Multifunctional liposomes loaded with paclitaxel and artemether for treatment of invasive brain glioma

Trojan Horse Delivery Strategies of Natural Medicine Monomers: Challenges and Limitations in Improving Brain Targeting

Central nervous system (CNS) diseases, such as brain tumors, Alzheimer's disease, and Parkinson's disease, significantly impact patients' quality of life and impose substantial economic burdens on society. The blood-brain barrier (BBB) limits the effective delivery of most therapeutic drugs, especially natural products, despite their potential therapeutic effects. The Trojan Horse strategy, using nanotechnology to disguise drugs as "cargo", enables them to bypass the BBB, enhancing targeting and therapeutic efficacy. This review explores the applications of natural products in the treatment of CNS diseases, discusses the challenges posed by the BBB, and analyzes the advantages and limitations of the Trojan Horse strategy. Despite the existing technical challenges, future research is expected to enhance the application of natural drugs in CNS treatment by integrating nanotechnology, improving delivery mechanisms, and optimizing targeting characteristics.

Recent advances on brain drug delivery via nanoparticles: alternative future materials for neuroscience applications; a review

Essentially, the blood-brain barrier (BBB) serves as a line of demarcation between neural tissues and the bloodstream. A unique and protective characteristic of the blood-brain barrier is its ability to maintain cerebral homeostasis by regulating the flux of molecules and ions. The inability to uphold proper functioning in any of these constituents leads to the disruption of this specialized multicellular arrangement, consequently fostering neuroinflammation and neurodegeneration. Recent advancements in nanomedicine have been regarded as a promising avenue for improving the delivery of drugs to the central nervous system in the modern era. A major benefit of this innovation is that it allows drugs to accumulate selectively within the cerebral area by circumventing the blood-brain barrier. Although brain-targeted nanomedicines have demonstrated impressive achievements, certain limitations in targeting specificity still exist. In this examination, we scrutinize the distinctive physical and chemical attributes of nanoparticles (NPs) contributing to their facilitation in BBB traversal. We explore the various mechanisms governing NP passage over the BBB, encompassing paracellular conveyance, mediated transport, as well as adsorptive- and receptor-mediated transcytosis. The therapeutic success of NPs for the treatment of brain tumors has been extensively investigated through the use of various categories of NPs. Among these are polymeric nanoparticles, liposomes, solid lipid nanoparticles, dendrimers, metallic nanoparticles, quantum dots, and nanogels. The potential utility of nanoparticles goes beyond their ability to transport pharmaceuticals. They can serve as adept imaging contrast agents, capable of being linked with imaging probes. This will facilitate tumor visualization, delineate lesion boundaries and margins, and monitor drug delivery and treatment response. Versatile nanoparticles can be engineered to effectively target neoplastic lesions, serving dual roles in diagnostic imaging and therapeutic interventions. Subsequently, this discourse explores the constraints associated with nanoparticles in the context of treating brain tumors.

Biological characteristics and immune responses of NK Cells in commonly used experimental mouse models

The biology of natural killer (NK) cells in commonly used mouse models is discussed in this review, along with their crucial function in a variety of immunological responses. It has been demonstrated that the formation, maturation, subtype variety, and immunological recognition mechanisms of NK cells from various mice strains exhibit notable differences. These variations shed light on the intricacy of NK cell function and offer crucial information regarding their possible uses in treating human illnesses. The application of flow cytometry in mouse NK cell research is also covered in the article. Improved knowledge of the biology of NK cells across species may facilitate the development of new NK cell-based therapeutic approaches.

A multifunctional targeted nano-delivery system with radiosensitization and immune activation in glioblastoma

Glioblastoma (GBM), the most common primary brain malignancy in adults, is notoriously difficult to treat due to several factors: tendency to be radiation resistant, the presence of the blood brain barrier (BBB) which limits drug delivery and immune-privileged status which hampers effective immune responses. Traditionally, high-dose irradiation (8 Gy) is known to effectively enhance anti-tumor immune responses, but its application is limited by the risk of severe brain damage. Currently, conventional dose segmentation (2 Gy) is the standard radiotherapy method, which does not fully exploit the potential of high-dose irradiation for immune activation. The hypothesis of our study posits that instead of directly applying high doses of radiation, which is risky, a strategy could be developed to harness the immune-stimulating benefits of high-dose irradiation indirectly. This involves using nanoparticles to enhance antigen presentation and immune responses in a safer manner. Angiopep-2 (A2) was proved a satisfactory BBB and brain targeting and Dbait is a small molecule that hijack DNA double strand break damage (DSB) repair proteins to make cancer cells more sensitive to radiation. In view of that, the following two nanoparticles were designed to combine immunity of GBM, radiation resistance and BBB innovatively. One is cationic liposome nanoparticle interacting with Dbait (A2-CL/Dbait NPs) for radiosensitization effect; the other is PLGA-PEG-Mal nanoparticle conjugated with OX40 antibody (A2-PLGA-PEG-Mal/anti-OX40 NPs) for tumor-derived protein antigens capture and optimistic immunoregulatory effect of anti-OX40 (which is known to enhance the activation and proliferation T cells). Both types of nanoparticles showed favorable targeting and low toxicity in experimental models. Specifically, the combination of A2-CL/Dbait NPs and A2-PLGA-PEG-Mal/anti-OX40 NPs led to a significant extension in the survival time and a significant tumor shrinkage of mice with GBM. The study demonstrates that combining these innovative nanoparticles with conventional radiotherapy can effectively address key challenges in GBM treatment. It represents a significant step toward more effective and safer therapeutic options for GBM patients.

Liposomal Nanomaterials: A Rising Star in Glioma Treatment

Glioma is a primary malignant tumor in the central nervous system. In recent years, the treatment of glioma has developed rapidly, but the overall survival of glioma patients has not significantly improved. Due to the presence of the blood-brain barrier and intracranial tumor barrier, many drugs with good effects to cure glioma in vitro cannot be accurately transported to the corresponding lesions. In order to enable anti-tumor drugs to overcome the barriers and target glioma, nanodrug delivery systems have emerged recently. It is gratifying that liposomes, as a multifunctional nanodrug delivery carrier, which can be compatible with hydrophilic and hydrophobic drugs, easily functionalized by various targeted ligands, biodegradable, and hypoimmunogenic in vivo, has become a quality choice to solve the intractable problem of glioma medication. Therefore, we focused on the liposome nanodrug delivery system, and summarized its current research progress in glioma. Hopefully, this review may provide new ideas for the research and development of liposome-based nanomaterials for the clinical treatment of glioma.

Lysosome Targeting Chimaeras for Glut1-Facilitated Targeted Protein Degradation

Targeted protein degradation technology holds great potential in biomedicine, particularly in treating tumors and other protein-related diseases. Research on intracellular protein degradation using molecular glues and PROTAC technology is leading, while research on the degradation of membrane proteins and extracellular proteins through the lysosomal pathway is still in the preclinical stage. The scarcity of useful targets is an immense limitation to technological advancement, making it essential to explore novel, potentially effective approaches for targeted lysosomal degradation. Here, we employed the glucose transporter Glut1 as an innovative lysosome-targeting receptor and devised the Glut1-Facilitated Lysosomal Degradation (GFLD) strategy. We synthesized potential Glut1 ligands via reversible addition-fragmentation chain transfer (RAFT) polymerization and acquired antibody-glycooligomer conjugates through bioorthogonal reactions as lysosome-targeting protein degradation molecules, utilized in the management of PD-L1 high-expressing triple-negative breast cancer. The glucose transporter Glut1 as a lysosome-targeting receptor exhibits potential for the advancement of a broader array of medications in the future.

