Nano-structures mediated co-delivery of therapeutic agents for glioblastoma treatment: A review

Better together: nanoscale co-delivery systems of therapeutic agents for high-performance cancer therapy

Combination therapies can enhance the sensitivity of cancer to drugs, lower drug doses, and reduce side effects in cancer treatment. However, differences in the physicochemical properties and pharmacokinetics of different therapeutic agents limit their application. To avoid the above dilemma and achieve accurate control of the synergetic ratio, a nanoscale co-delivery system (NCDS) has emerged as a prospective tool for combined therapy in cancer treatment, which is increasingly being used to co-load different therapeutic agents. In this study, we have summarized the mechanisms of therapeutic agents in combination for cancer therapy, nanoscale carriers for co-delivery, drug-loading strategies, and controlled/targeted co-delivery systems, aiming to give a general picture of these powerful approaches for future NCDS research studies.

Delivery of Doxorubicin by Ferric Ion-Modified Mesoporous Polydopamine Nanoparticles and Anticancer Activity against HCT-116 Cells In Vitro

In clinical cancer research, photothermal therapy is one of the most effective ways to increase sensitivity to chemotherapy. Here, we present a simple and effective method for developing a nanotherapeutic agent for chemotherapy combined with photothermal therapy. The nanotherapeutic agent mesoporous polydopamine-Fe(III)-doxorubicin-hyaluronic acid (MPDA-Fe(III)-DOX-HA) was composed of mesoporous polydopamine modified by ferric ions and loaded with the anticancer drug doxorubicin (DOX), as well as an outer layer coating of hyaluronic acid. The pore size of the mesoporous polydopamine was larger than that of the common polydopamine nanoparticles, and the particle size of MPDA-Fe(III)-DOX-HA nanoparticles was 179 ± 19 nm. With the presence of ferric ions, the heat generation effect of the MPDA-Fe(III)-DOX-HA nanoparticles in the near-infrared light at 808 nm was enhanced. In addition, the experimental findings revealed that the active targeting of hyaluronic acid to tumor cells mitigated the toxicity of DOX on normal cells. Furthermore, under 808 nm illumination, the MPDA-Fe(III)-DOX-HA nanoparticles demonstrated potent cytotoxicity to HCT-116 cells, indicating a good anti-tumor effect in vitro. Therefore, the system developed in this work merits further investigation as a potential nanotherapeutic platform for photothermal treatment of cancer.

Therapeutic efficacy of 166Holmium siloxane in microbrachytherapy of induced glioblastoma in minipig tumor model

Glioblastoma is considered the most common malignant primary tumor of central nervous system. In spite of the current standard and multimodal treatment, the prognosis of glioblastoma is poor. For this reason, new therapeutic approaches need to be developed to improve the survival time of the glioblastoma patient. In this study, we performed a preclinical experiment to evaluate therapeutic efficacy of 166Ho microparticle suspension administered by microbrachytherapy on a minipig glioblastoma model. Twelve minipigs were divided in 3 groups. Minipigs had injections into the tumor, containing microparticle suspensions of either 166Ho (group 1; n = 6) or 165Ho (group 2; n = 3) and control group (group 3; n = 3). The survival time from treatment to euthanasia was 66 days with a good state of health of all minipigs in group 1. The median survival time from treatment to tumor related death were 8.6 and 7.3 days in groups 2 and control, respectively. Statistically, the prolonged life of group 1 was significantly different from the two other groups (p < 0.01), and no significant difference was observed between group 2 and control (p=0.09). Our trial on the therapeutic effect of the 166Ho microparticle demonstrated an excellent efficacy in tumor control. The histological and immunohistochemical analysis showed that the efficacy was related to a severe 166Ho induced necrosis combined with an immune response due to the presence of the radioactive microparticles inside the tumors. The absence of reflux following the injections confirms the safety of the injection device.

Optimization of Tumor Targeting Gold Nanoparticles for Glioblastoma Applications

Glioblastoma brain tumors represent an aggressive form of gliomas that is hallmarked by being extremely invasive and aggressive due to intra and inter-tumoral heterogeneity. This complex tumor microenvironment makes even the newer advancements in glioblastoma treatment less effective long term. In developing newer treatment technologies against glioblastoma, one should tailor the treatment to the tumor microenvironment, thus allowing for a more robust and sustained anti-glioblastoma effect. Here, we present a novel gold nanoparticle therapy explicitly designed for bioactivity against glioblastoma representing U87MG cell lines. We employ standard conjugation techniques to create oligonucleotide-coated gold nanoparticles exhibiting strong anti-glioblastoma behavior and optimize their design to maximize bioactivity against glioblastoma. Resulting nanotherapies are therapy specific and show upwards of 75% inhibition in metabolic and proliferative activity with stark effects on cellular morphology. Ultimately, these gold nanotherapies are a good base for designing more multi-targeted approaches to fighting against glioblastoma.

Multifunctional nanotheranostics for near infrared optical imaging-guided treatment of brain tumors

Malignant brain tumors, a heterogeneous group of primary and metastatic neoplasms in the central nervous system (CNS), are notorious for their highly invasive and devastating characteristics, dismal prognosis and low survival rate. Recently, near-infrared (NIR) optical imaging modalities including fluorescence imaging (FLI) and photoacoustic imaging (PAI) have displayed bright prospect in innovation of brain tumor diagnoses, due to their merits, like noninvasiveness, high spatiotemporal resolution, good sensitivity and large penetration depth. Importantly, these imaging techniques have been widely used to vividly guide diverse brain tumor therapies in a real-time manner with high accuracy and efficiency. Herein, we provide a systematic summary of the state-of-the-art NIR contrast agents (CAs) for brain tumors single-modal imaging (e.g., FLI and PAI), dual-modal imaging (e.g., FLI/PAI, FLI/magnetic resonance imaging (MRI) and PAI/MRI) and triple-modal imaging (e.g., MRI/FLI/PAI and MRI/PAI/computed tomography (CT) imaging). In addition, we update the most recent progress on the NIR optical imaging-guided therapies, like single-modal (e.g., photothermal therapy (PTT), chemotherapy, surgery, photodynamic therapy (PDT), gene therapy and gas therapy), dual-modal (e.g., PTT/chemotherapy, PTT/surgery, PTT/PDT, PDT/chemotherapy, PTT/chemodynamic therapy (CDT) and PTT/gene therapy) and triple-modal (e.g., PTT/PDT/chemotherapy, PTT/PDT/surgery, PTT/PDT/gene therapy and PTT/gene/chemotherapy). Finally, we discuss the opportunities and challenges of the CAs and nanotheranostics for future clinic translation.

