD34 [Formula: see text]vessels, and the expression of VEGF and IL-8. Taken together, platycodin D directly and indirectly prevents VEGF-induced and IL-8-induced angiogenesis by blocking the activation of mitogen-activated protein kinases (MAPKs). Platycodin D may be beneficial for the prevention or treatment of tumor angiogenesis and angiogenesis-related human diseases.

Anticancer Effect of Heparin-Taurocholate Conjugate on Orthotopically Induced Exocrine and Endocrine Pancreatic Cancer

Simple Summary

Pancreatic cancer has a less than 9% 5-year survival rate among patients because it is very difficult to detect and diagnose early. Combinatorial chemotherapy with surgery or radiotherapy is a potential remedy to treat pancreatic cancer. However, these strategies still have side effects such as hair loss, skin soreness and fatigue. To overcome these side effects, angiogenesis inhibitors such as sunitinib are used to deliver targeted blood vessels around tumor tissues, including pancreatic cancer tumors. It is still controversial whether antiangiogenesis therapy is sufficient to treat pancreatic cancer. So far, many scientists have not been focused on the tumor types of pancreatic cancer when they have developed antipancreatic cancer medication. Here, we used heparin–taurocholate (LHT) as an anticancer drug to treat pancreatic cancer through inhibition of angiogenic growth factors. In this study, we examined the anticancer efficacy of LHT on various types of pancreatic cancer in an orthotopic model.

Abstract

Pancreatic cancers are classified based on where they occur, and are grouped into those derived from exocrine and those derived from neuroendocrine tumors, thereby experiencing different anticancer effects under medication. Therefore, it is necessary to develop anticancer drugs that can inhibit both types. To this end, we developed a heparin–taurocholate conjugate, i.e., LHT, to suppress tumor growth via its antiangiogenic activity. Here, we conducted a study to determine the anticancer efficacy of LHT on pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumor (PNET), in an orthotopic animal model. LHT reduced not only proliferation of cancer cells, but also attenuated the production of VEGF through ERK dephosphorylation. LHT effectively reduced the migration, invasion and tube formation of endothelial cells via dephosphorylation of VEGFR, ERK1/2, and FAK protein. Especially, these effects of LHT were much stronger on PNET (RINm cells) than PDAC (PANC1 and MIA PaCa-2 cells). Eventually, LHT reduced ~50% of the tumor weights and tumor volumes of all three cancer cells in the orthotopic model, via antiproliferation of cancer cells and antiangiogenesis of endothelial cells. Interestingly, LHT had a more dominant effect in the PNET-induced tumor model than in PDAC in vivo. Collectively, these findings demonstrated that LHT could be a potential antipancreatic cancer medication, regardless of pancreatic cancer types.

DW14383 is an irreversible pan-FGFR inhibitor that suppresses FGFR-dependent tumor growth in vitro and in vivo

Fibroblast growth factor receptor (FGFR) is a promising anticancer target. Currently, most FGFR inhibitors lack sufficient selectivity and have nonnegligible activity against kinase insert domain receptor (KDR), limiting their feasibility due to the serious side effects. Notably, compensatory activation occurs among FGFR1-4, suggesting the urgent need to develop selective pan-FGFR1-4 inhibitors. Here, we explored the antitumor activity of DW14383, a novel irreversible FGFR1-4 inhibitor. DW14383 exhibited equivalently high potent inhibition against FGFR1, 2, 3 and 4, with IC₅₀ values of less than 0.3, 1.1, less than 0.3, and 0.5 nmol/L, respectively. It is a selective FGFR inhibitor, exhibiting more than 1100-fold selectivity for FGFR1 over recombinant KDR, making it one of the most selective FGFR inhibitors over KDR described to date. Furthermore, DW14383 significantly inhibited cellular FGFR1-4 signaling, inducing G1/S cell cycle arrest, which in turn antagonized FGFR-dependent tumor cell proliferation. In contrast, DW14383 had no obvious antiproliferative effect against cancer cell lines without FGFR aberration, further confirming its selectivity against FGFR. In representative FGFR-dependent xenograft models, DW14383 oral administration substantially suppressed tumor growth by simultaneously inhibiting tumor proliferation and angiogenesis via inhibiting FGFR signaling. In summary, DW14383 is a promising selective irreversible pan-FGFR inhibitor with pan-tumor spectrum potential in FGFR1-4 aberrant cancers, which has the potential to overcome compensatory activation among FGFR1-4.