The Synthesis and Characterization of a Delivery System Based on Polymersomes and a Xanthone with Inhibitory Activity in Glioblastoma

Glioblastoma (GBM) is the most common and deadly primary malignant brain tumor. Current therapies are insufficient, and survival for individuals diagnosed with GBM is limited to a few months. New GBM treatments are urgent. Polymeric nanoparticles (PNs) can increase the circulation time of a drug in the brain capillaries. Polymersomes (PMs) are PNs that have been described as having attractive characteristics, mainly due to their stability, prolonged circulation period, biodegradability, their ability to sustain the release of drugs, and the possibility of surface functionalization. In this work, a poly(ethylene glycol)-ε-caprolactone (PEG-PCL) copolymer was synthesized and PMs were prepared and loaded with an hydrolytic instable compound, previously synthesized by our research team, the 3,6-bis(2,3,4,6-tetra-O-acetyl-β-glucopyranosyl)xanthone (XGAc), with promising cytotoxicity on glioblastoma cells (U-373 MG) but also on healthy cerebral endothelial cells (hCMEC/D3). The prepared PMs were spherical particles with uniform morphology and similar sizes (mean diameter of 200 nm) and were stable in aqueous suspension. The encapsulation of XGAc in PMs (80% encapsulation efficacy) protected the healthy endothelial cells from the cytotoxic effects of this compound, while maintaining cytotoxicity for the glioblastoma cell line U-373 MG. Our studies also showed that the prepared PMs can efficiently release XGAc at intratumoral pHs.

Recent advances in drug delivery systems for targeting brain tumors

Brain tumor accounts for about 1.6% of incidence and 2.5% of mortality of all tumors, and the median survival for brain tumor patients is only about 20 months. The treatment for brain tumor still faces many challenges, such as the blood-brain barrier (BBB), blood-brain tumor barrier (BBTB), the overexpressed efflux pumps, the infiltration, invasion, high heterogeneity of tumor cells, drug resistance and immune escape caused by tumor microenvironment (TME) and cancer stem cells (CSC). This review attempts to clarify the challenges for multi-functional nano drug delivery systems (NDDS) to cross the BBB and target the cancer cells or organelles, and also provides a brief description of the different types of targeted multi-functional NDDS that have shown potential for success in delivering drugs to the brain. Further, this review also summarizes the research progress of multi-functional NDDS in the combination therapy of brain tumors from the following sections, the combination of chemotherapy drugs, chemotherapy-chemodynamic combination therapy, chemotherapy-immunization combination therapy, and chemotherapy-gene combination therapy. We also provide an insight into the recent advances in designing multi-functional NDDS for combination therapy.

Molecular modelling of shockwave-mediated delivery of paclitaxel aggregates across the neuronal plasma membrane

Shock-assisted paclitaxel (PTX) transport across the blood-brain barrier offers a promising treatment strategy for brain tumors. Here, based on a realistically complex human brain plasma membrane (PM) model, we investigated the dynamic transmembrane behavior of a PTX cluster by shock induced bubble collapse, focusing on the effect of impulse (I), bubble diameter (D) and arrays. The results show that all three factors can control the transport depth (ΔDPM) of PTX. For a fixed D, the ΔDPM grows exponentially with I, ΔDPM ∼ exp (I), and eventually reaches a critical depth. But the depth, ΔDPM, can be adjusted linearly in a wider range of D. This mainly depends on the size of jets from bubble collapse. For bubble arrays, the bubbles in series can transport PTX deeper than a single bubble, while the parallel does the opposite. In addition, only PTX clusters in the range of jet action can be successfully transported. Finally, the absorption of PTX clusters was examined via recovery simulation. Not all PTX clusters across the membrane can be effectively absorbed by cells. The shallow PTX clusters are quickly attracted by the membrane and embedded into it. The critical depth at which PTX clusters can be effectively absorbed is about 20 nm. These molecular-level mechanisms and dynamic processes of PTX clusters crossing the PM membrane may be helpful in optimizing the application of shock-induced bubble collapse for the delivery of PTX to tumor cells.

Dynamic nanoassemblies derived from small-molecule homodimeric prodrugs for in situ drug activation and safe osteosarcoma treatment

Supramolecular prodrug self-assembly is a cost-effective and powerful approach for creating injectable anticancer nanoassemblies. Herein, we describe the self-assembly of small-molecule prodrug nanotherapeutics for tumor-restricted pharmacology that can be self-activated and independent of the exogenous stimuli. Covalent dimerization of the anticancer agent cabazitaxel via reactive oxygen species (ROS)- and esterase-activatable linkages produced the homodimeric prodrug diCTX, which was further coassembled with an ROS generator, dimeric dihydroartemisinin (diDHA). The coassembled nanoparticles were further refined in an amphiphilic matrix, making them suitable for in vivo administration. The ROS obtained from the coassembled diDHA synergized with intracellular esterase to activate the neighboring diCTX, which in turn induced potent cytotoxicity. In a preclinical orthotopic model of human osteosarcomas, nanoparticle administration exhibited durable antitumor efficacy. Furthermore, this smart, dual-responsive nanotherapeutic exhibited lower toxicity in animals than those of free drug combinations. We predict that this platform has great potential for further clinical translation.

Liposomes for the Treatment of Brain Cancer-A Review

Due to their biocompatibility, non-toxicity, and surface-conjugation capabilities, liposomes are effective nanocarriers that can encapsulate chemotherapeutic drugs and facilitate targeted delivery across the blood-brain barrier (BBB). Additionally, strategies have been explored to synthesize liposomes that respond to internal and/or external stimuli to release their payload controllably. Although research into liposomes for brain cancer treatment is still in its infancy, these systems have great potential to fundamentally change the drug delivery landscape. This review paper attempts to consolidate relevant literature regarding the delivery to the brain using nanocarriers, particularly liposomes. The paper first briefly explains conventional treatment modalities for cancer, followed by describing the blood-brain barrier and ways, challenges, and techniques involved in transporting drugs across the BBB. Various nanocarrier systems are introduced, with attention to liposomes, due to their ability to circumvent the challenges imposed by the BBB. Relevant studies involving liposomal systems researched to treat brain tumors are reviewed in vitro, in vivo, and clinical studies. Finally, the challenges associated with the use of liposomes to treat brain tumors and how they can be addressed are presented.

A, Gota V, Goda JS. Insight into lipid-based nanoplatform-mediated drug and gene delivery in neuro-oncology and their clinical prospects

Tumors of the Central nervous System (CNS) are a spectrum of neoplasms that range from benign lesions to highly malignant and aggressive lesions. Despite aggressive multimodal treatment approaches, the morbidity and mortality are high with dismal survival outcomes in these malignant tumors. Moreover, the non-specificity of conventional treatments substantiates the rationale for precise therapeutic strategies that selectively target infiltrating tumor cells within the brain, and minimize systemic and collateral damage. With the recent advancement of nanoplatforms for biomaterials applications, lipid-based nanoparticulate systems present an attractive and breakthrough impact on CNS tumor management. Lipid nanoparticles centered immunotherapeutic agents treating malignant CNS tumors could convene the clear need for precise treatment strategies. Immunotherapeutic agents can selectively induce specific immune responses by active or innate immune responses at the local site within the brain. In this review, we discuss the therapeutic applications of lipid-based nanoplatforms for CNS tumors with an emphasis on revolutionary approaches in brain targeting, imaging, and drug and gene delivery with immunotherapy. Lipid-based nanoparticle platforms represent one of the most promising colloidal carriers for chemotherapeutic, and immunotherapeutic drugs. Their current application in oncology especially in brain tumors has brought about a paradigm shift in cancer treatment by improving the antitumor activity of several agents that could be used to selectively target brain tumors. Subsequently, the lab-to-clinic transformation and challenges towards translational feasibility of lipid-based nanoplatforms for drug and gene/immunotherapy delivery in the context of CNS tumor management is addressed.

