Vitamin E-rich Nanoemulsion Enhances the Antitumor Efficacy of Low-Dose Paclitaxel by Driving Th1 Immune Response

Current challenges ahead in preparation, characterization, and pharmaceutical applications of nanoemulsions

Nanoemulsions (NEs) are emulsions with particle size of less than around 100 nm. Reviewing the literature, several reports are available on NEs, including preparation, characterization, and applications of them. This review aims to brief challenges that researchers or formulators may encounter when working with NEs. For instance, when selecting NE components and identifying their concentrations, stability and safety of the preparation should be evaluated. When preparing an NE, issues over scale-up of the preparation as well as possible effects of the preparation process on the active ingredient need to be considered. When characterizing the NEs, the two major concerns are accuracy of the method and accessibility of the characterizing instrument. Also a highly efficient NE for clinical use to deliver the active ingredient to the target tissue with maximum safety profile is commonly sought. Throughout the review we also have tried to suggest approaches to overcome the challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Enhanced apoptosis and mitochondrial cell death by paclitaxel-loaded TPP-TPGS1000-functionalized nanoemulsion

Background: The present research was designed to develop a nanoemulsion (NE) of triphenylphosphine-D-α-tocopheryl-polyethylene glycol succinate (TPP-TPGS₁₀₀₀) and paclitaxel (PTX) to effectively deliver PTX to improve breast cancer therapy. Materials & methods: A quality-by-design approach was applied for optimization and in vitro and in vivo characterization were performed. Results: The TPP-TPGS₁₀₀₀-PTX-NE enhanced cellular uptake, mitochondrial membrane depolarization and G₂M cell cycle arrest compared with free-PTX treatment. In addition, pharmacokinetics, biodistribution and in vivo live imaging studies in tumor-bearing mice showed that TPP-TPGS₁₀₀₀-PTX-NE had superior performance compared with free-PTX treatment. Histological and survival investigations ascertained the nontoxicity of the nanoformulation, suggesting new opportunities and potential to treat breast cancer. Conclusion: TPP-TPGS₁₀₀₀-PTX-NE improved the efficacy of breast cancer treatment by enhancing its effectiveness and decreasing drug toxicity.

Lipid-core nanoparticles: Classification, preparation methods, routes of administration and recent advances in cancer treatment

Nanotechnological drug delivery platforms represent a new paradigm for cancer therapeutics as they improve the pharmacokinetic profile and distribution of chemotherapeutic agents over conventional formulations. Among nanoparticles, lipid-based nanoplatforms possessing a lipid core, that is, lipid-core nanoparticles (LCNPs), have gained increasing interest due to lipid properties such as high solubilizing potential, versatility, biocompatibility, and biodegradability. However, due to the wide spectrum of morphologies and types of LCNPs, there is a lack of consensus regarding their terminology and classification. According to the current state-of-the-art in this critical review, LCNPs are defined and classified based on the state of their lipidic components in liquid lipid nanoparticles (LLNs). These include lipid nanoemulsions (LNEs) and lipid nanocapsules (LNCs), solid lipid nanoparticles (SLNs) and nanostructured lipid nanocarriers (NLCs). In addition, we present a comprehensive and comparative description of the methods employed for their preparation, routes of administration and the fundamental role of physicochemical properties of LCNPs for efficient antitumoral drug-delivery application. Market available LCNPs, clinical trials and preclinical in vivo studies of promising LCNPs as potential treatments for different cancer pathologies are summarized.