Osteogenic and Angiogenic Properties of Heparin as a System for Delivery of Biomolecules for Bone Bioengineering: a Brief Critical Review

The review considers complex, controversial, and individual effects of heparin and its derivatives on the bone and circulatory systems in dependence of the dose, the state of the cells and tissues of the recipient. General data on the anticoagulant activity of heparin and its derivatives are presented; special attention is paid to the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis. We also discuss the ability of heparin to bind osteogenic and angiogenic biomolecules in the context of the development of systems for their delivery and sustained controlled release and propose a schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering.

[Osteogenic and angiogenic properties of heparin as a system of biomolecule delivery for bone bioengineering: a brief critical review]

The review discusses the complex, ambiguous and individual effects of heparin and its derivatives on the bone and circulatory systems, in dependence of the dosage, the state of the cells and tissues of recipients. General data on the anticoagulant activity of heparin and its derivatives are presented; aspects of the effect of heparin on mesenchymal cells and tissues and its role in angiogenesis are considered in details. Particular attention is paid to the ability of heparin to bind osteogenic and angiogenic biomolecules: thus us especially important for the development of systems for their delivery and sustained controlled release. A schematic representation of the positive and side effects of heparin as a delivery system for biomolecules in tissue engineering is proposed.

Implications of venous thromboembolism GWAS reported genetic makeup in the clinical outcome of ovarian cancer patients

Ovarian cancer (OC) represents the most lethal gynaecological neoplasia. Conversely, venous thromboembolism (VTE) and OC are intricately connected, with many haemostatic components favouring OC progression. In light of this bilateral relationship, genome-wide association studies (GWAS) have reported several single-nucleotide polymorphisms (SNPs) associated with VTE risk that could be used as predictors of OC clinical outcome for better therapeutic management strategies. Thus, the present study aimed to analyse the impact of VTE GWAS-identified SNPs on the clinical outcome of 336 epithelial ovarian cancer (EOC) patients. Polymorphism genotyping was performed using the TaqMan^® Allelic Discrimination methodology. Carriers with the ZFPM2 rs4734879 G allele presented a significantly higher 5-year OS, 10-year OS and disease-free survival (DFS) compared to AA genotype patients with FIGO I/II stages (P = 0.009, P = 0.001 and P = 0.003, respectively). Regarding SLC19A2 rs2038024 polymorphism, carriers with the CC genotype presented a significantly lower 5-year OS, 10-year OS and DFS compared to A allele carriers in the same FIGO subgroup (P < 0.001, P = 0.004 and P = 0.005, respectively). As for CNTN6 rs6764623 polymorphism, carriers with the CC genotype presented a significantly lower 5-year OS compared to A allele carriers with FIGO I/II stages (P = 0.015). As for OTUD7A rs7164569, F11 rs4253417 and PROCR rs10747514, no significant impact on EOC patients' survival was observed. However, future studies are required to validate these results and uncover the biological mechanisms underlying our results.

Anti-Angiogenic Effect of Orally Available Pemetrexed for Metronomic Chemotherapy

