Polysaccharide-decorated nanoparticles

Hybrid organic nanotubes with dual functionalities localized on cylindrical nanochannels control the release of doxorubicin

A method to control the release of the anti-cancer drug doxorubicin (Dox) from cylindrical nanocapsules, known as organic nanotubes (ONTs), is reported. Co-assembly of a tube-forming glycolipid and its hydrophobized analogue yield novel ONTs with both -COOH and hydrophobic benzyloxycarbonyl groups localized on cylindrical nanochannels. The hydrophobicity of the ONTs nanochannels is easily tunable by adjusting the mixing ratio of the two glycolipids in the co-assembly process. The resultant biologically stable ONTs are able to capture Dox with high efficiency into the cylindrical nanochannels via ion complexation between cationic Dox and anionic -COO(-) , and the release of Dox from hybrid ONTs is effectively controlled by tuning the electrostatic interaction and the hydrophobicity. This controlled release by tuning the hydrophobicity of the ONTs' nanochannels greatly reduces the cytotoxicity of Dox@ONTs for HeLa cells.

CYTOTOXICITY AND CELLULAR UPTAKE OF CELLULOSE NANOCRYSTALS

There is growing evidence that filamentous nanoparticles offer advantages over spherical ones in drug delivery applications. The purpose of this study was to assess the potential of rod-like, plant-derived cellulose nanocrystals (CNCs) for nanomedical uses. Besides a nonspherical morphology, their facile bioconjugation, surface hydrophilicity and small size render CNCs promising drug carriers. The cytotoxicity of CNCs against nine different cell lines (HBMEC, bEnd.3, RAW 264.7, MCF-10A, MDA-MB-231, MDA-MB-468, KB, PC-3 and C6) was determined by MTT and LDH assay. CNCs showed no cytotoxic effects against any of these cell lines in the concentration range and exposure time studied (0–50 μg/mL and 48 h, respectively). Cellular uptake of fluorescein-5′-isothiocyanate-labeled CNCs by these cell lines, quantified with a fluorescence microplate reader, was minimal. The lack of cytotoxicity and the low nonspecific cellular uptake support our hypothesis that CNCs are good candidates for nanomedical applications.

Airway delivery of peptides and proteins using nanoparticles

Delivery of peptides and proteins via the airways is one of the most exciting potential applications of nanomedicine. These macromolecules could be used for many therapeutic applications, however due to their poor stability in physiological medium and difficulties in delivering them across biological barriers, they are very difficult to use in therapy. Nanoparticulate drug delivery systems have emerged as one of the most promising technologies to overcome these limitations, owing mainly to their proven capacity to cross biological barriers and to enter cells in high yields, thus improving delivery of macromolecules. In this review, we summarize the current advances in nanoparticle designed for transmucosal delivery of peptides and proteins. Challenges that must be overcome in order to derive clinical benefits are also discussed.

In vitro and in vivo antitumor activity of doxorubicin-loaded alginic-acid-based nanoparticles

The antitumor activities of DOX-loaded alginic acid/poly[2-(diethylamino)ethyl methacrylate] (ALG-PDEA) nanoparticles are evaluated both in vitro and in vivo. TEM imaging shows that the ALG-PDEA NPs have a spherical morphology with a size of about 120 nm. CLSM observations reveal that the negatively charged ALG-PDEA NPs can be taken up well by cells. In vivo NIR fluorescence imaging shows that the ALG-PDEA NPs can passively target the tumor area because of the EPR effect in the H22 tumor-bearing mouse. In vivo antitumor efficacy examinations indicate that DOX-loaded ALG-PDEA NPs have significantly superior efficacy in impeding tumor growth compared to free DOX and low toxicity to living mice.

