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Driven by a lack of appropriate human placenta models, recent years have seen the introduction of bioengineered in vitro models to better understand placental health and disease. Thus far, the focus has been on the maternal–foetal barrier. However, there are many other physiologically and pathologically significant aspects of the placenta that would benefit from state-of-the-art bioengineered models, in particular, integrating advanced culture systems with contemporary biological concepts such as organoids. This critical review defines and discusses the key parameters required for the development of physiologically relevant in vitro models of the placenta. Specifically, it highlights the importance of cell type, mechanical forces, and culture microenvironment towards the use of physiologically relevant models to improve the understanding of human placental function and dysfunction. Refereed/Peer-reviewed

Rapid diagnosis of preeclampsia is necessary to ensure timely administration of appropriate care and prevent the potentially catastrophic complications of the condition affecting both mothers and babies. While the diagnostic superiority of angiogenic blood biomarkers such as placental growth factor has recently been demonstrated, there is an urgent need to develop point-of-care (PoC) technologies that allow rapid, quantitative, and accurate testing for these markers within local communities. Towards addressing this need, here we report on a fully integrated biodiagnostic platform based on nanoscale indium oxide field effect transistor (FET) sensors. The high-performance FET sensors are integrated with blood sample processing cartridges that minimize the need for operator intervention during the assay and eliminate the need for analytical equipment. Within 40 minutes and from 30 µL of blood, the FET platform could reliably measure PlGF with a limit of detection of 0.06 pg/mL and a five order of magnitudes dynamic range. Pilot clinical validation in four preeclamptic pregnancies confirmed that the accuracy and reliability of the FET platform, paving the way for further development to a much-needed point-of-care preeclampsia testing. Refereed/Peer-reviewed

Detection of circulating tumor cells (CTCs), at the single-cell level, can be of great value for subsequent treatment of tumors but remains a significant challenge. Herein, we report a phage-based detection strategy for the identification of single CTC. The key assay component is the flexible recombinant M13@anti-CEA-scFv probe (M13, CEA, and scFv stand for M13 phage, carcinoembryonic antigen, and single-chain variable region fragment, respectively), which has a high, monoclonal antibody-like binding affinity for tumor cell-expressed CEA antigen, as confirmed by enzyme-linked immunosorbent assay (ELISA). Cell immunofluorescence experiments by confocal microscopy also demonstrate that the M13@anti-CEA-scFv could specifically bind to CEA-positive colon cancer cells such as Caco-2 and HT29, instead of CEA-negative HEK293T cells even when in great excess. Quantitative polymerase chain reaction (qPCR) further proves the ability to pin down single Caco-2 cell in 1 mL of spiked samples by 1,000 copies of M13@anti-CEA-scFv probe, after merely 15 min incubation. Another probe, the rigid magnetic microparticle (MMP), loaded with anti-CEA antibody, is used for the initial screening of the single CTC, which is mixed with numerous lymphocytes. The CEA on the resultant MMPs/CTC complex is subsequently recognized by numerous copies of M13@anti-CEA-scFv to form an MMP/CTC/M13@anti-CEA-scFv sandwich complex. Probing the phage DNA in this complex by qPCR leads to the unambiguous identification of the single Caco-2 cell in 1 mL of spiked blood samples. The phage-based detection strategy holds promise for the single-cell detection of any CTCs since the scFv displayed at the end of phage can be customized to the unique antigen of a specific CTC. Refereed/Peer-reviewed