Multimodal targeting of glioma with functionalized nanoparticles

The most common and aggressive primitive intracranial tumor of the central nervous system is the glioma. The blood–brain barrier (BBB) has proven to be a significant obstacle to the effective treatment of glioma. To effectively treat glioma, different ways have been used to cross the BBB to deliver drugs to the brain. Drug delivery through nanocarriers proves to be an effective and non-invasive technique for the treatment of glioma and has great potential in the treatment of glioma. In this review, we will provide an overview of nanocarrier-mediated drug delivery and related glioma therapy. Nanocarrier-mediated drug delivery techniques to cross the BBB (liposomes, micelles, inorganic systems, polymeric nanoparticles, nanogel system, and biomimetic nanoparticles) are explored. Finally, the use of nanotherapeutic approaches in the treatment of glioblastoma including chemotherapy, radiotherapy, photothermal therapy, gene therapy, glioma genome editing, immunotherapy, chimeric antigen receptor (CAR) T-cells, immune checkpoint modulators, immune photothermal therapy, vaccine-based immunotherapy, and combination therapy is summarized. Furthermore, this article offers various views on the clinical applicability of nanomedicine.

Recent Advances in Nanoparticle-Based Co-Delivery Systems for Cancer Therapy

Cancer therapies have advanced tremendously throughout the last decade, yet multiple factors still hinder the success of the different cancer therapeutics. The traditional therapeutic approach has been proven insufficient and lacking in the suppression of tumor growth. The simultaneous delivery of multiple small-molecule chemotherapeutic drugs and genes improves the effectiveness of each treatment, thus optimizing efficacy and improving synergistic effects. Nanomedicines integrating inorganic, lipid, and polymeric-based nanoparticles have been designed to regulate the spatiotemporal release of the encapsulated drugs. Multidrug-loaded nanocarriers are a potential strategy to fight cancer and the incorporation of co-delivery systems as a feasible treatment method has projected synergistic benefits and limited undesirable effects. Moreover, the development of co-delivery systems for maximum therapeutic impact necessitates better knowledge of the appropriate therapeutic agent ratio as well as the inherent heterogeneity of the cancer cells. Co-delivery systems can simplify clinical processes and increase patient quality of life, even though such systems are more difficult to prepare than single drug delivery systems. This review highlights the progress attained in the development and design of nano carrier-based co-delivery systems and discusses the limitations, challenges, and future perspectives in the design and fabrication of co-delivery systems.

Progress and Viewpoints of Multifunctional Composite Nanomaterials for Glioblastoma Theranostics

The most common malignant tumor of the brain is glioblastoma multiforme (GBM) in adults. Many patients die shortly after diagnosis, and only 6% of patients survive more than 5 years. Moreover, the current average survival of malignant brain tumors is only about 15 months, and the recurrence rate within 2 years is almost 100%. Brain diseases are complicated to treat. The reason for this is that drugs are challenging to deliver to the brain because there is a blood–brain barrier (BBB) protection mechanism in the brain, which only allows water, oxygen, and blood sugar to enter the brain through blood vessels. Other chemicals cannot enter the brain due to their large size or are considered harmful substances. As a result, the efficacy of drugs for treating brain diseases is only about 30%, which cannot satisfy treatment expectations. Therefore, researchers have designed many types of nanoparticles and nanocomposites to fight against the most common malignant tumors in the brain, and they have been successful in animal experiments. This review will discuss the application of various nanocomposites in diagnosing and treating GBM. The topics include (1) the efficient and long-term tracking of brain images (magnetic resonance imaging, MRI, and near-infrared light (NIR)); (2) breaking through BBB for drug delivery; and (3) natural and chemical drugs equipped with nanomaterials. These multifunctional nanoparticles can overcome current difficulties and achieve progressive GBM treatment and diagnosis results.

Nanobiotechnology-assisted therapies to manage brain cancer in personalized manner

There are numerous investigated factors that limit brain cancer treatment efficacy such as ability of prescribed therapy to cross the blood-brain barrier (BBB), tumor specific delivery of a therapeutics, transport within brain interstitium, and resistance of tumor cells against therapies. Recent breakthroughs in the field of nano-biotechnology associated with developing multifunctional nano-theranostic emerged as an effective way to manage brain cancer in terms of higher efficacy and least possible adverse effects. Keeping challenges and state-of-art accomplishments into consideration, this review proposes a comprehensive, careful, and critical discussion focused on efficient nano-enabled platforms including nanocarriers for drug delivery across the BBB and nano-assisted therapies (e.g., nano-immunotherapy, nano-stem cell therapy, and nano-gene therapy) investigated for brain cancer treatment. Besides therapeutic efficacy point-of-view, efforts are being made to explore ways projected to tune such developed nano-therapeutic for treating patients in personalized manner via controlling size, drug loading, delivery, and retention. Personalized brain tumor management based on advanced nano-therapies can potentially lead to excellent therapeutic benefits based on unique genetic signatures in patients and their individual disease profile. Moreover, applicability of nano-systems as stimulants to manage the brain cancer growth factors has also been discussed in photodynamic therapy and radiotherapy. Overall, this review offers a comprehensive information on emerging opportunities in nanotechnology for advancing the brain cancer treatment.

Combining Augmented Radiotherapy and Immunotherapy through a Nano-Gold and Bacterial Outer-Membrane Vesicle Complex for the Treatment of Glioblastoma

Glioblastoma, formerly known as glioblastoma multiforme (GBM), is refractory to existing adjuvant chemotherapy and radiotherapy. We successfully synthesized a complex, Au-OMV, with two specific nanoparticles: gold nanoparticles (AuNPs) and outer-membrane vesicles (OMVs) from E. coli. Au-OMV, when combined with radiotherapy, produced radiosensitizing and immuno-modulatory effects that successfully suppressed tumor growth in both subcutaneous G261 tumor-bearing and in situ (brain) tumor-bearing C57BL/6 mice. Longer survival was also noted with in situ tumor-bearing mice treated with Au-OMV and radiotherapy. The mechanisms for the successful treatment were evaluated. Intracellular reactive oxygen species (ROS) greatly increased in response to Au-OMV in combination with radiotherapy in G261 glioma cells. Furthermore, with a co-culture of G261 glioma cells and RAW 264.7 macrophages, we found that GL261 cell viability was related to chemotaxis of macrophages and TNF-α production.