Metronomic chemotherapy (MCT) is defined as the frequent administration of low-dose chemotherapeutics, without long drug-free periods, with the exertion of antitumor activity exclusively through anti-angiogenic mechanisms. In this study, we have developed an orally available formulation of pemetrexed (PMX) for MCT. PMX was first complexed ionically with N^α-deoxycholyl-l-lysyl-methylester (DCK) as the permeation enhancer. This was followed by dispersion with poloxamer 188 and Labrasol to form the solid oral formulation of PMX (PMX/DCK-OP). PMX/DCK-OP exhibited a 10.6-fold increase in permeability across a Caco-2 cell monolayer compared to PMX alone. This resulted in a 70-fold increase in the oral bioavailability of PMX/DCK-OP in mice over oral PMX alone. In the A549 xenograft model, tumor volume was reduced by 51.1% in the PMX/DCK-OP treated group compared to only 32.8% in the maximum tolerated dose (MTD)-treated group. Furthermore, PMX/DCK-OP exhibited a significant anti-angiogenic effect on the A549 xenograft mice when compared to the MTD-treated group, as indicated by microvessel density quantification for CD-31. In addition, PMX/DCK-OP enhanced the release of an endogenous angiogenesis inhibitor, thrombospondin-1 (TSP-1), into both the blood circulation and the tumor microenvironment. Therefore, due to its oral route of administration, PMX/DCK-OP appears to be a better alternative to the conventional treatment of PMX.

Inhibition of Inflammation-Associated Thrombosis with ROS-Responsive Heparin-DOCA/PVAX Nanoparticles

Inflammation-associated thrombosis is a non-negligible source of mortalities and morbidities worldwide. To manipulate inflammation-associated coagulation, nanoparticles that contain anti-inflammatory polymer (copolyoxalate containing vanillyl alcohol, PVAX) and anti-thrombotic heparin derivative deoxycholic acid (Hep-DOCA) are prepared. The strategy takes advantage of the reducted side effects of heparin through heparin conjugation, achievement of long-term anti-inflammation by inflammation-trigged release of anti-inflammatory agents, and formation of PVAX/heparin-DOCA nanoparticles by co-self-assembly. It is demonstrated that the Hep-DOCA conjugate and PVAX are synthesized successfully; PVAX and Hep-DOCA nanodrugs (HDP) are obtained by co-assembly; the HDP nanoparticles effectively reduce the inflammation and coagulation without inducing lethal bleeding both in vivo and in vitro. The method provided here is versatile and effective, which paves new way to develop nanodrugs to treat inflammation-associated thrombosis safely.

LMWH and its derivatives represent new rational for cancer therapy: construction strategies and combination therapy

Low-molecular-weight heparin (LMWH) has attracted increasing attention as a tumor treatment because of its board range of physiological functions. Over the past decade, diverse LMWH derivatives have increased the variety of antitumor strategies available, serving not only as anti-tumor agents, but also as drug delivery platforms. In this review, we introduce the basic strategy for structural modification of LMWH to attenuate its antitumor activity while reducing its risk of bleeding and immune responses, as well as highlighting current applications of LMWH and its derivatives in cancer therapy. We select representative drug delivery systems involving LMWH derivatives and discuss the construction principles and therapeutic effects associated with their use. We also analyze progress made in the development of antitumor combination therapies, in which LMWH has shown synergistic or combined effects with other treatment strategies.

The non-anticoagulant promise of heparin and its mimetics

Heparin, the widely used anticoagulant and antithrombotic polysaccharide, has other potential therapeutic uses that arise from its similarity to heparan sulfate. This review provides a brief overview of the most recent developments in this field, paying particular respect to pulmonary and respiratory pharmacology. It has often been said that heparin, with its mimetics and derivatives, shows great promise in the treatment of inflammatory, infectious, and malignant conditions. Difficulties are encountered, however, in translating this promise into worthwhile treatment strategies for patients in some conditions. Several clinical trials of low molecular weight heparins as adjuvant therapy to standard treatment of lung cancers have recently provided no evidence to support the supposed beneficial effects of low molecular weight heparin.

Chitosan sulfate inhibits angiogenesis via blocking the VEGF/VEGFR2 pathway and suppresses tumor growth in vivo

SCTS inhibits neovascularization by blocking the VEGF/VEGFR2 signal pathway and exerts anti-tumor effects.

