Folate-mediated mitochondrial targeting with doxorubicin-polyrotaxane nanoparticles overcomes multidrug resistance

Mitochondrial signaling pathways and their role in cancer drug resistance

Mitochondria, traditionally known as cellular powerhouses, now emerge as critical signaling centers influencing cancer progression and drug resistance. The review highlights the role that apoptotic signaling, DNA mutations, mitochondrial dynamics and metabolism play in the development of resistance mechanisms and the advancement of cancer. Targeted approaches are discussed, with an emphasis on managing mitophagy, fusion, and fission of the mitochondria to make resistant cancer cells more susceptible to traditional treatments. Additionally, metabolic reprogramming can be used to effectively target metabolic enzymes such GLUT1, HKII, PDK, and PKM2 in order to avoid resistance mechanisms. Although there are potential possibilities for therapy, the complex structure of mitochondria and their subtle role in tumor development hamper clinical translation. Novel targeted medicines are put forth, providing fresh insights on combating drug resistance in cancer. The study also emphasizes the significance of glutamine metabolism, mitochondrial respiratory complexes, and apoptotic pathways as potential targets to improve treatment effectiveness against drug-resistant cancers. Combining complementary and nanoparticle-based techniques to target mitochondria has demonstrated encouraging results in the treatment of cancer, opening doors to reduce resistance and enable individualized treatment plans catered to the unique characteristics of each patient. Suggesting innovative approaches such as drug repositioning and mitochondrial drug delivery to enhance the efficacy of mitochondria-targeting therapies, presenting a pathway for advancements in cancer treatment. This thorough investigation is a major step forward in the treatment of cancer and has the potential to influence clinical practice and enhance patient outcomes.

Mitochondrial adaptation in cancer drug resistance: prevalence, mechanisms, and management

Drug resistance represents a major obstacle in cancer management, and the mechanisms underlying stress adaptation of cancer cells in response to therapy-induced hostile environment are largely unknown. As the central organelle for cellular energy supply, mitochondria can rapidly undergo dynamic changes and integrate cellular signaling pathways to provide bioenergetic and biosynthetic flexibility for cancer cells, which contributes to multiple aspects of tumor characteristics, including drug resistance. Therefore, targeting mitochondria for cancer therapy and overcoming drug resistance has attracted increasing attention for various types of cancer. Multiple mitochondrial adaptation processes, including mitochondrial dynamics, mitochondrial metabolism, and mitochondrial apoptotic regulatory machinery, have been demonstrated to be potential targets. However, recent increasing insights into mitochondria have revealed the complexity of mitochondrial structure and functions, the elusive functions of mitochondria in tumor biology, and the targeting inaccessibility of mitochondria, which have posed challenges for the clinical application of mitochondrial-based cancer therapeutic strategies. Therefore, discovery of both novel mitochondria-targeting agents and innovative mitochondria-targeting approaches is urgently required. Here, we review the most recent literature to summarize the molecular mechanisms underlying mitochondrial stress adaptation and their intricate connection with cancer drug resistance. In addition, an overview of the emerging strategies to target mitochondria for effectively overcoming chemoresistance is highlighted, with an emphasis on drug repositioning and mitochondrial drug delivery approaches, which may accelerate the application of mitochondria-targeting compounds for cancer therapy.

Peptides vs. Polymers: Searching for the Most Efficient Delivery System for Mitochondrial Gene Therapy

Together with the nucleus, the mitochondrion has its own genome. Mutations in mitochondrial DNA are responsible for a variety of disorders, including neurodegenerative diseases and cancer. Current therapeutic approaches are not effective. In this sense, mitochondrial gene therapy emerges as a valuable and promising therapeutic tool. To accomplish this goal, the design/development of a mitochondrial-specific gene delivery system is imperative. In this work, we explored the ability of novel polymer- and peptide-based systems for mitochondrial targeting, gene delivery, and protein expression, performing a comparison between them to reveal the most adequate system for mitochondrial gene therapy. Therefore, we synthesized a novel mitochondria-targeting polymer (polyethylenimine-dequalinium) to load and complex a mitochondrial-gene-based plasmid. The polymeric complexes exhibited physicochemical properties and cytotoxic profiles dependent on the nitrogen-to-phosphate-group ratio (N/P). A fluorescence confocal microscopy study revealed the mitochondrial targeting specificity of polymeric complexes. Moreover, transfection mediated by polymer and peptide delivery systems led to gene expression in mitochondria. Additionally, the mitochondrial protein was produced. A comparative study between polymeric and peptide/plasmid DNA complexes showed the great capacity of peptides to complex pDNA at lower N/P ratios, forming smaller particles bearing a positive charge, with repercussions on their capacity for cellular transfection, mitochondria targeting and, ultimately, gene delivery and protein expression. This report is a significant contribution to the implementation of mitochondrial gene therapy, instigating further research on the development of peptide-based delivery systems towards clinical translation.

Actively Targeted Nanomedicines in Breast Cancer: From Pre-Clinal Investigation to Clinic

Simple Summary

Despite all the efforts and advances made in the treatment of breast cancer, this pathology continues to be one of the main causes of cancer death in women, particularly triple-negative breast cancer (TNBC), and, although to a lesser degree, HER-2 receptor-positive tumors. Chemotherapy is one of the main treatments available. However, it shows numerous limitations due to its lack of selectivity. In this sense, the selective delivery of antineoplastics to cancer cells can reduce their adverse effects and increase their efficacy. The use of active targeted nanomedicine is a good strategy to achieve this selective chemotherapy. In fact, in recent decades, several active targeted nanoformulations have been approved or reached clinical investigation with excellent results. Among all nanomedicines, antibody-drug conjugates are the most promising.

