Co-delivery of docetaxel and silibinin using pH-sensitive micelles improves therapy of metastatic breast cancer

Natural compounds-based nanomedicines for cancer treatment: Future directions and challenges

Several efforts have been extensively accomplished for the amelioration of the cancer treatments using different types of new drugs and less invasives therapies in comparison with the traditional therapeutic modalities, which are widely associated with numerous drawbacks, such as drug resistance, non-selectivity and high costs, restraining their clinical response. The application of natural compounds for the prevention and treatment of different cancer cells has attracted significant attention from the pharmaceuticals and scientific communities over the past decades. Although the use of nanotechnology in cancer therapy is still in the preliminary stages, the application of nanotherapeutics has demonstrated to decrease the various limitations related to the use of natural compounds, such as physical/chemical instability, poor aqueous solubility, and low bioavailability. Despite the nanotechnology has emerged as a promise to improve the bioavailability of the natural compounds, there are still limited clinical trials performed for their application with various challenges required for the pre-clinical and clinical trials, such as production at an industrial level, assurance of nanotherapeutics long-term stability, physiological barriers and safety and regulatory issues. This review highlights the most recent advances in the nanocarriers for natural compounds secreted from plants, bacteria, fungi, and marine organisms, as well as their role on cell signaling pathways for anticancer treatments. Additionally, the clinical status and the main challenges regarding the natural compounds loaded in nanocarriers for clinical applications were also discussed.

Genipin-crosslinked albumin nanoparticles containing neratinib and silibinin: A dual-death therapy for triple negative breast cancer

Triple negative breast cancer (TNBC) cells resist chemotherapy by hijacking apoptosis. Alternative cell death forms like ferroptosis offer new treatment options. A combined therapy using neratinib (NTB; ferroptosis inducer) and silibinin (SLB; apoptosis inducer) via albumin-based nanocarriers (N-S Alb NPs) was explored to target TNBC. N-S Alb NPs had optimal size (134.26 ± 10.23 nm), PDI (0.224 ± 0.01), and % entrapment efficiency (∼80 % for NTB and ∼87 % for SLB). Transmission electron microscopy confirmed their spherical shape. In vitro release studies showed sustained drug release without hemolysis risk. N-S Alb NPs had higher cellular uptake and cytotoxicity than individual drugs or their mixture. IC50 values for N-S Alb NPs were significantly reduced in MDA-MB-231 (∼2.23-fold) and 4T1 (∼1.85-fold) cell lines and apoptosis index were significantly higher in MDA-MB-231 (∼1.31-fold) and 4T1 cell line (∼1.35-fold) than the physical mixture of both drugs (NTB + SLB). N-S Alb NPs generated more reactive oxygen species (ROS) and caused mitochondrial membrane depolarization, indicating increased cell death. They also exhibited better ferroptosis induction by reducing glutathione (GSH), increasing Fe2+ activity and MDA levels in TNBC cells. Thus, N-S Alb NPs had the ability to promote "mixed" type cell death, showed promise in enhancing the payload capabilities and targeting in TNBC.

Lipid-based nanoparticle-mediated combination therapy for breast cancer management: a comprehensive review

Breast cancer due to the unpredictable and complex etiopathology combined with the non-availability of any effective drug treatment has become the major root of concern for oncologists globally. The number of women affected by the said disease state is increasing at an alarming rate attributed to environmental and lifestyle changes indicating at the exploration of a novel treatment strategy that can eradicate this aggressive disease. So far, it is treated by promising nanomedicine monotherapy; however, according to the numerous studies conducted, the inadequacy of these nano monotherapies in terms of elevated toxicity and resistance has been reported. This review, therefore, puts forth a new multimodal strategic approach to lipid-based nanoparticle-mediated combination drug delivery in breast cancer, emphasizing the recent advancements. A basic overview about the combination therapy and its index is firstly given. Then, the various nano-based combinations of chemotherapeutics involving the combination delivery of synthetic and herbal agents are discussed along with their examples. Further, the recent exploration of chemotherapeutics co-delivery with small interfering RNA (siRNA) agents has also been explained herein. Finally, a section providing a brief description of the delivery of chemotherapeutic agents with monoclonal antibodies (mAbs) has been presented. From this review, we aim to provide the researchers with deep insight into the novel and much more effective combinational lipid-based nanoparticle-mediated nanomedicines tailored specifically for breast cancer treatment resulting in synergism, enhanced antitumor efficacy, and low toxic effects, subsequently overcoming the hurdles associated with conventional chemotherapy.