Heparin impairs angiogenic signaling and compensatory lung growth after left pneumonectomy

Children with hypoplastic lung diseases, such as congenital diaphragmatic hernia, can require life support via extracorporeal membrane oxygenation and systemic anticoagulation, usually in the form of heparin. The role of heparin in angiogenesis and organ growth is inconclusive, with conflicting data reported in the literature. This study aimed to investigate the effects of heparin on lung growth in a model of compensatory lung growth (CLG). Compared to the absence of heparin, treatment with heparin decreased the vascular endothelial growth factor (VEGF)-mediated activation of VEGFR2 and mitogenic effect on human lung microvascular endothelial cells in vitro. Compared to non-heparinized controls, heparinized mice demonstrated impaired pulmonary mechanics, decreased respiratory volumes and flows, and reduced activity levels after left pneumonectomy. They also had lower lung volume, pulmonary septal surface area and alveolar density on morphometric analyses. Lungs of heparinized mice displayed decreased phosphorylation of VEGFR2 compared to the control group, with consequential downstream reduction in markers of cellular proliferation and survival. The use of bivalirudin, an alternative anticoagulant that does not interact with VEGF, preserved lung growth and pulmonary mechanics. These results demonstrated that heparin impairs CLG by reducing VEGFR2 activation. These findings raise concern for the clinical use of heparin in the setting of organ growth or regeneration.

Cisplatin induces the release of extracellular vesicles from ovarian cancer cells that can induce invasiveness and drug resistance in bystander cells

Ovarian cancer has a poor overall survival that is partly caused by resistance to drugs such as cisplatin. Resistance can be acquired as a result of changes to the tumour or due to altered interactions within the tumour microenvironment. Extracellular vesicles (EVs), small lipid-bound vesicles that are loaded with macromolecular cargo and released by cells, are emerging as mediators of communication in the tumour microenvironment. We previously showed that EVs mediate the bystander effect, a phenomenon in which stressed cells can communicate with neighbouring naive cells leading to various effects including DNA damage; however, the role of EVs released following cisplatin treatment has not been tested. Here we show that treatment of cells with cisplatin led to the release of EVs that could induce invasion and increased resistance when taken up by bystander cells. This coincided with changes in p38 and JNK signalling, suggesting that these pathways may be involved in mediating the effects. We also show that EV uptake inhibitors could prevent this EV-mediated adaptive response and thus sensitize cells in vitro to the effects of cisplatin. Our results suggest that preventing pro-tumourigenic EV cross-talk during chemotherapy is a potential therapeutic target for improving outcome in ovarian cancer patients.This article is part of the discussion meeting issue 'Extracellular vesicles and the tumour microenvironment'.

Biomacromolecules as carriers in drug delivery and tissue engineering

Natural biomacromolecules have attracted increased attention as carriers in biomedicine in recent years because of their inherent biochemical and biophysical properties including renewability, nontoxicity, biocompatibility, biodegradability, long blood circulation time and targeting ability. Recent advances in our understanding of the biological functions of natural-origin biomacromolecules and the progress in the study of biological drug carriers indicate that such carriers may have advantages over synthetic material-based carriers in terms of half-life, stability, safety and ease of manufacture. In this review, we give a brief introduction to the biochemical properties of the widely used biomacromolecule-based carriers such as albumin, lipoproteins and polysaccharides. Then examples from the clinic and in recent laboratory development are summarized. Finally the current challenges and future prospects of present biological carriers are discussed.

Overviews on the cellular uptake mechanism of polysaccharide colloidal nanoparticles

Nanoparticulate drug/gene carriers have gained much attention in the past decades because of their versatile and tunable properties. However, efficacy of the therapeutic agents can be further enhanced using naturally occurring materials-based nanoparticles. Polysaccharides are an emerging class of biopolymers; therefore, they are generally considered to be safe, non-toxic, biocompatible and biodegradable. Considering that the target of nanoparticle-based therapeutic strategies is localization of biomedical agents in subcellular compartments, a detailed understanding of the cellular mechanism involved in the uptake of polysaccharide-based nanoparticles is essential for safe and efficient therapeutic applications. Uptake of the nanoparticles by the cellular systems occurs with a process known as endocytosis and is influenced by the physicochemical characteristics of nanoparticles such as size, shape and surface chemistry as well as the employed experimental conditions. In this study, we highlight the main endocytosis mechanisms responsible for the cellular uptake of polysaccharide nanoparticles containing drug/gene.