Abstract

Breast cancer is one of the most frequently diagnosed tumors and the second leading cause of cancer death in women worldwide. The use of nanosystems specifically targeted to tumor cells (active targeting) can be an excellent therapeutic tool to improve and optimize current chemotherapy for this type of neoplasm, since they make it possible to reduce the toxicity and, in some cases, increase the efficacy of antineoplastic drugs. Currently, there are 14 nanomedicines that have reached the clinic for the treatment of breast cancer, 4 of which are already approved (Kadcyla^®, Enhertu^®, Trodelvy^®, and Abraxane^®). Most of these nanomedicines are antibody–drug conjugates. In the case of HER-2-positive breast cancer, these conjugates (Kadcyla^®, Enhertu^®, Trastuzumab-duocarmycin, RC48, and HT19-MMAF) target HER-2 receptors, and incorporate maytansinoid, deruxtecan, duocarmicyn, or auristatins as antineoplastics. In TNBC these conjugates (Trodelvy^®, Glembatumumab-Vedotin, Ladiratuzumab-vedotin, Cofetuzumab-pelidotin, and PF-06647263) are directed against various targets, in particular Trop-2 glycoprotein, NMB glycoprotein, Zinc transporter LIV-1, and Ephrin receptor-4, to achieve this selective accumulation, and include campthotecins, calicheamins, or auristatins as drugs. Apart from the antibody–drug conjugates, there are other active targeted nanosystems that have reached the clinic for the treatment of these tumors such as Abraxane^® and Nab-rapamicyn (albumin nanoparticles entrapping placlitaxel and rapamycin respectively) and various liposomes (MM-302, C225-ILS-Dox, and MM-310) loaded with doxorubicin or docetaxel and coated with ligands targeted to Ephrin A2, EPGF, or HER-2 receptors. In this work, all these active targeted nanomedicines are discussed, analyzing their advantages and disadvantages over conventional chemotherapy as well as the challenges involved in their lab to clinical translation. In addition, examples of formulations developed and evaluated at the preclinical level are also discussed.

Polymeric Nanoparticles for Mitochondria Targeting Mediated Robust Cancer Therapy

Despite all sorts of innovations in medical researches over the past decades, cancer remains a major threat to human health. Mitochondria are essential organelles in eukaryotic cells, and their dysfunctions contribute to numerous diseases including cancers. Mitochondria-targeted cancer therapy, which specifically delivers drugs into the mitochondria, is a promising strategy for enhancing anticancer treatment efficiency. However, owing to their special double-layered membrane system and highly negative potentials, mitochondria remain a challenging target for therapeutic agents to reach and access. Polymeric nanoparticles exceed in cancer therapy ascribed to their unique features including ideal biocompatibility, readily design and synthesis, as well as flexible ligand decoration. Significant efforts have been put forward to develop mitochondria-targeted polymeric nanoparticles. In this review, we focused on the smart design of polymeric nanosystems for mitochondria targeting and summarized the current applications in improving cancer therapy.

Dual-Responsive and Deep-Penetrating Nanomicelles for Tumor Therapy via Extracellular Matrix Degradation and Oxidative Stress

Tumor microenvironment (TME), with complex composition, plays a vital role in the occurrence, development, and metastasis of tumors. TME becomes an important obstacle to the accessibility of nanotherapy, thus indicating the need to improve the functional design to overcome this challenge. In this study, we generate an intelligent nano-drug-delivery system (DOX@PssP-Hh NPs) with dual environmental response, which involves heparanase (HPSE) in TME and glutathione (GSH) in tumor cells. The nanosystem consists of a nanoskeleton formed by self-assembly of mPEG-ss-PEI and α-CD (PssP), chemotherapy drug doxorubicin (DOX) for enhancing antitumor efficacy, together with hyaluronidase (HAase), which is designed to degrade extracellular matrix to increase drug penetration, and an outer shell of heparin. Through the process of "responsive disintegration-remodeling tumor microenvironment-enhancing drug penetration-inducing oxidative stress", the semi-rotaxaneself-assembled nanomicelles were constructed to achieve the progressive function. DOX@PssP-Hh NPs with the size of 81.85 ± 1.85 nm exhibited satisfactory cytotoxicity (IC₅₀ = 0.80 ± 0.33 μg/mL). With the disulfide bond-mediated GSH depletion and DOX-mediated reactive oxygen species (ROS) production, treatment with DOX@PssP-Hh NPs prominently reduced glutathione peroxidase 4 (GPX4) level and would lead to enhanced oxidative stresses. Hyaluronic acid (HA), collagen I, and α-smooth muscle actin (α-SMA) were significantly reduced for TME remodulation. Moreover, the antitumor effect in vivo implied that DOX@PssP-Hh NPs could inhibit tumor growth effectively and reduce tumor interstitial fluid pressure (IFP) evidently. In conclusion, DOX@PssP-Hh NPs improved the penetration of drugs and exhibited enhanced antitumor efficacy.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.