Co-encapsulation of flavonoids with anti-cancer drugs: a challenge ahead

Flavonoids have been considered as promising molecules for cancer treatment due to their pleiotropic properties such as anti-carcinogenic, anti-angiogenic or efflux proteins inhibition. However, due to their lipophilic properties and their chemical instability, vectorization seems compulsory to administer flavonoids. Flavonoids have been co-encapsulated with other anti-cancer agents in a broad range of nanocarriers aiming to i) achieve a synergistic/additive effect at the tumor site, ii) delay drug resistance apparition by combining agents with different action mechanisms or iii) administer a lower dose of the anti-cancer drug, reducing its toxicity. However, co-encapsulation could lead to a change in the nanoparticles' diameter and drug-loading, as well as a decrease in their stability during storage. The preparation process should also take into accounts the physico-chemical properties of both the flavonoid and the anti-cancer agent. Moreover, the co-encapsulation could affect the release and activity of each drug. This review aims to study the formulation, preparation and characterization strategies of these co-loaded nanomedicines, as well as their stability. The in vitro assays to predict the nanomedicines' behavior in biological fluids, as well as their in vivo efficacy, are also discussed. A special focus concerns the evaluation of their synergistic effect on tumor treatment.

Nano drug delivery systems improve metastatic breast cancer therapy

Despite continual progress in the technologies and regimens for cancer therapy, the treatment outcome of fatal metastatic breast cancer is far from satisfactory. Encouragingly, nanotechnology has emerged as a valuable tool to optimize drug delivery process in cancer therapy via preventing the cargos from degradation, improving the tumor-targeting efficiency, enhancing therapeutic agents' retention in specific sites, and controlling drug release. In the last decade, several mechanisms of suppressing tumor metastasis by functional nano drug delivery systems (NDDSs) have been revealed and a guidance for the rational design of anti-metastasis NDDSs is summarized, which consist of three aspects: optimization of physiochemical properties, tumor microenvironment remodeling, and biomimetic strategies. A series of medicinal functional biomaterials and anti-metastatic breast cancer NDDSs constructed by our team are introduced in this review. It is hoped that better anti-metastasis strategies can be inspired and applied in clinic.

Enhanced anticancer efficacy of docetaxel through galbanic acid encapsulated into PLA-PEG nanoparticles in treatment of colon cancer, in vitro and in vivo study

Cancer is one of the most leading causes of human mortality and despite outstanding breakthrough in introducing new therapeutic approaches, the clinical outcomes are disappointing. Therefore, extensive research in design and preparation of more efficient drug delivery systems can open a window to shine light into the therapeutic modality. In this study, we evaluated the effect of galbanic acid (GBA) encapsulated into PLA-PEG nanoparticles (NPs) to enhanced anticancer efficacy of docetaxel (DOC) for the treatment of colon cancer. Prepared NPs were characterized by different methods in terms of size, zeta potential, and drug loading capacity. MTT assay was used to investigate the anti-proliferation of GBA-loaded PEG-PLA NPs along with DOC. The therapeutic efficacy of PEG-PLA@GBA NPs & DOC was further investigated in C26 tumor-bearing BALB/c mice model. The resulting NPs were narrowly distributed (PDI = 0.06) with the mean diameter of 148 ± 9 nm with somewhat negative charge. GBA were efficiently loaded into mPEG-PLA NPs with encapsulation efficiency of about 40% ± 3. Cytotoxicity studies showed that NPs loaded with GBA and fixed concentration of docetaxel (20 nM) have higher toxicity (IC50 = 6 ± 1.8 µM) than either PEG-PLA@GBA (IC50 = 8 ± 1.2 µM) or free GBA (IC50 = 15 ± 3.5 µM) in C26 cells. In vivo studies revealed a synergistic effect of PEG-PLA@GBA NPs and DOC on tumor growth inhibition and survival rate in comparison with monotherapy approach.

Breast Tumor-Derived Exosomal MicroRNA-200b-3p Promotes Specific Organ Metastasis Through Regulating CCL2 Expression in Lung Epithelial Cells

