Nanomedicine: Nanotechnology, Biology and Medicine - Articles in Press

Shell Cross-linked and Hepatocyte Targeting Nanoparticles Containing Doxorubicin via Acid-Cleavable Linkage - Accepted Manuscript

Changhai Lu, Malcolm M.Q. Xing, Wen Zhong — 2010-07-21

Abstract: Hepatocyte targeting and shell cross-linked nanoparticles with lactose moiety on the surface and Doxorubicin (DOX) in the core were prepared from lactose-PEG-DOX conjugate. The process consists of the synthesis of a novel α-hydrazine-ω-propargyl PEG with a double bond in the PEG backbone, followed by the bonding of a lactose molecule containing an azide group to the ω-end of PEG via ‘click’ chemistry and, finally, the conjugation of DOX to the α-end of PEG via an acid-liable hydrazone linkage. The resultant conjugate can be self-assembled into nanoparticles. Thiolated tri(ethylene glycol) was introduced into the shell of nanoparticles as a cross-linking agent. The release of DOX is more rapid from Lactose-PEG-DOX at pH 5.0 than at pH 7.4. Fluorescent microscope studies suggest that the Lac/Dox-nanoparticles are internalized by HepG2 cells through a lactose-receptor-mediated mechanism, while the lactose-free nanoparticles are not endocytosed as rapidly as Lac/Dox-nanoparticles. MTT assay also shows that Lac/Dox-nanoparticles have a stronger inhibition against HepG2 than DOX-nanoparticles and pure DOX.

A new thermography based early detection of cancer approach based on magnetic nanoparticles Theory simulation and in vitro validation - Accepted Manuscript

Arie Levy, Abraham Dayan, Moshe Ben-David, Israel Gannot — 2010-07-09

Abstract: This work offers the utilization of tumor-specific magnetic nanoparticles together with an alternating magnetic field as a means to thermally mark a tumor in order to detect it using thermal imaging system. Experiments were conducted using an in-vitro tissue model, an inductive heating system and an IR camera. The thermal images, recorded by the IR camera during the experiments, were analyzed using an algorithm, which was developed as part of this work. The results show that small tumor phantoms (diameter of 0.5mm) which were embedded under the surface of the tissue phantom (up to 14mm below the surface) can be detected and located, indicating that the proposed method could potentially offer considerable advantages over conventional thermography and other methods for cancer early detection. Nevertheless, several issues should be clarified in future researches before the method could be offered for clinical use.

Pulmonary toxicity by carbon nanotubes: A systematic report - Accepted Manuscript

Jitendra Kayat, Virendra Gajbhiye, Rakesh Kumar Tekade, Narendra Kumar Jain — 2010-07-09

Abstract: Carbon nanotubes (CNTs) are nanosized, cylindrical, hollow tubes consisting entirely of carbon element. Now a days, CNTs are playing an important role in drug delivery as a carrier system owing to several unique physical and chemical properties. Literature shows that CNTs are toxic in nature, which depends upon properties of CNTs material, such as their structure (SWCNTs or MWCNTs), length and aspects ratio, surface area, degree of aggregation, extent of oxidation, bound functional group(s), method of manufacturing and on their concentration as well as dose. People could get exposed to CNTs through accidental exposure by coming in contact with the aerosol form of CNTs during production, or exposure as a result of biomedical use. Numerous in vitro and in vivo studies have shown that carbon nanotubes and/or associated contaminants or catalytic materials that arise during the production process may induce oxidative stress, prominent pulmonary inflammation, apoptosis in different cell types and able to induce cytotoxic effects on lungs. Studies on the toxicity of CNTs have mainly focused on the pulmonary effects of intra-tracheal or pharyngeal administered CNTs. This review examines the potential pulmonary toxicity of CNTs.

C60 Fullerene-Pentoxifylline Dyad Nanoparticles Enhance Autophagy to Avoid Cytotoxic Effects Caused by the beta-Amyloid Peptide - Accepted Manuscript

2010-07-09

Abstract: Many studies focused on the neuroprotective effects of C60 fullerene-derived nanomaterials. The peculiar structure of C60 fullerene, which is capable of “adding” multiple radicals per molecule, serves as a “radical sponge”, and it can be an effective antioxidant by reducing cytotoxic effects caused by intracellular oxidative stress. In this study, PEG-C60-3, a C60 fullerene derivative, and its pentoxifylline-bearing hybrid (PTX-C60-2) were investigated against β-amyloid (Aβ)25-35-induced toxicity toward Neuro-2A cells. PEG-C60-3 and PTX-C60-2 significantly reduced Aβ25-35-induced cytotoxicity, with comparable activities in decreasing reactive oxygen species and maintaining the mitochondrial membrane potential. Aβ25-35 treatment elicited AMPK-associated autophagy. Cytoprotection by PEG-C60-3 and PTX-C60-2 was partially diminished by an autophagy inhibitor, indicating that the elicited autophagy and antioxidative activities protect cells from Aβ damage. PTX-C60-2 was more effective than PEG-C60-3 at enduring the induced autophagy. Our results offer new insights into therapeutic drug design using C60 fullerene-PTX dyad nanoparticles against Aβ-associated diseases.

Photothermolysis of glioblastoma stem-like cells targeted by carbon nanotubes conjugated with CD133 monoclonal antibody - Accepted Manuscript

2010-07-09

Abstract: Since CD133+cells in glioblastoma (GBM) present cancer stem-like property and have been considered as the culprit of tumor recurrence, exploration of potential therapeutic modalities targeting CD133+cancer stem-like cells has its ground. For photothermolysis studies, GBM-CD133+and GBM-CD133– cells mixed with various ratios were challenged with single-walled carbon nanotubes (SWNTs) conjugated with CD133 monoclonal antibody (anti-CD133) and then irradiated with near-infrared (NIR) laser light. Results showed GBM-CD133+cells were selectively targeted and eradicated, while GBM-CD133– cells remained viable. In addition, in vitro tumorigenic and self-renewal capability of GBM-CD133+treated with localized hyperthermia were significantly blocked. Furthermore, GBM-CD133+cells pretreated with anti-CD133-SWNTs and irradiated by NIR laser 2 days after xenotransplanted in nude mice did not exhibit sustainability of cancer stem-like cell features for tumor growth. Taken altogether, our studies demonstrated that anti-CD133-SWNT has the potential to be utilized as a thermal-coupling agent to effectively target and destroy glioblastoma cancer stem-like cells in vitro and in vivo.