Challenges and advances for glioma therapy based on inorganic nanoparticles

Glioma is one of the most serious central nervous system diseases, with high mortality and poor prognosis. Despite the continuous development of existing treatment methods, the median survival time of glioma patients is still only 15 months. The main treatment difficulties are the invasive growth of glioma and the obstruction of the blood-brain barrier (BBB) to drugs. With rapid advancements in nanotechnology, inorganic nanoparticles (INPs) have shown favourable application prospects in the diagnosis and treatment of glioma. Due to their extraordinary intrinsic features, INPs can be easily fabricated, while doping with other elements and surface modification by biological ligands can be used to enhance BBB penetration, targeted delivery and biocompatibility. Guided glioma theranostics with INPs can improve and enhance the efficacy of traditional methods such as chemotherapy, radiotherapy and gene therapy. New strategies, such as immunotherapy, photothermal and photodynamic therapy, magnetic hyperthermia therapy, and multifunctional inorganic nanoplatforms, have also been facilitated by INPs. This review emphasizes the current state of research and clinical applications of INPs, including glioma targeting and BBB penetration enhancement methods, in vivo and in vitro biocompatibility, and diagnostic and treatment strategies. As such, it provides insights for the development of novel glioma treatment strategies.

Metabolic Reprogramming of NK Cells by Black Phosphorus Quantum Dots Potentiates Cancer Immunotherapy

Low persistence, metabolic dysfunction in microenvironment, and tumor-derived immunosuppression of Natural killer (NK) cells in patients are greatly limited the successful clinical application of NK cell-based cancer immunotherapy. Interestingly, herein that human serum albumin-encapsulated black phosphorus quantum dots (BPQDs@HSA) can effectively augment antitumor efficacy of clinical patients-derived NK cell immunotherapy is found. As the donor of phosphate group, BPQDs@HSA binds with the protein of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1A) and activates the downstream PI3K-Akt and mTOR signaling pathways to reprogram cell metabolism of glycolysis and further promote the oxidative phosphorylation, sequentially maintains the cell viability and immunity of NK cells. And multiomics analysis is therefore conducted to reveal the underlying immunoregulation mechanisms, and that BPQDs@HSA can interact with the Toll-like receptor (TLR) on the NK cell surface and increase the expression level of mTOR, and thus activate downstream NF-κB signalling pathways to regulate cytokine secretion and enhance immune tumoricidal is found. BPQDs@HSA can also enhance immune surveillance, relieve immune suppression, and inhibit tumor immune escape. Collectively, this study not only demonstrates a successful strategy for nanomedicine-potentiated immune-cancer therapy, but also sheds light on the understanding of interface between nanomedicine and immune cells activation.

TPGS Decorated Liposomes as Multifunctional Nano-Delivery Systems

Liposomes are sphere-shaped vesicles that can capture therapeutics either in the outer phospholipid bilayer or inner aqueous core. Liposomes, especially when surface-modified with functional materials, have been used to achieve many benefits in drug delivery, including improving drug solubility, oral bioavailability, pharmacokinetics, and delivery to disease target sites such as cancers. Among the functional materials used to modify the surface of liposomes, the FDA-approved non-ionic surfactant D-alpha-tocopheryl polyethylene glycol succinate (TPGS) is increasingly being applied due to its biocompatibility, lack of toxicity, applicability to various administration routes and ability to enhance solubilization, stability, penetration and overall pharmacokinetics. TPGS decorated liposomes are emerging as a promising drug delivery system for various diseases and are expected to enter the market in the coming years. In this review article, we focus on the multifunctional properties of TPGS-coated liposomes and their beneficial therapeutic applications, including for oral drug delivery, vaccine delivery, ocular administration, and the treatment of various cancers. We also suggest future directions to optimise the manufacture and performance of TPGS liposomes and, thus, the delivery and effect of encapsulated diagnostics and therapeutics.

Synthesis & Evaluation of Novel Mannosylated Neoglycolipids for Liposomal Delivery System Applications

Glycosylated NPs, including liposomes, are known to target various receptors involved in cellular carbohydrate transport, of which the mannoside binding receptors are attracting particular attention for their expression on various immune cells, cancers, and cells involved in maintaining central nervous system (CNS) integrity. As part of our interest in NP drug delivery, mannosylated glycoliposomal delivery systems formed from the self-assembly of amphiphilic neoglycolipids were developed, with a C12-alkyl mannopyranoside (ML-C12) being identified as a lead compoundcapable of entrapping, protecting, and improving the delivery of structurally diverse payloads. However, ML-C12 was not without limitations in both the synthesis of the glycolipids, and the physicochemical properties of the resulting glycoliposomes. Herein, the chemical syntheses of a novel series of mannosylated neoglycolipids are reported with the goal of further improving on the previous ML-C12 glyconanoparticles. The current work aimed to use a self-contingent strategy which overcomes previous synthetic limitations to produce neoglycolipids that have one exposed mannose residue, an aromatic scaffold, and two lipid tails with varied alkyl chains. The azido-ending carbohydrates and the carboxylic acid-ending lipid tails were ligated using a new one-pot modified Staudinger chemistry that differed advantageously to previous syntheses. The formation of stable neoglycoliposomes of controllable and ideal sizes (≈100-400 nm) was confirmed via dynamic light scattering (DLS) experiments and transmission electron microscopy (TEM). Beyond chemical advantages, the present study further aimed to establish potential improvements in the biological activity of the neoglycoliposomes. Concanavalin A (Con A) agglutination studies demonstrated efficient and stable cross-linking abilities dependent on the length of the linkers and lipid tails. The efficacy of the glycoliposomes in improving cytosolic uptake was investigated using Nile Red as probe in immune and cancer cell lines. Preliminary ex vivo safety assessments showed that the mannosylated glycoliposomes are hemocompatible, and non-immunogenic. Finally, using a model peptide therapeutic, the relative entrapment capacity and plasma stability of the optimal glycoliposome delivery system was evaluated and compared to the previous neoglycoliposomes. Overall, the new lead glycoliposome showed improved biological activity over ML-C12, in addition to having several chemical benefits including the lack of stereocenters, a longer linker allowing better sugar availability, and ease of synthesis using novel one-pot modified Staudinger chemistry.

Artemether-loaded polymeric lipid-core nanocapsules reduce cell viability and alter the antioxidant status of U-87 MG cells

Glioblastomas are tumors that present a high mortality rate. Artemether (ART) is a lactone with antitumor properties, demonstrating low bioavailability and water solubility. In the present study, we developed lipid-core nanocapsules (LNC) containing pequi oil (Caryocar brasiliense Cambess) as the oily core for ART-loaded LNCs (LNC_ART) and evaluated their effect on human glioblastoma cells (U-87 MG). LNCs were developed by interfacial deposition of a preformed polymer, followed by physicochemical characterization. LNC_ART revealed a diameter of 0.216 µm, polydispersity index of 0.161, zeta potential of -12.0 mV, and a pH of 5.53. Furthermore, mitochondrial viability, proliferation, total antioxidant status, and antioxidant enzyme activity were evaluated. ART reduced cell viability after 24 h and proliferation after 48 h of treatment at concentrations equal to or above 40 µg . mL^-1. LNC_ART, at 1.25 µg . mL^-1, reduced these parameters after 24 h of treatment. Furthermore, superoxide dismutase (SOD) activity was elevated, while glutathione reductase (GR) activity was reduced. These findings suggest that ART loaded into LNC may be a promising alternative to improve its pharmacological action and possible application as a therapeutic agent for glioblastoma.