Cyclodextrins in Drug Delivery Systems and Their Effects on Biological Barriers

Cyclodextrins are widely used excipients, composed of glucopyranose units with a cyclic structure. One of their most important properties, is that their inner cavity is hydrophobic, while their surface is hydrophilic. This enables them for the complex formation with lipophilic molecules. They have several applications in the pharmaceutical field like solubility enhancers or the building blocks of larger drug delivery systems. On the other hand, they have numerous effects on cells or biological barriers. In this review the most important properties of cyclodextrins and cyclodextrin-based drug delivery systems are summarized with special focus on their biological activity.

Folate-conjugated nanovehicles: Strategies for cancer therapy

Cancer theranostics represents a strategy that aims at combining diagnosis with therapy through the simultaneous imaging and targeted delivery of therapeutics to cancer cells. Recently, the folate receptor alpha has emerged as an attractive theranostic target due to its overexpression in multiple solid tumors and its great functional versatility. In fact, it can be incorporated into folate-conjugated nano-systems for imaging and drug delivery. Hence, it can be used along the line of personalized clinical strategies as both an imaging tool and a delivery method ensuring the selective transport of treatments to tumor cells, thus highlighting its theranostic qualities. In this review, we will explore these theranostic characteristics in detail and assess their clinical potential. We will also discuss the technological advances that have allowed the design of sophisticated folate-based nanocarriers harboring various chemical properties and suited for the transport of various therapeutic agents.

Active Cellular and Subcellular Targeting of Nanoparticles for Drug Delivery

Nanoparticle (NP)-mediated drug delivery (NMDD) for active targeting of diseases is a primary goal of nanomedicine. NPs have much to offer in overcoming the limitations of traditional drug delivery approaches, including off-target drug toxicity and the need for the administration of repetitive doses. In the last decade, one of the main foci in NMDD has been the realization of NP-mediated drug formulations for active targeted delivery to diseased tissues, with an emphasis on cellular and subcellular targeting. Advances on this front have included the intricate design of targeted NP-drug constructs to navigate through biological barriers, overcome multidrug resistance (MDR), decrease side effects, and improve overall drug efficacy. In this review, we survey advancements in NP-mediated drug targeting over the last five years, highlighting how various NP-drug constructs have been designed to achieve active targeted delivery and improved therapeutic outcomes for critical diseases including cancer, rheumatoid arthritis, and Alzheimer's disease. We conclude with a survey of the current clinical trial landscape for active targeted NP-drug delivery and how we envision this field will progress in the near future.

Implications of nanotechnology for the treatment of cancer: Recent advances

The use of nanoparticles dramatically increases the safety and efficacy of the most common anticancer drugs. The main advantages of nano-drugs and delivery systems based on nano-technology are effective targeting, delayed release, increased half-life, and less systemic toxicity. The use of nano-carriers has led to significant improvements in drug delivery to targets compared with traditional administration of these drugs. In this review, the main tendencies in nano-drug formulations as well as factors limiting their use in clinical settings are discussed. Additionally, the current status of approved nano-drugs for cancer treatment is reviewed.

Enhanced Subcellular Trafficking of Resveratrol Using Mitochondriotropic Liposomes in Cancer Cells

Mitochondria are membrane-enclosed organelles present in most eukaryotic cells, described as “power houses of the cell”. The mitochondria can be a target for inducing cancer cell death and for developing strategies to bypass multi drug resistance (MDR) mechanisms. 4-Carboxybutyl triphenylphosphonium bromide-polyethylene glycol-distearoylphosphatidylethanolamine (TPP-DSPE-PEG) and dequalinium-polyethylene glycol-distearoylphosphatidylethanolamine (DQA-DSPE-PEG) were synthesized as mitochondriotropic molecules. Mitochondria-targeting liposomes carrying resveratrol were constructed by modifying the liposome’s surface with TPP-PEG or DQA-PEG, resulting in TLS (Res) and DLS (Res), respectively, with the aim to obtain longer blood circulation and enhanced permeability and retention (EPR). Both TLS (Res) and DLS (Res) showed dimensions of approximately 120 nm and a slightly positive zeta potential. The enhanced cellular uptake and selective accumulation of TLS (Res) and DLS (Res) into the mitochondria were demonstrated by behavioral observation of rhodamine-labeled TLS or DLS, using confocal microscopy, and by resveratrol quantification in the intracellular organelle, using LC–MS/MS. Furthermore, TLS (Res) and DLS (Res) induced cytotoxicity of cancer cells by generating reactive oxygen species (ROS) and by dissipating the mitochondrial membrane potential. Our results demonstrated that TLS (Res) and DLS (Res) could provide a potential strategy to treat cancers by mitochondrial targeting delivery of therapeutics and stimulation of the mitochondrial signaling pathway.

Strategies to target bioactive molecules to subcellular compartments. Focus on natural compounds

Many potential pharmacological targets are present in multiple subcellular compartments and have different pathophysiological roles depending on location. In these cases, selective targeting of a drug to the relevant subcellular domain(s) may help to sharpen its impact by providing topological specificity, thus limiting side effects, and to concentrate the compound where needed, thus increasing its effectiveness. We review here the state of the art in precision subcellular delivery. The major approaches confer "homing" properties to the active principle via permanent or reversible (in pro-drug fashion) modifications, or through the use of special-design nanoparticles or liposomes to ferry a drug(s) cargo to its desired destination. An assortment of peptides, substituents with delocalized positive charges, custom-blended lipid mixtures, pH- or enzyme-sensitive groups provide the main tools of the trade. Mitochondria, lysosomes and the cell membrane may be mentioned as the fronts on which the most significant advances have been made. Most of the examples presented here have to do with targeting natural compounds - in particular polyphenols, known as pleiotropic agents - to one or the other subcellular compartment.