Nanoscale phase dynamics of the normal tear film - Accepted Manuscript

Santosh Khanal, Thomas J. Millar — 2010-07-05

Abstract: The tear film is a dynamic multilayered structure. The interactions and the interfacial dynamics between the layers that occur during a blink cycle must be such that they allow for maintenance of a stable tear film. Attempts to understand these dynamics have been limited by the techniques and biomarkers used. Quantum dots (qdots) offer a new potential to monitor the dynamics of the tear film layers in real without the drawbacks of previously used methodologies. Indium galium posphide (InGaP) qdots were used to differentially assess the dynamics of the lipid and aqueous layers of the tear film in real time. In the aqueous, qdots dispersed to form a stable local region which was swept away into the upper and lower menisci during a blink. They did not redisperse onto the ocular surface, but were progressively removed from the menisci through the puncta. Some of these qdots adhered to the mucin layer on the ocular surface in a mesh-like pattern and remained there for 5 – 6 blinks before they were removed. The organic qdots dispersed quickly but patchily over the whole outer surface of the tear film. They also strongly marked both eyelid margins and slowly dispersed onto the skin and eyelashes and not through the puncta. Some were trapped in the menisci as blobs that rolled along the meniscus. These data support the view of a distinct three layered tear film: an inner mucin layer attached to the epithelial cells; a fluid aqueous layer; and an outer viscoelastic lipid layer.

Preparation and characterization of ketoprofen loaded solid lipid nanoparticles made from beeswax and carnauba wax - Accepted Manuscript

2010-07-05

Abstract: Solid lipid nanaoparticles (SLNs) have been proposed as suitable colloidal carriers for delivery of drugs with limited solubility. Ketoprofen as model drug was incorporated into SLNs prepared from a mixture of beeswax and carnauba wax using tween 80 and egg lecithin as emulsifiers. The characteristics of the SLNs with various lipid and surfactant composition were investigated. The mean particle size of drug loaded SLNs decreased by mixing tween 80 and egg lecithin as well as by increasing total surfactant concentration. SLNs of 75±4 nm with a polydispersity index of 0.2±0.02 were obtained using 1% (v/v) mixed surfactant at a ratio of 60:40 tween80 to egg lecithin. The zeta potential of these SLNs varied at the range of-15 to-17 (mV) suggesting the presence of similar interface properties. High drug entrapment efficiency of 97% revealed the ability of SLNs to incorporate low water soluble drug such as ketoprofen. DSC thermograms and HPLC analysis indicated the stability of nanoparticles with negligible drug leakage after 45 days of storage. It was also found that nanoparticles with more beeswax content in their core, exhibited faster drug release compared to those containing more carnauba wax in their structure.

The how, when and why of the aging signals appearing on the human erythrocyte membrane: An atomic force microscopy study of surface roughness - Accepted Manuscript

2010-07-05

Abstract: We recently developed an Atomic Force Microscopy-based protocol to use the roughness of the plasma membrane of erythrocytes as a morphological parameter, independently from the cell shape, to investigate the membrane-skeleton integrity in healthy and pathological cells.Here, we apply the method to investigate a complex physiological phenomenon, such as the RBCs aging, that plays a major role in the regulation of the erythrocytes’ turnover. The aging, monitored morphologically and biochemically, has been accelerated and modulated by preventing oxidative stresses, effects of proteases and divalent cations, and by artificially consuming the intracellular ATP. The collected data evidence that the progression of aging causes a drastic decrease of the measured roughness, that is diagnostic of a progressive, ATP-dependent, alteration of the membrane-skeleton properties. Lastly, the degree of reversibility of such effects have been investigated as function of aging time, enabling the detection of irreversible transformation in the erythrocytes’ structure and metabolism.

MR and fluorescence imaging of doxorubicin loaded nanoparticles using a novel in vivo model - Accepted Manuscript

2010-07-05

Abstract: We report here the in vivo combined-modality imaging of multifunctional drug delivery nanoparticles. These dextran core-based stealth liposomal nanoparticles (nanosomes) contained doxorubicin, iron oxide for MRI contrast, and Bodipy for fluorescence. The particles were long-lived in vivo due to surface decoration with polyethylene glycol (PEG) and the incorporation of acetylated lipids which were UV cross-linked for physical stability. We developed a rodent dorsal skinfold window chamber which facilitated both MRI and non-destructive optical imaging of nanoparticle accumulation in the same tumors. Chamber tumors were genetically labeled with DsRed-2 that enabled the MR images, the red fluorescence of the tumor, and the blue fluorescence of the nanoparticles to be co-localized. The nanoparticle design and MR imaging developed with the window chamber were then extended to orthotopic pancreatic tumors expressing DsRed-2. The tumors were MR imaged using iron oxide-dextran liposomes and by fluorescence to demonstrate the deep imaging capability of these nanoparticles.

Antioxidant idebenone-loaded nanoparticles based on chitosan and N-carboxymethylchitosan - Accepted Manuscript

2010-07-05

Abstract: Nanoparticles based on chitosan (Ch) and N-carboxymethylchitosan (N-CMCh) cross-linked with tripolyphosphate (TPP) were developed by co-drying with idebenone in different polymer:drug ratios (1.3:1- 16:1) with 20% (w/w) colloidal silicon dioxide and TPP (0.2 mg.mL-1). At high ratios (8:1 and 16:1) the spray dried powder showed spherical and dense particles with a size close to 1 µm, allowing almost complete drug coating by the polymeric system and a high efficiency of drug incorporation (>90% and>80%, for Ch and N-CMCh, respectively). The nanoparticles showed a 10-fold increase of drug stability in comparison with free drug and preserved antioxidant activity in vitro. Compared to the severely irritative free form of idebenone the nanoparticle formulation showed decreased mucous-membrane irritation. These results revealed the potential of Ch and N-CMCh nanoparticles as carrier for a hydrophobic and irritative drug such as idebenone for topical or nasal use.

