Polymer–Drug Nanoparticles Combine Doxorubicin Carrier and Heparin Bioactivity Functionalities for Primary and Metastatic Cancer Treatment

Anionic polysaccharides as delivery carriers for cancer therapy and theranostics: An overview of significance

Recently, cancer therapy has witnessed remarkable advancements with a growing focus on precision medicine and targeted drug delivery strategies. The application of anionic polysaccharides has gained traction in various drug delivery systems. Anionic polysaccharides have emerged as promising delivery carriers in cancer therapy and theranostics, offering numerous advantages such as biocompatibility, low toxicity, and the ability to encapsulate and deliver therapeutic agents to tumor sites with high specificity. This review underscores the significance of anionic polysaccharides as essential components of the evolving landscape of cancer therapy and theranostics. These polymers can be tailored to carry a wide range of therapeutic cargo, including chemotherapeutic agents, nucleic acids, and imaging agents. Their negative charge enables electrostatic interactions with positively charged drugs and facilitates the formation of stable nanoparticles, liposomes, or hydrogels for controlled drug release. Additionally, their hydrophilic nature aids in prolonging circulation time, reducing drug degradation, and minimizing off-target effects. Besides, some of them could act as targeting agents or therapeutic compounds that lead to improved therapeutic performance. This review offers valuable information for researchers, clinicians, and biomedical engineers. It provides insights into the recent progress in the applications of anionic polysaccharide-based delivery platforms in cancer theranostics to transform patient outcomes.

d-type peptides based fluorescent probes for "turn on" sensing of heparin

Developing "turn on" fluorescent probes was desirable for the detection of the effective anticoagulant agent heparin in clinical applications. Through combining the aggregation induced emission (AIE) fluorogen tetraphenylethene (TPE) and heparin specific binding peptide AG73, the promising "turn on" fluorescent probe TPE-1 has been developed. Nevertheless, although TPE-1 could achieve the sensitive and selective detection of heparin, the low proteolytic stability and undesirable poor solubility may limit its widespread applications. In this study, seven TPE-1 derived fluorescent probes were rationally designed, efficiently synthesized and evaluated. The stability and water solubility were systematically estimated. Especially, to achieve real-time monitoring of proteolytic stability, the novel Abz/Dnp-based "turn on" probes that employ the internally quenched fluorescent (IQF) mechanism were designed and synthesized. Moreover, the detection ability of synthetic fluorescent probes for heparin were systematically evaluated. Importantly, the performance of d-type peptide fluorescent probe XH-6 indicated that d-type amino acid substitutions could significantly improve the proteolytic stability without compromising its ability of heparin sensing, and attaching solubilizing tag 2-(2-aminoethoxy) ethoxy) acid (AEEA) could greatly enhance the solubility. Collectively, this study not only established practical strategies to improve both the water solubility and proteolytic stability of "turn on" fluorescent probes for heparin sensing, but also provided valuable references for the subsequent development of enzymatic hydrolysis-resistant d-type peptides based fluorescent probes.

Extracellular matrix component-derived nanoparticles for drug delivery and tissue engineering

The extracellular matrix (ECM) consists of a complex combination of proteins, proteoglycans, and other biomolecules. ECM-based materials have been demonstrated to have high biocompatibility and bioactivity, which may be harnessed for drug delivery and tissue engineering applications. Herein, nanoparticles incorporating ECM-based materials and their applications in drug delivery and tissue engineering are reviewed. Proteins such as gelatin, collagen, and fibrin as well as glycosaminoglycans including hyaluronic acid, chondroitin sulfate, and heparin have been employed for cancer therapeutic delivery, gene delivery, and wound healing and regenerative medicine. Strategies for modifying and functionalizing these materials with synthetic and natural polymers or to enable stimuli-responsive degradation and drug release have increased the efficacy of these materials and nano-systems. The incorporation and modification of ECM-based materials may be used to drive drug targeting and increase tissue-specific cell differentiation more effectively.