Synthesis and assessment of drug-eluting microspheres for transcatheter arterial chemoembolization

Transcatheter arterial chemoembolization (TACE) is well known as an effective treatment for inoperable hepatocellular carcinoma (HCC). In this study, a novel embolic agent of ion-exchange poly(hydroxyethyl methacrylate-acrylic acid) microspheres (HAMs) was successfully synthesized by the inverse suspension polymerization method. Then, HAMs were assessed for their activity as an embolic agent by investigating morphology, particle size, water retention capability, elasticity and viscoelasticity, microcatheter/catheter deliverability, cytotoxicity, renal arterial embolization to rabbits and histopathological examinations. The ability of drug loading and drug eluting of HAMs was also investigated by using doxorubicin (Dox) as the model drug. HAMs showed to be feasible and effective for vascular embolization and to be as a drug vehicle for loading positively charged molecules and potential use in the clinical interventional chemoembolization therapy. STATEMENT OF SIGNIFICANCE: A novel embolic agent of ion-exchange poly(hydroxyethyl methacrylate-acrylic acid) microspheres (HAMs) was successfully synthesized by the inverse suspension polymerization method and was used as a drug vehicle to load positively charged molecules by ion absorption. Then, a series of assessments including physicochemical properties, mechanical properties, drug-loading capability, and embolic efficacy were performed. Surface and cross-section morphology and pore size of fully hydrated HAMs were first investigated by Phenom ProX SEM, which intuitively disclosed the "honeycomb" network morphology. HAMs also showed to be feasible and effective for vascular occlusion and have potential use in clinical interventional embolization therapy.

Su Yang Decoction induces human colon carcinoma cell apoptosis by activating caspases

Su Yang Decoction (SYD) is a popular healthcare product comprised of various brassicaceous vegetables known to exhibit anticancer activity. However, the effects of SYD on tumor growth, following its combination with brassicaceous vegetables into a compound formula, require further investigation. In the present study, a quality control of SYD was subjected to high-performance liquid chromatography for the quantitative and qualitative determination of sulforaphane, the main anticancer component of SYD. SYD inhibited colon cancer cell proliferation in a dose- and time-dependent manner and induced G1 phase arrest in colon cancer HT-29 cell lines. In addition, SYD triggered caspase-mediated apoptosis in a dose-dependent manner and induced the cleavage of poly (ADP-ribose) polymerase, tumor necrosis factor superfamily member 10, X-linked inhibitor of apoptosis, and truncated BH3 interacting domain death agonist. Furthermore, the expression of FADD-like interleukin-1β-converting enzyme (FLICE)-like inhibitory proteins (FLIPs) and long isoform of FLICE-inhibitory protein was reduced by SYD and the direct targeting of cellular-FLIP with small interfering RNA inhibited colon cancer cell proliferation and decreased the SYD concentration required for proliferation inhibition. SYD treatment was also associated with the translocation of proapoptotic BCL2 associated X, apoptosis regulator to the mitochondria and the release of cytochrome c from the mitochondria to the cytosol. The aforementioned results indicate that SYD exerts anti-colorectal cancer effects through an underlying mechanism that may involve caspase activation.

Doxorubicin-loaded poly(ε-caprolactone)-Pluronic micelle for targeted therapy of esophageal cancer

There is still lack of effective treatment of esophageal cancer, and it is urgently necessary to develop a new programs to treat this disease. More and more evidence suggests that the combination of 2 or more treatment strategies can enhance the antitumor activity in cancer treatment. We have established a new therapeutic strategy that combines doxorubicin-loaded poly(ε-caprolactone) (PCL)-Pluronic micelles and miR-34a to better combat esophageal cancer. Doxorubicin was loaded into PCL-Pluronic micelle to achieve better uptake. Confocal microscopy was used to assess in vitro cellular uptake of PCL-Pluronic micelle. Finally, the in vivo effect of this new combination therapy strategy was also studied. The results showed that PCL-Plannick micelles significantly enhanced the uptake of doxorubicin in esophageal cancer cells in vitro, thereby improving the accumulation of doxorubicin in the cells. In vitro and in vivo combination of doxorubicin-loaded PCL-Pluronic micelles and miR-34a, achieving a significantly synergistic therapeutic effect over the corresponding single treatment. These results suggested that the combinational therapy based on doxorubicin-loaded PCL-Pluronic micelle and miR-34a may provide a reasonable strategy for improving the outcome of esophageal cancer treatment.

Supramolecular Pharmaceutical Sciences: A Novel Concept Combining Pharmaceutical Sciences and Supramolecular Chemistry with a Focus on Cyclodextrin-Based Supermolecules

Supramolecular chemistry is an extremely useful and important domain for understanding pharmaceutical sciences because various physiological reactions and drug activities are based on supramolecular chemistry. However, it is not a major domain in the pharmaceutical field. In this review, we propose a new concept in pharmaceutical sciences termed "supramolecular pharmaceutical sciences," which combines pharmaceutical sciences and supramolecular chemistry. This concept could be useful for developing new ideas, methods, hypotheses, strategies, materials, and mechanisms in pharmaceutical sciences. Herein, we focus on cyclodextrin (CyD)-based supermolecules, because CyDs have been used not only as pharmaceutical excipients or active pharmaceutical ingredients but also as components of supermolecules.

