Integrated nanotechnology platform for tumor-targeted multimodal imaging and therapeutic cargo release.

A major challenge of targeted molecular imaging and drug delivery in cancer is establishing a functional combination of ligand-directed cargo with a triggered release system. Here we develop a hydrogel-based nanotechnology platform that integrates tumor targeting, photon-to-heat conversion, and triggered drug delivery within a single nanostructure to enable multimodal imaging and controlled release of therapeutic cargo. In proof-of-concept experiments, we show a broad range of ligand peptide-based applications with phage particles, heat-sensitive liposomes, or mesoporous silica nanoparticles that self-assemble into a hydrogel for tumor-targeted drug delivery. Because nanoparticles pack densely within the nanocarrier, their surface plasmon resonance shifts to near-infrared, thereby enabling a laser-mediated photothermal mechanism of cargo release. We demonstrate both noninvasive imaging and targeted drug delivery in preclinical mouse models of breast and prostate cancer. Finally, we applied mathematical modeling to predict and confirm tumor targeting and drug delivery. These results are meaningful steps toward the design and initial translation of an enabling nanotechnology platform with potential for broad clinical applications.

Predictors of Left Ventricle Remodeling: Combined Plasma B-type Natriuretic Peptide Decreasing Ratio and Peak Creatine Kinase-MB.

Background: Previous studies reported that patients who had an acute myocardial infarction (AMI) have found that measuring B-type natriuretic peptide (BNP) during the subacute phase of left ventricular (LV) remodeling can predict the possible course of LV remodeling. This study assessed the use of serial BNP serum levels combined with early creatine kinase-MB (CK-MB) to predict the development of significant LV remodeling in AMI patients. Methods: Nighty-seven patients with new onset AMI were assessed using serial echocardiographic studies and serial measurements of BNP levels, both performed on day-2 (BNP1), day-7 (BNP2), day-90 (BNP3), and day-180 (BNP4) after admission. LV remodeling was defined as >20% increase in biplane LV end-diastolic volume on day-180 compared to baseline (day-2). Results: Patients were divided into LV remodeling [LVR(+)] and non LV remodeling [LVR(-)] groups. No first-week BNP level was found to predict remodeling. However, the two groups had significantly different day-90 BNP level (208.1 ± 263.7 pg/ml vs. 82.4 ± 153.7 pg/ml, P = 0.039) and significantly different 3-month BNP decrease ratios ( R BNP13) (14.4 ± 92.2% vs. 69.4 ± 25.9%, P < 0.001). The appropriate cut-off value for R BNP13 was 53.2% (AUC = 0.764, P < 0.001). Early peak CK-MB (cut-off 48.2 ng/ml; AUC = 0.672; P = 0.014) was another independent predictor of remodeling. Additionally, combining peak CK-MB and R BNP13 offered an excellent discrimination for half-year remodeling when assessed by ROC curve (AUC = 0.818, P < 0.001). Conclusion: R BNP13 is a significant independent predictor of 6-month LV remodeling. The early peak CK-MB additionally offered an incremental power to the predictions derived from serial BNP examinations.

Porous ice phases with VI and distorted VII structures constrained in nanoporous silica.

High-pressure compression of water contained in nanoporous silica allowed fabrication of novel porous ice phases as a function of pressure. The starting liquid nanoporous H2O transformed to ice VI and VII at 1.7 and 2.5 GPa, respectively, which are 0.6 and 0.4 GPa higher than commonly accepted pressures for bulk H2O. The continuous increase of pressure drives the formation of a tetragonally distorted VII structure with the space group I4mm, rather than a cubic Pn3m phase in bulk ice. The enhanced incompressibility of the tetragonal ice is related to the unique nanoporous configuration, and the distortion ratio c/a gradually increases with increasing pressure. The structural changes and enhanced thermodynamic stability may be interpreted by the two-dimensional distribution of silanol groups on the porous silica surfaces and the associated anisotropic interactions with H2O at the interfaces.

A Ratiometric Fluorescent Sensor for Penicillin G Based on Color-Tunable Gold-Silver Nanoclusters.