Malignant metastasis is the most important cause of death in breast cancer (BC) patients, while the lung is a major inflammation and metastatic target organ. Exosomes are nano-sized vesicles that could be uptaken by resident cells to generate the pre-metastatic niche before tumor cells preferentially motility. In the present study, we demonstrated that high expression of C-C motif chemokine ligand 2 (CCL2) in lung could recruit the myeloid-derived suppressor cells (MDSCs) and contribute to the establishment of microenvironment. CCL2 provided recruitment of immune cells under carcinomas conditions and inflammatory responses. We also developed the novel mice model for specific over-expressing CCL2 in the lung, and verified that the BC organotropic metastasis was not because of the enhanced tumor cell proliferation, but the regulatory expression of CCL2 in the target organ. To better explore the crosstalk of exosomal molecules and CCL2 in host tissue, we constructed the "education" lung by exosomes intravenous injection and determined the prominent exosome-uptake by alveolar epithelial type II cells in vivo. Furthermore, we identified the exosomal microRNA-200b-3p could bind to PTEN, which may involved in the regulation of AKT/NF-κB/CCL2 cascades. Therefore, our study suggest that CCL2 expression in the lung was regulated by BC-derived exosomal microRNA, which primed the pre-metastastatic niche and may be a prognostic marker for the development of BC lung metastasis.

New Insights Toward Nanostructured Drug Delivery of Plant-Derived Polyphenol Compounds: Cancer Treatment and Gene Expression Profiles

The increasing prevalence of cancer has led to the expansion of traditional medicine objectives for developing novel drug delivery systems. A wide range of plant-derived polyphenol bioactive substances have been investigated in order to explore anti-cancer effects of these natural compounds and to promote effective treatment of cancer through apoptosis induction. In this regard, plant-derived polyphenol compounds including curcumin, silibinin, quercetin, and resveratrol have been the subject of intense interest for anti-cancer applications due to their ability in regulating apoptotic genes. However, some limitations of pure polyphenol compounds, such as poor bioavailability, short-term stability, low-cellular uptake, and insufficient solubility, have restricted their efficiency. Nanoscale formulations of bioactive agents have provided a novel platform to address these limitations. This paper reviews recent advances in nanoformulation approaches of polyphenolic drugs, and their effects on improving the delivery of chemotherapy agents to cancer cells.

Lipid/PAA-coated mesoporous silica nanoparticles for dual-pH-responsive codelivery of arsenic trioxide/paclitaxel against breast cancer cells

Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

Nano-soldiers Ameliorate Silibinin Delivery: A Review Study

Flavonoids are a large group of naturally occurring compounds, which are of interest due to their great pharmacological effects and health-promoting impacts. These properties have led to their extensive application in a variety of pathological conditions, particularly cancer. Flavonoids are used in large quantities in a human's daily diet and a high amount of flavonoids are found in the intestine after oral usage. However, flavonoid concentrations in tissue/plasma are low because of their low bioavailability, the leading to the low efficacy of flavonoids in different clinical disorders. For this reason, nanotechnology application for delivering flavonoids to tumor sites has recently received significant attention. Silibinin is a key member of flavonoids and a bioactive component of silymarin, which is widely isolated from Silybum marianum. This plant-derived chemical has a number of valuable biological and therapeutic activities such as antioxidant, anti-inflammatory, neuroprotective, anti-tumor, hepatoprotective, cardioprotective and anti-diabetic. These beneficial effects have been demonstrated in in vivo and in vitro experiments. However, it seems that silibinin has a variety of limitations and poor bioavailability is the most important factor restricting its wide application. Hence, there have been attempts to improve the bioavailability of silibinin and it has been suggested that nano-soldiers are potential candidates for this aim. In the present review, we describe the different drug delivery systems for improving the bioavailability of silibinin.

Path of Silibinin from diet to medicine: A dietary polyphenolic flavonoid having potential anti-cancer therapeutic significance

In the last few decades, targeting cancer by the use of dietary phytochemicals has gained enormous attention. The plausible reason and believe or mind set behind this fact is attributed to either lesser or no side effects of natural compounds as compared to the modern chemotherapeutics, or due to their conventional use as dietary components by mankind for thousands of years. Silibinin is a naturally derived polyphenol (a flavonolignans), possess following biochemical features; molecular formula C₂₅H₂₂O₁₀, Molar mass: 482.44 g/mol, Boiling point 793 °C, with strikingly high antioxidant and anti-tumorigenic properties. The anti-cancer properties of Silibinin are determined by a variety of cellular pathways which include induction of apoptosis, cell cycle arrest, inhibition of angiogenesis and metastasis. In addition, Silibinin controls modulation of the expression of aberrant miRNAs, inflammatory response, and synergism with existing anti-cancer drugs. Therefore, modulation of a vast array of cellular responses and homeostatic aspects makes Silibinin an attractive chemotherapeutic agent. However, like other polyphenols, the major hurdle to declare Silibinin a translational chemotherapeutic agent, is its lesser bioavailability. After summarizing the chemistry and metabolic aspects of Silibinin, this extensive review focuses on functional aspects governed by Silibinin in chemoprevention with an ultimate goal of summarizing the evidence supporting the chemopreventive potential of Silibinin and clinical trials that are currently ongoing, at a single platform.