The nanoscopic range and the effect of architecture on nano-properties - Accepted Manuscript

L.P. Balogh — 2010-06-23

Advances in Polymeric Micelles for Drug Delivery and Tumor Targeting - Accepted Manuscript

Uttam Kedar, Prasanna Phutane, Supriya Shidhaye, Vilasrao Kadam — 2010-06-14

Abstract: Plethora of the formulation techniques were reported in literature for targeting the drug to specific site. Polymeric micelle can be targeted to tumor site by passive as well as active mechanism. Some inherent properties of polymeric micelle such as size in nanorange, stability in plasma, longevity in vivo and pathological characteristics of tumor make polymeric micelles to be targeted at the tumor site by passive mechanism called enhanced permeability and retention (EPR) effect. Polymeric micelle formed from the amphiphilic block copolymer is suitable for encapsulation of poorly water soluble, hydrophobic anticancer drugs. Other characteristics of polymeric micelles like separated functionality at the outer shell are useful for targeting the anticancer drug to tumor by active mechanisms. Polymeric micelles can be conjugated with many ligands such as antibodies fragments, epidermal growth factors, α2-glycoprotein, transferrin, folate to target micelles to cancer cells. Application of heat, ultrasound are the alternative method to enhance drug accumulation in tumoral cells. Targeting using micelles can also be done to tumor angiogenesis which is the potentially promising target for anticancer drugs. Polymeric micelles have been used for the delivery of many anticancer agents in the pre-clinical and clinical studies. This review summarizes about recently available information regarding targeting the anticancer drug to the tumor site using polymeric micelles.

New metal-based nanoparticles for intravenous use: Requirements for clinical success with focus on medical imaging - Accepted Manuscript

Tore Skotland, Tore-Geir Iversen, Kirsten Sandvig — 2010-05-31

Abstract: Animal studies have during the last years revealed a large potential for in vivo imaging with new metal-based nanoparticles and will certainly during the next years also continue to improve our understanding of basic biological processes. In the present article we discuss what is needed to bring such non-iron-oxide particles into clinical imaging. For imaging agents it is essential to have a rapid clearance from blood in order to obtain low background signals and good images. The surface charge and hydrodynamic diameter of the nanoparticles in the presence of plasma proteins are important for their biodistribution, excretion and a rapid clearance from blood. As discussed, some major challenges remain to be solved regarding safety and metabolism issues. Measurements and optimization of the critical parameters will shorten the time needed for such particles to be accepted for widespread medical use.

Reduced dose-limiting toxicity of intraperitoneal mitoxantrone chemotherapy using cardiolipin-based anionic liposomes - Accepted Manuscript

2010-05-31

Abstract: Intraperitoneal chemotherapy confers limited clinical benefit due to the dose-limiting toxicity of anticancer drugs. We aimed to develop optimized liposomes for mitoxantrone (MTO) that provides high encapsulation efficiency and increases the therapeutic index. Cationic MTO was loaded onto anionic liposomes by electrostatic surface complexation. The anticancer activity was evaluated in a peritoneal carcinomatosis model. The retention of MTO at tumor site was monitored by molecular imaging. MTO loading efficiencies by electrostatic complexation were> 95% for all anionic liposomes, but< 5% for neutral liposomes. Among anionic liposomes, cardiolipin liposomes (CL) exhibited the strongest binding affinity for MTO, the highest anti-cancer activity and the lowest toxicity. MTO delivered by CL showed prolonged retention at tumor sites. Unlike free MTO showing significant cardiotoxicity, MTO administered in CL provided negligible cardiotoxicity. CL-mediated delivery may increase the therapeutic index of MTO chemotherapy by prolonged retention and reduced cardiotoxicity.

Phosphate ester hydrolysis of biologically relevant molecules by cerium oxide nanoparticles - Accepted Manuscript

2010-05-31

Abstract: In an effort to characterize the interaction of cerium oxide nanoparticles (CNP) in biological systems, we explored the reactivity of CNP with the phosphate ester bonds of p-nitrophenylphosphate (pNPP), ATP, o-phospho-L-tyrosine, and DNA. The activity of the bond cleavage for pNPP at pH 7 is calculated to be 0.860 ± 0.010 nmoles p-nitrophenol/min/µg CNP. Interestingly, when CNP bind to plasmid DNA, no cleavage products are detected. While cerium(IV) complexes generally exhibit the ability to break phosphorous-oxygen bonds, the reactions we report appear to be dependent on the availability of cerium(III) sites, not cerium(IV) sites. We investigated the dephosphorylation mechanism from the first principles and find the reaction proceeds through inversion of the phosphate group similar to an SN2 mechanism. The ability of CNP to interact with phosphate ester bonds of biologically relevant molecules has important implications for their use as potential therapeutics.

Effect of cholesterol and Amyloid-Beta peptide on structure and function of mixed lipid films and pulmonary surfactant BLES. An Atomic Force Microscopy study - Accepted Manuscript

Francis Hane, Elizabeth Drolle, Zoya Leonenko — 2010-05-21

Abstract: Pulmonary surfactant forms a thin molecular film inside mammalian lung alveoli and lowers the surface tension of the air/fluid interface to reduce the work of breathing. Upon compression functional surfactant forms characteristic multilayer structures, which indicate surfactant surface activity. We showed that cholesterol adversely affects both structural and surface active properties of BLES surfactant and DPPC-DOPG lipid films. Incorporation of small concentrations of fibril forming peptide amyloid-ß 1-40 helps to counteract the distractive effect of cholesterol by improving characteristic multilayer formation which occurs upon compression. In contrast to many negative effects of amyloid forming peptides reported earlier, we report a positive effect of amyloid-ß peptide on surfactant function, which may aid in the designing of novel surfactant formulations.