Tri-block polymer with interfacial layer formation ability and its use in maintaining supersaturated drug solution after dissolution of solid dispersions

Background

Maintaining a supersaturated drug solution after the dissolution of the solid dispersions of water insoluble drugs continues to be a great challenge and is important to the oral bioavailability enhancement of hardly soluble drugs.

Methods

Nimodipine solid dispersions were prepared by hot-melt extrusion and a special tri-block polymer was employed as a co-carrier. The solid dispersions were characterized by modulated differential scanning calorimetry, transmission electron microscopy, hydrogen-nuclear magnetic resonance and so on.

Results

The tri-block polymer was able to inhibit the formation of drug crystals after dissolution of the solid dispersions. Due to the unique interfacial layer formation ability of the tri-block polymer, a special drug loading micelle which encapsulated the compound and the hydrophobic fragments of the copolymers appeared in the release media. The tri-block polymer was composed of a hydrophilic part forming the shell of micelles, a hydrophobic part shaping the core of micelles, and a special intermediate hydrophilicity part constructing the interfacial layer of micelles.

Conclusion

The tri-block polymer was not only able to stabilize the supersaturated drug solution of solid dispersions to enhance the oral bioavailability of hardly soluble drugs, but is also a potential candidate to construct micelles for systemic administration, due to the good compatibility and organic solvents free micelle formation procedure.

Quercetin and doxorubicin co-encapsulated biotin receptor-targeting nanoparticles for minimizing drug resistance in breast cancer

The combination of a chemotherapeutic drug with a chemosensitizer has emerged as a promising strategy for cancers showing multidrug resistance (MDR). Herein we describe the simultaneous targeted delivery of two drugs to tumor cells by using biotin-decorated poly(ethylene glycol)-b-poly(ε-caprolactone) nanoparticles encapsulating the chemotherapeutic drug doxorubicin and the chemosensitizer quercetin (BNDQ). Next, the potential ability of BNDQ to reverse MDR in vitro and in vivo was investigated. Studies demonstrated that BNDQ was more effectively taken up with less efflux by doxorubicin-resistant MCF-7 breast cancer cells (MCF-7/ADR cells) than by the cells treated with the free drugs, single-drug–loaded nanoparticles, or non-biotin–decorated nanoparticles. BNDQ exhibited clear inhibition of both the activity and expression of P-glycoprotein in MCF-7/ADR cells. More importantly, it caused a significant reduction in doxorubicin resistance in MCF-7/ADR breast cancer cells both in vitro and in vivo, among all the groups. Overall, this study suggests that BNDQ has a potential role in the treatment of drug-resistant breast cancer.

Aminoglucose-functionalized, redox-responsive polymer nanomicelles for overcoming chemoresistance in lung cancer cells

Background

Chemotherapeutic drugs used for cancer therapy frequently encounter multiple-drug resistance (MDR). Nanoscale carriers that can target tumors to accumulate and release drugs intracellularly have the greatest potential for overcoming MDR. Glucose transporter-1 (GLUT-1) and glutathione (GSH) overexpression in cancer cells was exploited to assemble aminoglucose (AG)-conjugated, redox-responsive nanomicelles from a single disulfide bond-bridged block polymer of polyethylene glycol and polylactic acid (AG-PEG-SS-PLA). However, whether this dual functional vector can overcome MDR in lung cancer is unknown.

Results

In this experiment, AG-PEG-SS-PLA was synthetized successfully, and paclitaxel (PTX)-loaded AG-PEG-SS-PLA (AG-PEG-SS-PLA/PTX) nanomicelles exhibited excellent physical properties. These nanomicelles show enhanced tumor targeting as well as drug accumulation and retention in MDR cancer cells. Caveolin-dependent endocytosis is mainly responsible for nanomicelle internalization. After internalization, the disulfide bond of AG-PEG-SS-PLA is cleaved in the presence of high intracellular glutathione levels, causing the hydrophobic core to become a polar aqueous solution, which subsequently results in nanomicelle disassembly and the rapid release of encapsulated PTX. Reduced drug resistance was observed in cancer cells in vitro. The caspase-9 and caspase-3 cascade was activated by the AG-PEG-SS-PLA/PTX nanomicelles through upregulation of the pro-apoptotic proteins Bax and Bid and suppression of the anti-apoptotic protein Bcl-2, thereby increasing apoptosis. Furthermore, significantly enhanced tumor growth inhibition was observed in nude mice bearing A549/ADR xenograft tumors after the administration of AG-PEG-SS-PLA/PTX nanomicelles via tail injection.

Conclusions

These promising results indicate that AG-PEG-SS-PLA/PTX nanomicelles could provide the foundation for a paradigm shift in MDR cancer therapy.

Electronic supplementary material

The online version of this article (10.1186/s12951-017-0316-z) contains supplementary material, which is available to authorized users.

