Search

Abstract Background NAD(P)-dependent steroid dehydrogenase-like protein (NSDHL), which is involved in breast tumor growth and metastasis, has been implicated in the maintenance of cancer stem cells. However, its role in regulating breast cancer stem-like cells (BCSCs) remains unclear. We have previously reported the clinical significance of NSDHL in patients with estrogen receptor-positive (ER +) breast cancer. This study aimed to elucidate the molecular mechanisms by which NSDHL regulates the capacity of BCSCs in the ER + human breast cancer cell line, MCF-7. Methods NSDHL knockdown suppressed tumor spheroid formation in MCF-7 human breast cancer cells grown on ultralow-attachment plates. RNA sequencing revealed that NSDHL knockdown induced widespread transcriptional changes in the MCF-7 spheroids. TGF-β signaling pathway was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway (fold change ≥ 2, P ≤ 0.05) identified in NSDHL-knockdown MCF-7 spheroids compared with the control. In orthotopic tumor models injected with NSDHL-knockdown MCF-7 spheroids, tumor initiation and growth were strongly suppressed compared with those in the control. Results BCSC populations with CD44+/CD24- and CD49f+/EpCAM + phenotypes and high ALDH activity were decreased in NSDHL-knockdown MCF-7 spheroids and xenograft tumors relative to controls, along with decreased secretion of TGF-β1 and 3, phosphorylation of Smad2/3, and expression of SOX2. In RNA-sequencing data from The (TCGA) database, a positive correlation between the expression of NSDHL and SOX2 was found in luminal-type breast cancer specimens (n = 998). Our findings revealed that NSDHL plays an important role in maintaining the BCSC population and tumor-initiating capacity of ER-positive MCF-7 spheroids, suggesting that NSDHL is an attractive therapeutic target for eliminating BCSCs, thus preventing breast cancer initiation and progression. Conclusions Our findings suggest that NSDHL regulates the BCSC/tumor-initiating cell population in MCF-7 spheroids and xenograft tumors.

The tumor microenvironment (TME) has a crucial role in tumor development, metastasis, and recurrence. The chaotic and complex physical structure of the TME not only limits drug delivery but also contributes to the development of resistance to immunotherapy. Breaking the physical barrier limitation of the TME could further optimize the existing tumor treatment protocols. Physical stimulation, such as ionizing radiation, light, electricity, magnetic field, and ultrasound, modulate the TME by altering tumor vasculature, remodeling the extracellular matrix, and activating immune responses to achieve the goal of adjuvant to other tumor therapeutic approaches. In addition to adjuvant chemotherapy and immunotherapy, these physical stimulations also enhance the efficacy of other physical treatments for cancer. In this review we discuss the structural characteristics of TME and focus on the modulation of TME by different physical stimulations. We also analyze the adjuvant effects of these stimulations on other tumor therapies.

Abstract Background Heterogeneous tumor cells are thought to be a significant factor in the failure of endocrine therapy in estrogen receptor-positive (ER+) cancers. Culturing patient-derived breast cancer cells (PDBCCs) provides an invaluable tool in pre-clinical and translational research for the heterogeneity of cancer cells. This study aimed to investigate the effects of different media components and culture methods on the BCSC-associated immunophenotypes and gene expression in ER + PDBCCs. Methods Ten patients with ER + breast cancer were employed in this study, six of whom had neoadjuvant chemotherapy and four of whom did not. PDBCCs were isolated by enzymatic methods using collagen I and hyaluronidase. PDBCCs were grown as monolayers in mediums with different compositions and as multicellular spheroid in a suspended condition. Collagen I-coated plate and ultralow attachment plate coated with polymer-X were used for monolayer and spheroid culture. Flow cytometry, immunofluorescent staining, RT-PCR, and RNA-sequencing were employed to examine the immunophenotype and genetic profile of PDBCCs. Results More than 95% of PDBCCs sustain EpCAM high/+/fibroblast marker- phenotypes in monolayer conditions by subculturing 3–4 times. A83-01 removal induced senescent cells with high β-galactosidase activity. PDBCCs grown as monolayers were characterized by the majority of cells having an EpCAM+/CD49f + phenotype. Compared to full media in monolayer culture, EGF removal increased EpCAM+/CD49f − phenotype (13.8-fold, p = 0.028), whereas R-spondin removal reduced it (0.8-fold, p = 0.02). A83-01 removal increased EpCAM+/CD24 + phenotype (1.82-fold, p = 0.023) and decreased EpCAM low/-/CD44+/CD24- phenotype (0.45-fold, p = 0.026). Compared to monolayer, spheroid resulted in a significant increase in the population with EpCAM-/CD49+ (14.6-fold, p = 0.006) and EpCAM low/-/CD44+/CD24- phenotypes (4.16-fold, p = 0.022) and ALDH high activity (9.66-fold, p = 0.037). ALDH1A and EMT-related genes were upregulated. In RNA-sequencing analysis between spheroids and monolayers, a total of 561 differentially expressed genes (2-fold change, p

