Nanoscale materials for tackling brain cancer: recent progress and outlook

Machine learning assisted-nanomedicine using magnetic nanoparticles for central nervous system diseases

Magnetic nanoparticles possess unique properties distinct from other types of nanoparticles developed for biomedical applications. Their unique magnetic properties and multifunctionalities are especially beneficial for central nervous system (CNS) disease therapy and diagnostics, as well as targeted and personalized applications using image-guided therapy and theranostics. This review discusses the recent development of magnetic nanoparticles for CNS applications, including Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis, and drug addiction. Machine learning (ML) methods are increasingly applied towards the processing, optimization and development of nanomaterials. By using data-driven approach, ML has the potential to bridge the gap between basic research and clinical research. We review ML approaches used within the various stages of nanomedicine development, from nanoparticle synthesis and characterization to performance prediction and disease diagnosis.

Modulation of the Blood-Brain Barrier for Drug Delivery to Brain

The blood-brain barrier (BBB) precisely controls brain microenvironment and neural activity by regulating substance transport into and out of the brain. However, it severely hinders drug entry into the brain, and the efficiency of various systemic therapies against brain diseases. Modulation of the BBB via opening tight junctions, inhibiting active efflux and/or enhancing transcytosis, possesses the potential to increase BBB permeability and improve intracranial drug concentrations and systemic therapeutic efficiency. Various strategies of BBB modulation have been reported and investigated preclinically and/or clinically. This review describes conventional and emerging BBB modulation strategies and related mechanisms, and safety issues according to BBB structures and functions, to try to give more promising directions for designing more reasonable preclinical and clinical studies.

Nonviral Locally Injected Magnetic Vectors for In Vivo Gene Delivery: A Review of Studies on Magnetofection

Magnetic nanoparticles have been widely used in nanobiomedicine for diagnostics and the treatment of diseases, and as carriers for various drugs. The unique magnetic properties of "magnetic" drugs allow their delivery in a targeted tumor or tissue upon application of a magnetic field. The approach of combining magnetic drug targeting and gene delivery is called magnetofection, and it is very promising. This method is simple and efficient for the delivery of genetic material to cells using magnetic nanoparticles controlled by an external magnetic field. However, magnetofection in vivo has been studied insufficiently both for local and systemic routes of magnetic vector injection, and the relevant data available in the literature are often merely descriptive and contradictory. In this review, we collected and systematized the data on the efficiency of the local injections of magnetic nanoparticles that carry genetic information upon application of external magnetic fields. We also investigated the efficiency of magnetofection in vivo, depending on the structure and coverage of magnetic vectors. The perspectives of the development of the method were also considered.

Preparation and Evaluation of a Self-Nanoemulsifying Drug Delivery System Loaded with Heparin Phospholipid Complex

A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the absorption of heparin after oral administration, in which heparin was compounded with phospholipids to achieve better fat solubility in the form of heparin-phospholipid (HEP-Pc) complex. HEP-Pc complex was prepared using the solvent evaporation method, which increased the solubility of heparin in n-octanol. The successful preparation of HEP-Pc complex was confirmed by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, NMR, and SEM. A heparin lipid microemulsion (HEP-LM) was prepared by high-pressure homogenization and characterized. HEP-LM can enhance the absorption of heparin after oral administration, significantly prolong activated partial thromboplastin time (APTT) and thrombin time (TT) in mice, and reduce fibrinogen (FIB) content. All these outcomes indicate that HEP-LM has great potential as an oral heparin formulation.

Investigation of Combination Effect Between 6 MV X-Ray Radiation and Polyglycerol Coated Superparamagnetic Iron Oxide Nanoparticles on U87-MG Cancer Cells

Background

Radiosensitization using nanoparticles is proposed as a novel strategy for treatment of different cancers. Superparamagnetic iron oxide nanoparticles (SPIONs) have been reported to enhance effects of radiotherapy in several researches.