Measuring tumour cell invasiveness through three-dimensional (3D) tissues, particularly at the single cell level, can provide important mechanistic understanding and assist in identifying therapeutic targets of tumour invasion. However, current experimental approaches, including standard in vitro invasion assays, have limited physiological relevance and offer insufficient insight about the vast heterogeneity in tumour cell migration through tissues. To address these issues, here we report on the concept of optical cellular micromotion, where digital holographic microscopy (DHM) is used to map the optical thickness fluctuations at sub-micron scale within single cells. These fluctuations are driven by the dynamic movement of subcellular structures including the cytoskeleton and inherently associated with the biological processes involved in cell invasion within tissues. We experimentally demonstrate that the optical cellular micromotion correlates with tumour cells motility and invasiveness both at the population and single cell levels. In addition, the optical cellular micromotion significantly reduced upon treatment with migrastatic drugs that inhibit tumour cell invasion. These results demonstrate that micromotion measurements can rapidly and non-invasively determine the invasive behaviour of single tumour cells within tissues, yielding a new and powerful tool to assess the efficacy of approaches targeting tumour cell invasiveness.Significance StatementTumour cells invasion through tissues is a key hallmark of malignant tumour progression and its measurement is essential to unraveling biological processes and screening for new approaches targeting cell motility. To address the limitations of current approaches, we demonstrate that sub-micron scale mapping of the dynamic optical thickness fluctuations within single cells, referred to as optical cellular micromotion, correlates with their motility in ECM mimicking gel, both at the population and single cell levels. We anticipate that 3D optical micromotion measurement will provide a powerful new tool to address important biological questions and screen for new approaches targeting tumour cell invasiveness.

Recently, organ-on-a-chip models, which are microfluidic devices that mimic the cellular architecture and physiological environment of an organ, have been developed and extensively investigated. The chips can be tailored to accommodate the disease conditions pertaining to many organs; and in the case of this review, the lung. Lung-on-a-chip models result in a more accurate reflection compared to conventional in vitro models. Pharmaceutical drug testing methods traditionally use animal models in order to evaluate pharmacological and toxicological responses to a new agent. However, these responses do not directly reflect human physiological responses. In this review, current and future applications of the lung-on-a-chip in the respiratory system will be discussed. Furthermore, the limitations of current conventional in vitro models used for respiratory disease modeling and drug development will be addressed. Highlights of additional translational aspects of the lung-on-a-chip will be discussed in order to demonstrate the importance of this subject for medical research. Refereed/Peer-reviewed

The presence or absence of tumor cells within patient lymph nodes is an important prognostic indicator in a number of cancer types and an essential element of the staging process. However, patients with the same pathological stage will not necessarily have the same outcome. Therefore, additional factors may aid in identifying patients at a greater risk of developing metastasis. In this proof of principle study, initially, spiked tumor cells in rat lymph nodes were used to mimic a node with a small cancer deposit. Next, human lymph nodes were obtained from cancer patients for morphological characterization. Nodes were dissociated with a manual tissue homogenizer and stained with fluorescent antibodies against CD45 and Pan-Cytokeratin and then imaging flow cytometry (AMNIS ImageStreamX Mark II) was performed. We show here that imaging flow cytometry can be used for the detection and characterization of small numbers of cancer cells in lymph nodes and we also demonstrate the phenotypical and morphological characterization of cancer cells in gastrointestinal cancer patient lymph nodes. When used in addition to conventional histological techniques, this high throughput detection of tumor cells in lymph nodes may offer additional information assisting in the staging process with therapeutic and prognostic applications.

M cells are an epithelial cell population found in the follicle-associated epithelium overlying gut-associated lymphoid tissues. They are specialized in the transcytosis of luminal antigens. Their transcytotic capacity and location in an immunocompetent environment has prompted the study of these cells as possible targets for oral drug delivery systems. Currently, the models most commonly used to study M cells are restricted to in vivo experiments conducted in mice, and in vitro studies conducted in models comprised either of primary epithelial cells or established cell lines of murine or human origin. In vitro models of the follicle-associated epithelium can be constructed in several ways. Small intestinal Lgr5+ stem cells can be cultured into a 3D organoid structure where M cells are induced with RANKL administration. Additionally, in vitro models containing an “M cell-like” population can be obtained through co-culturing intestinal epithelial cells with cells of lymphocytic origin to induce the M cell phenotype. The evaluation of the efficiency of the variations of these models and their relevance to the in vivo human system is hampered by the lack of a universal M cell marker. This issue has also hindered the advancement of M cell-specific targeting approaches aimed at improving the bioavailability of orally administered compounds. This critical review discusses the different approaches utilized in the literature to identify M cells, their efficiency, reliability and relevance, in the context of commonly used models of the follicle-associated epithelium. The outcome of this review is a clearly defined and universally recognized criteria for the assessment of the relevance of models of the follicle-associated models currently used.Impact statementThe study of M cells, a specialized epithelial cell type found in the follicle-associated epithelium, is hampered by the lack of a universal M cell marker. As such, many studies lack reliable and universally recognized methods to identify M cells in their proposed models. As a result of this it is difficult to ascertain whether the effects observed are due to the presence of M cells or an unaccounted variable. The outcome of this review is the thorough evaluation of the many M cell markers that have been used in the literature thus far and a proposed criterion for the identification of M cells for future publications. This will hopefully lead to an improvement in the quality of future publications in this field.