Recent advances in pH/enzyme-responsive polysaccharide-small-molecule drug conjugates as nanotherapeutics

Now-a-days, the polysaccharides are extensively employed for the delivery of small-molecule drugs ascribed to their excellent biocompatibility, biodegradability and modifiability. An array of drug molecules is often chemically conjugated with different polysaccharides to augment their bio-performances. As compared to their therapeutic precursors, these conjugates could typically demonstrate an improved intrinsic solubility, stability, bioavailability and pharmacokinetic profiles of the drugs. In current years, various stimuli-responsive particularly pH and enzyme-sensitive linkers or pendants are also exploited to integrate the drug molecules into the polysaccharide backbone. The resulting conjugates could experience a rapid molecular conformational change upon exposure to the microenvironmental pH and enzyme changes of the diseased states, triggering the release of the bioactive cargos at the targeted sites and eventually minimize the systemic side effects. Herein, the recent advances in pH and enzyme -responsive polysaccharide-drug conjugates and their therapeutic benefits are systematically reviewed, following a brief description on the conjugation chemistry of the polysaccharides and drug molecules. The challenges and future perspectives of these conjugates are also precisely discussed.

Smart Chondroitin Sulfate Micelles for Effective Targeted Delivery of Doxorubicin Against Breast Cancer Metastasis

Introduction

Metastasis is a major challenge in breast cancer therapy. The successful chemotherapy of breast cancer largely depends on the ability to block the metastatic process. Herein, we designed a dual-targeting and stimuli-responsive drug delivery system for targeted drug delivery against breast cancer metastasis.

Methods

AS1411 aptamer-modified chondroitin sulfate A-ss-deoxycholic acid (ACSSD) was synthesized, and the unmodified CSSD was used as the control. Chemotherapeutic drug doxorubicin (DOX)-containing ACSSD (D-ACSSD) micelles were prepared by a dialysis method. The ACSSD conjugate was confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and transmission electron microscopy (TEM). In vitro cellular uptake and cytotoxicity of D-ACSSD micelles were studied by confocal laser scanning microscopy (CLSM) and MTT assay in breast tumor cells. The inhibition capability of D-ACSSD micelles in cell migration and invasion was carried out in 4T1 cells. In vivo antitumor activity of DOX-containing micelles was investigated in metastatic 4T1-bearing Balb/c mice.

Results

D-ACSSD and DOX-loaded CSSD (D-CSSD) micelles exhibited high drug encapsulation content and reduction-responsive characteristics. D-ACSSD micelles were spherical in shape. Compared with D-CSSD, D-ACSSD showed higher cellular uptake and more potent killing activity in 4T1 and MDA-MB-231 cells. Additionally, D-ACSSD exhibited stronger inhibitory effects on the invasion and migration of highly metastatic 4T1 cells than unmodified D-CSSD. Among the DOX-containing formulations, D-ACSSD micelles presented the most effective inhibition of tumor growth and lung metastasis in orthotopic 4T1-bearing mice in vivo. It also revealed that ACSSD micelles did not exhibit obvious systemic toxicity.

Conclusion

The smart D-ACSSD micelles could be a promising delivery system for the therapy of metastatic breast cancer.

Nanoaggregates of Biphilic Carboxyl-Containing Copolymers as Carriers for Ionically Bound Doxorubicin

Application of nanocarriers for drug delivery brings numerous advantages, allowing both minimization of side effects common in systemic drug delivery and improvement in targeting, which has made it the focal point of nanoscience for a number of years. While most of the studies are focused on encapsulation of hydrophobic drugs, delivery of hydrophilic compounds is typically performed via covalent attachment, which often requires chemical modification of the drug and limits the release kinetics. In this paper, we report synthesis of biphilic copolymers of various compositions capable of self-assembly in water with the formation of nanoparticles and suitable for ionic binding of the common anticancer drug doxorubicin. The copolymers are synthesized by radical copolymerization of N-vinyl-2-pyrrolidone and acrylic acid using n-octadecyl-mercaptan as a chain transfer agent. With an increase of the carboxyl group's share in the chain, the role of the electrostatic stabilization factor of the nanoparticles increased as well as the ability of doxorubicin as an ion binder. A mathematical description of the kinetics of doxorubicin binding and release is given and thermodynamic functions for the equilibrium ionic binding of doxorubicin are calculated.