Objective

The objective of this research is to investigate the radiosensitization properties of polyglycerol coated SPIONs (PG-SPIONs) on U87-MG cancer cells.

Material and Methods

In this experimental study, polyglycerol coated SPIONs were synthesized by thermal decomposition method and characterized by FTIR, TEM and VSM analysis. Cellular uptake of nanoparticles by cells was examined via AAS. Cytotoxicity and radiosensitization of nanoparticles in combination with radiation were evaluated by MTT and colony assay, respectively.

Results

Mean size of nanoparticles was 17.9±2.85 nm. FTIR verified SPIONs coating by Polyglycerol and VSM showed that they have superparamagnetic behaviour. Viability significantly (P < 0.001) decreased at concentrations above 100µg/ml for SPIONs but not for PG-SPIONs (P > 0.05). Dose verification results by TLD for doses of 2 and 4 Gy were 2±0.19 and 4±0.12 Gy respectively. The combination index for all situations was less than 1 and the effect is antagonism.

Conclusion

However, PG-SPIONs combination with 6 MV X-ray reduced survival of U87-MG cells compared to radiation alone but the effect is antagonism.

Multifunctional gold nanoparticles as smart nanovehicles with enhanced tumour-targeting abilities for intracellular pH mapping and in vivo MR/fluorescence imaging

A number of multimodal agents have been developed for tumour imaging and diagnosis, but most of them cannot be used to study the detailed physiological or pathological changes in living cells at the same time. Herein, a series of pH-responsive magnetic resonance and fluorescence imaging (MRI/FI) dual-modal "nanovehicles" are developed and tested. These new dual-modal materials allow for intercellular pH sensing, and those with units that are dually sensitive towards both acidic and basic environments have the ability for intracellular pH mapping and can be used to quantify pH at the cellular level. In addition, detailed pH changes in organelles (including lysosomes and mitochondria) can be investigated at the same time. On the other hand, with the tumour-targeting peptide (cRGD)-modified dual-modal nanovehicles, in vivo tumour MR and fluorescence imaging, which is suitable for cancer diagnosis, can be achieved. Moreover, it has been proved that these materials can pass through the blood brain barrier (BBB). By combining the above mentioned promising properties, these novel multifunctional "nanovehicles" may provide a new method for studying the role of pH during cancer diagnosis and treatment.

Hypoxia-induced biosynthesis of gold nanoparticles in the living brain

While a large number of studies deal with biomedical applications of various types of nanoparticles synthesized using wet chemistry, we propose the concept of targeted biosynthesis of nanoparticles in the living brain. Here we demonstrate that the pathological biochemical process of accumulation of reduced pyridine nucleotides under deleterious conditions of brain hypoxia can be redirected to drive the biosynthesis of biocompatible Au nanoparticles from a precursor salt in situ in the immediate vicinity of the hypoxia site, thereby restoring the redox status of the brain.

Mesoporous Silica Nanomaterials: Versatile Nanocarriers for Cancer Theranostics and Drug and Gene Delivery

Mesoporous silica nanomaterials (MSNs) have made remarkable achievements and are being thought of by researchers as materials that can be used to effect great change in cancer therapies, gene delivery, and drug delivery because of their optically transparent properties, flexible size, functional surface, low toxicity profile, and very good drug loading competence. Mesoporous silica nanoparticles (MSNPs) show a very high loading capacity for therapeutic agents. It is well known that cancer is one of the most severe known medical conditions, characterized by cells that grow and spread rapidly. Thus, curtailing cancer is one of the greatest current challenges for scientists. Nanotechnology is an evolving field of study, encompassing medicine, engineering, and science, and it has evolved over the years with respect to cancer therapy. This review outlines the applications of mesoporous nanomaterials in the field of cancer theranostics, as well as drug and gene delivery. MSNs employed as therapeutic agents, as well as their importance and future prospects in the ensuing generation of cancer theranostics and drug and therapeutic gene delivery, are discussed herein. Thus, the use of mesoporous silica nanomaterials can be seen as using one stone to kill three birds.