The detection and molecular analysis of circulating tumour cells (CTCs) potentially provides a significant insight to the characterisation of disease, stage of progression and therapeutic options for cancer patients. Following on from the protocol by Warkiani et al. 2016, which describes a method of enriching CTCs from cancer patient blood with inertial microfluidics, we describe a method to measure the CTC RNA expression in the enriched fraction using droplet digital PCR and compare transcript detection with and without RNA pre-amplification. • Inertial microfluidics combined with droplet digital PCR is advantageous as it allows for CTC enrichment and subsequent RNA analysis from patient blood. This allows for patient tumour analysis with increased sensitivity and precision compared to quantitative Real Time PCR and enables the direct quantification of nucleic acids without the need for tumour biopsy. • This method demonstrates an efficient approach providing important insights into the analysis of colorectal cancer patients’ CTCs using a specific gene subset or biomarkers, an approach that may be tailored to tumour type or expanded to larger panels. Method name: Circulating tumour cells isolation and analysis with droplet digital PCR, Keywords: Circulating tumour cell, Droplet digital PCR, Colorectal cancer

The use of nitric oxide (NO), a naturally occurring antimicrobial agent, as an alternative strategy to combat bacterial biofilms has recently gained considerable momentum in light of the global threat of emerging antibiotic resistance. While previous NO-based anti-biofilm approaches were aimed at killing bacterial cells within biofilms, NO has also been recently identified as a key mediator of biofilm dispersal, causing the release of cells from the biofilm community. This is of great interest towards the design of more effective anti-biofilm strategies but further studies are warranted to validate this concept. Therefore, in the present study we investigated whether a NO precursor, isosorbide mononitrate (ISMN) or its analogue D-isosorbide can induce bacteria cell dispersal from Staphylococcus aureus (S. aureus) biofilms and explored the potential synergy of ISMN and the antimicrobial compounds mupirocin and ciprofloxacin in biofilm eradication. This study demonstrate that ISMN causes dispersal of S. aureus biofilm bacteria, particularly when exposed to high levels of drug. ISMN at 60 mg/mL increased the number of colony forming units (CFU) (~ 3log 10 and ~ 5log 10 ) of planktonic bacteria after 6 and 24-h exposure respectively, compared to control biofilms. This suggests that ISMN induces the transition of sessile biofilm cells to free-swimming planktonic cells. In addition, ISMN exhibits synergistic effects against S. aureus biofilms with ciprofloxacin when tested above its minimum inhibitory concentration (MIC). Specifically, exposure to ISMN significantly enhanced the efficacy of ciprofloxacin by reducing the number of CFU (~ 3log 10 or ~ 2log 10 ) of biofilm-associated and planktonic bacteria respectively, compared to drug alone. Combined exposure to both ISMN and certain antimicrobial agents may therefore offer an innovative approach to control persistent biofilm and biofilm-associated infections. Refereed/Peer-reviewed