Tumor-targeting intravenous lipid emulsion of paclitaxel: Characteristics, stability, toxicity, and toxicokinetics

Lipid nanoemulsions are promising nanodrug delivery carriers that can improve the efficacy and safety of paclitaxel (PTX). However, no intravenous lipid emulsion of PTX has been approved for clinical treatment, and systemic safety profiles have not yet been reported. Here we outline the development of a PTX-loaded tumor-targeting intravenous lipid emulsion (PTX Emul) and describe its characteristics, colloidal stability, and systemic safety profiles in terms of acute toxicity, long-term toxicity, and toxicokinetics. We also compare PTX Emul with conventional PTX injection. Results showed that PTX Emul exhibited an ideal average particle size (approximately 160 nm) with narrow size distribution and robust colloidal stability under different conditions. Hypersensitivity reaction and hemolysis tests revealed that PTX Emul did not induce hypersensitivity reactions and had no hemolytic potential. In addition, where the alleviated systemic toxicity of PTX Emul may be attributed to the altered toxicokinetic characteristics in beagle dogs, including the decreased AUC and increased plasma clearance and volume of distribution, PTX Emul alleviated acute and long-term toxicity as evidenced by the enhanced the median lethal dose and approximate lethal dose, moderate body weight change, decreased bone marrow suppression and organ toxicity compared with those under PTX injection at the same dose. A fundamental understanding of the systemic safety profiles, high tumor-targeting efficiency, and superior antitumor activity in vivo of PTX Emul can provide powerful evidence of its therapeutic potential as a future treatment for breast cancer.

Macrophage immunomodulatory activity of Acanthopanax senticousus polysaccharide nanoemulsion via activation of P65/JNK/ikkαsignaling pathway and regulation of Th1/Th2 Cytokines

Nanoemulsions (NE) are used widely in pharmaceutical drug formulations and vaccine preparation, and Acanthopanax senticousus polysaccharide (ASPS) is a natural bioactive compound with immunostimulatory activity. Therefore, NE-loaded ASPS is expected to provide immunological enhancement for effective treatment. In the present study, Acanthopanax senticousus polysaccharide (ASPS was encapsulated into nanoemulsions, the resultant ASPS-NE were coated with a negative charge, and the immune enhancement mechanism of these ASPS-NE formulations was analyzed. The immunosuppressive animal models (70 ICR mice, male) for the study were established using cyclophosphamide. In addition, the activation of splenocyte proliferation, phagocytosis of the macrophages, the ratio of CD4⁺ to CD8⁺, the concentrations of the cytokines in serum, Western blot analysis was used for the analysis of the P65/JNK/ikk α signaling pathway in the peritoneal macrophage s. The results revealed that the ASPS-NE could stimulated the proliferation of splenocytes and enhance immunity. The ASPS-NE induced the expression of different cytokines (TNF-α, IFN-γ, IL-2, and IL-6), could activate the expressions of P65, JNK, and ikkα, and regulated the Th1/Th2 cytokines. These findings demonstrated the potential of ASPS-NE formulations for drug delivery and to induce potent and sustained immune responses.

Immunotherapy Strategy Targeting Programmed Cell Death Ligand 1 and CD73 with Macrophage-Derived Mimetic Nanovesicles to Treat Bladder Cancer

Combination immunotherapy is a promising strategy to remove the inhibitory effect of the tumor microenvironment on immune effector cells, improving the efficacy of immune checkpoint inhibitor treatment in bladder cancer. However, it is challenging to deliver multiple drugs to the tumor tissue effectively and simultaneously to ensure optimal therapeutic effects. Macrophage-derived exosome-mimetic nanovesicles (EMVs) were designed and validated as a nanoplatform for coloading and delivery of the CD73 inhibitor (AB680) and the monoclonal antibody to programmed cell death ligand 1 (aPDL1). The tumor-targeting, biosafety, and therapeutic effects of these nanocomplexes (AB680@EMVs-aPDL1), as a combined immunotherapy strategy for bladder cancer, were assessed in vitro and in vivo. Our results indicate that the nanodrug system was highly stable, provided adequate biosafety, and enhanced tumor targeting in a mouse model of bladder cancer. Moreover, the CD73 inhibitor reduced extracellular adenosine production, and the combination therapy significantly promoted the activation and infiltration of cytotoxic T-lymphocytes, which helped to optimally suppress tumor growth and extend median survival in vivo. Therefore, using EMVs to deliver a combination of aPDL1 and the CD73 inhibitor may be a useful combined immunotherapy strategy for treating bladder cancer.