Study of the stabilization of zinc phthalocyanine in sol-gel TiO2 for photodynamic therapy applications - Accepted Manuscript

2010-05-21

Abstract: Background: Photodynamic therapy (PDT) has emerged as an alternative and promising non-invasive treatment for cancer. It is a two-step procedure that uses a combination of molecular oxygen, visible light, and photosensitizer (PS) agents; phthalocyanine (Pc) was supported over titanium oxide, has not been used yet for cell inactivation.Methods: Zinc Phthalocyanine (ZnPc) molecules were incorporated in the porous network of TiO2 using the sol-gel method. It was prepared stock solutions of ZnPc, TiO2, ZnPc-TiO2 and were tested with four cancer cell lines.Results: The characterization of supported ZnPc showed that phthalocyanine is linked by the N-pyrrole to the support, is stable up to 250°C and were tested for PDT. The preferential localization in target organelles, as mitochondria or lysosomes, could determine the cell death mechanism after PDT.Conclusions: The results suggest that nanoparticulated TiO2 sensitized with ZnPc is an excellent candidate as sensitizer in PDT against cancer and infectious diseases.

Caspase-9-dependent decrease of nuclear pore channel hydrophobicity is accompanied by nuclear envelope leakiness - Accepted Manuscript

Armin Kramer, Ivan Liashkovich, Hans Oberleithner, Victor Shahin — 2010-05-13

Abstract: Advances in nano-medicine require conceptual understanding of physiological processes. Apoptosis is a fundamental physiological process, which is characterised among other things by an increased permeability of the nuclear envelope (NE). The latter is a tight transport barrier, known to restrict nuclear delivery rate of therapeutic nano-particles. Therefore, an understanding of the underlying mechanism, which leads to the breakdown of the barrier during apoptosis, could stimulate the development of new approaches in gene therapy. We set out to elucidate this mechanism following induction of apoptosis on isolated cell nuclei. We tested the hypothesis whether caspases, mediators of apoptosis, trigger the NE leakiness at the level of the nuclear pore complexes (NPCs) using fluorescence techniques. As the permeability barrier inside the NPC channel is thought to be based on hydrophobic-hydrophobic protein interactions we further investigated the NPC channel hydrophobicity using atomic force microscopy (AFM). Caspase-9 was found to induce NE leakiness to large macromolecules. Leakiness was prevented by pretreatment of NPCs with an importin-β mutant, which irreversibly binds and thereby obstructs the NPC channel. Utilizing an ultra sharp, hydrophobic AFM tip as a chemical nano-sensor, which reaches deep into the apoptotic NPC channel, a remarkable decrease of hydrophobic binding sites was detected therein. We conclude that caspase 9 gives rise to NE leakiness by perturbing the hydrophobicty-based barrier inside the NPC channel. This explains the high passive NE permeability in early apoptosis.

Viral nanoparticles as platforms for next-generation therapeutics and imaging devices - Accepted Manuscript

Nicole F. Steinmetz — 2010-04-30

Abstract: Nanomaterials have been developed for potential applications in biomedicine, such as tissue-specific imaging and drug delivery. There are many different platforms under development, each with advantages and disadvantages, but viral nanoparticles (VNPs) are particularly attractive because they are naturally occurring nanomaterials, and as such they are both biocompatible and biodegradable. VNPs can be designed and engineered using both genetic and chemical protocols. The use of VNPs has evolved rapidly since their introduction 20 years ago, encompassing numerous chemistries and modification strategies that allow the functionalization of VNPs with imaging reagents, targeting ligands and therapeutic molecules. This review discusses recent advances in the design of “smart” targeted VNPs for therapeutic and imaging applications.

Perspectives David versus Goliath - Corrected Proof

2010-04-23

In 2010 three new Nanomedicine Research Centers have been launched in Denmark. The three Centers of Excellence emerged via an open call for proposals posted by the private funding organization The Lundbeck Foundation. The foundation will provide a total financing of €13 million (US $17.7 million) for an initial period of 5 years to the three Centers. For a country like Denmark, this represents a massive investment into frontline research. The real dimension can best be visualized by relating it to the gross domestic product of Denmark and scaling it to the gross domestic products of Germany or the United States. Doing so, the financial support would correspond to investments of €139 million (US $189 million) and €540 million (US $735 million) for Germany and the United States, respectively, which is well in the scale of larger national programs. The three Centers will investigate novel strategies for exploiting nanoscaled biostructures in combating major human diseases, including cancer as well as neurological, infectious, cardiovascular, and musculoskeletal disorders.

Inorganic nanomedicine—Part 2 - Corrected Proof

Bhupinder S. Sekhon, Seema R. Kamboj — 2010-04-23

Abstract: Inorganic nanomaterials (INMs) and nanoparticles (NPs) are important in our lives because of their use as drugs, imaging agents, and antiseptics. Among the most promising INMs being developed are metal, silica, dendrimers, organic-inorganic hybrids, and bioinorganic hybrids. Gold NPs are important in imaging, as drug carriers, and for thermotherapy of biological targets. Gold NPs, nanoshells, nanorods, and nanowires have the extensive potential to be an integral part of our imaging toolbox and useful in the fight against cancer. Metal NP contrast agents enhance magnetic resonance imaging and ultrasound results in biomedical applications of in vivo imaging. Hollow and porous INMs have been exploited for drug and gene delivery, diagnostic imaging, and photothermal therapy. Silver NPs show improved antimicrobial activity. Silica NPs have been used in drug delivery and gene therapy. Biomolecular inorganic nanohybrids and nanostructured biomaterials have been exploited for targeted imaging and therapy, drug and gene delivery, and regenerative medicine. Dendrimers find use as drug or gene carriers, contrast agents, and sensors for different metal ions.