Many highly effective chemotherapeutic agents can only be administered intravenously as their oral delivery is compromised by low gastro-intestinal solubility and permeability. SN-38 (7-ethyl-10-hydroxycamptothecin) is one such drug; however, recently synthesized lipophilic prodrugs offer a potential solution to the low oral bioavailability issue. Here we introduce a microfluidic-based intestine-on-A-chip (IOAC) model, which has the potential to provide new insight into the structure-permeability relationship for lipophilic prodrugs. More specifically, the IOAC model utilizes external mechanical cues that induce specific differentiation of an epithelial cell monolayer to provide a barrier function that exhibits an undulating morphology with microvilli expression on the cell surface; this is more biologically relevant than conventional Caco-2 Transwell models. IOAC permeability data for SN38 modified with fatty acid esters of different chain lengths and at different molecular positions correlate excellently with water-lipid partitioning data and have the potential to significantly advance their preclinical development. In addition to advancing mechanistic insight into the permeability of many challenging drug candidates, we envisage the IOAC model to also be applicable to nanoparticle and biological entities. Refereed/Peer-reviewed

Staphylococcus aureus and Pseudomonas aeruginosa are primary pathogens in chronic rhinosinusitis (CRS), and the presence of S. aureus and P. aeruginosa biofilms has been associated with negative outcomes after surgery. This study investigated the inhibition effect of cetylpyridinium chloride (CPC)-quatsomes at low concentrations on both S. aureus and P. aeruginosa biofilms in vitro, as well as their toxicities towards cultured human airway epithelial (NuLi-1) cells. S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were used to establish biofilms. CPC-quatsome and CPC micelle solutions at concentrations of 0.01%, 0.025%, and 0.05% were prepared. AlamarBlue was used to test the viability of both planktonic S. aureus and P. aeruginosa and their biofilms after treatment for 5 min and 2 h, respectively. Confocal laser scanning microscopy (CLSM) was used to investigate the interactions between CPC-quatsomes and S. aureus and P. aeruginosa biofilms. A lactate dehydrogenase (LDH) assay was used to determine the toxicity of CPC-quatsomes on NuLi-1 cells. CPC-quatsome and CPC micelle solutions had significant inhibition effects at all tested concentrations on planktonic S. aureus and P. aeruginosa and their biofilms after 5-min exposure ( P < 0.05). In the CLSM study, different interactions between CPC-quatsomes and S. aureus or P. aeruginosa biofilms were observed. After 2-h treatment, the size of S. aureus biofilms decreased, while the number of dead bacteria increased in P. aeruginosa biofilms. Neither CPC-quatsomes nor CPC micelle solutions showed significant toxicity on NuLi-1 cell at all tested CPC concentrations ( P < 0.05). CPC-quatsomes at low concentrations inhibited S. aureus and P. aeruginosa in both planktonic form and biofilms. No adverse effects on NuLi-1 cells were observed, indicating their promising potential in the treatment of CRS. Impact statement Staphylococcus aureus and Pseudomonas aeruginosa biofilms are significant contributors to chronic rhinosinusitis (CRS), and are associated with poor prognosis. The killing effect of CPC-quatsomes on S. aureus biofilm at or above the CPC concentration of 0.5% (5 mg/mL) has been reported previously. This is the first study that showed the significant inhibition effect of CPC-quatsomes at low concentrations on both S. aureus and P. aeruginosa biofilms in vitro, and no adverse effects towards cultured human airway epithelial (NuLi-1) cells. In our study, CPC-quatsomes at concentrations of 0.01%, 0.025%, and 0.05% had significant inhibition effects on both planktonic and biofilms of S. aureus and P. aeruginosa. The result of this study indicates the promising potential of CPC-quatsome in the treatment of CRS.

Bacteria in biofilms are more difficult to eradicate than planktonic bacteria and result in treatment challenges for many chronic infectious diseases. Nitric oxide (NO) is an endogenous molecule that offers potential as an alternative to conventional antibiotics; however its sustained topical delivery to biofilms is not readily achieved. With this in mind, we report the development of biodegradable poly(lactide-co-glycolide) (PLGA) based microparticles (MP) and nanoparticles (NP) for encapsulation of the NO precursor isosorbide mononitrate (ISMN) and the controlled delivery to Staphylococcus aureus (S. aureus) biofilms. Firstly, water-in-oil-in-water (w/o/w) emulsification/solvent evaporation methods for PLGA NP and MP syntheses were experimentally optimised with respect to particle size and ISMN loading/encapsulation efficiency. The influence of various experiment parameters, such as the volume of inner aqueous phase, concentration of surfactants, mixing time on the particle size, drug loading and encapsulation efficiency were investigated systematically. Both PLGA MP and NP formulations enabled sustained ISMN release in physiological media over 3 to 5 days. PLGA MP with diameters of ∼3 μm and ISMN loading of 2.2% (w/w) were identified as the optimum delivery system and demonstrated significant antibacterial activity in S. aureus biofilms. This behaviour is considered to be due to targeted biofilm delivery through a combination of effective penetration and sustained release of ISMN. Refereed/Peer-reviewed