Self-assembled poly(ε-caprolactone)-g-chondroitin sulfate copolymers as an intracellular doxorubicin delivery carrier against lung cancer cells

The aim of this study was to utilize self-assembled polycaprolactone (PCL)-grafted chondroitin sulfate (CS) as an anticancer drug carrier. We separately introduced double bonds to the hydrophobic PCL and the hydrophilic CS. The modified PCL was reacted with the modified CS through a radical reaction (CSMA-g-PCL). The copolymer without doxorubicin (DOX) was noncytotoxic in CRL-5802 and NCI-H358 cells at a concentration ranging from 5–1000 μg/mL and DOX-loaded CSMA-g-PCL (Micelle DOX) had the lowest inhibitory concentration of 50% cell growth values against the NCI-H358 cells among test samples. The cellular uptake of Micelle DOX into the cells was confirmed by flow cytometric data and confocal laser scanning microscopic images. The in vivo tumor-targeting efficacy of Micelle DOX was realized using an NCI-H358 xenograft nude mouse model. The mice administered with Micelle DOX showed suppressed growth of the NCI-H358 lung tumor compared with those administered with phosphate-buffered saline and free DOX.

Amino-functionalized cellulose nanoparticles: preparation, characterization, and interactions with living cells

Spherical nanoparticles with sizes from 80 to 200 nm are obtained by self-assembly of highly functionalized 6-deoxy-6-(ω-aminoalkyl)aminocellulosecarbamates. The particles are very stable, nontoxic, and possess primary amino groups that are accessible to further modifications in aqueous suspension. The particles can be labeled with rhodamine B isothiocyanate without changing their size, stability, and shape. The nanoparticles obtained are investigated by means of photo correlation spectroscopy, zeta potential measurements, SEM and fluorescence spectroscopy. Incorporation of the nanoparticles in human foreskin fibroblasts BJ-1-htert and breast carcinoma MCF-7 cells without any transfection reagent is proved by means of confocal laser scanning microscopy.

Endocytosis at the nanoscale

Endocytosis is a fundamental process in which eukaryotic cells internalise molecules and macromolecules via deformation of the membrane and generation of membrane-bound carriers. Functional aspects are not only limited to uptake of nutrients, but also play a primary role in evolutionary conserved processes such as the regulation of plasma membrane protein activity (i.e. signal-transducing receptors, small-molecule transporters and ion channels), cell motility and mitosis. The macromolecular nature of the material transported by endocytosis makes this route one of the most important targets for nanomedicine. Indeed, many nanoparticle formulations have been customised to enter cells through endocytosis and deliver the cargo within the cell. In this critical review, we present an overview of the biology of endocytosis and discuss its implications in cell internalisation of nanoparticles. We discuss how nanoparticle size, shape and surface chemistry can control this process effectively. Finally, we discuss different drug delivery strategies on how to evade lysosomal degradation to promote effective release of the cargo (376 references).

Monosaccharides versus PEG-functionalized NPs: influence in the cellular uptake

Magnetic nanoparticles (NPs) hold great promise for biomedical applications. The core composition and small size of these particles produce superparamagnetic behavior, thus facilitating their use in magnetic resonance imaging and magnetically induced therapeutic hyperthermia. However, the development and control of safe in vivo applications for NPs call for the study of cell-NP interactions and cell viability. Furthermore, as for most biotechnological applications, it is desirable to prevent unspecific cell internalization of these particles. It is also crucial to understand how the surface composition of the NPs affects their internalization capacity. Here, through accurate control over unspecific protein adsorption, size distribution, grafting density, and an extensive physicochemical characterization, we correlated the cytotoxicity and cellular uptake mechanism of 6 nm magnetic NPs coated with several types and various densities of biomolecules, such as glucose, galactose, and poly(ethylene glycol). We found that the density of the grafted molecule was crucial to prevent unspecific uptake of NPs by Vero cells. Surprisingly, the glucose-coated NPs described here showed cellular uptake as a result of lipid raft instead of clathrin-mediated cellular internalization. Moreover, these glucose-functionalized NPs could be one of the first examples of NPs being endocytosed by caveolae that finally end up in the lysosomes. These results reinforce the use of simple carbohydrates as an alternative to PEG molecules for NPs functionalization when cellular uptake is required.