Anti-angiogenic activity and antitumor efficacy of amphiphilic twin drug from ursolic acid and low molecular weight heparin

Heparin, a potential blood anti-coagulant, is also known for its binding ability to several angiogenic factors through electrostatic interactions due to its polyanionic character. However, the clinical application of heparin for cancer treatment is limited by several drawbacks, such as unsatisfactory therapeutic effects and severe anticoagulant activity that could induce hemorrhaging. Herein, low molecular weight heparin (LMWH) was conjugated to ursolic acid (UA), which is also an angiogenesis inhibitor, by binding the amine group of aminoethyl-UA (UA-NH2) with the carboxylic groups of LMWH. The resulting LMWH-UA conjugate as an amphiphilic twin drug showed reduced anticoagulant activity and could also self-assemble into nanomicelles with a mean particle size ranging from 200-250 nm. An in vitro endothelial tubular formation assay and an in vivo Matrigel plug assay were performed to verify the anti-angiogenic potential of LMWH-UA. Meanwhile, the in vivo antitumor effect of LMWH-UA was also evaluated using a B16F10 mouse melanoma model. LMWH-UA nanomicelles were shown to inhibit angiogenesis both in vitro and in vivo. In addition, the i.v. administration of LMWH-UA to the B16F10 tumor-bearing mice resulted in a significant inhibition of tumor growth as compared to the free drug solutions. These findings demonstrate the therapeutic potential of LMWH-UA as a new therapeutic remedy for cancer therapy.

Redox-sensitive self-assembled nanoparticles based on alpha-tocopherol succinate-modified heparin for intracellular delivery of paclitaxel

To remedy the problems riddled in cancer chemotherapy, such as poor solubility, low selectivity, and insufficient intra-cellular release of drugs, novel heparin-based redox-sensitive polymeric nanoparticles were developed. The amphiphilic polymer, heparin-alpha-tocopherol succinate (Hep-cys-TOS) was synthesized by grafting hydrophobic TOS to heparin using cystamine as the redox-sensitive linker, which could self-assemble into nanoparticles in phosphate buffer saline (PBS) with low critical aggregation concentration (CAC) values ranging from 0.026 to 0.093mg/mL. Paclitaxel (PTX)-loaded Hep-cys-TOS nanoparticles were prepared via a dialysis method, exhibiting a high drug-loading efficiency of 18.99%. Physicochemical properties of the optimized formulation were characterized by dynamic light scattering (DLS), transmission electron microscope (TEM) and differential scanning calorimetry (DSC). Subsequently, the redox-sensitivity of Hep-cys-TOS nanoparticles was confirmed by the changes in size distribution, morphology and appearance after dithiothreitol (DTT) treatment. Besides, the in vitro release of PTX from Hep-cys-TOS nanoparticles also exhibited a redox-triggered profile. Also, the uptake behavior and pathways of coumarin 6-loaded Hep-cys-TOS nanoparticles were investigated, suggesting the nanoparticles could be taken into MCF-7 cells in energy-dependent, caveolae-mediated and cholesterol-dependent endocytosis manners. Later, MTT assays of different PTX-free and PTX-loaded formulations revealed the desirable safety of PTX-free nanoparticles and the enhanced anti-cancer activity of PTX-loaded Hep-cys-TOS nanoparticles (IC₅₀=0.79μg/mL). Apoptosis study indicated the redox-sensitive formulation could induce more apoptosis of MCF-7 cells than insensitive one (55.2% vs. 41.7%), showing the importance of intracellular burst release of PTX. Subsequently, the hemolytic toxicity confirmed the safety of the nanoparticles for intravenous administration. The results indicated the developed redox-sensitive nanoparticles were promising as intracellular drug delivery vehicles for cancer treatment.