Excessive administration of penicillin G and improper disposal of its residues pose a serious risk to human health; therefore, the development of convenient methods for monitoring penicillin G levels in products is essential. Herein, novel gold-silver nanoclusters (AuAgNCs) were synthesized using chicken egg white and 6-aza-2-thiothymine as dual ligands with strong yellow fluorescence at 509 and 689 nm for the highly selective detection of penicillin G. The AuAgNCs were characterized using transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible absorption spectrophotometry, and fluorescence spectrophotometry. Under optimum conditions, the fluorescence intensity decreased linearly with the concentration of penicillin G from 0.2 to 6 µM, with a low detection limit of 18 nM. Real sample analyses indicated that a sensor developed using the AuAgNCs could detect penicillin G in urine and water samples within 10 min, with the recoveries ranging from 99.7 to 104.0%. The particle size of the AuAgNCs increased from 1.80 to 9.06 nm in the presence of penicillin G. We believe the aggregation-induced quenching of the fluorescence of the AuAgNCs was the main mechanism for the detection of penicillin G. These results demonstrate the ability of our sensor for monitoring penicillin G levels in environmental and clinic samples.

Re-examining the size/charge paradigm: differing in vivo characteristics of size- and charge-matched mesoporous silica nanoparticles.

The combination of nanoparticle (NP) size, charge, and surface chemistry (e.g., extent of modification with polyethylene glycol (PEG)) is accepted as a key determinant of NP/cellular interactions. However, the influence of spatial arrangement and accessibility of the charged molecules on the NP surface vis-à-vis the average surface charge (zeta (ζ) potential) is incompletely understood. Here we demonstrate that two types of mesoporous silica nanoparticles (MSNP) that are matched in terms of primary and hydrodynamic particle size, shape, pore structure, colloidal stability, and ζ potential, but differ in surface chemistry, viz. the spatial arrangement and relative exposure of surface amines, have profoundly different interactions with cells and tissues when evaluated in vitro and in vivo. While both particles are ∼50 nm in diameter, PEGylated, and positively charged (ζ = +40 mV), PEG-PEI (MSNPs modified with exposed polyamines), but not PEG-NMe3(+) (MSNP modified with distributed, obstructed amines) rapidly bind serum proteins, diverse cells types in vitro, and endothelial and white blood cells in vivo (ex ovo chick embryo model). This finding helps elucidate the relative role of surface exposure of charged molecules vs ζ potential in otherwise physicochemically matched MSNP and highlights protein corona neutrality as an important design consideration when synthesizing cationic NPs for biological applications.

Electrochemically synthesized green fluorescent carbon dots for quantitation of hypochlorite and carbendazim.

Green emission carbon dots (CDs) electrochemically prepared from 2,6-pyridinedicarboxylic acid and o-phenyl-enediamine were applied separately for the quantitation of hypochlorite and carbendazim. The characteristic and optical properties of the CDs were studied through fluorescence, UV-vis absorption, X-ray photoelectron spectroscopy, and transmission electron microscopy. The synthesized CDs were mainly 0.8-2.2 nm in size, with an average size of 1.5 nm. The CDs exhibited green luminescence centered at 520 nm when excited by 420 nm light. The green emission of the CDs is quenched after the addition of hypochlorite, mainly through the redox reaction between hypochlorite and hydroxyl groups on the CDs surface. Furthermore, the hypochlorite-induced fluorescence quenched can be prevented in the presence of carbendazim. The sensing approaches exhibit good linear ranges of 1-50 µM and 0.05-5 µM for hypochlorite and carbendazim, respectively, with low detection limits of 0.096 and 0.005 µM, respectively. Practicalities of the luminescent probes were separately validated by the quantitation of the two analytes in real sample matrix with recoveries ranging from 96.3 to 108.9% and the relative standard deviation values below 5.51%. Our results show the potential of the sensitive, selective, and simple CD probe for water and food quality control.

Ultrastable, redispersible, small, and highly organomodified mesoporous silica nanotherapeutics.