Surface decoration by Spirulina polysaccharide enhances the cellular uptake and anticancer efficacy of selenium nanoparticles

A simple and solution-phase method for functionalization of selenium nanoparticles (SeNPs) with Spirulina polysaccharides (SPS) has been developed in the present study. The cellular uptake and anticancer activity of SPS-SeNPs were also evaluated. Monodisperse and homogeneous spherical SPS-SeNPs with diameters ranging from 20 nm to 50 nm were achieved under optimized conditions, which were stable in the solution phase for at least 3 months. SPS surface decoration significantly enhanced the cellular uptake and cytotoxicity of SeNPs toward several human cancer cell lines. A375 human melanoma cells were found extremely susceptible to SPS-SeNPs with half maximal (50%) inhibitory concentration value of 7.94 μM. Investigation of the underlying mechanisms revealed that SPS-SeNPs inhibited cancer cell growth through induction of apoptosis, as evidenced by an increase in sub-G(1) cell population, deoxyribonucleic acid fragmentation, chromatin condensation, and phosphatidylserine translocation. Results suggest that the strategy to use SPS as a surface decorator could be an effective way to enhance the cellular uptake and anticancer efficacy of nanomaterials. SPS-SeNPs may be a potential candidate for further evaluation as a chemopreventive and chemotherapeutic agent against human cancers.

Hyaluronic acid-based nanocarriers for intracellular targeting: interfacial interactions with proteins in cancer

The therapeutic efficacy of most drugs is greatly depends on their ability to cross the cellular barrier and reach their intracellular target sites. To transport the drugs effectively through the cellular membrane and to deliver them into the intracellular environment, several interesting smart carrier systems based on both synthetic or natural polymers have been designed and developed. In recent years, hyaluronic acid (HA) has emerged as a promising candidate for intracellular delivery of various therapeutic and imaging agents because of its innate ability to recognize specific cellular receptors that overexpressed on diseased cells. The aim of this review is to highlight the significance of HA in cancer, and to explore the recent advances of HA-based drug carriers towards cancer imaging and therapeutics.

Responsive theranostic systems: integration of diagnostic imaging agents and responsive controlled release drug delivery carriers

For decades, researchers and medical professionals have aspired to develop mechanisms for noninvasive treatment and monitoring of pathological conditions within the human body. The emergence of nanotechnology has spawned new opportunities for novel drug delivery vehicles capable of concomitant detection, monitoring, and localized treatment of specific disease sites. In turn, researchers have endeavored to develop an imaging moiety that could be functionalized to seek out specific diseased conditions and could be monitored with conventional clinical imaging modalities. Such nanoscale detection systems have the potential to increase early detection of pathophysiological conditions because they can detect abnormal cells before they even develop into diseased tissue or tumors. Ideally, once the diseased cells are detected, clinicians would like to treat those cells simultaneously. This idea led to the concept of multifunctional carriers that could target, detect, and treat diseased cells. The term "theranostics" has been created to describe this promising area of research that focuses on the combination of diagnostic detection agents with therapeutic drug delivery carriers. Targeted theranostic nanocarriers offer an attractive improvement to disease treatment because of their ability to execute simultaneous functions at targeted diseased sites. Research efforts in the field of theranostics encompass a broad variety of drug delivery vehicles, imaging contrast agents, and targeting modalities for the development of an all-in-one, localized detection and treatment system. Nanotheranostic systems that utilize metallic or magnetic imaging nanoparticles can also be used as thermal therapeutic systems. This Account explores recent advances in the field of nanotheranostics and the various fundamental components of an effective theranostic carrier.