Recent advances in co-delivery nanosystems for synergistic action in cancer treatment

Nanocarrier delivery systems have been widely studied to carry unique or dual chemical drugs. The major challenge of chemotherapies is to overcome the multidrug-resistance (MDR) of cells to antineoplastic medicines. In this context, nano-scale technology has allowed researchers to develop biocompatible nano-delivery systems to overcome the limitation of chemical agents. The development of nano-vehicles may also be directed to co-deliver different agents such as drugs and genetic materials. The delivery of nucleic acids targeting specific cells is based on gene therapy principles to replace the defective gene, correct genome errors or knock-down a particular gene. Co-delivery systems are attractive strategies due to the possibility of achieving synergistic therapeutic effects, which are more effective in overcoming the MDR of cancer cells. These combined therapies can provide better outcomes than separate delivery approaches carrying either siRNA, miRNA, pDNA, or drugs. This article reviews the main design features that need to be associated with nano-vehicles to co-deliver drugs, genes, and gene-drug combinations with efficacy. The advantages and disadvantages of co-administration approaches are also overviewed and compared with individual nanocarrier systems. Herein, future trends and perspectives in designing novel nano-scale platforms to co-deliver therapeutic agents are also discussed.

Co-encapsulation of tertinoin and resveratrol by solid lipid nanocarrier (SLN) improves mice in vitro matured oocyte/ morula-compact stage embryo development

As a promising strategy in overcoming drug resistance, the nano drug co-delivery system (NDCDS) can transport two or more drugs into the cell. In this study, we sought to compare the dual and single drug-delivery system, to deliver the optimal dose of Resveratrol (RES) and Tretinoin (TTN) into the in vitro matured oocyte and morula-compact stage embryonic cells. The formation of single (RES/TTN) and dual-drug (RES + TTN)-SLN were confirmed by Uv-vis spectrophotometery, dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) technologies. In two experiments, the oocytes/presumptive zygotes were cultured under various concentrations of the single (RES/TTN) and dual-drug (RES + TTN)-SLN. In vitro toxicity studies, including nuclear staining (Aceto-orcein and Hoechst 33342), H2DCFDA fluorescent staining, chemiluminescence assay, and quantitative reverse transcription-PCR (qRT-PCR) techniques, indicated an excellent oocyte/embryo internalization of RES and TTN. Moreover, when oocytes/embryos were treated with the lowest concentration of RES + TTN-SLN, antioxidants-related genes were upregulated, apoptotic-related genes were downregulated, and intra/extracellular ROS production was reduced. In vitro cytotoxicity studies also demonstrated that single/dual-encapsulation of RES or TTN were safe even at the highest concentration (10 and 5 μM) compared to the control group. To sum it up, both delivery systems of RES and TTN by SLN (dual or single encapsulation) can deliver the optimal dose of RES and TTN into the oocyte/embryo. Where the dual-delivery of RES and TTN even at the lowest concentration (0.25 μM + 0.1 μm) showed a synergistic anti-oxidative effect in oocyte/embryo with a better inhibition of intra/extra-cellular ROS production by an enhanced/controlled intracellular penetration.

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

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

Recent advances on drug delivery nanocarriers for cerebral disorders

Pharmacotherapies for brain disorders are generally faced with obstacles from the blood-brain barrier (BBB). There are a variety of drug delivery systems that have been put forward to cross or bypass the BBB with the access to the central nervous system. Brain drug delivery systems have benefited greatly from the development of nanocarriers, including lipids, polymers and inorganic materials. Consequently, various kinds of brain drug delivery nano-systems have been established, such as liposomes, polymeric nanoparticles (PNPs), nanomicelles, nanohydrogels, dendrimers, mesoporous silica nanoparticles and magnetic iron oxide nanoparticles. The characteristics of their carriers and preparations usually differ from each other, as well as their transportation mechanisms into intracerebral lesions. In this review, different types of brain drug delivery nanocarriers are classified and summarized, especially their significant achievements, to present several recommendations and directions for future strategies of cerebral delivery.

Drug Delivery Nanosystems in Glioblastoma Multiforme Treatment: Current State of the Art

Glioblastoma multiforme (GBM) is the most common primary malignant Central Nervous System cancer, responsible for about 4% of all deaths associated with neoplasia, characterized as one of the fatal human cancers. Tumor resection does not possess curative character, thereby radio and/or chemotherapy are often necessary for the treatment of GBM. However, drugs used in GBM chemotherapy present some limitations, such as side effects associated with non-specific drug biodistribution as well as limited bioavailability, which limits their clinical use. To attenuate the systemic toxicity and overcome the poor bioavailability, a very attractive approach is drug encapsulation in drug delivery nanosystems. The main focus of this review is to explore the actual cancer global problem, enunciate barriers to overcome in the pharmacological treatment of GBM, as well as the most updated drug delivery nanosystems for GBM treatment and how they influence biopharmaceutical properties of anti-GBM drugs. The discussion will approach lipid-based and polymeric nanosystems, as well as inorganic nanoparticles, regarding their technical aspects as well as biological effects in GBM treatment. Furthermore, the current state of the art, challenges to overcome and future perspectives in GBM treatment will be discussed.

Enhanced Cryoprotective Effect of Melatonin and Resveratrol by Coencapsulation: Improved In Vitro Development of Vitrified-Warmed Mouse Germinal Vesicle Oocytes

Oocyte vitrification, as a vital step in reproductive medicine, is strongly associated with lower development caused by cryodamaging factors, such as oxidative stress. In this study, we evaluated the antioxidative synergistic effects of Melatonin (Mel) and Resveratrol (RES) coencapsulated by solid lipid nanocarriers (SLNs) against the pure antioxidant combination (Mel+RES). In this research, the formation of Mel+RES-SLN was confirmed by Fourier-transformed infrared spectroscopy. The average mean diameter, size distribution, polydispersity index, and zeta potential of particles were measured by Zetasizer, and the morphology was evaluated by scanning electron microscopy. In addition, the encapsulation efficiency (EE%) or drug loading capacity (DL%) of the nanocapsule was determined by spectrophotometric methods. Germinal vesicle (GV)-stage oocytes harvested from 6- to 12-week-old female NMRI mice were randomly divided into seven groups for in vitro studies. In these groups, (0, 10^-12 M + 0.5 μM, 10^-9 M + 2 μM, or 10^-6 M + 10 μM) of Mel+RES/Mel+RES-SLN were added into vitrification media. After thawing, oocytes were matured, fertilized, and cultured for 3 days. Extra/intracellular reactive oxygen species (ROS) levels were measured in in vitro maturation medium after 24 hours. Our results revealed a significant improvement in the normal morphology of warmed GV-stage oocytes, GV breakdown (GVBD) rate, Metaphase II (MII)-stage oocyte formation, fertilization rate, early embryo development, and a significant reduction in intra/extracellular ROS level when vitrification media was supplemented with the lowest Mel+RES-SLN concentration. In vitro studies also demonstrated that the highest concentration of Mel+RES-SLN was safe, without a detrimental effect on embryonic development upon treatment. In conclusion, the lowest concentration of Mel+RES-SLN supplementation in GV-stage oocyte vitrification media improved maturation, fertilization, and embryo development rate and decreased extra/intracellular ROS level through an enhanced/controlled intracellular penetration compared to the pure Mel+RES.