Nanoparticle-based diagnostic and therapeutic systems for brain tumors

Many theranostic nanoparticles have been tailored for high-efficiency diagnostic or therapeutic agents or applied as carriers and might provide new possibilities for brain tumor diagnosis and treatment.

Ultrasensitive detection enabled by nonlinear magnetization of nanomagnetic labels

Geometrically confined magnetic particles due to their unique response to external magnetic fields find a variety of applications, including magnetic guidance, heat and drug delivery, magneto-mechanical actuation, and contrast enhancement. Highly sensitive detection and imaging techniques based on the nonlinear properties of nanomagnets were recently proposed as innovative strong-translational potential methods applicable in complex, often opaque, biological systems. Here we report on the significant enhancement of the detection capability using optical-lithography-defined, ferromagnetic iron-nickel alloy disk-shaped particles. We show that an irreversible transition between strongly non-collinear (vortex) and single domain states, driven by an alternating magnetic field, translates into a nonlinear magnetic response that enables ultrasensitive detection of these particles. The record sensitivity of ∼3.5 × 10-9 emu, which is equivalent to ∼39 pg of magnetic material is demonstrated at room temperature for arrays of patterned disks. We also show that unbound disks suspended in the aqueous buffer can be successfully detected and quantified in real-time when administered into a live animal allowing for tracing of their biodistribution. The use of nanoscale ferromagnetic particles with engineered nonlinear properties opens prospects for further enhancing the sensitivity, scalability, and tunability of noise-free magnetic tag detection in high-background environments for various applications spanning from biosensing and medical imaging to anti-counterfeiting technologies.

Shape Tailored Magnetic Nanorings for Intracellular Hyperthermia Cancer Therapy

ABSTARCT

This work explores a new class of vortex/magnetite/iron oxide nanoparticles designed for magnetic hyperthermia applications. These nanoparticles, named Vortex Iron oxide Particles (VIPs), are an alternative to the traditional Superparamagnetic Iron Oxide Nanoparticles (SPIONs), since VIPs present superior heating power while fulfilling the main requirements for biomedical applications (low cytotoxicity and nonremanent state). In addition, the present work demonstrates that the synthesized VIPs also promote an internalization and aggregation of the particles inside the cell, resulting in a highly localized hyperthermia in the presence of an alternating magnetic field. Thereby, we demonstrate a new and efficient magnetic hyperthermia strategy in which a small, but well localized, concentration of VIPs can promote an intracellular hyperthermia process.

Multiplexed RNAi therapy against brain tumor-initiating cells via lipopolymeric nanoparticle infusion delays glioblastoma progression

Brain tumor-initiating cells (BTICs) have been identified as key contributors to therapy resistance, recurrence, and progression of diffuse gliomas, particularly glioblastoma (GBM). BTICs are elusive therapeutic targets that reside across the blood-brain barrier, underscoring the urgent need to develop novel therapeutic strategies. Additionally, intratumoral heterogeneity and adaptations to therapeutic pressure by BTICs impede the discovery of effective anti-BTIC therapies and limit the efficacy of individual gene targeting. Recent discoveries in the genetic and epigenetic determinants of BTIC tumorigenesis offer novel opportunities for RNAi-mediated targeting of BTICs. Here we show that BTIC growth arrest in vitro and in vivo is accomplished via concurrent siRNA knockdown of four transcription factors (SOX2, OLIG2, SALL2, and POU3F2) that drive the proneural BTIC phenotype delivered by multiplexed siRNA encapsulation in the lipopolymeric nanoparticle 7C1. Importantly, we demonstrate that 7C1 nano-encapsulation of multiplexed RNAi is a viable BTIC-targeting strategy when delivered directly in vivo in an established mouse brain tumor. Therapeutic potential was most evident via a convection-enhanced delivery method, which shows significant extension of median survival in two patient-derived BTIC xenograft mouse models of GBM. Our study suggests that there is potential advantage in multiplexed targeting strategies for BTICs and establishes a flexible nonviral gene therapy platform with the capacity to channel multiplexed RNAi schemes to address the challenges posed by tumor heterogeneity.