Cytotoxicity and cellular uptake of newly synthesized fucoidan-coated nanoparticles

The aim was to synthesize and characterize fucoidan-coated poly(isobutylcyanoacrylate) nanoparticles. The nanoparticles were prepared by anionic emulsion polymerization (AEP) and by redox radical emulsion polymerization (RREP) of isobutylcyanoacrylate using fucoidan as a new coating material. The nanoparticles were characterized, and their cytotoxicity was evaluated in vitro on J774 macrophage and NIH-3T3 fibroblast cell lines. Cellular uptake of labeled nanoparticles was investigated by confocal fluorescence microscopy. Results showed that both methods were suitable to prepare stable formulations of fucoidan-coated PIBCA nanoparticles. Stable dispersions of nanoparticles were obtained by AEP with up to 100% fucoidan as coating material. By the RREP method, stable suspensions of nanoparticles were obtained with only up to 25% fucoidan in a blend of polysaccharide composed of dextran and fucoidan. The zeta potential of fucoidan-coated nanoparticles was decreased depending on the percentage of fucoidan. It reached the value of -44 mV for nanoparticles prepared by AEP with 100% of fucoidan. Nanoparticles made by AEP appeared more than four times more cytotoxic (IC(50) below 2 μg/mL) on macrophages J774 than nanoparticles made by RREP (IC(50) above 9 μg/mL). In contrast, no significant difference in cytotoxicity was highlighted by incubation of the nanoparticles with a fibroblast cell line. On fibroblasts, both types of nanoparticles showed similar cytotoxicity. Confocal fluorescence microscopy observations revealed that all types of nanoparticles were taken up by both cell lines. The distribution of the fluorescence in the cells varied greatly with the type of nanoparticles.

Fabrication of silver nanocomposite films impregnated with curcumin for superior antibacterial applications

Silver nanocomposite films are found to be very effective material for anti-bacterial application. In the present work, sodium carboxylmethyl cellulose silver nanocomposite films (SCMC SNCF) were tried for antibacterial applications. To enhance their applicability novel film-silver nanoparticle-curcumin composites have been developed. SCMC SNCF are developed from sodium carboxylmethyl cellulose (SCMC), N,N(1)-methylenebisacrylamide (MBA) and silver nitrate solution. These films were characterized by FTIR, UV-visible, XRD, TGA, DSC and TEM techniques. The formed silver nanoparticles have an average particle size of ~15 nm as observed by transmission electron microscopy (TEM). Curcumin loading into SCMC SNCF is achieved by diffusion mechanism. The UV-Visible analysis indicated that higher encapsulation of curcumin in the films with higher SCMC content. Further, it was observed that the presence of silver nanoparticles in the films enhanced the encapsulation of curcumin indicating an interaction between them. Moreover, the antibacterial activity showed that the SCMC films generated with silver nanoparticles have a synergistic effect in the antimicrobial activity against Escherichia coli (E. coli). In order improve the healing efficacy as antibacterial agents, curcumin loaded with SCMC SNCFs were developed which showed significant inhibition of E. coli growth than the silver nanoparticles and curcumin alone film. Therefore, the present study clearly provides novel antimicrobial films which are potentially useful in preventing/treating infections.

Pathogen-mimetic stealth nanocarriers for drug delivery: a future possibility

The Mononuclear Phagocyte System (MPS) is a major constraint to nanocarrier-based drug-delivery systems (DDS) by exerting a negative impact on blood circulation times and biodistribution. Current approaches rely on the protein- and cell-repelling properties of inert hydrophilic polymers, to enable escape from the MPS. Poly(ethylene glycol) (PEG) has been particularly useful in this regard, and it also exerts positive effects in other blood compatibility parameters, being correlated with decreased hemolysis, thrombogenicity, complement activation and protein adsorption, due to its uncharged and hydrophilic nature. However, PEGylated nanocarriers are commonly found in the liver and spleen, the major MPS organs. In fact, a hydrophilic and cell-repelling delivery system is not always beneficial, as it might decrease the interaction with the target cell and hinder drug release. Here, a full scope of the immunological and biochemical barriers is presented along with some selected examples of alternatives to PEGylation. We present a novel conceptual approach that includes virulence factors for the engineering of bioactive, immune system-evasive stealth nanocarriers.