Incidence and Risk Factors for Venous Thromboembolism in Female Patients Undergoing Breast Surgery

Albeit it does not have the highest venous thromboembolism (VTE) incidence compared to other neoplasms, breast cancer contributes to many VTE events because it is the most diagnosed tumor in women. We aim to analyze the occurrence and timing of VTE during the follow-up of patients who underwent breast surgery, the possible correlated factors, and the overall survival. This retrospective study included all female patients diagnosed with mammary pathology and surgically treated in our clinic between January 2002 and January 2012. Of 5039 women who underwent breast surgery, 1056 were found to have no evidence of malignancy, whereas 3983 were diagnosed with breast cancer. VTE rate resulted significantly higher in patients with invasive breast cancer than in women with benign breast disease or carcinoma in situ. Invasive cancers other than lobular or ductal were associated with a higher VTE rate. In addition, chronic hypertension, high BMI, cancer type, and evidence of metastasis turned out to be the most significant risk factors for VTE in women who underwent breast surgery. Moreover, VTE occurrence significantly impacted survival in invasive breast cancer patients. Compared to women with benign mammary pathology, VTE prevalence in women with breast cancer is significantly higher. The knowledge about the risk factors of VTE could be helpful as prognostic information, but also to eventually target preventive treatment strategies for VTE, as far as the co-existence of invasive breast cancer and VTE has a significantly negative impact on survival.

Development of carrier-free nanodrugs based on low molecular weight heparin–doxorubicin conjugate assembly with smart pH-triggered drug release characteristics for combinatorial antitumor therapy

A LMWH–DOX nanodrug effectively released bioactive agents, providing a combination therapy of low molecular weight heparin and doxorubicin for angiogenesis suppression and carcinoma inhibition.

Systemic metastasis-targeted nanotherapeutic reinforces tumor surgical resection and chemotherapy

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Metastasis consists of three steps: (i) tumor cells extravasate from the primary sites into the circulation system via epithelial-mesenchymal transition (EMT), (ii) the circulating tumor cells (CTCs) form “micro-thrombi” with platelets to evade the immune surveillance in circulation, and (iii) the CTCs colonize in the pre-metastatic niche. Here, we design a systemic metastasis-targeted nanotherapeutic (H@CaPP) composed of an anti-inflammatory agent, piceatannol, and an anti-thrombotic agent, low molecular weight heparin, to hinder the multiple steps of tumor metastasis. H@CaPP is found efficiently impeded EMT, inhibited the formation of “micro-thrombi”, and prevented the development of pre-metastatic niche. When combined with surgical resection or chemotherapy, H@CaPP efficiently inhibits tumor metastasis and prolonged overall survival of tumor-bearing mice. Collectively, we provide a simple and effective systemic metastasis-targeted nanotherapeutic for combating tumor metastasis.

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Here, the authors show that a systemic metastasis-targeted nanotherapeutic may offer a powerful adjunct therapy for suppressing tumor metastasis.

Integrin αvβ3-targeted liposomal drug delivery system for enhanced lung cancer therapy

Conventional chemotherapy for tumor treatment remains flawed because it fails to limit cytotoxicity to a small set of selectable tissues. Active targeting techniques for the delivery of drugs to specific sites are increasingly used to enhance drug accumulation at tumor sites with the aim of reducing side effects in vivo. Liposomes, modified with different targeting ligands, are considered to be one of the most promising targeted drug carriers. Herein, novel linear and cyclic arginine-glycine-aspartate (RGD) peptide-based lipids were synthesized to develop modified liposomal drug delivery systems with active targeting and pH-sensitivity. The RGD-modified liposomes showed excellent active targeting ability for integrin α_vβ₃ receptors, resulting in improved cellular uptake. The modified liposomes also enhanced intracellular doxorubicin (DOX) release because of their degradation in an acidic environment. Consequently, the RGD-modified, DOX-loaded liposomes exhibited significant antitumor efficacy and low toxicity in vitro and in vivo. In particular, 5% cRGD-lipid modified DOX-loaded liposome showed the greatest inhibition of tumor growth in mice among the tested formulations, and much less toxicity than free DOX. In conclusion, the DOX-loaded pH-sensitive liposome modified with 5% cRGD-lipid developed in the current study provides a potential approach for improved tumor therapy.