Allogeneic stem cell transplantation is a curative immunotherapy where patients receive myeloablative chemotherapy and/or radiotherapy, followed by donor stem cell transplantation. Graft versus host disease (GVHD) is a major complication caused by dysregulated donor immune system, thus a novel strategy to modulate donor immunity is needed to mitigate GVHD. Tissue damage by conditioning regimen is thought to initiate the inflammatory milieu that recruits various donor immune cells for cross-priming of donor T cells against alloantigen and eventually promote strong Th1 cytokine storm escalating further tissue damage. Bilirubin nanoparticles (BRNP) are water-soluble conjugated of bilirubin and polyethylene glycol (PEG) with potent anti-inflammatory properties through its ability to scavenge reactive oxygen species generated at the site of inflammation. Here, we evaluated whether BRNP treatment post-transplantation can reduce initial inflammation and subsequently prevent GVHD in a major histocompatibility (MHC) mismatched murine GVHD model. After myeloablative irradiation, BALB/c mice received bone marrow and splenocytes isolated from C57BL/6 mice, with or without BRNP (10 mg/kg) daily on days 0 through 4 post-transplantation, and clinical GVHD and survival was monitored for 90 days. First, BRNP treatment significantly improved clinical GVHD score compared to untreated mice (3.4 vs 0.3, p=0.0003), and this translated into better overall survival (HR 0.0638, p=0.0003). Further, BRNPs showed a preferential accumulation in GVHD target organs leading to a reduced systemic and local inflammation evidenced by lower pathologic GVHD severity as well as circulating inflammatory cytokines such as IFN-γ. Lastly, BRNP treatment post-transplantation facilitated the reconstitution of CD4+ iNK T cells and reduced expansion of proinflammatory CD8α+ iNK T cells and neutrophils especially in GVHD organs. Lastly, BRNP treatment decreased ICOS+ or CTLA-4+ T cells but not PD-1+ T cells suggesting a decreased level of T cell activation but maintaining T cell tolerance. In conclusion, we demonstrated that BRNP treatment post-transplantation ameliorates murine GVHD via diminishing the initial tissue damage and subsequent inflammatory responses from immune subsets.

Cancer stem-like cells (CSCs) are considered promising targets for anti-cancer therapy owing to their role in tumor progression. Extensive research is, therefore, being carried out on CSCs to identify potential targets for anti-cancer therapy. However, this requires the availability of patient-derived CSCs ex vivo, which remains restricted due to the low availability and diversity of CSCs. To address this limitation, a functional polymer thin-film (PTF) platform was invented to induce the transformation of cancer cells into tumorigenic spheroids. In this study, we demonstrated the functionality of a new PTF, polymer X, using a streamlined production process. Polymer X induced the formation of tumor spheroids with properties of CSCs, as revealed through the upregulated expression of CSC-related genes. Signal transducer and activator of transcription 3 (STAT3) phosphorylation in the cancer cells cultured on polymer X was upregulated by the fibronectin-integrin α5-Janus kinase 2 (JAK2) axis and maintained by the cytosolic LMO2/LBD1 complex. In addition, STAT3 signaling was critical in spheroid formation on polymer X. Our PTF platform allows the efficient generation of tumor spheroids from cancer cells, thereby overcoming the existing limitations of cancer research.