Practical biomedical application of mesoporous silica nanoparticles is limited by poor particle dispersity and stability due to serious irreversible aggregation in biological media. To solve this problem, hydrothermally treated mesoporous silica nanoparticles of small size with dual-organosilane (hydrophilic and hydrophobic silane) surface modification have been synthesized. These highly organomodified mesoporous silica nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, N(2) adsorption-desorption, dynamic light scattering, zeta potential, and solid-state (29)Si NMR, and they prove to be very stable in simulated body fluid at physiological temperature. Additionally, they can be dried to a powdered solid and easily redispersed in biological media, maintaining their small size for a period of at least 15 days. Furthermore, this preparation method can be expanded to synthesize redispersible fluorescent and magnetic mesoporous silica nanoparticles. The highly stable and redispersible mesoporous silica NPs show minimal toxicity during in vitro cellular assays. Most importantly, two types of doxorubicin, water-soluble doxorubicin and poorly water-soluble doxorubicin, can be loaded into these highly stable mesoporous silica nanoparticles, and these drug-loaded nanoparticles can also be well-redispersed in aqueous solution. Enhanced cytotoxicity to cervical cancer (HeLa) cells was found upon treatment with water-soluble doxorubicin-loaded nanoparticles compared to free water-soluble doxorubicin. These results suggest that highly stable, redispersible, and small mesoporous silica nanoparticles are promising agents for in vivo biomedical applications.

On-chip evaluation of shear stress effect on cytotoxicity of mesoporous silica nanoparticles.

In this work, nanotoxicity in the bloodstream was modeled, and the cytotoxicity of sub-50 nm mesoporous silica nanoparticles to human endothelial cells was investigated under microfluidic flow conditions. Compared to traditional in vitro cytotoxicity assays performed under static conditions, unmodified mesoporous silica nanoparticles show higher and shear stress-dependent toxicity to endothelial cells under flow conditions. Interestingly, even under flow conditions, highly organo-modified mesoporous silica nanoparticles show no significant toxicity to endothelial cells. This paper clearly demonstrates that shear stress is an important factor to be considered in in vitro nanotoxicology assessments and provides a simple device for pursuing this consideration.

Proposed A2C2S2-VASc score for predicting atrial fibrillation development in patients with atrial flutter.

AIMS: The clinical outcome and threshold of oral anticoagulation differs between patients with solitary atrial flutter (AFL) and those with AFL developing atrial fibrillation (AF) (AFL-DAF). We therefore investigated previously unevaluated predictors of AF development in patients with AFL, and also the predictive values of risk scores in predicting the occurrence of AF and ischaemic stroke. METHODS AND RESULTS: Participants were those diagnosed with AFL between 1 January 2001 and 31 December 2013. Patients were classified into solitary AFL and AFL-DAF groups during follow-up. Finally, 4101 patients with solitary AFL and 4101 patients with AFL-DAF were included after 1:1 propensity score matching with CHA2DS2-VASc scores and their components, AFL diagnosis year and other comorbidities. The group difference in the prevalence of ischaemic stroke/transient ischaemic attack (TIA) and congestive heart failure (CHF) was substantial, that of vascular disease was moderate, and that of diabetes and hypertension was negligible. Therefore, we reweighted the component of heart failure as 2 (the same with stroke/TIA) and vascular disease as 1 in the proposed A2C2S2-VASc score. The proposed A2C2S2-VASc and CHA2DS2-VASC scores showed patients with AFL who had higher delta scores and follow-up scores had higher risk of AF development. The delta score outperformed the follow-up score in both scoring systems in predicting ischaemic stroke. CONCLUSION: This study showed that new-onset CHF, stroke/TIA and vascular disease were predictors of AF development in patients with AFL. The dynamic score and changes in both CHA2DS2-VASC and the proposed A2C2S2-VASc score could predict the development of AF and ischaemic stroke.

Impacts of mesoporous silica nanoparticle size, pore ordering, and pore integrity on hemolytic activity.