Intercalation of curcumin into liposomal chemotherapeutic agent augments apoptosis in breast cancer cells

Resistance to common chemotherapeutic agents is a frequent phenomenon in late-stage breast cancers. An ideal system capable of the co-delivery of hydrophobic and hydrophilic chemotherapeutic agents can regulate the dosage and co-localization of pharmaceutical compounds and thereby improve the anticancer efficacy. Here, for the first time, we have intercalated curcumin (Cur) into a double-layered membrane of cisplatin (Cis) liposomes to obtain a dosage controlled co-delivery formulation, capable of inducing apoptosis in breast cancer cells. The concentrations of Cur and Cis in nanoliposome (Cur-Cis@NLP) were optimized by response surface methodology (RSM); RSM optimization showed 99.81 and 23.86% entrapment efficiency for Cur and Cis, respectively. TEM analysis demonstrated the fabrication of nanoparticles with average diameter of 100 nm. The anticancer and apoptotic effects of Cur-Cis@NLPs were also evaluated using MTT assay, fluorescent staining and flow cytometry assays. Cytotoxicity assessments of various Cur-Cis@NLPs concentrations demonstrated a concentration-dependent manner. In comparison to free and liposomal Cis, Cur-Cis@NLP reduced breast cancer cells' viability (82.5%) in a significant manner at a final concentration of 32 μg.mL^-1 and 20 μg.mL^-1 of Cur and Cis, respectively. Combination index values calculation of Cur-Cis@NLP showed an overall CI value <1, indicating synergetic effect of the designed co-delivery system. Additionally, flow cytometry assay demonstrated Cur-Cis@NLPs triggered apoptosis about 10-folds higher than liposomal Cis. This co-drug delivery system has a potential for the encapsulation and release of both hydrophobic and hydrophilic drugs, while taking the advantages of the reduced cytotoxic effect along with achieving high potency.

Amphiphilic Block Copolymers-Guided Strategies for Assembling Nanoparticles: From Basic Construction Methods to Bioactive Agent Delivery Applications

Over recent decades, amphiphilic block copolymers (ABCs) comprising both hydrophobic and hydrophilic segments within their covalently bound structure have been extensively investigated from basic science to various biomedical applications. Nanoparticles (NPs) self-assembled from ABCs have been a center of interest for controlled delivery of various therapeutic drugs, genes, proteins, and imaging agents for decades and continue to attract attention owing to their unique physical and biological properties. In this Spotlight on Applications, we review and summarize recent optimized preparation techniques in the fabrication of "drugs"-loaded NPs from ABCs based on our group progress. These techniques can be categorized into four types including (i) emulsification and solvent evaporation, (ii) double emulsification and solvent evaporation, (iii) nanoprecipitation, and (iv) film dispersion. By selecting proper techniques, bioactive agents with different properties could be incorporated into the NPs either alone or in a combination pattern. We analyze the parameters of various techniques and specifically we highlight the improvements on the improved techniques to simultaneously coload both hydrophilic/hydrophobic drugs and therapeutic nucleic acids in the single NPs. These techniques will allow researchers to select proper methods in designing "drugs"-loaded NPs from ABCs.

Recent Progress of Nanocarrier-Based Therapy for Solid Malignancies

Conventional chemotherapy is still an important option of cancer treatment, but it has poor cell selectivity, severe side effects, and drug resistance. Utilizing nanoparticles (NPs) to improve the therapeutic effect of chemotherapeutic drugs has been highlighted in recent years. Nanotechnology dramatically changed the face of oncology by high loading capacity, less toxicity, targeted delivery of drugs, increased uptake to target sites, and optimized pharmacokinetic patterns of traditional drugs. At present, research is being envisaged in the field of novel nano-pharmaceutical design, such as liposome, polymer NPs, bio-NPs, and inorganic NPs, so as to make chemotherapy effective and long-lasting. Till now, a number of studies have been conducted using a wide range of nanocarriers for the treatment of solid tumors including lung, breast, pancreas, brain, and liver. To provide a reference for the further application of chemodrug-loaded nanoformulations, this review gives an overview of the recent development of nanocarriers, and the updated status of their use in the treatment of several solid tumors.

Development of Artificial Plasma Membranes Derived Nanovesicles Suitable for Drugs Encapsulation

Extracellular vesicles (EVs) are considered as promising nanoparticle theranostic tools in many pathological contexts. The increasing clinical employment of therapeutic nanoparticles is contributing to the development of a new research area related to the design of artificial EVs. To this aim, different approaches have been described to develop mimetic biologically functional nanovescicles. In this paper, we suggest a simplified procedure to generate plasma membrane-derived nanovesicles with the possibility to efficiently encapsulate different drugs during their spontaneously assembly. After physical and molecular characterization by Tunable Resistive Pulse Sensing (TRPS) technology, transmission electron microscopy, and flow cytometry, as a proof of principle, we have loaded into mimetic EVs the isoquinoline alkaloid Berberine chloride and the chemotherapy compounds Temozolomide or Givinostat. We demonstrated the fully functionality of these nanoparticles in drug encapsulation and cell delivery, showing, in particular, a similar cytotoxic effect of direct cell culture administration of the anticancer drugs. In conclusion, we have documented the possibility to easily generate scalable nanovesicles with specific therapeutic cargo modifications useful in different drug delivery contexts.