Abstract The tumor microenvironment (TME) plays a crucial role in tumorigenesis and cancer cell metastasis. Accordingly, a drug‐delivery system (DDS) that is capable of targeting tumor and releasing drugs in response to TME‐associated stimuli should lead to potent antitumor efficacy. Here, a cancer targeting, reactive oxygen species (ROS)‐responsive drug delivery vehicle as an example of a TME‐targeting DDS is reported. Tumor targeting is achieved using biotin as a ligand for “biotin transporter”–overexpressing malignant tumors, and bilirubin‐based nanoparticles (BRNPs) are used as a drug‐delivery carrier that enables ROS‐responsive drug release. Doxorubicin‐loaded, biotinylated BRNPs (Dox@bt‐BRNPs) with size of ≈100 nm are prepared by a one‐step self‐assembly process. Dox@bt‐BRNPs exhibit accelerated Dox‐release behavior in response to ROS and show specific binding as well as anticancer activity against biotin transporter–overexpressing HeLa cells in vitro. bt‐BRNPs labeled with cypate, near‐infrared dye, show much greater accumulation at tumor sites in HeLa tumor‐bearing mice than BRNPs lacking the biotin ligand. Finally, intravenous injection of Dox@bt‐BRNPs into HeLa tumor‐bearing mice results in greater antitumor efficacy compared with free Dox, bt‐BRNPs only, and Dox@BRNPs without causing any appreciable body weight loss. Collectively, these findings suggest that bt‐BRNPs hold potential as a new TME‐responsive DDS for effectively treating various tumors.

Nanomaterials offer new opportunities for cancer diagnosis and treatment. Multifunctional nanoparticles harboring various functions including targeting, imaging, therapy, and etc have been intensively studied aiming to overcome limitations associated with conventional cancer diagnosis and therapy. Of various nanoparticles, magnetic iron oxide nanoparticles with superparamagnetic property have shown potential as multifunctional nanoparticles for clinical translation because they have been used asmagnetic resonance imaging (MRI) constrast agents in clinic and their features could be easily tailored by including targeting moieties, fluorescence dyes, or therapeutic agents. This review summarizes targeting strategies for construction of multifunctional nanoparticles including magnetic nanoparticles-based theranostic systems, and the various surface engineering strategies of nanoparticles for in vivo applications.

Purpose: This study was performed to compare the cytotoxicity and magnetic resonance (MR) contrast in diverse cultured cells and xenograft tumors models of two ultra-small superparamagnetic iron oxides (USPIOs), thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) and monocrystalline iron oxide nanoparticles (MION-47).Materials and methods: Transmission electron microscopy (TEM) images and R2 relaxivity values of the TCL-SPION and MION-47 were obtained and the cell viability and cell growth velocity of treated and untreated human fibroblasts and human umbilical vein endothelial cells (HUVEC) were evaluated. The effect of TCL-SPION and MION-47 on the secretion of interlukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), the production of nitric oxides and the mitochondrial membrane potentials in murine macrophage cells (RAW264.7) was compared. Human hepatocellular carcinoma cells (HepG2, 5x105) were subcutaneously injected into nude mice (BALB/c) and in vivo MR imaging of tumors before and after injection with TCL-SPION or MION-47 (12.5 mg Fe/kg) was performed on a 1.5 Tesla MRI scanner.Results: On TEM images, the average core diameter of TCL-SPION was 9 nm whereas that of MION-47 was 5 nm. TCL- SPION (345.0 ± 6.2 mM-1sec-1) had higher relaxivity (R2) than MION-47 (130.7 ± 1.1 mM-1sec-1). Significant changes in cell viability and growth were not found in human fibroblasts and HUVEC exposed to TCL-SPION and MION-47. However, IL-6 and TNF-α secretions increased dose-dependently and significantly in the macrophages treated with MION-47 or TCL-SPION. TCL-SPION had a lower stimulatory effect on IL-6 secretions than did MION-47 (P in vivo MR imaging, 33.0 ± 1.3% and 7.5 ± 0.4% signal intensity decrease on T2*-weighted images was observed in the tumors injected with TCL-SPION and MION-47, respectively.Conclusion: Due to the modified surface properties and larger core size of its iron oxide nanoparticles, TCL-SPION achieves lower cytotoxicity and better tumor MR contrast than MION-47. Our study suggests that TCL-SPION may be used as a new platform for tumor imaging and therapy monitoring.