This paper uses the measure of hemolysis to evaluate the toxicity of nonporous and porous silica nanoparticles with varied sizes and investigates the effects of porous structure and integrity on the nanoparticle-cell interaction. The results show that both nonporous and porous silica cause red blood cell membrane damage in a concentration- and size-dependent manner. In the case of mesoporous silica nanoparticles, the size-dependent hemolysis effect is only present when the nanoparticles have long-range ordered porous structure, revealing that pore structure is critical in cell-nanoparticle interactions. Mesoporous silica nanoparticles show lower hemolytic activity than their nonporous counterparts of similar size, likely due to fewer silanol groups on the cell-contactable surface of the porous silica nanoparticles. The extent of hemolysis by mesoporous silica nanoparticles increases as the pore structure is compromised by mild aging in phosphate-buffered solutions, initiating mesopore collapse. The pore integrity of mesoporous silica nanoparticles is examined by TEM, XRD, N(2) adsorption-desorption isotherms, and quantification of dissolved silica. In these nanoparticles, pore stability is clearly an important factor in determining the hemolytic activity; further work demonstrates that nanoparticle-induced hemolysis can be eliminated by modifying the silanol surface with a poly(ethylene glycol) coating.

Female sex as a risk factor for ischaemic stroke varies with age in patients with atrial fibrillation.

OBJECTIVES: Female sex is an inconsistent ischaemic stroke risk factor in patients with atrial fibrillation (AF). We hypothesised that the ischaemic stroke risk varies with age among women compared with men. METHODS: We retrieved the patients with newly diagnosed AF during 2001-2013 from Taiwan's National Health Insurance Research Database. Patients with missing information, age <20 years, history of valvular heart disease and surgery, rheumatic heart disease, hyperthyroidism or anticoagulation and/or antiplatelet use were excluded. Propensity score matching (PSM) included patient comorbidities, medications and index date stratified by age and sex groups. Primary outcome was defined as ischaemic stroke at follow-up. RESULTS: After exclusion criteria, 87 369 men and 71 853 women remained for analysis (aged 73.1±14.4 years). After 1:1 PSM, we included 59 583 men (aged 73.5±13.7 years) and 59 583 women (aged 73.4±13.8 years) for analysis. We also stratified patients by age. The ischaemic stroke risk varied with age in women compared with men: lower in the ≤55 years (subdistribution HR (SHR)=0.75, 95% CI 0.62 to 0.90) and 56-65 years (SHR=0.87, 95% CI 0.78 to 0.98) groups, neutral in the 66-75 years group (SHR=1.01, 95% CI 0.94 to 1.08) and adverse in the >75 years group (SHR=1.14, 95% CI 1.09 to 1.19). CONCLUSIONS: The female/male ischaemic stroke risk ratio varied with age. Only women aged >75 years had a higher risk, whereas women aged <65 years had a lower risk compared with men. These findings challenge the 'sex category' component of the CHA2DS2-VASc score, used to make decision regarding anticoagulation treatment in AF patients.

Uniform mesoporous silica hexagon and its two-dimensional colloidal crystal.

Well-ordered mesoporous silica nanoparticles with uniform hexagonal disk shapes are synthesized under dilute alkaline conditions with a two-step process, separating the nucleation and growth process. The resulting monodisperse hexagons can be arranged in a 2-dimensional (2D) ordered periodical super-structure. The hexagonal symmetry is similar in both scales. A statistical mechanical cell model is applied to analyze consequences of the interesting packing structure, including osmotic bulk modulus, phase separation and defects.

Synthesis of hollow silica nanospheres with a microemulsion as the template.

We demonstrate a sol-gel approach, using a water-in-oil microemulsion as the template, for the synthesis of hollow and yolk/shell silica nanospheres, which can encapsulate pre-formed hydrophobic nanoparticles, and we then explore these multifunctional hollow nanospheres in cell-labeling applications.

The functional assessment of Alpinia pricei on metabolic syndrome induced by sucrose-containing drinking water in mice.

This study was designed to test whether Alpinia pricei (AP), a member of the ginger family indigenous to Taiwan, reduced metabolic syndrome induced by sucrose-containing drinking water in C57BL/6J mice. Mice given a chow diet were divided into a control group (C) or a test group given 30% sucrose water (SW) to drink ad libitum. After 22 weeks, mice in the SW group were subdivided into SW and SW + AP groups, the latter receiving a chow diet with an ethanol extract of AP (1500 mg/kg dosage). Four weeks later, bio-indexes associated with metabolic syndrome were measured. Compared with the C group, the SW group had significantly higher body weight, visceral fat weights, serum and tissue lipid, serum insulin level and the area under the curve for blood glucose of the insulin tolerance test (p < 0.05). These indicators in the SW + AP group were lower than in the SW group except for serum lipid, although slightly higher than the C group. The SW + AP group also showed significantly lower serum levels of leptin and tumor necrosis factor-alpha and a significantly higher level of adiponectin than the SW group. These results indicated that visceral adiposity and insulin resistance induced by sucrose water drinking might be alleviated by AP supplementation.