Heparin modified photosensitizer-loaded liposomes for tumor treatment and alleviating metastasis in phototherapy

Phototherapy holds promise in cancer treatment for its prominent antitumor efficacy and low systematic toxicity compared with traditional chemotherapy. However, the higher risk of tumor metastasis caused by the severe hypoxic state during phototherapy is a threat in practical use. Here, in order to tackle this challenge, we developed a delivery system via loading the photosensitizer indocyanine green (ICG) into the low molecular weight heparin (LMWH) modified liposomes (LMWH-ICG-Lip) to realize the synergistic effects between photosensitizer and drug vehicle, achieving better phototherapeutic efficacy and meanwhile alleviating the potential risk of tumor metastasis caused by phototherapy. In this system, besides elongating the photosensitizers' circulation time and enhancing their accumulating efficacy to tumor tissues, LMWH itself also exhibited anti-metastasis efficacy via inhibiting adhesion of platelets to tumor cells and decreasing migration and invasion capability of tumor cells. In vivo efficacy evaluation was conducted on orthotopic 4T1 breast cancer model, and the system of LMWH-ICG-Lip could alleviate metastasis potential of residual tumor cells after irradiation, and elicit optimistic antitumor and anti-metastasis efficacy for phototherapy.

Smart Nanotheranostics Responsive to Pathological Stimuli

The development of nanotheranostics represents one of the most dynamic technological frontiers in the treatment of different pathological conditions. With the goal in mind to generate nanocarriers with both therapeutic and diagnostic properties, current research aims at implementing these technologies with multiple functions, including targeting, multimodal imaging, and synergistic therapies. The working mechanism of some nanotheranostics relies on physical, chemical, and biological triggers allowing for the activation of the therapeutic and/or the diagnostic properties only at the diseased site. In this review, we explored new advances in the development of smart nanotheranostics responsive to pathological stimuli, including altered pH, oxidative stress, enzymatic expression, and reactive biological molecules with a deep focus on the material used in the field to generate the particles in the context of the analyzed disease.

Enhanced anti-tumor and anti-metastasis therapy for triple negative breast cancer by CD44 receptor-targeted hybrid self-delivery micelles

Tumor growth and metastasis are multistep processes regulated by multiple signaling pathways. The successful treatment of cancer largely depends on the ability to inhibit metastatic process. Multiphase inhibition of metastasis is a promising approach. Here, we described a targeting delivery system which was constructed by mixing hyaluronic acid-d-α-tocopheryl succinate (HA-TOS, HT) and low molecular weight heparin-TOS (LMWH-TOS, LT) to form a stable hybrid micelle (HT-LT), encapsulating chemotherapeutic drug doxorubicin (DOX). The prepared HT-LT NPs was about 125 nm in diameter with high drug encapsulation rate and continuous drug release behavior. We confirmed that HT-LT NPs exhibited an effective targeting ability both in vitro and in vivo using a 4T1 model that was attributed to HA binding to CD44 receptors. In addition, HT-LT NPs acted on different phases of the invasion-metastasis cascade and inhibited tumor cell migration and invasion, thus inhibiting tumor metastasis. This combinatorial strategy provided an alternative approach for triple negative breast cancer therapy.

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin (DOX) and Toll-like receptor 7 agonist imiquimod (IMQ) in low molecular weight heparin (LMWH)-d-α-tocopheryl succinate (TOS) micelles (LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles (LT-DOX) generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles (LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1 (PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8+ CTLs/Treg and CD4+ Teff/Treg. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

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.

Molecular determinants as therapeutic targets in cancer chemotherapy: An update

It is well known that cancer cells are heterogeneous in nature and very distinct from their normal counterparts. Commonly these cancer cells possess different and complementary metabolic profile, microenvironment and adopting behaviors to generate more ATPs to fulfill the requirement of high energy that is further utilized in the production of proteins and other essentials required for cell survival, growth, and proliferation. These differences create many challenges in cancer treatments. On the contrary, such situations of metabolic differences between cancer and normal cells may be expected a promising strategy for treatment purpose. In this article, we focus on the molecular determinants of oncogene-specific sub-organelles such as potential metabolites of mitochondria (reactive oxygen species, apoptotic proteins, cytochrome c, caspase 9, caspase 3, etc.), endoplasmic reticulum (unfolded protein response, PKR-like ER kinase, C/EBP homologous protein, etc.), nucleus (nucleolar phosphoprotein, nuclear pore complex, nuclear localization signal), lysosome (microenvironment, etc.) and plasma membrane phospholipids, etc. that might be exploited for the targeted delivery of anti-cancer drugs for therapeutic benefits. This review will help to understand the various targets of subcellular organelles at molecular levels. In the future, this molecular level understanding may be combined with the genomic profile of cancer for the development of the molecularly guided or personalized therapeutics for complete eradication of cancer.