NIR-Responsive Polycationic Gatekeeper-Cloaked Hetero-Nanoparticles for Multimodal Imaging-Guided Triple-Combination Therapy of Cancer

Responsive multifunctional organic/inorganic nanohybrids are promising for effective and precise imaging-guided therapy of cancer. In this work, a near-infrared (NIR)-triggered multifunctional nanoplatform comprising Au nanorods (Au NRs), mesoporous silica, quantum dots (QDs), and two-armed ethanolamine-modified poly(glycidyl methacrylate) with cyclodextrin cores (denoted as CD-PGEA) has been successfully fabricated for multimodal imaging-guided triple-combination treatment of cancer. A hierarchical hetero-structure is first constructed via integration of Au NRs with QDs through a mesoporous silica intermediate layer. The X-ray opacity and photoacoustic (PA) property of Au NRs are utilized for tomography (CT) and PA imaging, and the imaging sensitivity is further enhanced by the fluorescent QDs. The mesoporous feature of silica allows the loading of a typical antitumor drug, doxorubicin (DOX), which are sealed by the polycationic gatekeepers, low toxic hydroxyl-rich CD-PGEA/pDNA complexes, realizing the co-delivery of drug and gene. The photothermal effect of Au NRs is utilized for photothermal therapy (PTT). More interestingly, such photothermal effect also induces a cascade of NIR-triggered release of DOX through the facilitated detachment of CD-PGEA gatekeepers for controlled chemotherapy. The resultant chemotherapy and gene therapy for glioma tumors are complementary for the efficiency of PTT. This work presents a novel responsive multifunctional imaging-guided therapy platform, which combines fluorescent/PA/CT imaging and gene/chemo/photothermal therapy into one nanostructure.

Magnetic nanoparticles: A multifunctional vehicle for modern theranostics

Magnetic nanoparticles provide a unique multifunctional vehicle for modern theranostics since they can be remotely and non-invasively employed as imaging probes, carrier vectors and smart actuators. Additionally, special delivery schemes beyond the typical drug delivery such as heat or mechanical stress may be magnetically triggered to promote certain cellular pathways. To start with, we need magnetic nanoparticles with several well-defined and reproducible structural, physical, and chemical features, while bio-magnetic nanoparticle design imposes several additional constraints. Except for the intrinsic requirement for high quality of magnetic properties in order to obtain the maximum efficiency with the minimum dose, the surface manipulation of the nanoparticles is a key aspect not only for transferring them from the growth medium to the biological environment but also to bind functional molecules that will undertake specific targeting, drug delivery, cell-specific monitoring and designated treatment without sparing biocompatibility and sustainability in-vivo. The ability of magnetic nanoparticles to interact with matter at the nanoscale not only provides the possibility to ascertain the molecular constituents of a disease, but also the way in which the totality of a biological function may be affected as well. The capacity to incorporate an array of structural and chemical functionalities onto the same nanoscale architecture also enables more accurate, sensitive and precise screening together with cure of diseases with significant pathological heterogeneity such as cancer. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.

Advances in Molecular Imaging of Locally Delivered Targeted Therapeutics for Central Nervous System Tumors

Thanks to the recent advances in the development of chemotherapeutics, the morbidity and mortality of many cancers has decreased significantly. However, compared to oncology in general, the field of neuro-oncology has lagged behind. While new molecularly targeted chemotherapeutics have emerged, the impermeability of the blood–brain barrier (BBB) renders systemic delivery of these clinical agents suboptimal. To circumvent the BBB, novel routes of administration are being applied in the clinic, ranging from intra-arterial infusion and direct infusion into the target tissue (convection enhanced delivery (CED)) to the use of focused ultrasound to temporarily disrupt the BBB. However, the current system depends on a “wait-and-see” approach, whereby drug delivery is deemed successful only when a specific clinical outcome is observed. The shortcomings of this approach are evident, as a failed delivery that needs immediate refinement cannot be observed and corrected. In response to this problem, new theranostic agents, compounds with both imaging and therapeutic potential, are being developed, paving the way for improved and monitored delivery to central nervous system (CNS) malignancies. In this review, we focus on the advances and the challenges to improve early cancer detection, selection of targeted therapy, and evaluation of therapeutic efficacy, brought forth by the development of these new agents.