FROM THE CLINICAL EDITOR

The efficacy of nanocarrier-based drug-delivery systems is often dampened by the Mononuclear Phagocyte System (MPS). Current approaches to circumvent MPS rely on protein- and cell-repelling properties of inert hydrophilic polymers, including PEG. This paper discusses the full scope of the immunological and biochemical barriers along with selected examples of alternatives to PEGylation.

Glycol chitosan/heparin immobilized iron oxide nanoparticles with a tumor-targeting characteristic for magnetic resonance imaging

We described the preparation of the glycol chitosan/heparin immobilized iron oxide nanoparticles (composite NPs) as a magnetic resonance imaging agent with a tumor-targeting characteristic. The iron oxide nanoseeds used clinically as a magnetic resonance imaging agent were immobilized into the glycol chitosan/heparin network to form the composite NPs. To induce the ionic interaction between the iron oxide nanoseeds and glycol chitosan, gold was deposited on the surface of iron oxide nanoseeds. After the immobilization of gold-deposited iron oxide NPs into the glycol chitosan network, the NPs were stabilized with heparin based on the ionic interaction between cationic glycol chitosan and anionic heparin. FE-SEM (field emission-scanning electron microscopy) and a particle size analyzer were used to observe the formation of the stabilized composite NPs, and a Jobin-Yvon Ultima-C inductively coupled plasma-atomic emission spectrometer (ICP-AES) was used to measure the contents (%) of formed iron oxide nanoseeds as a function of reaction temperature and formed gold deposited on the iron oxide nanoparticles. We also evaluated the time-dependent excretion profile, in vivo biodistribution, circulation time, and tumor-targeting ability of the composite NPs using a noninvasive NIR fluorescence imaging technology. To observe the MRI contrast characteristic, the composite NPs were injected into the tail veins of tumor-bearing mice to demonstrate their selective tumoral distribution. The MR images were collected with conventional T(2)-weighted spin echo acquisition parameters.

Ocular drug delivery - a look towards nanobioadhesives

IMPORTANCE OF THE FIELD

A major challenge emanating in the design of topical ophthalmic preparations is their short precorneal residence time. Retention of a drug delivery system in the front of the eye is thus desirable. One solution identified to address this concern is a retentive system that can preferably be delivered in a liquid drop form and ultimately remain attached to the corneal tissue owing to incorporation of a bioadhesive component. Forward-thinking approaches are required to achieve advancements in this approach for the attainment of an effective drug concentration at the site of action. Accordingly, several investigators have identified the benefits of nanotechnology-based drug delivery systems for ophthalmic drug delivery.

AREAS COVERED IN THIS REVIEW

A concerted effort was made to review critically all 'nanobioadhesives', that is, nanosystems designed for ocular drug delivery with the goal of attaining prolonged ocular retention, in a systematic, chronological manner, from their reported point of inception to the present.

WHAT THE READER WILL GAIN

A perspective on possible future trends in this growing field of ocular drug delivery is formulated.

TAKE HOME MESSAGE

The importance of and need for new developments in the field of ocular nanobioadhesives is emphasized.