Cytosolic delivery of the immunological adjuvant Poly I:C and cytotoxic drug crystals via a carrier-free strategy significantly amplifies immune response

Co-delivery of chemotherapeutics and immunostimulant or chemoimmunotherapy is an emerging strategy in cancer therapy. The precise control of the targeting and release of agents is critical in this methodology. This article proposes the asynchronous release of the chemotherapeutic agents and immunostimulants to realize the synergistic effect between chemotherapy and immunotherapy. To obtain a proof-of-concept, a co-delivery system was prepared via a drug-delivering-drug (DDD) strategy for cytosolic co-delivery of Poly I:C, a synthetic dsRNA analog to activate RIG-I signaling, and PTX, a commonly used chemotherapeutics, in which pure PTX nanorods were sequentially coated with Poly I:C and mannuronic acid via stimulating the RIG-I signaling axis. The co-delivery system with a diameter of 200 nm enables profound immunogenicity of cancer cells, exhibiting increased secretion of cytokines and chemokines, pronounced immune response in vivo, and significant inhibition of tumor growth. Also, we found that intracellularly sustained release of cytotoxic agents could elicit the immunogenicity of cancer cells. Overall, the intracellular asynchronous release of chemotherapeutics and immunomodulators is a promising strategy to promote the immunogenicity of cancer cells and augment the antitumor immune response.

Comparative colloidal stability, antitumor efficacy, and immunosuppressive effect of commercial paclitaxel nanoformulations

Background

Standard chemotherapy with taxanes, such as paclitaxel (PTX), remains the mainstay of systemic treatment of triple-negative breast cancer. Nanotechnology-based formulations have gradually replaced PTX injection and are widely used in China. However, no studies have compared the colloidal stability, antitumor efficacy, and safety of commercial PTX nanoformulations. Additionally, the desire to evaluate preclinical antitumor efficacy in human-derived tumor cells led to the widespread application of immunodeficient mouse models that likely contributed to the neglect of nanomedicines-immune system interactions. The present study investigated the colloidal stability, antitumor efficacy and safety, and nanomedicines-host immune system interactions of PTX nanoformulations. A further comparative analysis was performed to evaluate the clinical potential.

Results

Compared with liposome, PTX emulsion and PTX nanoparticle exhibited favorable colloidal stability. PTX emulsion was superior in inducing apoptosis and had a more pronounced inhibitory effect on 4T1-tumor spheroids compared with PTX liposome and PTX nanoparticle. Although PTX emulsion exhibited superior in vitro antitumor effect, no significant differences in the in vivo antitumor efficacy were found among the three types of PTX nanoformulations in an immunocompetent orthotopic 4T1 murine triple-negative breast cancer model. All PTX nanoformulations at maximum tolerated dose (MTD) induced lymphopenia and immunosuppression, as evidenced by the reduction of T cell subpopulations and inhibition of the dendritic cells maturation.

Conclusions

The MTD PTX nanomedicines-induced lymphopenia and immunosuppression may weaken the lymphocyte-mediated antitumor cellular immune response and partly account for the lack of differences in the in vivo antitumor outcomes of PTX nanoformulations. Understanding of what impacts PTX nanomedicines has on the immune system may be critical to improve the design and conduct of translational research of PTX nanomedicines in monotherapy or combination therapy with immunotherapy.

Graphic abstract

Recent Development of Copolymeric Nano-Drug Delivery System for Paclitaxel

Background:

Paclitaxel (PTX) has been clinically used for several years due to its good therapeutic effect against cancers. Its poor water-solubility, non-selectivity, high cytotoxicity to normal tissue and worse pharmacokinetic property limit its clinical application.

Objective:

To review the recent progress on the PTX delivery systems.