The fabrication and characterization of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) and their application to the dual imaging of cancer in vivo are described. The studies have shown that TCL-SPION does not bear any targeting ligands on its surface, but is highly effective for tumor detection in vivo by dual imaging.

A new computed tomography (CT) contrast agent based on gold nanoparticles (GNPs) that could be useful for a blood pool and hepatoma imaging is presented.

The fabrication and characterization of antifouling polymer-coated magnetic nanoparticles as nanoprobes for magnetic resonance (MR) contrast agents is reported. A random copolymer synthesized from (trimethoxysilyl)propyl methacylate and poly(ethylene) glycol methacrylate, that is poly(TMSMA-r-PEGMA), -coated superparamagnetic iron oxide nanoparticles (SPION) does not have any targeting ligands on their surface, but they are useful for cancer diagnosis in vivo.

The novel artificial ion channels based on CB[n] (n = 6 and 5) transport proton and alkali metal ions across a lipid membrane with ion selectivity. The novel ion channel system could be useful in applications such as drug discovery, detection of small molecules, ion separation, and construction of molecular devices.

Despite the appreciable success of synthetic nanomaterials for targeted cancer therapy in preclinical studies, technical challenges involving their large-scale, cost-effective production and intrinsic toxicity associated with the materials, as well as their inability to penetrate tumor tissues deeply, limit their clinical translation. Here, we describe biologically derived nanocarriers developed from a bioengineered yeast strain that may overcome such impediments. The budding yeast Saccharomyces cerevisiae was genetically engineered to produce nanosized vacuoles displaying human epidermal growth factor receptor 2 (HER2)-specific affibody for active targeting. These nanosized vacuoles efficiently loaded the anticancer drug doxorubicin (Dox) and were effectively endocytosed by cultured cancer cells. Their cancer-targeting ability, along with their unique endomembrane compositions, significantly enhanced drug penetration in multicellular cultures and improved drug distribution in a tumor xenograft. Furthermore, Dox-loaded vacuoles successfully prevented tumor growth without eliciting any prolonged immune responses. The current study provides a platform technology for generating cancer-specific, tissue-penetrating, safe, and scalable biological nanoparticles for targeted cancer therapy. [ABSTRACT FROM AUTHOR]

This study was investigated the change of concentration and toxicity of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) on tissues of Sprague-Dawley rats. TCL-SPION at the dose of 15 mg/kg body weight was intravenously injected into the tail vein of the male Sprague-Dawley rats. The fate of TCL-SPION in serum, urine and tissues was observed during 28 days. Serum iron level was maximal at 0.25 h post-injection and gradually declined thereafter. In addition, the sinusoids of liver and the red pulp area of spleen were mainly accumulated iron from 0.5 h to 28-day post-injection. In kidney, iron deposition was detected in the tubular area until 0.5 h after injection. Malondialdehyde concentration in the liver slightly increased with time and was not different with that at zero time. In the liver and spleen, TNF-α and IL-6 levels of TS treated with TCL-SPION were not different with those of the control during the experimental period. From the results, TCL-SPION could stay fairly long-time in certain tissues after intravenous injection without toxicity. The results indicated that TCL-SPION might be useful and safe as a contrast for the diagnosis of cancer or a carrier of therapeutic reagents to treat diseases. [ABSTRACT FROM AUTHOR]

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body. [ABSTRACT FROM AUTHOR]

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs) are widely used as T2-contrast agents for magnetic resonance imaging (MRI). Herein we develop various antibiofouling amphiphilic polymer-coated SPIONs using a one-step nanoemulsion method. This methodology yielded ultrasmall polymer-coated SPIONs, of average diameter less than 30 nm, which were stable under physiological conditions. In vitrocell cytotoxicity tests revealed that no SPION showed toxicity even at relatively high concentrations. In vivoMRI with Lewis lung carcinoma (LLC) tumor-bearing mice resulted in an approximately 30% T2 signal drop in tumor tissues, indicating that the SPIONs reached such tissues viapassive targeting. In summary, the ultrasmall, stable, amphiphilic polymer-coated SPIONs can be used as MRI contrast agents for cancer imaging. [ABSTRACT FROM AUTHOR]