Feasibility of intratumoral 165Holmium siloxane delivery to induced U87 glioblastoma in a large animal model, the Yucatan minipig

Glioblastoma is the most aggressive primary brain tumor leading to death in most of patients. It comprises almost 50-55% of all gliomas with an incidence rate of 2-3 per 100,000. Despite its rarity, overall mortality of glioblastoma is comparable to the most frequent tumors. The current standard treatment combines surgical resection, radiotherapy and chemotherapy with temozolomide. In spite of this aggressive multimodality protocol, prognosis of glioblastoma is poor and the median survival remains about 12-14.5 months. In this regard, new therapeutic approaches should be developed to improve the life quality and survival time of the patient after the initial diagnosis. Before switching to clinical trials in humans, all innovative therapeutic methods must be studied first on a relevant animal model in preclinical settings. In this regard, we validated the feasibility of intratumoral delivery of a holmium (Ho) microparticle suspension to an induced U87 glioblastoma model. Among the different radioactive beta emitters, 166Ho emits high-energy β(-) radiation and low-energy γ radiation. β(-) radiation is an effective means for tumor destruction and γ rays are well suited for imaging (SPECT) and consequent dosimetry. In addition, the paramagnetic Ho nucleus is a good asset to perform MRI imaging. In this study, five minipigs, implanted with our glioblastoma model were used to test the injectability of 165Ho (stable) using a bespoke injector and needle. The suspension was produced in the form of Ho microparticles and injected inside the tumor by a technique known as microbrachytherapy using a stereotactic system. At the end of this trial, it was found that the 165Ho suspension can be injected successfully inside the tumor with absence or minimal traces of Ho reflux after the injections. This injection technique and the use of the 165Ho suspension needs to be further assessed with radioactive 166Ho in future studies.

Paclitaxel/methotrexate co-loaded PLGA nanoparticles in glioblastoma treatment: Formulation development and in vitro antitumor activity evaluation

AIM

The aim of this study was to improve the therapeutic index of chemotherapeutic drugs on glioblastoma cells through an improved co-drug delivery system.

MATERIALS AND METHODS

Methotrexate (MTX) and paclitaxel (PTX) were co-loaded into poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) coated with polyvinyl alcohol (PVA) and Poloxamer188 (P188).

KEY FINDINGS

The mean size of the NPs was about 212 nm, with a zeta potential of about -15.7 mV. Encapsulation efficiency (EE%) and drug loading (DL%) were determined to be 72% and 4% for MTX and 85% and 4.9% for PTX, respectively. The prepared NPs were characterized by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). Moreover, an in vitro sustained release profile was observed for both drug loaded PLGA NPs. Glioblastoma cellular uptake of the NPs was confirmed by fluorescence microscopy and cell survival rate was investigated through the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method after 48 h of incubation showing IC₅₀ values of 24.5 μg·mL^-1 for PTX and 9.5 μg·mL^-1 for MTX for the MTX/PTX co-loaded PLGA nanoparticles coated with PVA/P188 (Co-2 NPs). Apoptosis and necrosis were also studied via flow cytometry, the lactate dehydrogenase (LDH) assay and the amount of anti-apoptotic protein (Bcl-2) expression. Blood compatibility of the co-delivery of PTX and MTX loaded PLGA NPs was investigated using a hemolysis method as well.

SIGNIFICANCE

The co-delivery of PTX and MTX loaded PLGA NPs is promising for the treatment of glioblastoma compared to their respective free drug formulations and, thus, should be further investigated.

Rational design and latest advances of codelivery systems for cancer therapy

Current treatments have limited effectiveness in treating tumors. The combination of multiple drugs or treatment strategies is widely studied to improve therapeutic effect and reduce adverse effects of cancer therapy. The codelivery system is the key to realize combined therapies. It is necessary to design and construct different codelivery systems in accordance with the variable structures and properties of cargoes and vectors. This review presented the typical design considerations about codelivery vectors for cancer therapy and described the current state of codelivery systems from two aspects: different types of vectors and collaborative treatment strategies. The commonly used loading methods of cargoes into the vectors, including physical and chemical processes, are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of codelivery systems.

Salinomycin-Loaded Iron Oxide Nanoparticles for Glioblastoma Therapy

Salinomycin is an antibiotic introduced recently as a new and effective anticancer drug. In this study, magnetic iron oxide nanoparticles (IONPs) were utilized as a drug carrier for salinomycin for potential use in glioblastoma (GBM) chemotherapy. The biocompatible polyethylenimine (PEI)-polyethylene glycol (PEG)-IONPs (PEI-PEG-IONPs) exhibited an efficient uptake in both mouse brain-derived microvessel endothelial (bEnd.3) and human U251 GBM cell lines. The salinomycin (Sali)-loaded PEI-PEG-IONPs (Sali-PEI-PEG-IONPs) released salinomycin over 4 days, with an initial release of 44% ± 3% that increased to 66% ± 5% in acidic pH. The Sali-IONPs inhibited U251 cell proliferation and decreased their viability (by approximately 70% within 48 h), and the nanoparticles were found to be effective in reactive oxygen species-mediated GBM cell death. Gene studies revealed significant activation of caspases in U251 cells upon treatment with Sali-IONPs. Furthermore, the upregulation of tumor suppressors (i.e., p53, Rbl2, Gas5) was observed, while TopII, Ku70, CyclinD1, and Wnt1 were concomitantly downregulated. When examined in an in vitro blood–brain barrier (BBB)-GBM co-culture model, Sali-IONPs had limited penetration (1.0% ± 0.08%) through the bEnd.3 monolayer and resulted in 60% viability of U251 cells. However, hyperosmotic disruption coupled with an applied external magnetic field significantly enhanced the permeability of Sali-IONPs across bEnd.3 monolayers (3.2% ± 0.1%) and reduced the viability of U251 cells to 38%. These findings suggest that Sali-IONPs combined with penetration enhancers, such as hyperosmotic mannitol and external magnetic fields, can potentially provide effective and site-specific magnetic targeting for GBM chemotherapy.

Nanomedicine and Immunotherapy: A Step Further towards Precision Medicine for Glioblastoma

Owing to the advancement of technology combined with our deeper knowledge of human nature and diseases, we are able to move towards precision medicine, where patients are treated at the individual level in concordance with their genetic profiles. Lately, the integration of nanoparticles in biotechnology and their applications in medicine has allowed us to diagnose and treat disease better and more precisely. As a model disease, we used a grade IV malignant brain tumor (glioblastoma). Significant improvements in diagnosis were achieved with the application of fluorescent nanoparticles for intraoperative magnetic resonance imaging (MRI), allowing for improved tumor cell visibility and increasing the extent of the surgical resection, leading to better patient response. Fluorescent probes can be engineered to be activated through different molecular pathways, which will open the path to individualized glioblastoma diagnosis, monitoring, and treatment. Nanoparticles are also extensively studied as nanovehicles for targeted delivery and more controlled medication release, and some nanomedicines are already in early phases of clinical trials. Moreover, sampling biological fluids will give new insights into glioblastoma pathogenesis due to the presence of extracellular vesicles, circulating tumor cells, and circulating tumor DNA. As current glioblastoma therapy does not provide good quality of life for patients, other approaches such as immunotherapy are explored. To conclude, we reason that development of personalized therapies based on a patient's genetic signature combined with pharmacogenomics and immunogenomic information will significantly change the outcome of glioblastoma patients.