Inorganic nanomedicine—Part 1 - Corrected Proof

Bhupinder S. Sekhon, Seema R. Kamboj — 2010-04-23

Abstract: Inorganic nanomedicine refers to the use of inorganic or hybrid nanomaterials and nanosized objects to achieve innovative medical breakthroughs for drug and gene discovery and delivery, discovery of biomarkers, and molecular diagnostics. Potential uses for fluorescent quantum dots include cell labeling, biosensing, in vivo imaging, bimodal magnetic-luminescent imaging, and diagnostics. Biocompatible quantum dot conjugates have been used successfully for sentinel lymph node mapping, tumor targeting, tumor angiogenesis imaging, and metastatic cell tracking. Magnetic nanowires applications include biosensing and construction of nucleic acids sensors. Magnetic cell therapy is used for the repair of blood vessels. Magnetic nanoparticles (MNPs) are important for magnetic resonance imaging, drug delivery, cell labeling, and tracking. Superparamagnetic iron oxide nanoparticles are used for hyperthermic treatment of tumors. Multifunctional MNPs applications include drug and gene delivery, medical imaging, and targeted drug delivery. MNPs could have a vital role in developing techniques to simultaneously diagnose, monitor, and treat a wide range of common diseases and injuries.

Delivery of a peptide via poly(d,l-lactic-co-glycolic) acid nanoparticles enhances its dendritic cell–stimulatory capacity - Corrected Proof

2010-03-29

Abstract: Nanoparticles (NPs) are attractive carriers for vaccines. We have previously shown that a short peptide (Hp91) activates dendritic cells (DCs), which are critical for initiation of immune responses. In an effort to develop Hp91 as a vaccine adjuvant with NP carriers, we evaluated its activity when encapsulated in or conjugated to the surface of poly(d,l-lactic-co-glycolic) acid (PLGA) NPs. We found that Hp91, when encapsulated in or conjugated to the surface of PLGA-NPs, not only activates both human and mouse DCs, but is in fact more potent than free Hp91. Hp91 packaged within NPs was about fivefold more potent than the free peptide, and Hp91 conjugated to the surface of NPs was ∼20-fold more potent than free Hp91. Because of their capacity to activate DCs, such NP-Hp91 systems are promising as delivery vehicles for subunit vaccines against infectious disease or cancer.

Nanostructured surfaces for enhanced protein detection toward clinical diagnostics - Corrected Proof

2010-03-29

Abstract: “Label-free” biomolecule sensors for detection of inflammatory cardiovascular biomarker associated with vulnerable coronary vascular plaque rupture were designed and fabricated using micro- and nanotextured polystyrene (PS) polymer structures that functioned as sensing elements coupled with electronic measurement equipment. We demonstrated that scaling down the surface texturing from the micro- to the nanoscale enhances the amplitude of the measured detected signal strength. We believe that the nanoscale fiber morphology provides size-matched spaces for trapping and immobilizing the protein biomolecule, resulting in improved detection signal strength. We selected PS as the model system and demonstrated the detection of human serum C-reactive protein. We employed these findings in designing a platform “lab-on-a-chip” protein sensor. Comparative studies were performed on PS textured surfaces of two different surface features: a PS microsphere mat and an electrospun PS nanofiber matrix.

In vivo evaluation of the biodistribution and safety of PLGA nanoparticles as drug delivery systems - Corrected Proof

2010-03-15

Abstract: The remarkable physicochemical properties of particles in the nanometer range have been proven to address many challenges in the field of science. However, the possible toxic effects of these particles have raised some concerns. The aim of this article is to evaluate the effects of poly(lactide-co-glycolide) (PLGA) nanoparticles in vitro and in vivo compared to industrial nanoparticles of a similar size range such as zinc oxide, ferrous oxide, and fumed silica. An in vitro cytotoxicity study was conducted to assess the cell viability following exposure to PLGA nanoparticles. Viability was determined by means of a WST assay, wherein cell viability of greater than 75% was observed for both PLGA and amorphous fumed silica particles and ferrous oxide, but was significantly reduced for zinc oxide particles. In vivo toxicity assays were performed via histopathological evaluation, and no specific anatomical pathological changes or tissue damage was observed in the tissues of Balb/C mice. The extent of tissue distribution and retention following oral administration of PLGA particles was analyzed for 7 days. After 7 days, the particles remained detectable in the brain, heart, kidney, liver, lungs, and spleen. The results show that a mean percentage (40.04%) of the particles were localized in the liver, 25.97% in the kidney, and 12.86% in the brain. The lowest percentage was observed in the spleen. Thus, based on these assays, it can be concluded that the toxic effects observed with various industrial nanoparticles will not be observed with particles made of synthetic polymers such as PLGA when applied in the field of nanomedicine. Furthermore, the biodistribution of the particles warrants surface modification of the particles to avoid higher particle localization in the liver.

Synthesis, characterization, and evaluation of antimicrobial and cytotoxic effect of silver and titanium nanoparticles - Corrected Proof

2010-03-08

Abstract: Microbial resistance represents a challenge for the scientific community to develop new bioactive compounds. Nosocomial infections represent an enormous emerging problem, especially in patients with ambulatory treatment, which requires that they wear medical devices for an extended period of time. In this work, an evaluation of the antimicrobial activity of both silver and titanium nanoparticles was carried out against a panel of selected pathogenic and opportunistic microorganisms, some of them commonly associated with device-associated infections. Cytotoxicity assays monitoring DNA damage and cell viability were evaluated using human-derived monocyte cell lines. We show that silver-coated nanoparticles having a size of 20–25 nm were the most effective among all the nanoparticles assayed against the tested microorganisms. In addition, these nanoparticles showed no significant cytotoxicity, suggesting their use as antimicrobial additives in the process of fabrication of ambulatory and nonambulatory medical devices.