Functional oral nanoparticles for delivering silibinin and cryptotanshinone against breast cancer lung metastasis

Background

Breast cancer lung metastasis occurs in more than 60% of all patients with breast cancer, and most of those afflicted by it eventually die of recurrence. The tumor microenvironment plays vital roles in metastasis. Modulating the tumor microenvironment via multiple pathways could efficiently prevent or inhibit lung metastasis. Silibinin and cryptotanshinone are natural plant products that demonstrate anti-metastasis effects and modulate the tumor microenvironment via different pathways. However, they have poor aqueous solubility, membrane permeability, and oral bioavailability. Oral drug administration may help improve the quality of life and compliance of patients with breast cancer, primarily under long-term and/or follow-up therapy. Herein, we developed poly-N-(2-hydroxypropyl) methacrylamide (pHPMA)-coated wheat germ agglutinin-modified lipid-polymer hybrid nanoparticles, co-loaded with silibinin and cryptotanshinone (S/C-pW-LPNs). We assessed their oral bioavailability, and evaluated their anti-metastasis efficacy in a 4T1 breast cancer tumor-bearing nude mouse model.

Results

An in vitro mucus diffusion study revealed that pHPMA enhanced W-LPN mucus penetration. After oral administration, pHPMA enhanced nanoparticle distribution in rat jejunum and substantially augmented oral bioavailability. S/C-W-LPNs markedly increased 4T1 cell toxicity and inhibited cell invasion and migration. Compared to LPNs loaded with either silibinin or cryptotanshinone alone, S/C-pW-LPNs dramatically slowed tumor progression in 4T1 tumor-bearing nude mice. S/C-pW-LPNs presented with the most robust anti-metastasis activity on smooth lung surfaces and mitigated lung metastasis foci. They also downregulated tumor microenvironment biomarkers such as CD31, TGF-β1, and MMP-9 that promote metastasis.

Conclusions

Silibinin- and cryptotanshinone-co-loaded pW-LPNs efficiently penetrate intestinal barriers, thereby enhancing the oral bioavailability of the drug loads. These nanoparticles exhibit favorable anti-metastasis effects in breast cancer-bearing nude mice. Hence, S/C-pW-LPNs are promising oral drug nanocarriers that inhibit breast cancer lung metastasis.

Interface crosslinked mPEG-b-PAGE-b-PCL triblock copolymer micelles with high stability for anticancer drug delivery

The stability of polymeric micelles is a key property for anticancer drug delivery. In this study, a novel amphiphilic triblock copolymer, methoxy poly(ethylene glycol)-b-poly(allyl glycidyl ether)-b-poly(ε-caprolactone) (mPEG-b-PAGE-b-PCL), with different hydrophobic lengths was designed and synthesized using the combination of two successive ring-opening polymerizations. The products were characterized using ¹H NMR and gel permeation chromatography (GPC). The triblock copolymers could self-assemble into micelles to encapsulate doxorubicin (DOX). The diameter of the DOX-loaded micelles increased from 63 to 92 nm with increasing PCL block length in the copolymer composition. The interface of the mPEG-b-PAGE-b-PCL micelles was crosslinked by a thiol-ene reaction with 1,4-butanedithiol. The stability, drug release and in vitro cytotoxicity of the DOX-loaded micelles were studied. The results showed that the DOX-loaded micelles could be effectively endocytosed by cancer cells and have good antitumor efficacy. In addition, the crosslinked micelles (CLMs) had better tumor accumulation than the noncrosslinked micelles (NCLMs) after intravenous injection using the lipophilic dye DiR.

Co-Delivery Nanosystems for Cancer Treatment: A Review

Massive data available on cancer therapy more than ever lead our mind to the general concept that there is no perfect treatment for cancer. Indeed, the biological complexity of this disease is too excessive to be treated by a single therapeutic approach. Current delivery systems containing a specific drug or gene have their particular opportunities and restrictions. It is worth noting that a considerable number of studies suggest that single- drug delivery systems result in insufficient suppression of cancer growth. Therefore, one of the main ideas of co-delivery system designing is to enhance the intended response or to achieve the synergistic/combined effect compared to the single drug strategy. This review focuses on various strategies for co-delivery of therapeutic agents in the treatment of cancer. The primary approaches within the script are categorized into co-delivery of conventional chemotherapeutics, gene-based molecules, and plant-derived materials. Each one is explained in examples with the recent researches. In the end, a brief summary is provided to conclude the gist of the review.