Glyco-nanoparticles: New drug delivery systems in cancer therapy

Cancer is known as one of the most common diseases that are associated with high mobility and mortality in the world. Despite several efforts, current cancer treatment modalities often are highly toxic and lack efficacy and specificity. However, the application of nanotechnology has led to the development of effective nanosized drug delivery systems which are highly selective for tumors and allow a slow release of active anticancer agents. Different Nanoparticles (NPs) such as the silicon-based nano-materials, polymers, liposomes and metal NPs have been designed to deliver anti-cancer drugs to tumor sites. Among different drug delivery systems, carbohydrate-functionalized nanomaterials, specially based on their multi-valent binding capacities and desirable bio-compatibility, have attracted considerable attention as an excellent candidate for controlled release of therapeutic agents. In addition, these carbohydrate functionalized nano-carriers are more compatible with construction of the intracellular delivery platforms like the carbohydrate-modified metal NPs, quantum dots, and magnetic nano-materials. In this review, we discuss recent research in the field of multifunctional glycol-nanoparticles (GNPs) intended for cancer drug delivery applications.

Perspectives of Molecularly Imprinted Polymer-Based Drug Delivery Systems in Cancer Therapy

Despite the considerable effort made in the past decades, multiple aspects of cancer management remain a challenge for the scientific community. The severe toxicity and poor bioavailability of conventional chemotherapeutics, and the multidrug resistance have turned the attention of researchers towards the quest of drug carriers engineered to offer an efficient, localized, temporized, and doze-controlled delivery of antitumor agents of proven clinical value. Molecular imprinting of chemotherapeutics is very appealing in the design of drug delivery systems since the specific and selective binding sites created within the polymeric matrix turn these complex structures into value-added carriers with tunable features, notably high loading capacity, and a good control of payload release. Our work aims to summarize the present state-of-the art of molecularly imprinted polymer-based drug delivery systems developed for anticancer therapy, with emphasis on the particularities of the chemotherapeutics’ release and with a critical assessment of the current challenges and future perspectives of these unique drug carriers.

Nanoformulations for glioblastoma multiforme: a new hope for treatment

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor in adults, associated with a high mortality rate and a survival of between 12 and 15 months after diagnosis. Due to current treatment limitations involving surgery, radiotherapy and chemotherapy with temozolamide, there is a high rate of treatment failure and recurrence. To try to overcome these limitations nanotechnology has emerged as a novel alternative. Lipid, polymeric, silica and magnetic nanoparticles, among others, are being developed to improve GBM treatment and diagnosis. These nanoformulations have many advantages, including lower toxicity, biocompatibility and the ability to be directed toward the tumor. This article reviews the progress that have been made and the large variety of nanoparticles currently under study for GBM.

Factorial Design as a Tool for the Optimization of PLGA Nanoparticles for the Co-Delivery of Temozolomide and O6-Benzylguanine

Poly(d,l-lactic-co-glycolic) (PLGA) nanoparticles (NPs) have been widely studied for several applications due to their advantageous properties, such as biocompatibility and biodegradability. Therefore, these nanocarriers could be a suitable approach for glioblastoma multiforme (GBM) therapy. The treatment of this type of tumours remains a challenge due to intrinsic resistance mechanisms. Thus, new approaches must be envisaged to target GBM tumour cells potentially providing an efficient treatment. Co-delivery of temozolomide (TMZ) and O6-benzylguanine (O6BG), an inhibitor of DNA repair, could provide good therapeutic outcomes. In this work, a fractional factorial design (FFD) was employed to produce an optimal PLGA-based nanoformulation for the co-loading of both molecules, using a reduced number of observations. The developed NPs exhibited optimal physicochemical properties for brain delivery (dimensions below 200 nm and negative zeta potential), high encapsulation efficiencies (EE) for both drugs, and showed a sustained drug release for several days. Therefore, the use of an FFD allowed for the development of a nanoformulation with optimal properties for the co-delivery of TMZ and O6BG to the brain.

Synergistically enhanced anticancer effect of codelivered curcumin and siPlk1 by stimuli-responsive α-lactalbumin nanospheres

AIM

To achieve enhanced anticancer efficacy by combined siPlk1 and curcumin (cur) therapy using α-lactalbumin (α-lac) nanocarrier delivery.

MATERIALS & METHODS

α-Lac was partially hydrolyzed into amphiphilic peptides, and then self-assembled into nanospheres (NS). Cur was loaded into their hydrophobic core during the self-assembly process. siPlk1-SH was cross-linked with the endogenous cysteines on the NS. CRGDK peptide was conjugated on NS to target integrins overexpressed in HeLa cells.

RESULTS & CONCLUSION

The Cur and siPlk1 coloaded NS formulations possessed an enhanced tumor targeting and antitumor properties. Drugs were responsively released from disulfide bonds cross-linked RGD-NS/Cur/siPlk1 corresponding to the high intracellular glutathione concentrations of cancer cells. Both in vitro cell viability experiments and in vivo antitumor evaluations demonstrated that the codelivered nanosphere platform exhibited excellent tumor targeting and synergistic antitumor efficacy.

Bacterial magnetosomes-based nanocarriers for co-delivery of cancer therapeutics in vitro

In recent times, co-delivery of therapeutics has emerged as a promising strategy for treating dreadful diseases such as cancer.

MATERIALS AND METHODS

In this study, we developed a novel nanocarrier based on bacterial magnetosomes (BMs) that co-loaded with siRNA and doxorubicin (DOX) using polyethyleneimine (PEI) as a cross-linker (BMs/DP/siRNA). The delivery efficiency of siRNA as well as the pH-responsive release of DOX, and synergistic efficacy of these therapeutics in vitro were systematically investigated.

RESULTS

The structure of DOX-PEI (DP) conjugates that synthesized via hydrazone bond formation was confirmed by 1H nuclear magnetic resonance (NMR). The in vitro release experiments showed that the DP conjugate (DOX-loading efficiency - 5.77%±0.08%) exhibited the long-term release behavior. Furthermore, the optimal BMs/DP/siRNA particle size of 107.2 nm and the zeta potential value of 31.1±1.0 mV facilitated enhanced cellular internalization efficiency. Moreover, the agarose gel electrophoresis showed that the co-delivery system could protect siRNA from degradation in serum and RNase A. In addition, the cytotoxicity assay showed that BMs/DP/siRNA could achieve an excellent synergistic effect compared to that of siRNA delivery alone. The acridine orange (AO)/ethidium bromide (EB) double staining assay also showed that BMs/DP/siRNA complex could induce cells in a stage of late apoptosis and nanocomplex located in the proximity of the nucleus.