Nanoparticle radiosensitization has been demonstrated well to enhance the effects of radiotherapy,motivate the improvement of therapeutic ratios, and decrease morbidity in cancer treatment. A significant challenge existsin optimizing formulations and translation due to insufficient knowledge of the associated mechanisms, which have historically been limited to physical concepts. Here, we investigated a concept for the role of biological mechanisms.The mere presence of gold nanoparticles led to a down regulation of thymidylate synthase, important for DNA damage repair in the radioresistant S-phase cells. By developing a cross-correlative methodology to reveal probabilistic gold nanoparticle uptake by cell sub-populations and the associated sensitization as a function of the uptake, a number of revealing observations have been achieved.Surprisingly, for low numbers of nanoparticles, a desensitization action was observed. Sensitization was discovered to preferentially impact S-phase cells, in which impairment of the DNA damage response by the homologous recombination pathway dominates. This small but radio resistant cell population correlates with much greater proliferative ability. Thus, aparadigm is presented whereby enhanced DNA damage is not necessarily due to an increase in the number of DNA double-strand breaks (DSBs) created but can be from a nanoparticle-induced impairment of the damage response by down-regulating repair proteins such as thymidylate synthase. Refereed/Peer-reviewed

New tools for higher-resolution fetal genome analysis including microarray and next-generation sequencing have revolutionized prenatal screening. This article provides commentary on this rapidly advancing field and a future perspective emphasizing circulating fetal cell (CFC) utility. Despite the tremendous technological challenges associated with their reliable and cost-effective isolation from maternal blood, CFCs have a strong potential to bridge the gap between the diagnostic sensitivity of invasive procedures and the desirable noninvasive nature of cell-free fetal DNA (cffDNA). Considering the rapid advances in both rare cell isolation and low-input DNA analysis, we argue here that CFC-based noninvasive prenatal testing is poised to be implemented clinically in the near future Refereed/Peer-reviewed

Accuracy of sentinel lymph node identification using radioactive tracers in non-superficial cancers can be limited by radiation shine through and low spatial resolution of detection systems such as intraoperative gamma probes. By utilising a dual radioactive/magnetic tracer, sensitive lymphoscintigraphy can be paired with high spatial resolution intraoperative magnetometer probes to improve the accuracy of sentinel node detection in cancers with complex multidirectional lymphatic drainage. Dextran-coated magnetite nanoparticles (33 nm mean hydrodynamic diameter) were labelled with 99mTc and applied as a lymphotropic tracer in small and large animal models. The dual tracer could be radiolabelled with 98 ± 2% efficiency after 10 min of incubation at room temperature. Biodistribution studies of the tracer were conducted in normal rats (subdermal and intravenous tail delivery, n = 3) and swine (subdermal hind limb delivery, n = 5). In rats the dual tracer migrated through four tiers of lymph node, 20 min after subdermal injection. Results from intravenous biodistribution test for radiocolloids demonstrated no aggregation in vivo, however indicated the presence of some lower-molecular weight radioactive impurities (99mTc-dextran). In swine, the dual tracer could be effectively used to map lymphatic drainage from hind hoof to popliteal and inguinal basins using intraoperative gamma and magnetometer probes. Of the eight primary nodes excised, eight were positively identified by gamma probe and seven by magnetometer probe. The high-purity dual tracer shows early promise for sentinel node identification in complex lymphatic environments by combining sensitive preoperative lymphoscintigraphy with a high-resolution intraoperative magnetometer probe.