Mitochondria-Targeting Polydopamine Nanoparticles To Deliver Doxorubicin for Overcoming Drug Resistance

Mitochondria play a critical role in diverse cellular processes, such as energy production and apoptosis regulation. The mitochondria-targeted drug delivery is becoming a potential novel strategy for overcoming drug resistance in cancer therapy. Herein, we synthesize nature-inspired dopamine-derived polydopamine (PDA) nanoparticles. Using triphenylphosphonium (TPP) as the mitochondrial penetration molecule to improve the target efficiency, we synthesize poly(ethylene glycol) (PEG)-modified PDA (PDA-PEG) and TPP-functionalized PEG-modified PDA (PDA-PEG-TPP) nanoparticles. Then anticancer drug doxorubicin (DOX) was loaded on PDA-PEG and PDA-PEG-TPP (PDA-PEG-DOX and PDA-PEG-TPP-DOX) nanoparticles, which are apt to deliver DOX to cell nuclei and mitochondria, respectively. To mimic the repeated anticancer drug treatment in clinical cases, we repeatedly treated the MDA-MD-231 cancer cells for a long time using DOX-loaded nanoparticles and find that the mitochondria targeting PDA-PEG-TPP-DOX has higher potential to overcome the drug resistance than the regular delivery nanoparticles PDA-PEG-DOX. These results indicate the promising potential of applying PDA-PEG-TPP-DOX nanoparticles in mitochondria-targeted drug delivery to overcome the drug resistance in long-time anticancer chemotherapy.

Folate receptor-targeted hybrid lipid-core nanocapsules for sequential delivery of doxorubicin and tanespimycin

When exposed to cancer cells, cytotoxic drugs such as doxorubicin (DOX) can lead to the induction of heat shock protein 90 (Hsp90), a molecular chaperone associated with a number of cancer-related client proteins, and result in cell survival. Co-administration of DOX with tanespimycin (TNP), an Hsp90 inhibitor, can sensitize the cancer cells to the cytotoxic effects of DOX. The effect of such a combination has been found to depend on the schedule of administration. Sequential administration of DOX and TNP has been linked to highly synergistic combination effects. Therefore, we aimed to develop folate-receptor targeted hybrid lipid-core nanocapsules comprising a hybrid lipid core lodging TNP and a polymeric corona lodging DOX (F-DTN). These nanocarriers were capable of delivering DOX and TNP sequentially, which was well demonstrated by an in vitro release study. The in vitro release profiles displayed pH-dependent and sustained release features. F-DTN exhibited excellent morphological characteristics with highly monodispersed particles. In vitro tests with F-DTN in MCF-7 cell line demonstrated exceptional cytotoxicity, with high cellular uptake and apoptosis. These findings were appreciably more assertive than tests with free individual drugs (DOX, TNP), free drug combination (DOX/TNP), or non-folate receptor-targeted hybrid lipid-core nanocapsules (DTN). In vivo pharmacokinetic study revealed noticeable enhancement of bioavailability and plasma circulation time of the drugs when encapsulated in the carrier system. Therefore, hybrid lipid-core nanocapsules have the potential to be utilized for application in folate receptor-targeted combination chemotherapy.

Photosensitizer-mediated mitochondria-targeting nanosized drug carriers: Subcellular targeting, therapeutic, and imaging potentials

Mitochondria-targeting drug carriers have considerable potential because of the presence of many molecular drug targets in the mitochondria and their pivotal roles in cellular viability, metabolism, maintenance, and death. To compare the mitochondria-targeting abilities of triphenylphosphonium (TPP) and pheophorbide a (PhA) in nanoparticles (NPs), this study prepared mitochondria-targeting NPs using mixtures of methoxy poly(ethylene glycol)-(SS-PhA)₂ [mPEG-(SS-PhA)₂ or PPA] and TPP-b-poly(ε-caprolactone)-b-TPP [TPP-b-PCL-b-TPP or TPCL], which were designated PPA_n-TPCL_4-n (0≤n≤4) NPs. With increasing TPCL content, the formed PPA_n-TPCL_4-n NPs decreased in size from 33nm to 18nm and increased in terms of positive zeta-potentials from -12mV to 33mV. Although the increased TPCL content caused some dark toxicity of the PPA_n-TPCL_4-n NPs due to the intrinsic positive character of TPCL, the NPs showed strong light-induced killing effects in tumor cells. In addition, the mitochondrial distribution of the PPA_n-TPCL_4-n NPs was analyzed and imaged by flow cytometry and confocal microscopy, respectively. Thus, the PhA-containing NPs specifically targeted the mitochondria, and light stimulation caused PhA-mediated therapeutic effects and imaging functions. Expanding the capabilities of these nanocarriers by incorporating other drugs should enable multiple potential applications (e.g., targeting, therapy, and imaging) for combination and synergistic treatments.