Stimuli-responsive liposomal nanoformulations in cancer therapy: Pre-clinical & clinical approaches

The site-specific delivery of antitumor agents is of importance for providing effective cancer suppression. Poor bioavailability of anticancer compounds and the presence of biological barriers prevent their accumulation in tumor sites. These obstacles can be overcome using liposomal nanostructures. The challenges in cancer chemotherapy and stimuli-responsive nanocarriers are first described in the current review. Then, stimuli-responsive liposomes including pH-, redox-, enzyme-, light-, thermo- and magneto-sensitive nanoparticles are discussed and their potential for delivery of anticancer drugs is emphasized. The pH- or redox-sensitive liposomes are based on internal stimulus and release drug in response to a mildly acidic pH and GSH, respectively. The pH-sensitive liposomes can mediate endosomal escape via proton sponge. The multifunctional liposomes responsive to both redox and pH have more capacity in drug release at tumor site compared to pH- or redox-sensitive alone. The magnetic field and NIR irradiation can be exploited for external stimulation of liposomes. The light-responsive liposomes release drugs when they are exposed to irradiation; thermosensitive-liposomes release drugs at a temperature of >40 °C when there is hyperthermia; magneto-responsive liposomes release drugs in presence of magnetic field. These smart nanoliposomes also mediate co-delivery of drugs and genes in synergistic cancer therapy. Due to lack of long-term toxicity of liposomes, they can be utilized in near future for treatment of cancer patients.

Indocyanine green conjugated phototheranostic nanoparticle for photodiagnosis and photodynamic reaciton

BACKGROUND

Phototheranostics represents a highly promising paradigm for cancer therapy, although selecting an appropriate optical imager and sensitizer for clinical use remains challenging.

METHODS

Liposomally formulated phospholipid-conjugated indocyanine green, denoted as LP-iDOPE, was developed as phototheranostic nanoparticle and its cancer imaging-mediated photodynamic reaction, defined as the immune response induced by photodynamic and photothermal effects, was evaluated with a near-infrared (NIR)-light emitting diode (LED) light irradiator.

RESULTS

Using in vivo NIR fluorescence imaging, we demonstrated that LP-iDOPE was selectively delivered to tumor sites with high accumulation and a long half-life. Following low-intensity NIR-LED light irradiation on the tumor region of LP-iDOPE accumulated, effector CD8⁺ T cells were activated at the secondary lymphoid organs, migrated, and subsequently released cytokines including interferon-γ and tumor necrosis factor-α, resulting in effective tumor regression.

CONCLUSIONS

Our anti-cancer strategy based on tumor-specific LP-iDOPE accumulation and low-intensity NIR-LED light irradiation to the tumor regions, i.e., photodynamic reaction, represents a promising approach to noninvasive cancer therapy.

Crossing the Blood-Brain Barrier: Advances in Nanoparticle Technology for Drug Delivery in Neuro-Oncology

The blood-brain barrier (BBB) constitutes a microvascular network responsible for excluding most drugs from the brain. Treatment of brain tumors is limited by the impermeability of the BBB and, consequently, survival outcomes for malignant brain tumors remain poor. Nanoparticles (NPs) represent a potential solution to improve drug transport to brain tumors, given their small size and capacity to target tumor cells. Here, we review the unique physical and chemical properties of NPs that aid in BBB transport and discuss mechanisms of NP transport across the BBB, including paracellular transport, carrier-mediated transport, and adsorptive- and receptor-mediated transcytosis. The major types of NPs investigated for treatment of brain tumors are detailed, including polymeric NPs, liposomes, solid lipid NPs, dendrimers, metals, quantum dots, and nanogels. In addition to their role in drug delivery, NPs can be used as imaging contrast agents and can be conjugated with imaging probes to assist in visualizing tumors, demarcating lesion boundaries and margins, and monitoring drug delivery and treatment response. Multifunctional NPs can be designed that are capable of targeting tumors for both imaging and therapeutic purposes. Finally, limitations of NPs for brain tumor treatment are discussed.

Gather wisdom to overcome barriers: Well-designed nano-drug delivery systems for treating gliomas

Due to the special physiological and pathological characteristics of gliomas, most therapeutic drugs are prevented from entering the brain. To improve the poor prognosis of existing therapies, researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy. Although these strategies can be used clinically to overcome the blood‒brain barrier (BBB), the accurate delivery of drugs to the glioma lesions cannot be ensured. Nano-drug delivery systems (NDDS) have been widely used for precise drug delivery. In recent years, researchers have gathered their wisdom to overcome barriers, so many well-designed NDDS have performed prominently in preclinical studies. These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions, drug release in response to the glioma microenvironment, biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein, and carriers created according to the active ingredients of traditional Chinese medicines. We reviewed these well-designed NDDS in detail. Furthermore, we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy, and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.

Artemisinin-Type Drugs in Tumor Cell Death: Mechanisms, Combination Treatment with Biologics and Nanoparticle Delivery

Artemisinin, the most famous anti-malaria drug initially extracted from Artemisia annua L., also exhibits anti-tumor properties in vivo and in vitro. To improve its solubility and bioavailability, multiple derivatives have been synthesized. However, to reveal the anti-tumor mechanism and improve the efficacy of these artemisinin-type drugs, studies have been conducted in recent years. In this review, we first provide an overview of the effect of artemisinin-type drugs on the regulated cell death pathways, which may uncover novel therapeutic approaches. Then, to overcome the shortcomings of artemisinin-type drugs, we summarize the recent advances in two different therapeutic approaches, namely the combination therapy with biologics influencing regulated cell death, and the use of nanocarriers as drug delivery systems. For the former approach, we discuss the superiority of combination treatments compared to monotherapy in tumor cells based on their effects on regulated cell death. For the latter approach, we give a systematic overview of nanocarrier design principles used to deliver artemisinin-type drugs, including inorganic-based nanoparticles, liposomes, micelles, polymer-based nanoparticles, carbon-based nanoparticles, nanostructured lipid carriers and niosomes. Both approaches have yielded promising findings in vitro and in vivo, providing a strong scientific basis for further study and upcoming clinical trials.

Recent Developments and Anticancer Therapeutics of Paclitaxel: An Update

Plants are a source of diverse classes of secondary metabolites with anticancer properties. Paclitaxel (Taxol) is an anticancer drug isolated from various Taxus species and is used as a chemotherapeutic agent against various cancers. The biosynthesis of paclitaxel is a complex pathway, making its total chemical synthesis commercially non-viable; hence, alternative novel sources - like plant cell culture and heterologous expression systems, are being investigated to overcome this issue. Advancements in the field of genetic engineering, microbial fermentation engineering, and recombinant techniques have significantly increased the achievable yields of paclitaxel. Indeed, paclitaxel selectively targets microtubules and causes cell cycle arrest in the G2/M phase, inducing a cytotoxic effect in a concentration and time-dependent manner. Innovative drug delivery formulations, like the development of albumin-bound nanoparticles, nano-emulsions, nano-suspensions, liposomes, and polymeric micelles, have been applied to enhance the delivery of paclitaxel to tumor cells. This review focuses on the production, biosynthesis, mechanism of action, and anticancer effects of paclitaxel.