Enhancement of cell recognition in vitro by dual-ligand cancer targeting gold nanoparticles

A dual-ligand gold nanoparticle (DLGNP) was designed and synthesized to explore the therapeutic benefits of multivalent interactions between gold nanoparticles (GNPs) and cancer cells. DLGNP was tested on human epidermal cancer cells (KB), which had high expression of folate receptor. The cellular uptake of DLGNP was increased by 3.9 and 12.7 folds compared with GNP-folate or GNP-glucose. The enhanced cell recognition was due to multivalent interactions between both ligands on GNPs and cancer cells as shown by the ligand competition experiments. Furthermore, the multivalent interactions increased contrast between cells with high and low expression of folate receptors. The enhanced cell recognition enabled DLGNP to kill KB cells under X-ray irradiation at a dose that was safe to folate receptor low-expression (such as normal) cells. Thus DLGNP has the potential to be a cancer-specific nano-theranostic agent.

Thiolated chitosan nanoparticles for enhancing oral absorption of docetaxel: preparation, in vitro and ex vivo evaluation

The aim of this study was to prepare and evaluate mucoadhesive core-shell nanoparticles based on copolymerization of thiolated chitosan coated on poly methyl methacrylate cores as a carrier for oral delivery of docetaxel. Docetaxel-loaded nanoparticles with various concentrations were prepared via a radical emulsion polymerization method using cerium ammonium nitrate as an initiator. The physicochemical properties of the obtained nanoparticles were characterized by: dynamic light-scattering analysis for their mean size, size distribution, and zeta potential; scanning electron microscopy and transmission electron microscopy for surface morphology; and differential scanning calorimetry analysis for confirmation of molecular dispersity of docetaxel in the nanoparticles. Nanoparticles were spherical with mean diameter below 200 nm, polydispersity of below 0.15, and positive zeta potential values. The entrapment efficiency of the nanoparticles was approximately 90%. In vitro release studies showed a sustained release characteristic for 10 days after a burst release at the beginning. Ex vivo studies showed a significant increase in the transportation of docetaxel from intestinal membrane of rat when formulated as nanoparticles. Cellular uptake of nanoparticles was investigated using fluoresceinamine-loaded nanoparticles. Docetaxel nanoparticles showed a high cytotoxicity effect in the Caco-2 and MCF-7 cell lines after 72 hours. It can be concluded that by combining the advantages of both thiolated polymers and colloidal particles, these nanoparticles can be proposed as a drug carrier system for mucosal delivery of hydrophobic drugs.

Enhancing cell recognition by scrutinizing cell surfaces with a nanoparticle array

We report a dual-ligand nanoparticle array approach for discerning cells that have different surface receptor profiles surrounding a common primary receptor expressed at high or low levels. The achieved differentiation provides nanoparticles the ability for potential applications in treatment of patients at a personalized medicine level for drug delivery and radiation therapy with a much better safety profile.

Simple solid-phase synthesis and biological properties of carbohydrate-oligonucleotide conjugates modified at the 3'-terminus

A novel synthesis method for oligonucleotides possessing a functional moiety at the 3'-terminus was established based on solid-phase synthesis. In order to install the functional group at the 3'-terminus of the oligonucleotide, a solid support possessing the functional group was prepared. A carbohydrate was employed in this study for the functionalization of the oligonucleotide. To prepare a glycosylated solid support, a novel glycosyl acceptor (2) was synthesized using 4,4-dihydroxymethyl-cyclopenta-1-ene as the starting compound. The glycosylation reaction proceeded smoothly (yield = 95%) to yield the suitable glycosylated compound (3). After 8 was immobilized on the solid support, it was subjected to solid-phase oligonucleotide synthesis by the standard phosphoramidite coupling method. An oligonucleotide possessing a sugar moiety at the 3'-terminus was obtained after the products were deprotected and cleaved from the solid support. The stability of the carbohydrate-modified oligonucleotide was greatly increased even in the serum buffer, indicating that the sugar moiety at the 3'-position improved the resistance against enzymatic degradation. This technique was also applied to RNA synthesis. Galactose-ended siRNA was prepared and was confirmed to possess enough ability, at a concentration of 10 nM, to regulate the expression of the target gene.