Packaging cordycepin phycocyanin micelles for the inhibition of brain cancer

A novel small size and electroneutral Phy–Dex–Cord micelles was successfully developed, which can be delivered to tumor cells and inhibit the brain tumor.

Increased Gold Nanoparticle Retention in Brain Tumors by in Situ Enzyme-Induced Aggregation

The treatment of brain tumors remains a challenge due to the limited accumulation of drugs and nanoparticles. Here, we triggered the aggregation of gold nanoparticles (AuNPs) using legumain to enhance the retention of chemotherapeutics in brain tumors. This nanoplatform, AuNPs-A&C, is comprised of Ala-Ala-Asn-Cys-Lys modified AuNPs (AuNPs-AK) and 2-cyano-6-aminobenzothiazole modified AuNPs (AuNPs-CABT). AuNPs-AK could be hydrolyzed to expose the 1,2-thiolamino groups on AuNPs-AK in the presence of legumain, which occurs by a click cycloaddition with the contiguous cyano group on AuNPs-CABT, resulting in formation of AuNPs aggregates. This strategy led to an enhanced retention of the AuNPs in glioma cells both in vitro and in vivo due to the blocking of nanoparticle exocytosis and minimizing nanoparticle backflow to the bloodstream. After conjugation of doxorubicin (DOX) via a pH-sensitive linker to AuNPs-A&C, the efficiency for treating glioma was improved. The median survival time for the DOX-linked AuNPs-A&C increased to 288% in comparison to the saline group. We further show the use of the AuNPs-A&C for optical imaging applications. In conclusion, we provide a strategy to increase nanoparticle tumor accumulation with the potential to improve therapeutic outcome.

Tunable Lipidoid-Telodendrimer Hybrid Nanoparticles for Intracellular Protein Delivery in Brain Tumor Treatment

A strategy to precisely engineer lipidoid-telodendrimer binary hybrid nanoparticles that offer enhanced cell membrane permeability for therapeutic proteins to reach the intracellular targets is established. The highly controllable biochemical and physical properties of the nanoparticles make them promising for protein-based brain cancer treatment with the assistance of convection-enhanced delivery.

In vivo delivery, pharmacokinetics, biodistribution and toxicity of iron oxide nanoparticles

Iron oxide nanoparticles (IONPs) have been extensively used during the last two decades, either as effective bio-imaging contrast agents or as carriers of biomolecules such as drugs, nucleic acids and peptides for controlled delivery to specific organs and tissues. Most of these novel applications require elaborate tuning of the physiochemical and surface properties of the IONPs. As new IONPs designs are envisioned, synergistic consideration of the body's innate biological barriers against the administered nanoparticles and the short and long-term side effects of the IONPs become even more essential. There are several important criteria (e.g. size and size-distribution, charge, coating molecules, and plasma protein adsorption) that can be effectively tuned to control the in vivo pharmacokinetics and biodistribution of the IONPs. This paper reviews these crucial parameters, in light of biological barriers in the body, and the latest IONPs design strategies used to overcome them. A careful review of the long-term biodistribution and side effects of the IONPs in relation to nanoparticle design is also given. While the discussions presented in this review are specific to IONPs, some of the information can be readily applied to other nanoparticle systems, such as gold, silver, silica, calcium phosphates and various polymers.