Cerium oxide nanoparticles protect gastrointestinal epithelium from radiation-induced damage by reduction of reactive oxygen species and upregulation of superoxide dismutase 2 - Corrected Proof

2010-02-22

Abstract: The ability of rare earth cerium oxide (CeO2) nanoparticles to confer radioprotection against gastrointestinal epithelium was examined. The pretreatment of normal human colon cells (CRL 1541) with varying concentrations of CeO2 nanoparticles 24 hours before single-dose radiation exposure conferred protection from radiation-induced cell death by reducing the amount of reactive oxygen species produced and increasing the expression of superoxide dismutase 2 (SOD2), in a dose-dependent manner. In subsequent experiments athymic nude mice were pretreated with intraperitoneal injections of CeO2 nanoparticles before a single dose of radiation to the abdominal area. Immunohistochemical analysis show a decrease in TUNEL-and caspase 3–positive cells in the colonic crypt, 4 hours after radiation. In sharp contrast, a significant increase in SOD2 expression was observed. In the end, these studies suggest that CeO2 nanoparticles protect the gastrointestinal epithelium against radiation-induced damage by (1) acting as free-radical scavengers and (2) increasing the production of SOD2 before radiation insult.

Discriminated effects of thiolated chitosan-coated pMMA paclitaxel-loaded nanoparticles on different normal and cancer cell lines - Corrected Proof

2010-02-22

Abstract: The aim of the present work was to prepare and characterize poly(methyl methacrylate) nanoparticles coated by chitosan–glutathione conjugate so as to encapsulate insoluble anticancer drugs. Nanoparticles were synthesized through radical polymerization of methyl methacrylate initiated by cerium (IV) ammonium nitrate. Paclitaxel (PTX), a model anticancer drug, was encapsulated in nanoparticles with a maximal encapsulation efficiency of 98.27%. These nanoparticles showed sustained in vitro release of the incorporated PTX (75% of the loaded dose was released in 10 days). All nanoparticles had positive charge and were spherical, with a size range of about 130–250 nm. The PTX-loaded nanoparticles showed cytotoxicity for NIH 3T3 and T47D breast carcinoma cells, along with no cytotoxicity for two colon cell lines (HT29, Caco2).

In vitro evaluation of novel polymer-coated magnetic nanoparticles for controlled drug delivery - Corrected Proof

2010-02-22

Abstract: Previously uncharacterized poly(N-isopropylacrylamide-acrylamide-allylamine)-coated magnetic nanoparticles (MNPs) were synthesized using silane-coated MNPs as a template for radical polymerization of N-isopropylacrylamide, acrylamide, and allylamine. Properties of these nanoparticles such as size, biocompatibility, drug loading efficiency, and drug release kinetics were evaluated in vitro for targeted and controlled drug delivery. Spherical core-shell nanoparticles with a diameter of 100 nm showed significantly lower systemic toxicity than did bare MNPs, as well as doxorubicin encapsulation efficiency of 72%, and significantly higher doxorubicin release at 41°C compared with 37°C, demonstrating their temperature sensitivity. Released drugs were also active in destroying prostate cancer cells (JHU31). Furthermore, the nanoparticle uptake by JHU31 cells was dependent on dose and incubation time, reaching saturation at 500 μg/mL and 4 hours, respectively. In addition, magnetic resonance imaging capabilities of the particles were observed using agarose platforms containing cells incubated with nanoparticles. Future work includes investigation of targeting capability and effectiveness of these nanoparticles in vivo using animal models.

Landscape Phage Fusion Protein-mediated Targeting of Nanomedicines Enhances their Prostate Tumor Cell Association and Cytotoxic Efficiency - Accepted Manuscript

2010-02-05

Abstract: Tumor-specific cytotoxicity of drugs can be enhanced by targeting them to tumor receptors using tumor-specific ligands. Phage display offers a high-throughput approach to screen for the targeting ligands. We have successfully isolated phage fusion peptides selective and specific for PC3 prostate cancer cells. Also, we have demonstrated a novel approach of targeting liposomes through tumor-specific phage fusion coat proteins, exploiting the intrinsic properties of the phage coat protein as an integral membrane protein. Here we describe the production of Rhodamine-labeled liposomes as well as doxorubicin-loaded long circulating liposomes targeted to PC3 prostate tumor cells via PC-specific phage peptides, as an extension of our previous studies. Targeting of labeled liposomes was demonstrated using fluorescence microscopy as well as flow cytometry. Targeting of doxorubicin-loaded liposomes enhanced their cytotoxic effect against PC3 cells in vitro indicating a possible therapeutic advantage. The simplicity of the approach for generating targeted liposomes coupled with the ability to rapidly obtain tumor-specific phage fusion proteins via phage display may contribute to a combinatorial system for the production of targeted liposomal therapeutics for advanced stages of prostate tumor.

Accurate quantitation of glutathione in cell lysates through surface-assisted laser desorption/ionization mass spectrometry using gold nanoparticles - Corrected Proof

Cheng-Kang Chiang, Yang-Wei Lin, Wen-Tsen Chen, Huan-Tsung Chang — 2010-02-05

Abstract: We developed a method for the determination of three aminothiols—cysteine, glutathione (GSH), and homocysteine—using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The analytes were first captured using the unmodified 14-nm gold nanoparticles; N-2-mercaptopropionylglycine–modified gold nanoparticles serving as internal standard were sequentially added, and then the sample was analyzed using SALDI-MS. This approach provided good quantitative linearity of the three analytes (R2 = ∼0.99), with good reproducibility (relative standard deviations: <10%), in the analyses of GSH in the lysates of human red blood cells and MCF-7 cancer breast cells in the presence and absence of the anti-inflammatory drug sulfasalazine. The internal-standard SALDI-MS approach provides simplicity, accuracy, and precision to the determination of GSH in cells under drug invasion, to open an avenue for SALDI-MS to be used for the precise quantitative determination of a variety of analytes.