The rise and rise of stealth nanocarriers for cancer therapy: passive versus active targeting

Research in designing and engineering long-circulating nanoparticles, so-called ‘stealth’ nanoparticles, has been attracting increasing interest as a new platform for targeted drug delivery, especially in chemotherapy. In particular, the modification of nanoparticulate surfaces with poly(ethylene glycol) derivatives has illustrated a decreased uptake of nanoparticles by mononuclear phagocyte system cells and, hence, an increased circulation time, allowing passive accumulation in the tumor. The clinical trials on patients with solid tumors are described in this article, to illustrate this generation of promising nanoparticles. In the last few years, the new-generation technique of grafting ligands on the nanoparticle surface in order to target and penetrate specific cancer cells has been developed. This article discusses the benefits of passive targeting for drug delivery to the solid tumors via the enhanced permeability and retention effect, when using stealth nanoparticles, and compares them with the advantages of active targeting.

Nanomedicine Faces Barriers

Targeted nanoparticles have the potential to improve drug delivery efficiencies by more than two orders of magnitude, from the ~ 0.1% which is common today. Most pharmacologically agents on the market today are small drug molecules, which diffuse across the body’s blood-tissue barriers and distribute not only into the lesion, but into almost all organs. Drug actions in the non-lesion organs are an inescapable part of the drug delivery principle, causing “side-effects” which limit the maximally tolerable doses and result in inadequate therapy of many lesions. Nanoparticles only cross barriers by design, so side-effects are not built into their mode of operation. Delivery rates of almost 90% have been reported. This review examines the significance of these statements and checks how far they need qualification. What type of targeting is required? Is a single targeting sufficient? What new types of clinical challenge, such as immunogenicity, might attend the use of targeted nanoparticles?

Nanostructured hyaluronic acid-based materials for active delivery to cancer

IMPORTANCE OF THE FIELD

Active targeting of bioactive molecules by physicochemical association with hyaluronic acid (HA) is an attractive approach in current nanomedicine because HA is biocompatible, non-toxic and non-inflammatory.

AREAS COVERED IN THIS REVIEW

This review focuses on synthesis, physicochemical characterization and biological properties of different nanoparticulate delivery systems that include HA in their structures. Chemically based approaches to the delivery of small molecule drugs, proteins and nucleic acids in which they become chemically or physically bound to hyaluronic acid are reviewed, including the use of molecular HA conjugates and nanocarriers. The systems are considered in terms of intracellular delivery to different cultured cells that express HA-specific receptors (hyaladherines) differently. The in vivo biodistribution and therapeutic effect of these systems are discussed.

WHAT THE READER WILL GAIN

Different synthetic methodologies for preparations of HA-based nanoparticles are presented extensively. HA nanoparticulate systems of various structures can be compared with respect to their in vitro assays and in vivo biodistribution.

TAKE HOME MESSAGE

To make HA useful as an intravenous targeting carrier, strategies have to be devised to: reduce HA clearance from the blood; suppress the HA uptake by liver and spleen; and provide tumor-triggered mechanisms of release of an active drug from the HA carrier.

Transcellular Transport of Heparin-coated Magnetic Iron Oxide Nanoparticles (Hep-MION) Under the Influence of an Applied Magnetic Field

In this study, magnetic iron oxide nanoparticles coated with heparin (Hep-MION) were synthesized and the transcellular transport of the nanoparticles across epithelial cell monolayers on porous polyester membranes was investigated. An externally applied magnetic field facilitated the transport of the Hep-MION across cell monolayers. However, high Hep-MION concentrations led to an increased aggregation of nanoparticles on the cell monolayer after application of the magnetic field. Our results indicate that magnetic guidance of Hep-MION most effectively promotes transcellular transport under conditions that minimize formation of magnetically-induced nanoparticle aggregates. Across cell monolayers, the magnet’s attraction led to the greatest increase in mass transport rate in dilute dispersions and in high serum concentrations, suggesting that magnetic guidance may be useful for in vivo targeting of Hep-MION.