Water-soluble L-cysteine-coated FePt nanoparticles as dual MRI/CT imaging contrast agent for glioma

Nanoparticles (NPs) are advantageous for the delivery of diagnosis agents to brain tumors. In this study, we attempted to develop an L-cysteine coated FePt (FePt-Cys) NP as MRI/CT imaging contrast agent for the diagnosis of malignant gliomas. FePt-Cys NPs were synthesized through a co-reduction route, which was characterized by transmission electron microscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, and dynamic light scattering. The MRI and CT imaging ability of FePt-Cys NPs was evaluated using different gliomas cells (C6, SGH44, U251) as the model. Furthermore, the biocompatibility of the as-synthesized FePt-Cys NPs was evaluated using three different cell lines (ECV304, L929, and HEK293) as the model. The results showed that FePt-Cys NPs displayed excellent biocompatibility and good MRI/CT imaging ability, thereby indicating promising potential as a dual MRI/CT contrast agent for the diagnosis of brain malignant gliomas.

Plasmonic gold nanostars for multi-modality sensing and diagnostics

Gold nanostars (AuNSs) are unique systems that can provide a novel multifunctional nanoplatform for molecular sensing and diagnostics. The plasmonic absorption band of AuNSs can be tuned to the near infrared spectral range, often referred to as the "tissue optical window", where light exhibits minimal absorption and deep penetration in tissue. AuNSs have been applied for detecting disease biomarkers and for biomedical imaging using multi-modality methods including surface-enhanced Raman scattering (SERS), two-photon photoluminescence (TPL), magnetic resonance imaging (MRI), positron emission tomography (PET), and X-ray computer tomography (CT) imaging. In this paper, we provide an overview of the recent development of plasmonic AuNSs in our laboratory for biomedical applications and highlight their potential for future translational medicine as a multifunctional nanoplatform.

Multifunctional nanoparticles for brain tumor imaging and therapy

Brain tumors are a diverse group of neoplasms that often carry a poor prognosis for patients. Despite tremendous efforts to develop diagnostic tools and therapeutic avenues, the treatment of brain tumors remains a formidable challenge in the field of neuro-oncology. Physiological barriers including the blood-brain barrier result in insufficient accumulation of therapeutic agents at the site of a tumor, preventing adequate destruction of malignant cells. Furthermore, there is a need for improvements in brain tumor imaging to allow for better characterization and delineation of tumors, visualization of malignant tissue during surgery, and tracking of response to chemotherapy and radiotherapy. Multifunctional nanoparticles offer the potential to improve upon many of these issues and may lead to breakthroughs in brain tumor management. In this review, we discuss the diagnostic and therapeutic applications of nanoparticles for brain tumors with an emphasis on innovative approaches in tumor targeting, tumor imaging, and therapeutic agent delivery. Clinically feasible nanoparticle administration strategies for brain tumor patients are also examined. Furthermore, we address the barriers towards clinical implementation of multifunctional nanoparticles in the context of brain tumor management.

Carbon nanotubes in hyperthermia therapy

Thermal tumor ablation therapies are being developed with a variety of nanomaterials, including single- and multiwalled carbon nanotubes. Carbon nanotubes (CNTs) have attracted interest due to their potential for simultaneous imaging and therapy. In this review, we highlight in vivo applications of carbon nanotube-mediated thermal therapy (CNMTT) and examine the rationale for use of this treatment in recurrent tumors or those resistant to conventional cancer therapies. Additionally, we discuss strategies to localize and enhance the cancer selectivity of this treatment and briefly examine issues relating the toxicity and long term fate of CNTs.