Targeted uptake of therapeutic nanoparticles in a cell-, tissue-, or disease-specific manner represents a potentially powerful technology. Using prostate cancer as a model, we report docetaxel (Dtxl)-encapsulated nanoparticles formulated with biocompatible and biodegradable poly(D,L-lactic-co-glycolic acid)-block-poly(ethylene glycol) (PLGA-b-PEG) copolymer and surface functionalized with the A10 2'-fluoropyrimidine RNA aptamers that recognize the extracellular domain of the prostate-specific membrane antigen (PSMA), a well characterized antigen expressed on the surface of prostate cancer cells. These Dtxl-encapsulated nanoparticle-aptamer bioconjugates (Dtxl-NP-Apt) bind to the PSMA protein expressed on the surface of LNCaP prostate epithelial cells and get taken up by these cells resulting in significantly enhanced in vitro cellular toxicity as compared with nontargeted nanoparticles that lack the PSMA aptamer (Dtxl-NP) (P < 0.0004). The Dtxl-NP-Apt bioconjugates also exhibit remarkable efficacy and reduced toxicity as measured by mean body weight loss (BWL) in vivo [body weight loss of 7.7 ± 4% vs. 18 ± 5% for Dtxl-NP-Apt vs. Dtxl-NP at nadir, respectively (mean ± SD); n = 7]. After a single intratumoral injection of Dtxl-NP-Apt bioconjugates, complete tumor reduction was observed in five of seven LNCaP xenograft nude mice (initial tumor volume of ≈300 mm³), and 100% of these animals survived our 109-day study. In contrast, two of seven mice in the Dtxl-NP group had complete tumor reduction with 109-day survivability of only 57%. Dtxl alone had a survivability of only 14%. Saline and nanoparticles without drug were similarly nonefficacious. This report demonstrates the potential utility of nanoparticle-aptamer bioconjugates for a therapeutic application. [ABSTRACT FROM AUTHOR]

We report an ultrasensitive DNA sensor using the rapid enhancement of electrocatalytic activity of DNA-conjugated Pd nanoparticles (NPs); the rapid enhancement results from the fast catalytic hydrolysis of NaBH4on Pd NPs and subsequent fast hydrogen sorption into Pd NPs. [ABSTRACT FROM AUTHOR]

Here we report the synthesis of a novel electrochemically active polymer, preparation of adlayers of the polymer on optically transparent electrodes, and an application of the adlayers to immobilization of engineered cells through a direct covalent coupling reaction. [ABSTRACT FROM AUTHOR]

We report rational design of amphiphilic polymers capable of making carbon nanotubes (CNTs) highly water dispersible and resistant to biofouling; such CNTs can be conjugated with bioactive molecules so as to be potential drug delivery vehicles. [ABSTRACT FROM AUTHOR]

We describe a sensitive electrochemical immunosensor that takes advantage of the low background current of an indium tin oxide electrode, the good electrocatalytic properties of multi-walled carbon nanotubes, and the low biofouling properties of poly(ethylene glycol)–silane copolymer. [ABSTRACT FROM AUTHOR]

An amphiphilic macrocyclic cavitand that shows good antibacterial activity, comparable to that of peptide-based antibiotics was developed by rational design and its antibacterial selectivity over mammalian cells was examined. [ABSTRACT FROM AUTHOR]

Self-assembled nanoparticles (NPs) have been intensively utilized as cancer drug delivery carriers because hydrophobic anticancer drugs may be efficiently loaded into the particle cores. In this study, we synthesized and evaluated the therapeutic index of self-assembled NPs chemically conjugated to a fibronectin extra domain B-specific peptide (APTEDB) and an anticancer agent SN38. The APTEDB–SN38 formed self-assembled structures with a diameter of 58 ± 3 nm in an aqueous solution and displayed excellent drug loading, solubility, and stability properties. A pharmacokinetic study revealed that the blood circulation half-life of SN38 following injection of the APTEDB–SN38 NPs was markedly higher than that of the small molecule CPT-11. The APTEDB–SN38 NPs delivered SN38 to tumor sites by both passive and active targeting. Finally, the APTEDB–SN38 NPs exhibited potent antitumor activities and low toxicities against EDB-expressing tumors (LLC, U87MG) in mice. This system merits further preclinical and clinical investigations for SN38 delivery. [ABSTRACT FROM AUTHOR]