Strategies to Overcome Heparins' Low Oral Bioavailability

Even after a century, heparin is still the most effective anticoagulant available with few side effects. The poor oral absorption of heparins triggered the search for strategies to achieve oral bioavailability since this route has evident advantages over parenteral administration. Several approaches emerged, such as conjugation of heparins with bile acids and lipids, formulation with penetration enhancers, and encapsulation of heparins in micro and nanoparticles. Some of these strategies appear to have potential as good delivery systems to overcome heparin’s low oral bioavailability. Nevertheless, none have reached the market yet. Overall, this review aims to provide insights regarding the oral bioavailability of heparin.

Sigma receptor-mediated targeted delivery of anti-angiogenic multifunctional nanodrugs for combination tumor therapy

The potential of low molecular weight heparin (LMWH) in anti-angiogenic therapy has been tempered by poor in vivo delivery to the tumor cell and potentially harmful side effects, such as the risk of bleeding due to heparin's anticoagulant activity. In order to overcome these limitations and further improve the therapeutic effect of LMWH, we designed a novel combination nanosystem of LMWH and ursolic acid (UA), which is also an angiogenesis inhibitor for tumor therapy. In this system, an amphiphilic LMWH-UA (LHU) conjugate was synthesized and self-assembled into core/shell nanodrugs with combined anti-angiogenic activity and significantly reduced anticoagulant activity. Furthermore, DSPE-PEG-AA-modified LHU nanodrugs (A-LHU) were developed to facilitate the delivery of nanodrugs to the tumor. The anti-angiogenic activity of A-LHU was investigated both in vitro and in vivo. It was found that A-LHU significantly inhibited the tubular formation of human umbilical vein endothelial cells (HUVECs) (p<0.01) and the angiogenesis induced by basic fibroblast growth factor (bFGF) in a Matrigel plug assay (p<0.001). More importantly, A-LHU displayed significant inhibition on the tumor growth in B16F10-bearing mice in vivo. The level of CD31 and p-VEGFR-2 expression has demonstrated that the excellent efficacy of antitumor was associated with a decrease in angiogenesis. In conclusion, A-LHU nanodrugs are a promising multifunctional antitumor drug delivery system.

Evasion and interactions of the humoral innate immune response in pathogen invasion, autoimmune disease, and cancer

The humoral innate immune system is composed of three major branches, complement, coagulation, and natural antibodies. To persist in the host, pathogens, such as bacteria, viruses, and cancers must evade parts of the innate humoral immune system. Disruptions in the humoral innate immune system also play a role in the development of autoimmune diseases. This review will examine how Gram positive bacteria, viruses, cancer, and the autoimmune conditions systemic lupus erythematosus and anti-phospholipid syndrome, interact with these immune system components. Through examining evasion techniques it becomes clear that an interplay between these three systems exists. By exploring the interplay and the evasion/disruption of the humoral innate immune system, we can develop a better understanding of pathogenic infections, cancer, and autoimmune disease development.

Heparin/Heparan sulfate proteoglycans glycomic interactome in angiogenesis: biological implications and therapeutical use

Angiogenesis, the process of formation of new blood vessel from pre-existing ones, is involved in various intertwined pathological processes including virus infection, inflammation and oncogenesis, making it a promising target for the development of novel strategies for various interventions. To induce angiogenesis, angiogenic growth factors (AGFs) must interact with pro-angiogenic receptors to induce proliferation, protease production and migration of endothelial cells (ECs). The action of AGFs is counteracted by antiangiogenic modulators whose main mechanism of action is to bind (thus sequestering or masking) AGFs or their receptors. Many sugars, either free or associated to proteins, are involved in these interactions, thus exerting a tight regulation of the neovascularization process. Heparin and heparan sulfate proteoglycans undoubtedly play a pivotal role in this context since they bind to almost all the known AGFs, to several pro-angiogenic receptors and even to angiogenic inhibitors, originating an intricate network of interaction, the so called "angiogenesis glycomic interactome". The decoding of the angiogenesis glycomic interactome, achievable by a systematic study of the interactions occurring among angiogenic modulators and sugars, may help to design novel antiangiogenic therapies with implications in the cure of angiogenesis-dependent diseases.