Evaluation of nanoscaled dual targeting drug-loaded liposomes on inhibiting vasculogenic mimicry channels of brain glioma

Brain glioma is the most common primary tumour of the central nervous system. Complete surgical removal of the brain glioma is virtually impossible. Chemotherapy is still an important treatment for brain glioma. However, blood-brain barrier (BBB) and vasculogenic mimicry (VM) channels remain two hindrances in regular treatments. Herein, we developed a novel nanoscaled dual targeting daunorubicin plus rofecoxib liposomes which could transport across the BBB, and eliminate brain glioma cells along with the VM channels. The liposomes were modified with two functional materials, and showed round in shape with a diameter about 120 nm. Evaluations were performed on human brain glioma U87MG cells in vitro and on intracranial brain glioma-bearing nude mice. The dual targeting liposomes demonstrated a long circulatory effect in the blood system, were able to transport across the BBB, and were accumulated into the brain. The results indicated that the dual targeting daunorubicin plus rofecoxib liposomes could inhibit the brain glioma VM channels and exhibited a significant efficacy in the treatment of intracranial glioma-bearing nude mice. The mechanisms are related to down regulations MMP-2, MMP-9, FAK and HIF-α. Hence, the established dual targeting liposomes could be a potential formulation to treat the brain glioma along with eliminating VM channels.

Polymeric magnetic nanoparticles: a multitargeting approach for brain tumour therapy and imaging

The most challenging task in targeting the brain is trespassing the blood-brain barrier (BBB) which restricts the movement of about 98% small molecules. Targeting the central nervous system using magnetic nanoparticles may deliver the drug to the target site along with a contrast imaging property. The use of magnetic nanoparticles can become non-invasive drug targeting and a bio-imaging method for brain cancer. The strategy to apply polymeric nanoparticles as a carrier of magnetic iron oxide nanoparticles can be a promising tool as a multitherapeutic drug delivery approach involving delivery of chemotherapeutic drugs with a magnetic targeting approach, imaging, and hyperthermia. This review will highlight the existing difficulties/barriers in crossing the BBB, types of magnetic materials, polymeric carriers for functionalization of magnetic nanoparticles, and targeting strategies as therapeutic and imaging modalities. Utilization of polymeric magnetic nanoparticles as an efficient targeting platform for better drug delivery and imaging for brain cancer and future prospects are also discussed. Polymeric magnetic nanoparticles as a drug delivery and bio-imaging vehicle for brain cancer.

The multifaceted NF-kB: are there still prospects of its inhibition for clinical intervention in pediatric central nervous system tumors?

Despite advances in the understanding of the molecular mechanisms underlying the basic biology and pathogenesis of pediatric central nervous system (CNS) malignancies, patients still have an extremely unfavorable prognosis. Over the years, a plethora of natural and synthetic compounds has emerged for the pharmacologic intervention of the NF-kB pathway, one of the most frequently dysregulated signaling cascades in human cancer with key roles in cell growth, survival, and therapy resistance. Here, we provide a review about the state-of-the-art concerning the dysregulation of this hub transcription factor in the most prevalent pediatric CNS tumors: glioma, medulloblastoma, and ependymoma. Moreover, we compile the available literature on the anti-proliferative effects of varied NF-kB inhibitors acting alone or in combination with other therapies in vitro, in vivo, and clinical trials. As the wealth of basic research data continues to accumulate, recognizing NF-kB as a therapeutic target may provide important insights to treat these diseases, hopefully contributing to increase cure rates and lower side effects related to therapy.

Carbohydrate-Based Macromolecular Biomaterials

Carbohydrates are the most abundant and one of the most important biomacromolecules in Nature. Except for energy-related compounds, carbohydrates can be roughly divided into two categories: Carbohydrates as matter and carbohydrates as information. As matter, carbohydrates are abundantly present in the extracellular matrix of animals and cell walls of various plants, bacteria, fungi, etc., serving as scaffolds. Some commonly found polysaccharides are featured as biocompatible materials with controllable rigidity and functionality, forming polymeric biomaterials which are widely used in drug delivery, tissue engineering, etc. As information, carbohydrates are usually referred to the glycans from glycoproteins, glycolipids, and proteoglycans, which bind to proteins or other carbohydrates, thereby meditating the cell-cell and cell-matrix interactions. These glycans could be simplified as synthetic glycopolymers, glycolipids, and glycoproteins, which could be afforded through polymerization, multistep synthesis, or a semisynthetic strategy. The information role of carbohydrates can be demonstrated not only as targeting reagents but also as immune antigens and adjuvants. The latter are also included in this review as they are always in a macromolecular formulation. In this review, we intend to provide a relatively comprehensive summary of carbohydrate-based macromolecular biomaterials since 2010 while emphasizing the fundamental understanding to guide the rational design of biomaterials. Carbohydrate-based macromolecules on the basis of their resources and chemical structures will be discussed, including naturally occurring polysaccharides, naturally derived synthetic polysaccharides, glycopolymers/glycodendrimers, supramolecular glycopolymers, and synthetic glycolipids/glycoproteins. Multiscale structure-function relationships in several major application areas, including delivery systems, tissue engineering, and immunology, will be detailed. We hope this review will provide valuable information for the development of carbohydrate-based macromolecular biomaterials and build a bridge between the carbohydrates as matter and the carbohydrates as information to promote new biomaterial design in the near future.

Improving the Utility of a Dynorphin Peptide Analogue Using Mannosylated Glycoliposomes

Peptide therapeutics offer numerous advantages in the treatment of diseases and disorders of the central nervous system (CNS). However, they are not without limitations, especially in terms of their pharmacokinetics where their metabolic lability and low blood–brain barrier penetration hinder their application. Targeted nanoparticle delivery systems are being tapped for their ability to improve the delivery of therapeutics into the brain non-invasively. We have developed a family of mannosylated glycoliposome delivery systems for targeted drug delivery applications. Herein, we demonstrate via in vivo distribution studies the potential of these glycoliposomes to improve the utility of CNS active therapeutics using dynantin, a potent and selective dynorphin peptide analogue antagonist of the kappa opioid receptor (KOR). Glycoliposomal entrapment protected dynantin against known rapid metabolic degradation and ultimately improved brain levels of the peptide by approximately 3–3.5-fold. Moreover, we linked this improved brain delivery with improved KOR antagonist activity by way of an approximately 30–40% positive modulation of striatal dopamine levels 20 min after intranasal administration. Overall, the results clearly highlight the potential of our glycoliposomes as a targeted delivery system for therapeutic agents of the CNS.

An update on actively targeted liposomes in advanced drug delivery to glioma

High-grade glioma is one of the most aggressive types of cancer with a low survival rate ranging from 12 to 15 months after the first diagnosis. Though being the most common strategy for glioma therapy, conventional chemotherapy suffers providing the therapeutic dosage of common therapeutics mostly because of limited permeability of blood-brain barrier (BBB), and blood-brain tumor barrier (BBTB) to anticancer agents. Among various nanoformulations, liposomes are considered as the most popular carriers aimed for glioma therapy. However, non-targeted liposomes which passively accumulate in most of the cancer tissues mainly through the enhanced permeation and retention effect (EPR), may not be applicable for glioma therapy due to BBB tight junctions. In the recent decade, the surface modification of liposomes with different active targeting ligands has shown promising results by getting different chemotherapeutics across the BBB and BBTB and leading them into the glioma cells. The present review discusses the major barriers for drug delivery systems to glioma, elaborates the existing mechanisms for liposomes to traverse across the BBB, and explores the main strategies for incorporation of targeting ligands onto the liposomes. It subsequently investigates the most recent and relevant studies of actively targeted liposomes modified with antibodies, aptamers, monosaccharides, polysaccharides, proteins, and peptides applied for effective glioma therapy, and highlights the common challenges facing this area. Finally, the actively targeted liposomes undergoing preclinical and clinical studies for delivery of different anticancer agents to glioma cells will be reviewed.