Hepatoma-targeted gene delivery using a tumor cell–specific gene regulation system combined with a human liver cell–specific bionanocapsule - Corrected Proof

2010-02-05

Abstract: Hepatoma (hepatocellular carcinoma) is the most common type of malignant tumor originating in the liver and has a relatively low 5-year survival rate. The development of hepatoma-targeted therapy is needed to increase treatment efficiency and to reduce the incidence of undesirable side effects. In this study we developed a novel hepatoma-targeted gene delivery system. The gene delivery system was prepared by combining a human liver cell–specific bionanocapsule (BNC) and a tumor cell–specific gene regulation polymer, which responds to hyperactivated protein kinase Cα in hepatoma cells. The complex of the polymer-DNA with BNCs was delivered into cells and tissues. The developed system showed increased transfection efficiency and resulted in cell-specific gene expression in hepatoma cells and tissues (HuH-7), but no gene expression in normal human hepatocytes or human epidermoid tumor cells (A431). The combination of a tumor cell-specific gene regulation system responding to protein kinase Cα and BNCs showed excellent potential for the selective treatment of hepatomas. The system could be a useful method with applications in hepatoma-specific gene therapy and molecular imaging.

Uptake and distribution of fullerenes in human mast cells - Corrected Proof

2010-02-05

Abstract: Fullerenes are carbon cages of variable size that can be derivatized with various side chain moieties resulting in compounds that are being developed into nanomedicines. Although fullerene use in several preclinical in vitro and in vivo models of disease has demonstrated their potential as diagnostic and therapeutic agents, little is known about how they enter cells, what organelles they target, and the time course for their cellular deposition. Fullerenes (C70) that have already been shown to be potent inhibitors of mast cell (MC)–mediated allergic inflammation were conjugated with Texas red (TR) and used in conjunction with confocal microscopy to determine mechanisms of uptake, the organelle localization, and the duration they can be detected in situ. We show that C70-TR are nonspecifically endocytosed into MCs, where they are shuttled throughout the cytoplasm, lysosomes, mitochondria, and into endoplasmic reticulum at different times. No nuclear or secretory granule localization was observed. The C70-TR remained detectable within cells at 1 week. These studies show that MCs endocytose fullerenes, where they are shuttled to organelles involved with calcium and reactive oxygen species production, which may explain their efficacy as cellular inhibitors.

Nanotopographical modification: a regulator of cellular function through focal adhesions - Corrected Proof

Manus Jonathan Paul Biggs, R. Geoff Richards, Matthew J. Dalby — 2010-02-05

Abstract: As materials technology and the field of biomedical engineering advances, the role of cellular mechanisms, in particular adhesive interactions with implantable devices, becomes more relevant in both research and clinical practice. A key tenet of medical device design has evolved from the exquisite ability of biological systems to respond to topographical features or chemical stimuli, a process that has led to the development of next-generation biomaterials for a wide variety of clinical disorders. In vitro studies have identified nanoscale features as potent modulators of cellular behavior through the onset of focal adhesion formation. The focus of this review is on the recent developments concerning the role of nanoscale structures on integrin-mediated adhesion and cellular function with an emphasis on the generation of medical constructs with regenerative applications.

β-casein–based nanovehicles for oral delivery of chemotherapeutic drugs: drug-protein interactions and mitoxantrone loading capacity - Corrected Proof

Alina Shapira, Gilad Markman, Yehuda G. Assaraf, Yoav D. Livney — 2010-01-25

Abstract: β-casein (β-CN), a major milk protein, is amphiphilic and self-associates into micelles in aqueous solutions. We have recently introduced a novel oral drug delivery system based on β-CN nanoparticles. The current research builds on and complements this work by studying the interactions of mitoxantrone (MX) and β-CN as they co-assemble into nanoparticles, using absorption and emission spectra, static and dynamic light scattering, and fluorescent emission of both MX and tryptophan 143 (Trp143) of β-CN. The optimal loading molar ratio was 3.3 MX/β-CN at 1 mg/mL β-CN, and the association constant was (2.45 ± 1.76) × 105 M–1 based on β-CN Trp143 fluorescence; independent MX fluorescence results provided supporting values. In these conditions a bimodal particle distribution was obtained (174.4 nm, 45.9%; 485.1 nm, 54.1%). The gastric digestibility of β-CN suggests possible targeting to stomach tumors. Hence, β-CN nanoparticles have potential to serve as effective vehicles of hydrophobic drugs for oral delivery preparations.

Enhanced transdermal delivery of an anti-HIV agent via ethanolic liposomes - Corrected Proof

Vaibhav Dubey, Dinesh Mishra, Manoj Nahar, Vikas Jain, Narendra Kumar Jain — 2010-01-20

Abstract: Indinavir, as a protease inhibitor with a short biological half life, variable pH-dependent oral absorption, and extensive first-pass metabolism, presents a challenge with respect to its oral administration. The current work aims to formulate and characterize indinavir-bearing ethanolic liposomes (ethosomes), and to investigate their enhanced transdermal delivery potential. The prepared ethanolic liposomes were characterized to be spherical, unilamellar structures having low polydispersity, nanometric size range, and improved entrapment efficiency over other delivery formulations. Permeation studies of indinavir across human cadaver skin resulted in enhanced transdermal flux from ethanolic liposomes that was significantly (P < 0.05) greater than that with ethanolic drug solution, conventional liposomes, or plain drug solution. Additionally, the ethanolic liposomes showed the shortest lag time for indinavir, thus presenting a suitable approach for transdermal delivery of this protease inhibitor.

Nanotechnology-based manipulation of dendritic cells for enhanced immunotherapy strategies - Corrected Proof

Rebecca Klippstein, David Pozo — 2010-01-18

Abstract: Dendritic cells (DCs) are potent antigen-presenting cells capable of initiating a primary immune response and possess the ability to activate T cells and stimulate the growth and differentiation of B cells. DCs provide a direct connection between innate and adaptive immune response, and arise from bone marrow precursors that are present in immature forms in peripheral tissues, where they are prepared to capture antigens. DCs migrate from the peripheral tissues to the closest lymph nodes through afferent lymphatic vessels to present the foreign antigens, stimulating T-cell activation and initiating a cellular immune response. Moreover, it is known that DCs have an important role in various diseases and conditions involving the immune system, particularly in cancer and autoimmune disorders. For these reasons, targeting nanoparticles (NPs) to DCs provides a promising strategy for developing an efficient balanced and protective immune response. NPs can modulate the immune response and might be potentially useful as effective vaccine adjuvants for infectious disease and cancer therapy. The objective of this review is to present the latest advances in NP delivery methods targeting DCs, the mechanisms of action, potential effects, and therapeutic results of these systems and their future applications, such as improved vaccination strategies, cancer immunotherapy, and immunomodulatory treatments.