Impact on drug cost and use of Medicare part D of medication therapy management services delivered in 2007.

OBJECTIVE: To describe experiences with medication therapy management (MTM) services delivered to benefciaries of Mirixa's health plan clients. SETTING: United States during 2007. PRACTICE DESCRIPTION: Three intervention modalities were offered to provide MTM services: community pharmacy, pharmacist-staffed call centers, and educational mailings. Available data were analyzed to identify any differences among patients receiving any of the three interventions. Patients included in the analysis were those who qualifed for MTM services between April 1, 2007, and June 30, 2007. MTM services were provided for these patients between May 1, 2007, and December 31, 2007. PRACTICE INNOVATION: The MirixaPro platform was created to document the activities associated with the five core elements of an MTM service (medication therapy review, creation of a personal medication record, creation of a medication-related action plan [MAP], intervention and/or referral, and documentation and follow-up). It provides a framework for capturing safety interventions, follow-ups with prescribers, and pharmacist instructions to the patients. MAIN OUTCOME MEASURES: Part D drug costs, use, and generic dispensing ratio in the pre- and post-MTM periods. RESULTS: 21,336 patients received MTM services from a community pharmacist (face to face, 9,140; by phone, 12,196), 3,436 patients received MTM services from a call center pharmacist, and 49,021 patients received an educational mailing. Patients who had a face-to-face session had a decline in mean monthly drug costs of $29 (from $658 to $629), while drug costs decreased by $40 (from $677 to $637) when the community pharmacist provided the services over the telephone. Mean monthly drug costs decreased by $15 (from $676 to $661) for patients receiving MTM services from a call center pharmacist and did not change for patients receiving an educational mailing ($698 in both periods). CONCLUSION: Among patients who received MTM services in 2007, drug costs decreased for those who received service from community pharmacists, decreased somewhat for patients who received service from a call center pharmacist, and were unchanged for those who received MTM via mailing. Further studies are needed to assess the effect of various types of MTM interventions on fnancial, clinical, and humanistic outcomes.

Cell-Templated Silica Microparticles with Supported Lipid Bilayers as Artificial Antigen-Presenting Cells for T Cell Activation.

Biomaterial properties that modulate T cell activation, growth, and differentiation are of significant interest in the field of cellular immunotherapy manufacturing. In this work, a new platform technology that allows for the modulation of various activation particle design parameters important for polyclonal T cell activation is presented. Artificial antigen presenting cells (aAPCs) are successfully created using supported lipid bilayers on various cell-templated silica microparticles with defined membrane fluidity and stimulating antibody density. This panel of aAPCs is used to probe the importance of activation particle shape, size, membrane fluidity, and stimulation antibody density on T cell outgrowth and differentiation. All aAPC formulations are able to stimulate T cell growth, and preferentially promote CD8+ T cell growth over CD4+ T cell growth when compared to commercially available pendant antibody-conjugated particles. T cells cultured with HeLa- and red blood cell-templated aAPCs have a less-differentiated and less-exhausted phenotype than those cultured with spherical aAPCs with matched membrane coatings when cultured for 14 days. These results support continued exploration of silica-supported lipid bilayers as an aAPC platform.

Mesoporous silica nanoparticles improve magnetic labeling efficiency in human stem cells.