CONCLUSION

The combination of gene and chemotherapeutic drug using BMs is highly efficient, and the BMs/DP/siRNA would be a promising therapeutic strategy for the future therapeutics.

Vesicular systems employing natural substances as promising drug candidates for MMP inhibition in glioblastoma: A nanotechnological approach

Glioblastoma multiforme (GBM), one of the most lethal Brain tumors, characterized by its high invasive nature and increased mortality rates forms a major bottleneck in transport of therapeutics across the Blood Brain Barrier (BBB). Matrix metalloproteinases (MMPs) are classified as enzymes, which are found to be up regulated in the Glioma tumor microenvironment and thus can be considered as a target for inhibition for curbing GBM. Many chemotherapeutics and techniques have been employed for inhibiting MMPs till now but all of them failed miserably and were withdrawn in clinical trials due to their inability in restricting the tumor growth or increasing the overall survival rates. Thus, the quest for finding the suitable MMP inhibitor is still on and there is a critical need for identification of novel compounds which can alter the BBB permeability, restrain tumor growth and prevent tumor recurrence. Currently, naturally derived substances are gaining widespread attention as tumor inhibitors and many studies have been reported by far highlighting their importance in restricting MMP expression thus serving as chemotherapeutics for cancer due to their minimal toxicity. These substances may serve as probable candidates for inhibiting MMP expression in GBM. However, targeting and delivering the inhibitor to its target site is an issue that needs to be overcome in order to attain maximum specificity and sustained release. The birth of nanotechnology served as a boon in delivering drugs to the most complicated areas thus paving way for Nano drug delivery. An efficient Nano carrier with ability to cross the BBB and competently kill the Glioma cells forms the prerequisite for GBM chemotherapy. Vesicular drug delivery systems are one such class of carriers, which have the capacity to release the drug at a predetermined rate at the target site thus minimizing any undesirable side effects. Exploiting vesicular systems as promising Nano drug carriers to formulate naturally derived substances, that can bypass the BBB and act as an inhibitor against MMPs in GBM is the main theme of this review.

Investigation of Effective Parameters on Size of Paclitaxel Loaded PLGA Nanoparticles

Purpose: The size of polymeric nanoparticles is considered as an effective factor in cancer therapy due to enterance into tumor tissue via the EPR effect. The purpose of this work was to investigate the effective parameters on poly(lactic-co-glycolic acid)-paclitaxel (PLGA –PTX) nanoparticles size.

Methods: We prepared PLGA-PTX nanoparticles via single emulsion and precipitation methods with variable paremeters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration.

Results: PLGA-PTX nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results exhibited that the diameter of nanoparticles enhanced with increasing drug, polymer and PVA concentrations whereas organic to aqueous phase volume ratio and sonication time required to the optimization for a given size.

Conclusion: The precipitation method provides smaller nanoparticles compared to emulsion one. Variable parameters including drug concentration, aqueous to organic phase volume ratio, polymer concentration, sonication time and PVA concentration affect diameter of nanoparticles.

Fe₃O₄ Nanoparticles in Targeted Drug/Gene Delivery Systems

Fe₃O₄ nanoparticles (NPs), the most traditional magnetic nanoparticles, have received a great deal of attention in the biomedical field, especially for targeted drug/gene delivery systems, due to their outstanding magnetism, biocompatibility, lower toxicity, biodegradability, and other features. Naked Fe₃O₄ NPs are easy to aggregate and oxidize, and thus are often made with various coatings to realize superior properties for targeted drug/gene delivery. In this review, we first list the three commonly utilized synthesis methods of Fe₃O₄ NPs, and their advantages and disadvantages. In the second part, we describe coating materials that exhibit noticeable features that allow functionalization of Fe₃O₄ NPs and summarize their methods of drug targeting/gene delivery. Then our efforts will be devoted to the research status and progress of several different functionalized Fe₃O₄ NP delivery systems loaded with chemotherapeutic agents, and we present targeted gene transitive carriers in detail. In the following section, we illuminate the most effective treatment systems of the combined drug and gene therapy. Finally, we propose opportunities and challenges of the clinical transformation of Fe₃O₄ NPs targeting drug/gene delivery systems.

Nanoscale polysaccharide derivative as an AEG-1 siRNA carrier for effective osteosarcoma therapy

Background

Nanomedicine, which is the application of nanotechnology in medicine to make medical diagnosis and treatment more accurate, has great potential for precision medicine. Despite some improvements in nanomedicine, the lack of efficient and low-toxic vectors remains a major obstacle.

Objective

The aim of this study was to prepare an efficient and low-toxic vector which could deliver astrocyte elevated gene-1 (AEG-1) small interfering RNA (siRNA; siAEG-1) into osteosarcoma cells effectively and silence the targeted gene both in vitro and in vivo.

Materials and methods

We prepared a novel polysaccharide derivative by click conjugation of azidized chitosan with propargyl focal point poly (L-lysine) dendrons (PLLD) and subsequent coupling with folic acid (FA; Cs-g-PLLD-FA). We confirmed the complexation of siAEG-1and Cs-g-PLLD or Cs-g-PLLD-FA by gel retardation assay. We examined the cell cytotoxicity, cell uptake, cell proliferation and invasion abilities of Cs-g-PLLD-FA/siAEG-1 in osteosarcoma cells. In osteosarcoma 143B cells tumor-bearing mice models, we established the therapeutic efficacy and safety of Cs-g-PLLD-FA/siAEG-1.

Results

Cs-g-PLLD-FA could completely encapsulate siAEG-1 and showed low cytotoxicity in osteosarcoma cells and tumour-bearing mice. The Cs-g-PLLD-FA/siAEG-1 nanocomplexes were capable of transferring siAEG-1 into osteosarcoma cells efficiently, and the knockdown of AEG-1 resulted in the inhibition of tumour cell proliferation and invasion. In addition, caudal vein injecting of Cs-g-PLLD-FA/siAEG-1 complexes inhibited tumor growth and lung metastasis in tumor-bearing mice by silencing AEG-1 and regulating MMP-2/9.