The potential value of dequalinium chloride in the treatment of cancer: Focus on malignant glioma

Dequalinium chloride has been known as one kind of antibiotic that displays a broad antimicrobial spectrum and has been clinically proven to be very safe. In recent years, studies have shown that dequalinium chloride can inhibit the growth of malignant tumours, and reports were mainly used for solid tumours. Glioblastoma is the most common malignant neuroepithelial tumour of the central nervous system in adults, and the prognosis of glioblastoma is poor as it has a high resistance to apoptosis. This review summarizes the current understanding of dequalinium chloride-induced cancer cell apoptosis and its potential role in glioblastoma resistance and progression. Particularly, we focus on dequalinium chloride as it exerts a wide range of anti-cancer activity through its ability to target and accumulate in the mitochondria, and it effectively inhibits the growth of glioblastoma cells in vitro and vivo. Dequalinium chloride is an inhibitor of XIAP and can also act as a mitochondrial targeting agent, which gives it an interesting perspective regarding recent advances in the treatment of malignant glioma.

2-(2-Cholesteroxyethoxyl)ethyl 3'-S-glutathionylpropionate and its self-assembled micelles for brain delivery: Design, synthesis and evaluation

The blood-brain barrier (BBB) is a barrier that prevents almost all large and most small exogenous molecules from reaching the brain. The barrier is the major cause of treatment failure for most brain diseases. Extensive efforts have been made to facilitate drug molecules to cross the BBB. One of the approaches is to employ an endogenous ligand or ligand analogue that can enter the brain through its transporter or receptor at the BBB as a brain-targeting agent. Glutathione (GSH) transporters are richly expressed at the BBB with limited presence in other tissues except kidneys. 2-(2-Cholesteroxyethoxyl)ethyl 3'-S-glutathionylpropionate (COXP), formed by connecting GSH with cholesterol through a linker, was designed as a GSH transporter-mediated brain targeting molecule. The amphiphilic nature of COXP enables the molecule to self-assemble to form micelles with a CMC value of 3.9 μM. By using DiR as a fluorescence tracking agent and the whole-body fluorescence imaging technique, the brain distribution of DiR delivered by COXP micelles in mice was 20 folds higher when compared with free DiR. Interestingly, the brain targeting effect was further enhanced by co-administration of GSH. The low CMC value and effective brain targeting make COXP micelles a promising drug delivery system to the brain.

The enhanced treatment efficacy of invasive brain glioma by dual-targeted artemether plus paclitaxel micelles

High grade-gliomas are highly invasive and prone to metastasis, leading to poor survival and prognosis. Currently, we urgently need a new treatment strategy to effectively inhibit glioma. In this study, artemether and paclitaxel were used as two agents for tumour suppression. Two functional materials were synthesised and modified on the surface of the micelle as targeting molecules. The addition of two functional materials confers the ability of the micelles to effectively cross the blood-brain barrier (BBB) and then target the glioma cells. Thus, this dual-targeted delivery system allows the drug to play a better role in inhibiting tumour invasion and vasculogenic mimicry (VM) channels. In this paper, the anticancer effects of dual-targeted artemether plus paclitaxel micelles on glioma U87 cells were studied in three aspects: (I) In vitro and in vivo targeting assessment, including the role of penetrating BBB and targeting glioma; (II) In vitro regulation of invasion-associated proteins; (III) Inhibition of VM channels formation and invasion in vitro; (IV) The study of pharmacodynamics in tumour-bearing mice. These results suggest that dual-targeted artemether plus paclitaxel micelle may provide a new strategy to treat glioma via inhibiting invasive and VM channels.

Nanostructured lipid carrier co-delivering paclitaxel and doxorubicin restrains the proliferation and promotes apoptosis of glioma stem cells via regulating PI3K/Akt/mTOR signaling

The development of safe and efficient nanocomposites remains a huge challenge in targeted therapy of glioma. Nanostructured lipid carriers (NLCs), which facilitate specific site drug delivery, have been widely used in glioma treatment. Herein, we aimed to investigate the underlying mechanisms and therapeutic impact of paclitaxel (PTX) and doxorubicin (DOX) loaded NLC (PTX-DOX-NLC) on glioma stem cells (GSCs). To this end, we used a melt-emulsification technique to generate PTX loaded NLC (PTX-NLC), DOX loaded NLC (DOX-NLC), and NLC loaded with both drugs (PTX-DOX-NLC). We firstly confirmed the stability of PTX-DOX-NLC and their ability to gradually release PTX and DOX. Next, we evaluated the effects of PTX-DOX-NLC on apoptosis and proliferation of GSCs by flow cytometry and CellTiter-Glo assay. Besides, the expression of relevant mRNA and proteins was determined by RT-qPCR and Western blot analysis, respectively. Mechanism of action of PTX-DOX-NLC was determined though bioinformatic analysis based on RNA-seq data performed in GSCs derived from different NLC-treated groups. In addition, a mouse xenograft model of glioma was established to evaluate the anti-tumor effects of PTX-DOX-NLCin vivo. Results indicated thar PTX-DOX-NLC showed greater inhibitory effects on proliferation and promotive effects on apoptosis of GSCs compared with PTX-NLC, DOX-NLC, free PTX, and free DOX treatment. Mechanistic investigations evidenced that PTX-DOX-NLC inhibited tumor progression by suppressing the PI3K/AKT/mTOR signalingin vitroandin vivo. Taken together, PTX-DOX-NLC played an inhibitory role in GSC growth, highlighting a potential therapeutic option against glioma.

Cholesterol-rich nanoemulsion (LDE) as a novel drug delivery system to diagnose, delineate, and treat human glioblastoma

We have prepared and characterized a cholesterol-rich nanoemulsion called LDE, a mimic of classic lipoprotein macromolecules, that can be applied as a new drug delivery system for aluminum phthalocyanine chloride (PcAlCl). The LDE containing PcAlCl system prepared herein had mean size and zeta potential of 127 nm and -29 mV, respectively, and encapsulation rate efficiency was 81%, and stability of 17 months. Compared to classical liposomes, LDE was more efficient, especially in brain diseases like glioblastoma (GBM), as revealed by tests on the U-87 MG cell line. The LDEPc formulation did not display dark cytotoxicity, as expected. The best light dose for LDEPc was 1.0 J·cm^-2: its activity was 55% higher than PcAlCl in a compatible organic medium. In the U-87 MG cells, apoptosis was the preferential pathway activated by PDT. These results strongly support the use of LDE as a new theranostic system.

Therapeutic Potentials and Mechanisms of Artemisinin and its Derivatives for Tumorigenesis and Metastasis

BACKGROUND

Tumor recurrence and metastasis are still leading causes of cancer mortality worldwide. The influence of traditional treatment strategies against metastatic tumors may still be limited. To search for novel and powerful agents against tumors has become a major research focus. In this study, Artemisinin (ARM), a natural compound isolated from herbs, Artemisia annua L., proceeding from drug repurposing methods, attracts more attention due to its good efficacy and tolerance in antimalarial practices, as well as newly confirmed anticancer activity.

METHODS

We have searched and reviewed the literatures about ARM and its derivatives (ARMs) for cancer using keywords "artemisinin" until May 2019.