The anti-biofilm effect of drug delivery systems composed of the antiseptic quaternary ammonium compound cetylpyridinium chloride (CPC) and cholesterol was evaluated in Staphylococcus aureus biofilm. Self-assembly of CPC/cholesterol to approximately 100 nm CPC-quatsomes was successfully accomplished by a simple sonication/dispersion method over a broad concentration range from 0.5 to 10 mg ml−1 CPC. CPC-quatsomes showed a dose-dependent anti-biofilm effect, killing >99% of biofilm-associated S. aureus from 5% mg ml−1 after 10 minutes exposure. Cell toxicity studies with CPC-quatsomes in Nuli-1 cells revealed no adverse effects at all tested CPC concentrations. CPC-quatsomes, therefore, have a promising potential as novel drug delivery systems with "built-in" anti-biofilm activity. Refereed/Peer-reviewed

Extracellular polymeric substances in bacterial biofilms reduce the penetration of antimicrobials and give rise to extreme recalcitrance and treatment challenges for many persistent biofilms and associated infections. Nitric oxide (NO) is a promising alternative to conventional antimicrobials but is challenging to deliver at precise concentrations for significant periods in a convenient and nontoxic manner. Here we report a unique NO delivery platform by incorporating the NO precursor isosorbide mononitrate (ISMN) into chitosan gels to facilitate sustained ISMN release and effective delivery. The chitosan gels were characterized with respect to the drug release kinetics, rheological properties, as well as antimicrobial efficacy against biofilms of Staphylococcus aureus in the absence and presence of the antibiotic ciprofloxacin. Chitosan gels loaded with ISMN alone (CS-ISMN) showed comparable antimicrobial effects compared to blank chitosan gel (approximately 2 log 10 reduction). However, there was strong synergy of CS-ISMN when combined with ciprofloxacin, that is, ∼4 log 10 reduction of bacterial colonies of CS-ISMN-CIP compared to the single treatments. These findings were confirmed by confocal imaging and highlight a potentially effective new way to overcome recalcitrant S aureus biofilms using NO precursors. Refereed/Peer-reviewed

The sentinel lymph node (SLN) concept has become a standard of care for patients with breast cancer and melanoma, yet its clinical application to other cancer types has been somewhat limited. This is mainly due to the reduced accuracy of conventional SLN mapping techniques (using blue dye and/or radiocolloids as lymphatic tracers) in cancer types where lymphatic drainage is more complex, and SLNs are within close proximity to other nodes or the tumour site. In recent years, many novel techniques for SLN mapping have been developed including fluorescence, x-ray, and magnetic resonant detection. Whilst each technique has its own advantages/disadvantages, the role of targeted contrast agents (for enhanced retention in the SLN, or for immunostaging) is increasing, and may represent the new standard for mapping the SLN in many solid organ tumours. This review article discusses current limitations of conventional techniques, limiting factors of nanoparticulate based contrast agents, and efforts to circumvent these limitations with modern tracer architecture. Refereed/Peer-reviewed

Accurate detection of lymph node metastases is critical for many solid tumours to guide treatment strategies and determine prognostic outcomes. The gold standard for detection of metastasis is by histological analysis of formalin-fixed paraffin-embedded (FFPE) sections of removed lymph nodes; this analysis method has remained largely unchanged for decades. Recent studies have highlighted limitations in the sensitivity of this approach, at least in its current clinical use, to detect very small metastatic deposits. Importantly, the poor prognostic outcomes associated with the presence of such small tumour deposits are now well established in a number of cancers. In addition, histological analysis of FFPE sections cannot be used practically for intraoperative node assessment. Novel lymph node staging technologies are therefore actively being developed. This review critically presents the main advances in this field and discusses why these technologies have not been able to provide a better alternative to the current gold standard diagnostic technique.