Methods:

In recent years, the copolymeric nano-drug delivery systems for PTX are broadly studied. It mainly includes micelles, nanoparticles, liposomes, complexes, prodrugs and hydrogels, etc. They were developed or further modified with target molecules to investigate the release behavior, targeting to tissues, pharmacokinetic property, anticancer activities and bio-safety of PTX. In the review, we will describe and discuss the recent progress on the nano-drug delivery system for PTX since 2011.

Results:

The water-solubility, selective delivery to cancers, tissue toxicity, controlled release and pharmacokinetic property of PTX are improved by its encapsulation into the nano-drug delivery systems. In addition, its activities against cancer are also comparable or high when compared with the commercial formulation.

Conclusion:

Encapsulating PTX into nano-drug carriers should be helpful to reduce its toxicity to human, keeping or enhancing its activity and improving its pharmacokinetic property.

Vegetable Oil-based Hybrid Submicron Particles Loaded with JMV5038: A Promising Formulation against Melanoma

The aim of this work was to carry out a preformulation study on JMV5038 as a new potent cytotoxic agent, and to develop its formulation within vegetable oil-based hybrid submicron particles (HNP) in order to obtain a versatile dosage form against melanoma. JMV5038 was first characterized through physico-chemical tests and it exhibited high melting point and logP value, an important pH-sensitivity that led to the formation of well-identified degradation products at low pH, as well as a substantial solubility value in silylated castor oil (ICO). Then, JMV5038-loaded HNP were formulated through a thermostabilized emulsion process based on the sol-gel cross-linking of ICO. They showed high loading efficiency and their in vitro release kinetic assessed in a biorelevant PBS/octanol biphasic system showed a constant sustained release over one month. The cytotoxic activity and cytocompatibility of HNP were evaluated on A375 melanoma cells and NIH 3T3 cells, respectively. JMV5038-loaded HNP exhibited a slightly enhanced cytotoxic activity of JMV5038 on melanoma cells while demonstrating their safety on NIH 3T3 cells. In conclusion, JMV5038-loaded HNP proved to be an efficient and safe drug subcutaneous delivery system that will be interesting to evaluate through preclinical studies.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

Boosting Natural Killer Cell-Based Cancer Immunotherapy with Selenocystine/Transforming Growth Factor-Beta Inhibitor-Encapsulated Nanoemulsion

Natural killer (NK) cell-based immunotherapy represents a promising strategy to overcome the bottlenecks of cancer treatment. However, the therapeutic efficacy is greatly limited by downregulation of recognition ligands on the tumor cell surface, and the immunosuppressive effects can be thwarted by the tumor microenvironment such as secretion of transforming growth factor-beta (TGF-β), which could stunt the NK cell-mediated immune response. To overcome these limitations, herein we developed a nanoemulsion system (SSB NMs) to co-deliver TGF-β inhibitor and selenocysteine (SeC) to achieve amplified anticancer efficacy. SSB NMs significantly enhanced the lytic potency of NK92 cells by 2.1-fold. Moreover, a subtoxic dose of SSB NMs effectively sensitized MDA-MB-231 triple-negative breast cancer (TNBC) cells to NK cells derived from seven clinical patients, resulting in an up to 13.8-fold increase in cancer lysis. Mechanistic studies reveal that the sensitizing effects relied on natural killer group 2, member D (NKG2D)/NKG2D ligands (NKG2DLs) signaling with the involvement of DNA damage response. SSB NMs also effectively restrained TGF-β/TGF-β RI/Smad2/3 signaling, which thus enhanced NKG2DL expression on tumor cells and stimulated NKG2D surface expression on NK92 cells, ultimately contributing to the enhanced immune response. Furthermore, SSB NMs sustained release of SeC and TGF-β inhibitor and synergized with NK92 cells to induce significant anticancer effects in vivo. Together, this study not only demonstrates a simple strategy for the design of a nanoemulsion to co-deliver synergistic drugs but also sheds light on the application and action mechanisms in NK cell adaptive therapy against breast cancer, especially TNBCs.