We describe hybrid nanoparticles, composed of iron oxide and gold nanoparticles, as potential dual contrast agents for both computed tomography (CT) and magnetic resonance imaging (MRI). The hybrid nanoparticles are synthesized by thermal decomposition of mixtures of Fe-oleate and Au-oleylamine complexes. Using a nano-emulsion method, the nanoparticles are coated with amphiphilic poly(DMA-r-mPEGMA-r-MA) to impart water-dispersity and antibiofouling properties. An in vitro phantom study shows that the hybrid nanoparticles have high CT attenuation, because of the constituent gold nanoparticles, and afford a good MR signal, attributable to the contained iron oxide nanoparticles. Intravenous injection of the hybrid nanoparticles into hepatoma-bearing mice results in high contrast between the hepatoma and normal hepatic parenchyma in both CT and MRI. These results suggest that the hybrid nanoparticles may be useful as CT/MRI dual contrast agents for in vivo hepatoma imaging. [ABSTRACT FROM AUTHOR]

In this paper, we suggest a facile and effective method for water-repellent coating of oxide surfaces. As a coating material, we synthesized a new random copolymer, referred to as poly(TMSMA-r-fluoroMA), by the radical polymerization of 3-(trimethoxysilyl)propyl methacrylate (TMSMA) and a fluoromonomer® bearing methacrylate moiety (fluoroMA). The random copolymer was designed to consist of a 'surface-reactive part' (trimethoxysilyl group) for anchoring onto oxide-based surfaces and a 'functional part' (perfluoro group) for water repellency. The polymeric self-assembled monolayers (pSAMs) of poly(TMSMA-r-fluoroMA) were constructed on three different aluminum oxide substrates, such as flat, concave-textured, and nanoporous plates, and the static water contact angle of each surface before and after the formation of pSAMs was measured. The formation of pSAMs resulted in significantly enhanced hydrophobicity compared with the corresponding bare surfaces. In particular, among three poly(TMSMA-r-fluoroMA)-coated surfaces, the nanoporous plate showed the highest water-repellent property, with a static contact angle of [?]163°, which is indicative of superhydrophobic surfaces. [ABSTRACT FROM AUTHOR]

Nanoparticles and microparticles have many potential biomedical applications ranging from imaging to drug delivery. Therefore, in vitro systems that can analyze and optimize the interaction of such particles with cells may be beneficial. Here, we report a microfluidic system that can be used to study these interactions. As a model system, we evaluated the interaction of polymeric nanoparticles and microparticles and similar particles conjugated to aptamers that recognize the transmembrane prostate specific membrane antigen (PSMA), with cells seeded in microchannels. The binding of particles to cells that expressed or did not express the PSMA (LNCaP or PC3, respectively) were evaluated with respect to changes in fluid shear stress, PSMA expression on target cells, and particle size. Nanoparticle-aptamer bioconjugates selectively adhered to LNCaP but not PC3 cells at static and low shear (<1 dyn/cm²) but not higher shear (∼4.5 dyn/cm²) conditions. Control nanoparticles and microparticles lacking aptamers and microparticle-aptamer bioconju gates did not adhere to LNCaP cells, even under very low shear conditions (∼0.28 dyn/cm²). These results demonstrate that the interaction of particles with cells can be studied under controlled conditions, which may aid in the engineering of desired particle characteristics. The scalability, low cost, reproducibility, and high-throughput capability of this technology is potentially beneficial to examining and optimizing a wide array of cell-particle systems prior to in vivo experiments. [ABSTRACT FROM AUTHOR]

The article informs that studies of artificial ion channels' have received much attention not only because they contribute to the fundamental understanding of natural ion channels, but also because they may lead to applications such as in drug discovery and sensors. To determine whether the transport occurs via a channel or carrier mechanism, planar bilayer conductance measurements were made. The article shows that the novel artificial ion channels based on Cucurbituril can transport proton and alkali metal ions across a lipid membrane with ion selectivity. At the moment, however, it is not clear how 1 and 2 form an ion channel in membranes, which is currently under investigation. Nevertheless, the novel ion channel system may find useful applications such as in drug discovery, detection of small molecules, ion separation, and construction of molecular devices.

This theme issue provides a timely collection of studies on magnetic nanoparticle-based imaging, bio-sensing, therapy and/or their combinations.