Chemotherapy priming of the Pancreatic Tumor Microenvironment Promotes Delivery and Anti-Metastasis Efficacy of Intravenous Low-Molecular-Weight Heparin-Coated Lipid-siRNA Complex

Pancreatic ductal adenocarcinoma (PDAC) is a type of malignant tumor with high lethality. Its high tumor cell-density and large variety of extracellular matrix (ECM) components present major barriers for drug delivery.

Methods: Paclitaxel-loaded PEGylated liposomes (PTX-Lip) were used as a tumor-priming agent to induce tumor cell apoptosis and decrease the abundance of ECM to promote cellular uptake and tumor delivery of nanodrugs. Paclitaxel exerts anti-cancer effects but, paradoxically, exacerbates cancer metastasis and drug resistance by increasing the expression of apoptotic B-cell lymphoma-2 protein (BCL-2). Thus, low-molecular-weight heparin-coated lipid-siRNA complex (LH-Lip/siBCL-2) was constructed to inhibit cancer metastasis and silence BCL-2 by BCL-2 siRNA (siBCL-2).

Results: Significant tumor growth inhibition efficacy was observed, accompanied by obvious inhibition of cancer metastasis in vivo.

Conclusion: These results suggested our sequential delivery of PTX-Lip and LH-Lip/siBCL-2 might provide a practical approach for PDAC or other ECM-rich tumors.

Low Molecular Weight Heparin-Coated and Dendrimer-Based Core-Shell Nanoplatform with Enhanced Immune Activation and Multiple Anti-Metastatic Effects for Melanoma Treatment

High-efficiency treatment for tumor is not easy to achieve owing to the existence of metastasis, which remains the arch-criminal of most tumor deaths. Conventional chemotherapy exhibits insufficient inhibitory efficiency on tumor metastasis and more powerful strategies to conquer metastatic tumors are urgently needed. In this study, a rational chemoimmunotherapy strategy was adopted to treat highly aggressive melanoma based on a newly developed multifunctional nanoplatform. Firstly, immunoadjuvant cytosine-phosphate-guanine oligonucleotides (CpG ODNs) were used to boost the doxorubicin (DOX)-elicited immune responses, which synergistically suppressed tumor growth and metastasis. And the anti-metastatic low molecular weight heparin (LMWH) was also integrated, thus multiple anti-metastatic effects to against tumor metastasis were achieved. Methods: G4 PAMAM was serving as the main support to conjugate DOX by pH-sensitive hydrazone bond (PPD) and the synthesized conjugates were confirmed by ¹H-NMR spectra, IR spectra and HRMS. Immunoadjuvant CpG ODNs were loaded by electrostatic adsorption to formulate PPD/CpG. After the coating of anti-metastatic LMWH, the designed LMWH/PPD/CpG was fabricated and characterized. The platelets-related and platelets-unrelated anti-metastatic mechanisms were investigated on B16F10 the immune activation effects, anti-tumor and anti-metastatic efficacy of LMWH/PPD/CpG were evaluated on a B16F10 melanoma xenograft model. Results: DOX elicited tumor-specific immune responses by ICD, and the immunological effects could be further promoted by CpG ODNs, exhibiting enhanced maturation of dendritic cells (DCs) and increased level of cytolytic T lymphocytes (CTLs) in vivo. Owing to the coating of LMWH, the platelets-induced epithelial-mesenchymal-like transition of tumor cells was hindered and the actin cytoskeletal arrangement of tumor cells was affected, thus the migration ability of tumor cells was further inhibited. This multifunctional nanoplatform showed enhanced treatment efficiency on melanoma primary tumor and pulmonary metastasis. Conclusion: The immune activation and multiple anti-metastatic effects of LMWH/PPD/CpG establish a novel therapeutic strategy for melanoma. This anti-metastatic nanoplatform could be broadly applied for the co-delivery of other nucleic acids and chemotherapeutic drugs to treat highly aggressive tumors.