RESULTS

In preclinical studies, ARMs can induce cell cycle arrest and cell death by apoptosis etc., to inhibit the progression of tumors, and suppress EMT and angiogenesis to inhibit the metastasis of tumors. Notably, the complex relationships of ARMs and autophagy are worth exploring. Inspired by the limitations of its antimalarial applications and the mechanical studies of artemisinin and cancer, people are also committed to develop safer and more potent ARM-based modified compounds (ARMs) or combination therapy, such as artemisinin dimers/ trimers, artemisinin-derived hybrids. Some clinical trials support artemisinins as promising candidates for cancer therapy.

CONCLUSION

ARMs show potent therapeutic potentials against carcinoma including metastatic tumors. Novel compounds derived from artemisinin and relevant combination therapies are supposed to be promising treatment strategies for tumors, as the important future research directions.

Recent advances in drug delivery systems for targeting cancer stem cells

Cancer stem cells (CSCs) are a subpopulation of cancer cells with functions similar to those of normal stem cells. Although few in number, they are capable of self-renewal, unlimited proliferation, and multi-directional differentiation potential. In addition, CSCs have the ability to escape immune surveillance. Thus, they play an important role in the occurrence and development of tumors, and they are closely related to tumor invasion, metastasis, drug resistance, and recurrence after treatment. Therefore, specific targeting of CSCs may improve the efficiency of cancer therapy. A series of corresponding promising therapeutic strategies based on CSC targeting, such as the targeting of CSC niche, CSC signaling pathways, and CSC mitochondria, are currently under development. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for CSC targeting are increasingly being developed. In this review, we summarize the advances in CSC-targeted DDSs. Furthermore, we highlight the latest developmental trends through the main line of CSC occurrence and development process; some considerations about the rationale, advantages, and limitations of different DDSs for CSC-targeted therapies were discussed.

Lipid-based nanocarriers co-loaded with artemether and triglycerides of docosahexaenoic acid: Effects on human breast cancer cells

Artemether (ART) was combined with triglyceride of docosahexaenoic acid (DHA) as the lipid-core in nanoemulsions (NE), nanostructured lipid carriers (NLC), and PEG-PLA nanocapsules (NC) formulations, and their effects on human breast cancer cells were evaluated. ART has been extensively used for malaria and has also therapeutic potential against different tumor cells in a repositioning strategy. The concentration-dependent cytotoxicity in vitro was determined in tumor lineages, MDA-MB-231 and MCF-7, and non-tumor MCF-10A cells for free-ART/DHA combination and its formulations. The cells were monitored for viability, effects on cell migration and clonogenicity, cell death mechanism, and qualitative and quantitative cell uptake of nanocarriers. The lipid-nanocarriers showed mean sizes over the range of 110 and 280 nm with monodisperse populations and zeta potential values ranging from -21 to -67 mV. The ART encapsulation efficiencies varied from 57 to 83 %. ART/DHA co-loaded in three different lipid nanocarriers reduced the MDA-MB-231 and MCF-7 viability in a dose-dependent manner with enhanced selectivity toward tumor cell lines. They also reduced clonogenicity and the ability of cells to migrate showing antimetastatic potential in both cell lines and triggered apoptosis in MCF-7 cells. Confocal microscopy and flow cytometry analysis showed that NC, NLC, and NE were rapidly internalized by cells, with higher interaction displayed by NE with MCF-7 cells compared to NC and NLC that was correlated with the strongest NE-fluorescence in cells. Therefore, this study not only demonstrated the value of this new combination of ART/DHA as a new strategy for breast cancer therapy but also showed enhanced cytotoxicity and potential metastatic activity of lipid-based formulations against human breast cancer cells that indicate great potential for pre-clinical and clinical translation.

Recent Nano-based Therapeutic Intervention of Bioactive Sesquiterpenes: Prospects in Cancer Therapeutics

In the recent scenario, nanotechnology-based therapeutics intervention has gained tremendous impetus all across the globe. Nano-based pharmacological intervention of various bioactive compounds has been explored on an increasing scale. Sesquiterpenes are major constituents of essential oils (EOs) present in various plant species which possess intriguing therapeutic potentials. However, owing to their poor physicochemical properties; they have pharmacological limitations. Recent advances in nano-based therapeutic interventions offer various avenues to improve their therapeutic applicability. Reckoning with these, the present review collates various nano-based therapeutic intervention of sesquiterpenes with prospective potential against various debilitating diseases especially cancer. In our viewpoint, considering the burgeoning advancement in the field of nanomedicine; in the near future, the clinical applicability of these nano-formulated sesquiterpenes can be foreseen with great enthusiasm.

Evaluation of hepatic drug-metabolism for glioblastoma using liver-brain chip

Glioma is one of the most aggressive and highly fatal diseases with an extremely poor prognosis. Considering the poor clinical response to therapy in glioma, it is urgent to establish an in vitro model to facilitate the screening and assessment of anti-brain-tumor drugs. The blood-brain barrier (BBB), as well as liver metabolism plays an important role in determining the pharmacological activity of many anti-brain-tumor drugs. In this work, we designed a multi-interface liver-brain chip integrating co-culture system to assess hepatic metabolism dependent cytotoxicity of anti-brain-tumor drug in vitro. This microdevice composed of three microchannels which were separated by porous membrane and collagen. HepG2 and U87 cells were cultured in separated channels as mimics of liver and glioblastoma. Brain microvascular endothelial cells (BMECS) and cerebral astrocytes were co-cultured on collagen to mimic the brain microvascular endothelial barrier. Three common anti-tumor drugs, paclitaxel (PTX), capecitabine (CAP) and temozolomide (TMZ), were evaluated on this chip. In integrated liver-brain chip, liver enhanced the cytotoxicity of CAP on U87 cells by 30%, but having no significant effect on TMZ. The BBB decreased the cytotoxicity of PTX by 20%, while no significant effects were observed on TMZ and CAP, indicating the importance of liver metabolism and blood-brain barrier on the evaluation of anti-brain-tumor drugs. This work provides a biomimetic liver-brain model to mimic the physiological and pharmacological processes in vitro and presents a simple platform for long-term cell co-culture, drug delivery and metabolism, and real-time analysis of drug effects on brain cancer.

Dual-Target Peptide-Modified Erythrocyte Membrane-Enveloped PLGA Nanoparticles for the Treatment of Glioma

Penetration of the blood–brain barrier (BBB) and the blood–brain tumor barrier (BBTB) remains a significant challenge for the delivery of drugs in the treatment of glioma. Therefore, the development of targeted preparations with the ability to penetrate the BBB and BBTB, and target gliomas, is an important approach if we are to improve the efficacy of glioma treatment. In the current study, an active targeting preparation based on PLGA nanoparticles coated with erythrocyte membranes (RBCNPs) and dual-modified with ^DWSW and NGR peptide ligands (^DWSW/NGR-RBCNPs). Euphorbia factor L1 (EFL1) extracted from euphorbiae semen was used as the model drug. The final nanoparticles were characterized by in vivo and in vitro tests. In vitro results showed that EFL1-loaded ^DWSW/NGR-RBCNPs were taken up by cells and had the ability to penetrate the BBB and BBTB and produce cytotoxic effects. Furthermore, in vivo studies in mice showed that when injected intravenously, these specialized NPs could enter the brain, target tumor tissue, and significantly extend life span. The results showed that dual-targeting EFL1-loaded ^DWSW/NGR-RBCNPs have significant potential as a nanotherapeutic tool for the treatment of brain glioma.