Design of a Mestranol 2-N-Piperazino-Substituted Derivative Showing Potent and Selective in vitro and in vivo Activities in MCF-7 Breast Cancer Models

Anticancer structure-activity relationship studies on aminosteroid (5α-androstane) derivatives have emerged with a promising lead candidate: RM-133 (2β-[1-(quinoline-2-carbonyl)pyrrolidine-2-carbonyl]-N-piperazine-5α-androstane-3α,17β-diol), which possesses high in vitro and in vivo activities against several cancer cells, and selectivity over normal cells. However, the relatively weak metabolic stability of RM-133 has been a drawback to its progression toward clinical trials. We investigated the replacement of the androstane backbone by a more stable mestranol moiety. The resulting compound, called RM-581 ({4-[17α-ethynyl-17β-hydroxy-3-methoxyestra-1,3,5(10)-trien-2-yl]piperazin-1-yl}[(2S)-1-(quinolin-2-ylcarbonyl)pyrrolidin-2-yl]methanone), was synthesized efficiently in only five steps from commercially available estrone. In comparison with RM-133, RM-581 was found to be twice as metabolically stable, retains potent cytotoxic activity in breast cancer MCF-7 cell culture, and fully blocks tumor growth in a mouse xenograft model of breast cancer. Advantageously, the selectivity over normal cells has been increased with this estrane version of RM-133. In fact, RM-581 showed a better selectivity index (15.3 vs. 3.0) for breast cancer MCF-7 cells over normal breast MCF-10A cells, and was found to be nontoxic toward primary human kidney proximal tubule cells at doses reaching 50 μm.

Immune activity and biodistribution of polypeptide K237 and folic acid conjugated amphiphilic PEG-PLGA copolymer nanoparticles radiolabeled with 99mTc

In a previous study, amphiphilic copolymer, polypeptide K237 (HTMYYHHYQHHL) and folic acid (FA) modified poly(ethylene glycol)-poly(lactic-co-glycolic acid) (K237/FA-PEG-PLGA) nanoparticles were developed and studied as a drug carrier. To further promote the clinical application of K237/FA-PEG-PLGA nanoparticles and provide guidance for future research, we need to examine their specific biodistribution in vivo. In this study, K237/FA-PEG-PLGA nanoparticles were effectively labeled by a direct method with Technetium-99m (99mTc) using stannous chloride as a reducing agent. The optimal stability of the labeled nanoparticles was determined by evaluating their radiochemical purity in serum, physiological saline, diethylenetriaminepentaacetic acid (DTPA) and cysteine solutions. The affinity of ligands and receptors was elicited by cell binding and blocking experiments in KDR/folate receptor high expressing SKOV-3 ovarian cancer cells. The nanoparticles biodistribution was studied after intravenous administration in healthy mice xenografted with SKOV-3 cells. A higher percent injected dose per gram of tissue (% ID/g) was observed in liver, kidney, spleen, blood and tumor at 3 and 9 h post-injection. Scintigraphic images revealed that the radioactivity was mainly concentrated in tumor, liver, kidney and bladder; and in the heart, lung, and muscle was significantly lower at 3 h. The radioactivity distribution in the images is consistent with the in vivo biodistribution data. Our works demonstrated that K237/FA-PEG-PLGA nanoparticles have great potential as biodegradable drug carriers, especially for tumors expressing the folate and KDr receptor.

Development of a multifunctional envelope-type nano device and its application to nanomedicine

Successful nanomedicines should be based on sound drug delivery systems (DDS) the permit intracellular trafficking as well as the biodistribution of cargos to be controlled. We have been developing new types of DDS that are multifunctional envelope-type nano devices referred to as MENDs. First, we will focus the in vivo delivery of siRNA to hepatocytes using a YSK-MEND which is composed of pH-responsive cationic lipids. The YSK-MEND is capable of inducing efficient silencing activity in hepatocytes and can be used to cure mice that are infected with hepatitis C or B. The YSK-MEND can also be applied to cancer immunotherapy through the activation of immune cells by delivering different compounds such as cyclic-di-GMP, siRNA or alpha-galactosylceramide as a lipid antigen. The findings indicate that, as predicted, these compounds, when encapsulated in the YSK-MEND, can be delivered to the site of action and induced immune activation through different mechanisms. Finally, a MITO-Porter, a membrane fusion-based delivery system to mitochondria, is introduced as an organelle targeting DDS and a new strategy for cancer therapy is proposed by delivering gentamicin to mitochondria of cancer cells. These new technologies are expected to extend the therapeutic area of Nanomedicine by increasing the power of DDS, especially from the view point of controlled intracellular trafficking.

Recent insights in nanotechnology-based drugs and formulations designed for effective anti-cancer therapy

The rapid development of nanotechnology provides alternative approaches to overcome several limitations of conventional anti-cancer therapy. Drug targeting using functionalized nanoparticles to advance their transport to the dedicated site, became a new standard in novel anti-cancer methods. In effect, the employment of nanoparticles during design of antineoplastic drugs helps to improve pharmacokinetic properties, with subsequent development of high specific, non-toxic and biocompatible anti-cancer agents. However, the physicochemical and biological diversity of nanomaterials and a broad spectrum of unique features influencing their biological action requires continuous research to assess their activity. Among numerous nanosystems designed to eradicate cancer cells, only a limited number of them entered the clinical trials. It is anticipated that progress in development of nanotechnology-based anti-cancer materials will provide modern, individualized anti-cancer therapies assuring decrease in morbidity and mortality from cancer diseases. In this review we discussed the implication of nanomaterials in design of new drugs for effective antineoplastic therapy and describe a variety of mechanisms and challenges for selective tumor targeting. We emphasized the recent advantages in the field of nanotechnology-based strategies to fight cancer and discussed their part in effective anti-cancer therapy and successful drug delivery.