Comparative study of mucoadhesive and mucus-penetrative nanoparticles based on phospholipid complex to overcome the mucus barrier for inhaled delivery of baicalein

Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein–phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced in vitro cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.

In-vitro and in-vivo anti-breast cancer activity of OEO (Oliveria decumbens vent essential oil) through promoting the apoptosis and immunomodulatory effects

ETHNOPHARMACOLOGICAL RELEVANCE

Oliveria decumbens vent is a valuable plant in Iran, used as a vegetable. Traditionally, the aerial parts of this plant are used to treat the cancer-related symptoms, inflammation, pain, and feverish conditions. However, the scientific evidence related to its traditional effects especially the possible cellular and molecular mechanisms needs to be illuminated.

AIM OF THE STUDY

The main objectives of our study were to explore in-vitro anti-cancer properties of OEO in 2D and 3D conditions, to understand the mechanism of OEO in the induction of death in cancer cells, and to identify in-vivo anti-tumor effect of OEO and induced immunomodulatory effects.

MATERIAL AND METHODS

OEO was extracted by hydrodistillation and analyzed by GC-MS method. To evaluate the cytotoxic effect of OEO on 4T1 cancer monolayer cells (2D culture) and spheroids (3D cultures), MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay was used. Fluorescence staining, various flow cytometry techniques, colorimetric assay, electrophoresis, and comet assay were performed to understand the anti-cancer mechanisms of OEO and determine the death mode in treated 4T1 cells. In animal studies, mouse mammary tumor model was established, the anti-tumor effect of OEO was investigated and ultimately by using the ELISA cytokine assay, immunostimulatory of OEO was studied.

RESULTS

According to GC/MS analysis, thymol, carvacrol, p-cymene, and γ-terpinene were identified as main components of OEO. Based on MTT assay, OEO inhibited viability in 4T1 cancer cell without any significant effect on L929 normal cells in 2D, also the anti-proliferative effects of OEO on 4T1 spheroids (3D) was significant but less extent. Our results revealed that OEO induces apoptosis through ROS generation, mitochondrial membrane potential (ΔΨm) disruption, caspase3 activation, and DNA damage. Evaluating the effectiveness of OEO on 4T1 tumor-challenging mice and cytokine assay confirmed anti-tumor effects of OEO and development of an immune response related to Th1 expansion.

CONCLUSION

These data shed light on the apoptotic mechanisms related to OEO cytotoxicity and introduced this compound as a candidate in cancer therapy.

Anti-tumor properties of anthocyanins from Lonicera caerulea 'Beilei' fruit on human hepatocellular carcinoma: In vitro and in vivo study

In this study, the anthocyanin from Lonicera caerulea 'Beilei' fruit (ABL) was extracted and purified. The purified component (ABL-2) was then evaluated for its anti-tumor properties on human hepatoma cells (SMMC-7721) in vitro and the murine hepatoma cells (H22) in vivo. In vitro, ABL-2 not only significantly inhibited the growth of SMMC-7721 cells, but also remarkably blocked the cells' cycle in G2/M phase, inducing DNA damage and eventually leading to apoptosis. In vivo, ABL also killed tumor cells, inhibited tumor growth, and improved the survival status of H22 tumor-bearing mice. These effects were associated with an increase in the activities of antioxidase and a decrease in the level of lipid peroxidation, as evidenced by changes in SOD, GSH-Px, GSH, and MDA levels. In addition, ABL-2 also regulated the levels of immune cytokines including IL-2, IFN-γ, and TNF-α. These results revealed that ABL-2 exerts an effective anti-tumor effect by dynamically adjusting the REDOX balance and improving the immunoregulatory activity of H22 tumor-bearing mice. High performance liquid chromatography (HPLC) analysis revealed that cyanidin-3,5-diglucoside (8.16 mg/g), cyanidin-3-glucoside (387.60 mg/g), cyanidin-3-rutinoside (23.62 mg/g), and peonidin-3-glucoside (22.20 mg/g) were the main components in ABL-2, which may contribute to its anti-tumor activity.