Tumblerlike magnetic/fluorescein isothiocyanate (FITC)-labeled mesoporous silica nanoparticles, Mag-Dye@MSNs, have been developed, which are composed of silica-coated core-shell superparamagnetic iron oxide (SPIO@SiO(2)) nanoparticles co-condensed with FITC-incorporated mesoporous silica. Mag-Dye@MSNs can label human mesenchymal stem cells (hMSCs) through endocytosis efficiently for magnetic resonance imaging (MRI) in vitro and in vivo, as manifested by using a clinical 1.5-T MRI system with requirements of simultaneous low incubation dosage of iron, low detection cell numbers, and short incubation time. Labeled hMSCs are unaffected in their viability, proliferation, and differentiation capacities into adipocytes and osteocytes, which can still be readily detected by MRI. Moreover, a higher MRI signal intensity decrease is observed in Mag-Dye@MSN-treated cells than in SPIO@SiO(2)-treated cells. This is the first report that MCM-41-type MSNs are advantageous to cellular uptake, as manifested by a higher labeling efficiency of Mag-Dye@MSNs than SPIO@SiO(2).

Understanding the Connection between Nanoparticle Uptake and Cancer Treatment Efficacy using Mathematical Modeling.

Nanoparticles have shown great promise in improving cancer treatment efficacy while reducing toxicity and treatment side effects. Predicting the treatment outcome for nanoparticle systems by measuring nanoparticle biodistribution has been challenging due to the commonly unmatched, heterogeneous distribution of nanoparticles relative to free drug distribution. We here present a proof-of-concept study that uses mathematical modeling together with experimentation to address this challenge. Individual mice with 4T1 breast cancer were treated with either nanoparticle-delivered or free doxorubicin, with results demonstrating improved cancer kill efficacy of doxorubicin loaded nanoparticles in comparison to free doxorubicin. We then developed a mathematical theory to render model predictions from measured nanoparticle biodistribution, as determined using graphite furnace atomic absorption. Model analysis finds that treatment efficacy increased exponentially with increased nanoparticle accumulation within the tumor, emphasizing the significance of developing new ways to optimize the delivery efficiency of nanoparticles to the tumor microenvironment.

Establishing the effects of mesoporous silica nanoparticle properties on in vivo disposition using imaging-based pharmacokinetics.

The progress of nanoparticle (NP)-based drug delivery has been hindered by an inability to establish structure-activity relationships in vivo. Here, using stable, monosized, radiolabeled, mesoporous silica nanoparticles (MSNs), we apply an integrated SPECT/CT imaging and mathematical modeling approach to understand the combined effects of MSN size, surface chemistry and routes of administration on biodistribution and clearance kinetics in healthy rats. We show that increased particle size from ~32- to ~142-nm results in a monotonic decrease in systemic bioavailability, irrespective of route of administration, with corresponding accumulation in liver and spleen. Cationic MSNs with surface exposed amines (PEI) have reduced circulation, compared to MSNs of identical size and charge but with shielded amines (QA), due to rapid sequestration into liver and spleen. However, QA show greater total excretion than PEI and their size-matched neutral counterparts (TMS). Overall, we provide important predictive functional correlations to support the rational design of nanomedicines.

The effect of surface charge on the uptake and biological function of mesoporous silica nanoparticles in 3T3-L1 cells and human mesenchymal stem cells.

Cellular uptake of nanoparticles for stem cell labeling/tracking is considered as the most promising method. Recently mesoporous silica nanoparticles (MSNs) are emerging as an idea agent for efficient stem cell labeling. The objective of this study was to evaluate the effect of surface charge on the highly efficient cellular uptake and in vitro cytotoxicity of MSNs in human mesenchymal stem cells (hMSCs). The surface charge was varied by the degree of surface modification with N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride and the uptake of MSNs was detected by flow cytometry. 3T3-L1 cells were also used to compare the uptake behavior of MSNs between cell types. A clear correlation of positive surface charge and the number of fluorescence-labeled cells was mainly observed in 3T3-L1 cells. In both cells, uptake of unmodified MSNs was inhibited by phenylarsine oxide (PAO) and cytochalasin D (Cyt D) suggesting a clathrin- and an actin-dependent endocytosis were involved. With strongly positive-charged MSNs, the inhibitory effects were observed in 3T3-L1 cells but not in hMSCs. Without regard to the surface charge, uptake of MSNs into both cells did not affect their viability, proliferation, and differentiation. Our results show that MSNs uptake by hMSCs can be regulated by a threshold of positive surface charge but also imply that the modulation of surface charge on MSNs uptake is specific to cell type.