Anti-tumour activity of low molecular weight heparin doxorubicin nanoparticles for histone H1 high-expressive prostate cancer PC-3M cells

Nucleus-targeting drug delivery systems (NTDDs) deliver chemotherapeutic agents to nuclei in order to improve the efficacy of anti-tumour therapy. Histone H1 (H1) plays a key role in establishing and maintaining higher order chromatin structures and could bind to cell membranes. In the present study, we selected H1 as a target to prepare a novel H1-mediated NTDD. Low molecular weight heparin (LMHP) and doxorubicin (DOX) were combined to form LMHP-DOX. Then, a novel NTDD consisting of LMHP-DOX nanoparticles (LMHP-DOX NPs) was prepared by self-assembly. The characteristics of LMHP-DOX and LMHP-DOX NPs were investigated. Histone H1 high-expressive prostate cancer PC-3M cell line was selected as the cell model. Cellular uptake, and the in vitro and in vivo anti-tumour activity of LMHP-DOX NPs were evaluated on H1 high-expressive human prostate cancer PC-3M cells. Our results indicated that intact LMHP-DOX NPs mediated by H1 could be absorbed by H1 high-expressive PC-3M cells, escape from the lysosomes to the cytoplasm, and localize in the perinuclear region via H1-mediated, whereby DOX could directly enter the cell nucleus and quickly increase the concentration of DOX in the nuclei of H1 high-expressive PC-3M cells to enhance the apoptotic activity of cancer cells. The anti-coagulant activity of LMHP-DOX NPs was almost completely diminished in rat blood compared with that of LMHP, indicating the safety of LMHP-DOX NPs. Compared to traditional NTDD strategies, LMHP-DOX NPs avoid the complicated modification of nucleus-targeting ligands and provide a compelling solution for the substantially enhanced nuclear uptake of chemotherapeutic agents for the development of more intelligent NTDDs.

The Degradation Products of Ascorbic Acid Inhibit Amyloid Fibrillation of Insulin and Destabilize Preformed Fibrils

Ascorbic acid (AsA) is an important antioxidant and enzyme cofactor in many biochemical processes. Most biological activities of AsA are closely related to its redox properties. Recent investigations have demonstrated that AsA is associated with amyloid-related diseases and can inhibit amyloid aggregation of polypeptides. In the present study, we determined the kinetics of AsA degradation and investigated the anti-amyloidogenic activities of AsA and its degradation products by utilizing insulin as a model polypeptide. The results showed that the half-life of AsA varied with the pH of the medium and the incubation temperature. The degradation products of AsA inhibited insulin fibrillation, with an activity positively correlated to the degree of AsA degradation. The degradation species, compared with intact AsA, also showed a stronger disruptive effect on mature amyloid fibrils and significantly decreased fibrillar cytotoxicity. Dehydroascorbic acid and diketogulonic acid, two key intermediates in AsA degradation, had similar anti-amyloidogenic activity toward the degradation species of AsA. The results of this work indicate that degradation of natural antioxidants must be considered when evaluating their anti-amyloidogenic effects. These insights into the action of AsA may also provide a novel route to understand its physiological/pharmacological roles in amyloid-related diseases.

Nanoalginates via Inverse-Micelle Synthesis: Doxorubicin-Encapsulation and Breast Cancer Cytotoxicity

Crosslinked-biopolymer nanoparticles provide a convenient platform for therapeutic encapsulation and delivery. Here, we present a robust inverse-micelle process to load water-soluble drugs into a calcium-crosslinked alginate matrix. The utility of the resulting nanoalginate (NALG) carriers was assessed by a doxorubicin (DOX) formulation (NALG-DOX) and evaluating its potency on breast cancer cells (4T1). This facile synthesis process produced doxorubicin-containing particles of ~ 83 nm by hydrodynamic size and zeta potential ~ 7.2 mV. The cyclohexane/dodecylamine microemulsion yielded uniform and spherical nanoparticles as observed by electron microscopy. The uptake of the drug from the NALG-DOX formulation in 4T1 cells was observed by fluorescence microscopy employing doxorubicin's inherent fluorescence. Therapeutic efficacy of the NALG-DOX against 4T1 cells was demonstrated qualitatively through a LIVE/DEAD fluorescence assay and quantitatively via cell viability assay (Alamar Blue). In addition, IC50 values were determined, with encapsulated doxorubicin having a slightly higher value. No toxicity of the empty NALG carrier was observed. Overall, these results demonstrate the utility of this synthesis process for encapsulation of hydrophilic therapeutics and NALG to function as a drug carrier.