Stimuli-responsive magnetic nanomicelles as multifunctional heat and cargo delivery vehicles

Hybrid nanoarchitectures are among the most promising nanotechnology-enabled materials for biomedical applications. Interfacing of nanoparticles with active materials gives rise to the structures with unique multiple functionality. Superparamagnetic iron oxide nanoparticles particles SPION are widely employed in the biology and in developing of advanced medical technologies. Polymeric micelles offer the advantage of multifunctional carriers which can serve as delivery vehicles carrying nanoparticles, hydrophobic chemotherapeutics and other functional materials and molecules. Stimuli-responsive polymers are especially attractive since their properties can be modulated in a controlled manner. Here we report on multifunctional thermo-responsive poly(N-isopropylacrylamide-co-acrylamide)-block-poly(ε-caprolactone) random block copolymer micelles as magnetic hyperthermia-mediated payload release and imaging agents. The combination of copolymers, nanoparticles and doxorubicin drug was tailored the way that the loaded micelles were cable to respond to magnetic heating at physiologically-relevant temperatures. A surface functionalization of the micelles with the integrin β4 antibody and consequent interfacing of the resulting nanobio hybrid with squamous head and neck carcinoma cells which is known to specifically over-express the A9 antigen resulted in concentration of the micelles on the surface of cells. No inherent cytotoxicity was detected for the magnetic micelles without external stimuli application. Furthermore, SPION-loaded micelles demonstrate significant MRI contrast enhancement abilities.

Phytosomes loaded with mitomycin C-soybean phosphatidylcholine complex developed for drug delivery

A novel formulation system of phytosomes loaded with mitomycin C-soybean phosphatidylcholine (MMC-SPC) complex (MMC-loaded phytosomes) was prepared by a solvent evaporation method combined with a nanoprecipitation technique for the purpose of development of an MMC drug delivery system. The MMC-loaded phytosomes were evaluated by average particle size, zeta-potential, and residual drug-loading content as well as an in vitro drug release profile. Furthermore, in vitro stability tests and in vitro/vivo biological evaluations of the MMC-loaded phytosomes were performed. DSC, FTIR, and XRD demonstrated that MMC interacted physically with SPC within the phytosomes. DLS and ELS described a dispersion with an average particle size of 210.87 nm, a narrow size distribution (PDI 0.251), and a zeta-potential of -33.38 mV. SEM, TEM, and AFM images showed that the MMC-loaded phytosomes were spherical and intact vesicles. In vitro stability tests demonstrated that the average particle size and residual drug-loading content of the MMC-loaded phytosomes had no evident change at different storage conditions. In vitro drug release profiles indicated biphasic behavior with an initial burst release, followed by a subsequent prolonged sustained release. In vitro cytotoxicity assays with H(22) cells showed that the MMC-loaded phytosomes had remarkable cytotoxicity. In vivo antitumor effect of the MMC-loaded phytosomes also revealed a dose-dependent and superior curative inhibitory effect on tumor growth without loss of body weight compared to free MMC. Histopathological analysis of specimens taken from tumor tissues indicated that MMC-loaded phytosomes had lethal effect to hepatoma cell. These findings suggested that the MMC-loaded phytosomes can serve as a promising and effective formulation for drug delivery and cancer therapy.

Targeted delivery system based on magnetic mesoporous silica nanocomposites with light-controlled release character

We report the facile synthesis and easy operation of a smart delivery system based on core-shell structured magnetic mesoporous silica nanocomposites covalently grafted with light-responsive azobenzene derivatives, which integrates magnetic targeting and stimuli-responsive release property. Irradiation with visible light triggers the release of guest molecules loaded in the mesopores.

Multifunctional ferromagnetic disks for modulating cell function

In this work, we focus on the methods for controlling cell function with ferromagnetic disk-shaped particles. We will first review the history of magnetically assisted modulation of cell behavior and applications of magnetic particles for studying physical properties of a cell. Then, we consider the biological applications of the microdisks such as the method for induction of cancer cell apoptosis, controlled drug release, hyperthermia and MRI imaging.