Artemisinins as Anticancer Drugs: Novel Therapeutic Approaches, Molecular Mechanisms, and Clinical Trials

Artemisinin and its derivatives have shown broad-spectrum antitumor activities in vitro and in vivo. Furthermore, outcomes from a limited number of clinical trials provide encouraging evidence for their excellent antitumor activities. However, some problems such as poor solubility, toxicity and controversial mechanisms of action hamper their use as effective antitumor agents in the clinic. In order to accelerate the use of ARTs in the clinic, researchers have recently developed novel therapeutic approaches including developing novel derivatives, manufacturing novel nano-formulations, and combining ARTs with other drugs for cancer therapy. The related mechanisms of action were explored. This review describes ARTs used to induce non-apoptotic cell death containing oncosis, autophagy, and ferroptosis. Moreover, it highlights the ARTs-caused effects on cancer metabolism, immunosuppression and cancer stem cells and discusses clinical trials of ARTs used to treat cancer. The review provides additional insight into the molecular mechanism of action of ARTs and their considerable clinical potential.

Potent in vivo antimalarial activity of water-soluble artemisinin nano-preparations

Artemisinin is a remarkable compound whose derivatives and combinations with multiple drugs have been utilized at the forefront of malaria treatment. However, the inherent issues of the parent compound such as poor bioavailability, short serum half-life, and high first-pass metabolism partially limit further applications of this drug. In this study, we enhanced the aqueous phase solubility of artemisinin by encapsulating it in two nanocarriers based on the polymer polycaprolactone (ART-PCL) and lipid-based Large Unilamellar Vesicles (ART-LIPO) respectively. Both nanoformulations exhibit in vitro parasite killing activity against Plasmodium falciparum with the ART-LIPO performing at comparable efficacy to the control drug solubilized in ethanol. These water-soluble formulations showed potent in vivo antimalarial activity as well in the mouse model of malaria at equivalent doses of the parent drug. Additionally, the artemisinin-PCL nanoformulation used in combination with either pyrimethamine or chloroquine increased the survival of the Plasmodium berghei infected mice for more than 34 days and effectively cured the mice of the infection. We highlight the potential for polymer and liposome-based nanocarriers in improving not only the aqueous phase solubility of artemisinin but also concomitantly retaining its therapeutic efficacy in vivo as well.

Recent Advancements in Liposome-Targeting Strategies for the Treatment of Gliomas: A Systematic Review

Malignant tumors represent some of the most intractable diseases that endanger human health. A glioma is a tumor of the central nervous system that is characterized by severe invasiveness, blurred boundaries between the tumor and surrounding normal tissue, difficult surgical removal, and high recurrence. Moreover, the blood-brain barrier (BBB) and multidrug resistance (MDR) are important factors that contribute to the lack of efficacy of chemotherapy in treating gliomas. A liposome is a biofilm-like drug delivery system with a unique phospholipid bilayer that exhibits high affinities with human tissues/organs (e.g., BBB). After more than five decades of development, classical and engineered liposomes consist of four distinct generations, each with different characteristics: (i) traditional liposomes, (ii) stealth liposomes, (iii) targeting liposomes, and (iv) biomimetic liposomes, which offer a promising approach to promote drugs across the BBB and to reverse MDR. Here, we review the history, preparatory methods, and physicochemical properties of liposomes. Furthermore, we discuss the mechanisms by which liposomes have assisted in the diagnosis and treatment of gliomas, including drug transport across the BBB, inhibition of efflux transporters, reversal of MDR, and induction of immune responses. Finally, we highlight ongoing and future clinical trials and applications toward further developing and testing the efficacies of liposomes in treating gliomas.

Targeted delivery of chlorogenic acid by mannosylated liposomes to effectively promote the polarization of TAMs for the treatment of glioblastoma

Tumor-associated macrophages (TAMs) generally display an immunosuppressive M2 phenotype and promote tumor progression and metastasis, suggesting their potential value as a target in cancer immunotherapy. Chlorogenic acid (CHA) has been identified as a potent immunomodulator that promotes the polarization of TAMs from an M2 to an M1 phenotype. However, rapid clearance in vivo and low tumor accumulation have compromised the immunotherapeutic efficacy of CHA in clinical trials. In this study, mannosylated liposomes are developed for targeted delivery of CHA to TAMs. The immunoregulatory effects of CHA, along with the overall antitumor efficacy of CHA-encapsulated mannosylated liposomes, are investigated through in vitro and in vivo experiments. The prepared CHA-encapsulated mannosylated liposomes exhibit an ideal particle size, favorable stability, and preferential accumulation in tumors via the mannose receptor-mediated TAMs-targeting effects. Further, CHA-encapsulated mannosylated liposomes inhibit G422 glioma tumor growth by efficiently promoting the polarization of the pro-tumorigenic M2 phenotype to the anti-tumorigenic M1 phenotype. Overall, these findings indicate that CHA-encapsulated mannosylated liposomes have great potential to enhance the immunotherapeutic efficacy of CHA by inducing a shift from the M2 to the M1 phenotype.

Development of long-circulating lapachol nanoparticles: formation, characterization, pharmacokinetics, distribution and cytotoxicity

Lapachol is an active compound for the treatment of malignant brain glioma. However, its physicochemical properties limit its clinical application. The purpose of this study is to develop a nano-drug delivery system (LPC-LP) loaded with lapachol (LPC), which remarkably prolongs the half-life in the body, and increases the brain intake, therefore, achieving a better anticancer effect in the treatment of glioma. In order to optimize the formulation of liposomes, an orthogonal design was adopted with entrapment efficiency (EE) as the index. The characterization of the optimized formulation was evaluated in vitro. To assess the safety profile and effect of LPC-LP, a rapid and sensitive ultra-fast liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed for studying the pharmacokinetics and brain distribution of LPC-LP and LPC. Finally, the cytotoxicity of the two preparations on C6 cells was studied by the MTT assay. The results showed that the average particle size of LPC-LP was 85.92 ± 2.35 nm, the EE of liposomes was 92.52 ± 1.81%, and the charge potential was -40.70 ± 9.20 mV. An in vitro release study showed that the release of lapachol from LPC-LP was delayed compared to LPC, indicating that LPC-LP was a sustained and controlled release system. The UPLC-MS/MS method was fully validated in both plasma and brain tissue according to the Food and Drug Administration (FDA) recommended guidelines, and successfully used for quantification of lapachol in vivo. After intravenous administration, LPC-LP prolonged circulation time of lapachol in the body and increased brain intake. Besides, the MTT results revealed that the IC50 value of LPC-LP on C6 cells significantly decreased, compared with LPC, which further confirmed that LPC-LP enhanced the inhibition of C6 cells and improved the anti-glioma effect. In conclusion, LPC-LP could serve as a promising candidate for the clinical application of lapachol in the treatment of glioma.

Nanoparticles Formulations of Artemisinin and Derivatives as Potential Therapeutics for the Treatment of Cancer, Leishmaniasis and Malaria

Cancer, malaria, and leishmaniasis remain the deadly diseases around the world although several strategies of treatment have been developed. However, most of the drugs used to treat the aforementioned diseases suffer from several pharmacological limitations such as poor pharmacokinetics, toxicity, drug resistance, poor bioavailability and water solubility. Artemisinin and its derivatives are antimalarial drugs. However, they also exhibit anticancer and antileishmanial activity. They have been evaluated as potential anticancer and antileishmanial drugs but their use is also limited by their poor water solubility and poor bioavailability. To overcome the aforementioned limitations associated with artemisinin and its derivatives used for the treatment of these diseases, they have been incorporated into nanoparticles. Several researchers incorporated this class of drugs into nanoparticles resulting in enhanced therapeutic outcomes. Their potential efficacy for the treatment of parasitic infections such as malaria and leishmaniasis and chronic diseases such as cancer has been reported. This review article will be focused on the nanoparticles formulations of artemisinin and derivatives for the treatment of cancer, malaria, and leishmaniasis and the biological outcomes (in vitro and in vivo).