Conclusion

In summary, Cs-g-PLLD-FA nanoparticles are a promising system for the effective delivery of AEG-1 siRNA for treating osteosarcoma.

Nanotherapeutics: An insight into healthcare and multi-dimensional applications in medical sector of the modern world

In recent years nanotechnology has revolutionized the healthcare strategies and envisioned to have a tremendous impact to offer better health facilities. In this context, medical nanotechnology involves design, fabrication, regulation, and application of therapeutic drugs and devices having a size in nano-range (1-100 nm). Owing to the revolutionary implications in drug delivery and gene therapy, nanotherapeutics has gained increasing research interest in the current medical sector of the modern world. The areas which anticipate benefits from nano-based drug delivery systems are cancer, diabetes, infectious diseases, neurodegenerative diseases, blood disorders and orthopedic problems. The development of nanotherapeutics with multi-functionalities has considerable potential to fill the lacunae existing in the present therapeutic domain. Nanomedicines in the field of cancer management have enhanced permeability and retention of drugs thereby effectively targeting the affected tissues. Polymeric conjugates of asparaginase, polymeric micelles of paclitaxel have been recmended for various types of cancer treatment .The advancement of nano therapeutics and diagnostics can provide the improved effectiveness of the drug with less or no toxicity concerns. Similarly, diagnostic imaging is having potential future applications with newer imaging elements at nano level. The newly emerging field of nanorobotics can provide new directions in the field of healthcare. In this article, an attempt has been made to highlight the novel nanotherapeutic potentialities of polymeric nanoparticles, nanoemulsion, solid lipid nanoparticle, nanostructured lipid carriers, dendrimers, nanocapsules and nanosponges based approaches. The useful applications of these nano-medicines in the field of cancer, nutrition, and health have been discussed in details. Regulatory and safety concerns along with the commercial status of nanosystems have also been presented. In summary, a successful translation of emerging nanotherapeutics into commercial products may lead to an expansion of biomedical science. Towards the end of the review, future perspectives of this important field have been introduced briefly.

Co-delivery nanoparticles of anti-cancer drugs for improving chemotherapy efficacy

To achieve superior therapeutic efficacy, the combination chemotherapy using two or more anticancer drugs in clinical practice has been generally accepted as a feasible strategy. On account of the concept of combination chemotherapy, co-delivery of anticancer drugs with nanotechnology gradually becomes a desired strategy and one of the research frontiers on modern drug delivery. In recent years, nano drug co-delivery system (NDCDS), which loads at least two anticancer drugs with different physicochemical and pharmacological properties into a combination delivery system, has achieved rapid development. NDCDS synergistically inhibited the growth of the tumor compared with the free drugs. In this review, we highlighted the current state of co-delivery nanoparticles and the most commonly used nanomaterial, discussed challenges and strategies, and prospect future development.

Nanotherapeutic systems for local treatment of brain tumors

Malignant brain tumor, including the most common type glioblastoma, are histologically heterogeneous and invasive tumors known as the most devastating neoplasms with high morbidity and mortality. Despite multimodal treatment including surgery, radiotherapy, chemotherapy, and immunotherapy, the disease inevitably recurs and is fatal. This lack of curative options has motivated researchers to explore new treatment strategies and to develop new drug delivery systems (DDSs); however, the unique anatomical, physiological, and pathological features of brain tumors greatly limit the effectiveness of conventional chemotherapy. In this context, we review the recent progress in the development of nanoparticle-based DDSs aiming to address the key challenges in transporting sufficient amount of therapeutic agents into the brain tumor areas while minimizing the potential side effects. We first provide an overview of the standard treatments currently used in the clinic for the management of brain cancers, discussing the effectiveness and limitations of each therapy. We then provide an in-depth review of nanotherapeutic systems that are intended to bypass the blood-brain barrier, overcome multidrug resistance, infiltrate larger tumorous tissue areas, and/or release therapeutic agents in a controlled manner. WIREs Nanomed Nanobiotechnol 2018, 10:e1479. doi: 10.1002/wnan.1479 This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

siRNA delivery using polyelectrolyte-gold nanoassemblies in neuronal cells for BACE1 gene silencing

Small interfering RNA (siRNA) mediated RNA interference is a versatile therapeutic tool for many intractable genetic disorders. Various nanoassemblies specifically designed to deliver the siRNAs could be utilized for efficient siRNA delivery which is one of the major concern for the success of this therapeutic. Thus, in the present study, polyelectrolyte-gold nanoassemblies (PE-Gold NAs) were selected for siRNA delivery of an in vitro verified siRNA. Three different polyelectrolytes (polyethyleneimine, citraconic anhydride modified poly (allylamine) hydrochloride and poly l-arginine) were used to formulate the PE-Gold NAs using the layer-by-layer technique. Successful physico-chemical characterizations of these PE-Gold NAs were performed using UV-Visible, FTIR, ¹H-NMR spectroscopies, XRD, TEM, DLS and Zeta potential measurements. In vitro studies for the cytotoxicity, the uptake of these nanoassemblies and the gene silencing were carried out using these PE-Gold NAs in N2a and NB4 1A3 (murine neuronal) cell lines. The three selected PE-Gold NAs showed significant BACE1 (β-site APP cleaving enzyme 1) gene silencing (50-60%). This work demonstrates the potential of PE-Gold NAs to deliver siRNA targeting BACE1 in neuronal cells. Finally, it was concluded that different polyelectrolytes used in the PE-Gold NAs achieve different gene silencing due to the variation in their delivery efficiencies.

A biomimetic Au@BSA-DTA nanocomposites-based contrast agent for computed tomography imaging

Early detection of cancer is increasingly important for being considered to increase the survival rate in the treatment process. The past decades years have witnessed the great progress in the biological detection application of gold nanoparticles. Herein, we reported a facile one-pot synthesis process to obtain gold nanoparticles (Au@BSA) with bovine serum albumin (BSA) as a biotemplate following with conjugation of diatrizoic acid (DTA) for a potential X-ray computed tomography (CT) imaging contrast agent (Au@BSA-DTA). The as-prepared biomimetic material was characterized systematically by several techniques. It was shown that the prepared biomaterial is colloid stable under the tested range of pH and temperature. The cell cytotoxicity assay, hemolytic assay and cell morphology observation showed that Au@BSA-DTA has good biocompatibility and hemocompatibility at a concentration of Au even up to 80μg/mL. Besides, the biomimetic material Au@BSA-DTA with double radiodense elements of Au and iodine displayed much stronger CT imaging effect compared with the traditional small molecule contrast agents, which paves the potential clinical application in cancer early diagnosis.