Enhanced Cytotoxicity of Folic Acid-Targeted Liposomes Co-Loaded with C6 Ceramide and Doxorubicin: In Vitro Evaluation on HeLa, A2780-ADR, and H69-AR Cells

Current research in cancer therapy is beginning to shift toward the use of combinational drug treatment regimens. However, the efficient delivery of drug combinations is governed by a number of complex factors in the clinical setting. Therefore, the ability to synchronize the pharmacokinetics of the individual therapeutic agents present in combination not only to allow for simultaneous tumor accumulation but also to allow for a synergistic relationship at the intracellular level could prove to be advantageous. In this work, we report the development of a novel folic acid-targeted liposomal formulation simultaneously co-loaded with C6 ceramide and doxorubicin [FA-(C6+Dox)-LP]. In vitro cytotoxicity assays showed that the FA-(C6+Dox)-LP was able to significantly reduce the IC50 of Dox when compared to that after the treatment with the doxorubicin-loaded liposomes (Dox-LP) as well as the untargeted drug co-loaded (C6+Dox)-LP on HeLa, A2780-ADR, and H69-AR cells. The analysis of the cell cycle distribution showed that while the C6 liposomes (C6-LP) did not cause cell cycle arrest, all the Dox-containing liposomes mediated cell cycle arrest in HeLa cells in the G2 phase at Dox concentrations of 0.3 and 1 μM and in the S phase at the higher concentrations. It was also found that this arrest in the S phase precedes the progression of the cells to apoptosis. The targeted FA-(C6+Dox)-LP were able to significantly enhance the induction of apoptotic events in HeLa cell monolayers as compared to the other treatment groups. Next, using time-lapse phase holographic imaging microscopy, it was found that upon treatment with the FA-(C6+Dox)-LP, the HeLa cells underwent rapid progression to apoptosis after 21 h as evidenced by a drastic drop in the average area of the cells after loss of cell membrane integrity. Finally, upon evaluation in a HeLa spheroid cell model, treatment with the FA-(C6+Dox)-LP showed significantly higher levels of cell death compared to those with C6-LP and Dox-LP. Overall, this study clearly shows that the co-delivery of C6 ceramide and Dox using a liposomal platform significantly correlates with an antiproliferative effect due to cell cycle regulation and subsequent induction of apoptosis and thus warrants its further evaluation in preclinical animal models.

Hemocompatibility of folic-acid-conjugated amphiphilic PEG-PLGA copolymer nanoparticles for co-delivery of cisplatin and paclitaxel: treatment effects for non-small-cell lung cancer

In this study, we used folic-acid-modified poly(ethylene glycol)-poly(lactic-co-glycolic acid) (FA-PEG-PLGA) to encapsulate cisplatin and paclitaxel (separately or together), and evaluated their antitumor effects against lung cancer; this study was conducted in order to investigate the antitumor effects of the co-delivery of cisplatin and paclitaxel by a targeted drug delivery system. Blood compatibility assays and complement activation tests revealed that FA-PEG-PLGA nanoparticles did not induce blood hemolysis, blood clotting, or complement activation. The results also indicated that FA-PEG-PLGA nanoparticles had no biotoxic effects, the drug delivery system allowed controlled release of the cargo molecules, and the co-delivery of cisplatin and paclitaxel efficiently induces cancer cell apoptosis and cell cycle retardation. In addition, co-delivery of cisplatin and paclitaxel showed the ability to suppress xenograft lung cancer growth and prolong the survival time of xenografted mice. These results implied that FA-PEG-PLGA nanoparticles can function as effective carriers of cisplatin and paclitaxel, and that co-delivery of cisplatin and paclitaxel by FA-PEG-PLGA nanoparticles results in more effective antitumor effects than the combination of free-drugs or single-drug-loaded nanoparticles.

Aloperine executes antitumor effects against multiple myeloma through dual apoptotic mechanisms

BACKGROUND

Aloperine, a natural alkaloid constituent isolated from the herb Sophora alopecuroides displays anti-inflammatory properties in vitro and in vivo. Our group previously demonstrated that aloperine significantly induced apoptosis in colon cancer SW480 and HCT116 cells. However, its specific target(s) remain to be discovered in multiple myeloma (MM) and have not been investigated.

METHODS

Human myeloma cell lines (n = 8), primary myeloma cells (n = 12), drug-resistant myeloma cell lines (n = 2), and animal models were tested for their sensitivity to aloperine in terms of proliferation and apoptosis both in vitro and in vivo, respectively. We also examined the functional mechanisms underlying the apoptotic pathways triggered by aloperine.

RESULTS

Aloperine induced MM cell death in a dose- and time-dependent manner, even in the presence of the proliferative cytokines interleukin-6 and insulin-like growth factor I. Mechanistic studies revealed that aloperine not only activated caspase-8 and reduced the expression of FADD-like interleukin-1β-converting enzyme (FLICE)-like inhibitory protein long (FLIPL) and FLICE-inhibitory proteins (FLIPS) but also activated caspase-9 and decreased the expression of phosphorylated (p)-PTEN. Moreover, co-activation of the caspase-8/cellular FLICE-inhibitory protein (cFLIP)- and caspase-9/p-PTEN/p-AKT-dependent apoptotic pathways by aloperine caused irreversible inhibition of clonogenic survival. Aloperine induce more MM apoptosis with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or borterzomib. A U266 xenograft tumor model and 5T33 MM cells recapitulated the antitumor efficacy of aloperine, and the animals displayed excellent tolerance of the drug and few adverse effects.

CONCLUSIONS

Aloperine has multifaceted antitumor effects on MM cells. Our data support the clinical development of aloperine for MM therapy.