Development of redox-responsive theranostic nanoparticles for near-infrared fluorescence imaging-guided photodynamic/chemotherapy of tumor

The development of imaging-guided smart drug delivery systems for combinational photodynamic/chemotherapy of the tumor has become highly demanded in oncology. Herein, redox-responsive theranostic polymeric nanoparticles (NPs) were fabricated innovatively using low molecular weight heparin (LWMH) as the backbone. Chlorin e6 (Ce6) and alpha-tocopherol succinate (TOS) were conjugated to LMWH via cystamine as the redox-sensitive linker, forming amphiphilic Ce6-LMWH-TOS (CHT) polymer, which could self-assemble into NPs in water and encapsulate paclitaxel (PTX) inside the inner core (PTX/CHT NPs). The enhanced near-infrared (NIR) fluorescence intensity and reactive oxygen species (ROS) generation of Ce6 were observed in a reductive environment, suggesting the cystamine-switched "ON/OFF" of Ce6. Also, the in vitro release of PTX exhibited a redox-triggered profile. MCF-7 cells showed a dramatically higher uptake of Ce6 delivered by CHT NPs compared with free Ce6. The improved therapeutic effect of PTX/CHT NPs compared with mono-photodynamic or mono-chemotherapy was observed in vitro via MTT and apoptosis assays. Also, the PTX/CHT NPs exhibited a significantly better in anti-tumor efficiency upon NIR irradiation according to the results of in vivo combination therapy conducted on 4T1-tumor-bearing mice. The in vivo NIR fluorescence capacity of CHT NPs was also evaluated in tumor-bearing nude mice, implying that the CHT NPs could enhance the accumulation and retention of Ce6 in tumor foci compared with free Ce6. Interestingly, the anti-metastasis activity of CHT NPs was observed against MCF-7 cells by a wound healing assay, which was comparable to LMWH, suggesting LMWH was promising for construction of nanocarriers for cancer management.

Low-Molecular-Weight Heparins: Reduced Size Particulate Systems for Improved Therapeutic Outcomes

A wide range of diseases have been treated using low-molecular-weight heparins (LMWHs), the drug of choice for anticoagulation. Owing to their better pharmacokinetic features compared to those of unfractionated heparin (uFH), several systems incorporating LMWHs have been investigated to deliver and improve their therapeutic outcomes, especially through development of their micro- and nano-particles. This review article describes current perspectives on the fabrication, characterization, and application of LMWHs-loaded micro- and nano-particles to achieve ameliorated bioavailability. The valuable applications of LMWH will continue to encourage researchers to identify efficient delivery systems that have specific release characteristics and ameliorated bioavailability, overcoming the challenges presented by biological obstructions and the physicochemical properties of LMWHs.

Development of low molecular weight heparin based nanoparticles for metastatic breast cancer therapy

Tumor metastasis is the primary obstacle in cancer treatment and is always the leading cause of human death. And heparin and its derivatives are potential anti-metastatic agents with good biocompatibility. In this work, low molecular weight heparin (LMWH) based LMWH-Cholesterol (LHC) conjugates were prepared for intravenous delivery of doxorubicin (DOX). The DOX/LHC nanoparticles (DOX/LHC NPs) exhibited a spherical shape with a mean diameter of 135.5±2.2nm and had a longer circulation time than that of DOX. The in vitro results confirmed that the DOX/LHC NPs was more effectively taken up by 4T1 cells and showed a stronger anti-metastatic effect by cell invasion and cell migration compared with DOX. Meanwhile, DOX/LHC NPs also exhibited superior anti-metastatic effects in the pulmonary metastasis model compared with other groups. The reason may be account for the synergistic effect between the cytotoxic drug of DOX and its drug carrier of LMWH based nanoparticles, which is capable of anti-metastatic and anti-angiogenic efficiency. Thus DOX/LHC nanoparticles could be a promising anti-metastatic drug delivery system for postoperative chemotherapy.

Low molecular weight heparin-based reduction-sensitive nanoparticles for antitumor and anti-metastasis of orthotopic breast cancer

Tumor metastasis has become a major obstacle for the clinical treatment of malignant breast cancer.