Poly(citric acid)-block-poly(ethylene glycol) Copolymers; New Candidates for Nanomedicine - Accepted Manuscript

Ashkan Tavakoli Naeini, Mohsen Adeli, Manouchehr Vossoughi — 2010-01-13

Abstract: Linear-dendritic ABA triblock copolymers containing poly(ethylene glycol) (PEG) as B block and hyperbranched poly(citric acid) (PCA) as A blocks were synthesized through polycondensation. The molecular self-assembly of synthesized PCA-PEG-PCA copolymers in water was led to nanoparticles and fibers in different sizes and shapes depend on the time and size of PCA blocks. Ten days after dissolving PCA-PEG-PCA copolymers in water, the size of fibers was reached to several millimeters. Mixing a water solution of fluorescein as a small guest molecule and PCA-PEG-PCA copolymers led to encapsulate fluorescein by products of molecular self-assembly. In order to investigate their potential application in nanomedicine and to understand the limitation and capability of these materials as nanoexcipients in biological systems, the different types of short-term in vitro cytotoxicity experiments on HT1080 cell line (human Fibrosarcoma) and hemocompatibility tests were performed.

Ag nanoparticles as a safe preservative for use in cosmetics - Accepted Manuscript

2010-01-08

Abstract: Concern is continuously raised regarding the safety of preservatives, which are crucial in most cosmetic preparations. The antimicrobial effects of silver (Ag) are well recognized; however, Ag has some limitations as a preservative, such as its interference with salts. In this study, we investigated the effects of recently synthesized Ag nanoparticles on microorganisms, the permeability of Ag nanoparticles in human skin, and the cytotoxicity of Ag nanoparticles in human keratinocytes under UVB-irradiation. Ag nanoparticles were found to be very stable, and they did not exhibit sedimentation for over one year. Ag nanoparticles showed sufficient preservation efficacy against mixed bacteria and mixed fungi, and did not penetrate normal human skin. At concentrations of 0.002 ppm~0.02 ppm, Ag nanoparticles had no effect on HaCaT keratinocytes, and did not enhance UVB-induced cell death. These results suggest that Ag nanoparticles are suitable for use as a preservative in cosmetics.

Delivery of amphotericin B nanosuspensions to the brain and determination of activity against Balamuthia mandrillaris amebas - Corrected Proof

Andreas Lemke, Albrecht F. Kiderlen, Boris Petri, Oliver Kayser — 2010-01-08

Abstract: Amphotericin B was formulated as nanosuspensions to develop a nanoparticulate brain delivery system. Nanosuspensions were produced with different surfactant solutions by high-pressure homogenization and then characterized by laser diffractometry and photon correlation spectroscopy. Before in vitro and in vivo testing all nanosuspensions were investigated for protein adsorption by two-dimensional polyacrylamide gel electrophoresis to predict brain-targeting capacities. Selected nanosuspensions were tested for amebicidal activity against Balamuthia mandrillaris, an agent of lethal encephalitis. Our results indicate that nanosuspensions coated with polysorbate 80 and sodium cholate markedly increased drug brain delivery and inhibited the parasite in vitro, though less in vivo.

Time-dependent measure of a nanoscale force-pulse driven by the axonemal dynein motors in individual live sperm cells - Corrected Proof

Michael J. Allen, Robert E. Rudd, Mike W. McElfresh, Rod Balhorn — 2010-01-07

Abstract: Nanoscale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces is important to developing motile biomimetic nanodevices powered by biological motors for nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding and give rise to rhythmic beating. This force-generating action pushes the sperm cell through viscous media. Here we report new nanoscale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Using a modified atomic force microscope, single-cell recordings reveal discrete ∼50-ms pulses oscillating with amplitude 9.8 ± 2.6 nN independent of pulse frequency (3.5–19.5 Hz). The average work carried out by each cell is 4.6 × 10-16 J per pulse, equivalent to the hydrolysis of ∼5500 molecules of adenosine triphosphate. The mechanochemical coupling at each active dynein head is ∼2.2 pN per adenosine triphosphate molecule and ∼3.9 pN per dynein arm.

Identification of deregulated genes by single wall carbon-nanotubes in human normal bronchial epithelial cells - Accepted Manuscript

2010-01-07

Abstract: In order to identify genes affected by single-wall carbon-nanotubes (SWCNTs) in human normal lung cells, we compared the gene expression profile of human normal bronchial epithelial (HNBE) cells with those SWCNTs-treated cells. A cDNA microarray analysis consisting of 54 675 human genes revealed significant changes in the expression of 14 294 genes, with 7 029 genes being up-regulated and 7 265 being down-regulated. This comprehensive list of genes included those associated with cell cycle, apoptosis, cell survival, cell adhesion and motility, signal transduction and transcription regulator. Additional analysis of 19 genes using reverse transcription (RT)-PCR supported the reliability of the microarray analysis. More specifically, our study demonstrates, for the first time, evidence that Rho GTPase-26, GTP binding protein-2, Protein phosphatase-1, Inhibin beta-E, Growth differentiation factor-15, Activating transcription factor-3 and Forkhead-a2 are up-regulated in the SWCNTs-treated HNBE cells compared to untreated cells; while Serpin peptidase inhibitor-4, Chemokine-11, Kinesins (14, 15 and 20A), Leupaxin, Repetin and Hyaluronan-mediated motility receptor are down-regulated in SWCNTs-treated HNBE cells in comparison with their control cells. These findings provide a large body of information regarding gene expression profiles associated with SWCNTs exposure in human lung bronchial epithelial cells, and also represent a source to investigate the mechanism of the effect of SWCNTs in human normal lung cells.