Microfabricated magnetic structures for future medicine: from sensors to cell actuators

In this review, we discuss the prospective medical application of magnetic carriers microfabricated by top-down techniques. Physical methods allow the fabrication of a variety of magnetic structures with tightly controlled magnetic properties and geometry, which makes them very attractive for a cost-efficient mass-production in the fast growing field of nanomedicine. Stand-alone fabricated particles along with integrated devices combining lithographically defined magnetic structures and synthesized magnetic tags will be considered. Applications of microfabricated multifunctional magnetic structures for future medicinal purposes range from ultrasensitive in vitro diagnostic bioassays, DNA sequencing and microfluidic cell sorting to magnetomechanical actuation, cargo delivery, contrast enhancement and heating therapy.

Temozolomide loaded PLGA-based superparamagnetic nanoparticles for magnetic resonance imaging and treatment of malignant glioma

Polysorbate 80 coated temozolomide-loaded PLGA-based superparamagnetic nanoparticles (P80-TMZ/SPIO-NPs) were successfully synthesized and characterized as drug carriers and diagnosis agent for malignant brain glioma. The mean size of P80-TMZ/SPIO-NPs was 220 nm with narrow hydrodynamic particle size distribution. The superparamagnetic characteristic of P80-TMZ/SPIO-NPs was proved by vibration simple magnetometer. P80-TMZ/SPIO-NPs exhibited high drug loading and encapsulation efficiency as well as good sustained drug release performance for 15 days. MTT assay demonstrated the antiproliferative effect of P80-TMZ/SPIO-NPs for C6 glioma cells. Significant cellular uptake of P80-TMZ/SPIO-NPs was evaluated in C6 glioma cells by fluorescence microscopy, Prussian blue staining, and atomic absorption spectrophotometer (AAS) for qualitative and quantitative study, respectively. MRI scanning analyses in vitro indicated that P80-TMZ/SPIO-NPs could be used as a good MRI contrast agent. Polysorbate 80 coated temozolomide-loaded PLGA-based superparamagnetic nanoparticles could be able to promise a multifunctional theragnostic carrier of brain cancer.

Strategies in biomimetic surface engineering of nanoparticles for biomedical applications

Engineered nanoparticles (NPs) play an increasingly important role in biomedical sciences and in nanomedicine. Yet, in spite of significant advances, it remains difficult to construct drug-loaded NPs with precisely defined therapeutic effects, in terms of release time and spatial targeting. The body is a highly complex system that imposes multiple physiological and cellular barriers to foreign objects. Upon injection in the blood stream or following oral administation, NPs have to bypass numerous barriers prior to reaching their intended target. A particularly successful design strategy consists in masking the NP to the biological environment by covering it with an outer surface mimicking the composition and functionality of the cell's external membrane. This review describes this biomimetic approach. First, we outline key features of the composition and function of the cell membrane. Then, we present recent developments in the fabrication of molecules that mimic biomolecules present on the cell membrane, such as proteins, peptides, and carbohydrates. We present effective strategies to link such bioactive molecules to the NPs surface and we highlight the power of this approach by presenting some exciting examples of biomimetically engineered NPs useful for multimodal diagnostics and for target-specific drug/gene delivery applications. Finally, critical directions for future research and applications of biomimetic NPs are suggested to the readers.

Cancer nanotheranostics: improving imaging and therapy by targeted delivery across biological barriers

Cancer nanotheranostics aims to combine imaging and therapy of cancer through use of nanotechnology. The ability to engineer nanomaterials to interact with cancer cells at the molecular level can significantly improve the effectiveness and specificity of therapy to cancers that are currently difficult to treat. In particular, metastatic cancers, drug-resistant cancers, and cancer stem cells impose the greatest therapeutic challenge for targeted therapy. Targeted therapy can be achieved with appropriately designed drug delivery vehicles such as nanoparticles, adult stem cells, or T cells in immunotherapy. In this article, we first review the different types of nanotheranostic particles and their use in imaging, followed by the biological barriers they must bypass to reach the target cancer cells, including the blood, liver, kidneys, spleen, and particularly the blood-brain barrier. We then review how nanotheranostics can be used to improve targeted delivery and treatment of cancer cells. Finally, we discuss development of nanoparticles to overcome current limitations in cancer therapy.