Optical coherence tomography (OCT) is a non-invasive interferometry imaging technique with micrometre scale resolution at millimetre scale penetration depths in highly scattering tissues. This study describes a new evolution of OCT, termed molecular optical coherence phase microscopy (molecular OCPM), which is capable of imaging the expression of molecular markers at the cellular level using gold nanorods as photothermal imaging agents. Gold nanorods were selected as the imaging agents due to their excellent photothermal energy conversion efficiency and tuneable plasmon bands. The gold nanorods were surface functionalized to achieve efficient and specific targeting of the tyrosine kinase human epidermal growth factor receptor HER2 molecular markers used as a model tumor biomarker. Phase modulation retrieval was used to generate photothermal maps which were overlayed on intensity images. Phase modulation within the filter corresponding to the laser excitation modulation frequency was clearly observed for cells targeted with the molecular photothermal imaging agents. These results confirm the ability of photothermal optical coherence phase microscopy to image accurately at the cellular level gold nanorods molecularly targeted to a biomarker expressed on cancer cell membranes, paving the way for its application to novel bioimaging procedures. Refereed/Peer-reviewed

The development of simple yet ultrasensitive biosensing approaches for the detection of cancer prognostic microRNA is an important step toward their successful clinical PEG implementation. We demonstrate the relevance for the detection of circulating miRNA of a novel signal amplification scheme based on surface plasmon resonance enhanced light scattering (SP-LS). In addition to experimental optimization carried out using gold nanoparticle (AuNP) tags conjugated with a monoclonal antibody with high affinity for RNA*DNA hybrid duplexes, simulation modeling was conducted to obtain insights about SP-LS biosensing. SP-LS enabled the detection of miRNA-122 at subpicomolar concentrations within 30 min, and a limit of detection of 2 attomoles (60 fM, 50 mu L) was determined. MiRNA-122 could also be reliably detected in a high concentration background of nontarget miRNA. The proposed SP-LS miRNA detection approach could be readily applied to other miRNA targets of diagnostic importance and further developed to allow for multiplex measurements of miRNA panels. The promising results obtained in this study and advantageous features of SP-LS warrant further development and its application to clinical samples. Refereed/Peer-reviewed

Polysaccharides form an important class of natural polymers with critical structural functions and biological activities in plants and all living organisms. It comes as no surprise that polysaccharides are key players in the area of biomaterials, where they have found applications in fi elds as diverse as drug delivery, tissue engineering and regenerative medicine, biosensing and biodiagnostics. Nonetheless, in the early phase of polyelectrolyte multilayers development, up to ~2002, there were only a few studies of layer-by-layer (LbL) assemblies containing polysaccharides. These natural polymers, intrinsically, are more difficult to handle than synthetic polymers or proteins that can be defined precisely in terms of structure, architecture, and molecular weight. Polysaccharides consist of carbohydrate units linked by glycosidic bonds and occur naturally with a range of molecular weights. Specific substituents, such as hydroxyls, sulfates, carboxylates, and amines linked to the glycoside rings, directly control the physicochemical and biological properties of polysaccharides. They also affect the multilayer assembly process, often in unpredictable ways. In addition, polysaccharides undergo facile degradation in strong acidic or alkaline environments. Hence, the multilayer construction conditions need to be selected carefully in order to avoid undesired side-reactions.

Conjugation of PEGylated superparamagnetic nanoparticles with the 3B9 mAb was reported and the specificity of reactions of these novel molecular hybrid medical resonance imaging (MRI) nanoprobes with apoptotic cells was examined. The PEGylated nanoparticles were activated with EDC/NHS and conjugated either with 3B9 or Sal5, an isotype-matched mAb of irrelevant specificity, to achieve immunotargeting. It is found that solvent-free PRGylation process produces nanoparticle aggregates that average 67 mm in diameter with a narrow polydispersity. Antibody immobilization is confirmed by the observation of frequency and dissipation shifts, which are observed after injection of a 100μg/mL 3B9 mAb solution into the flow cell. The concentration of 3B9-nnaoparticles required to reach half saturation is found to be equivalent to 0.65mM of Fe, which corresponds to 7.8nM 3B9 mAb.

Bacterial biofilms are associated with a number of recurring infectious diseases and are a majorcause for antibiotic resistance. Despite the broad use of polymeric microparticles and nanoparticles in biomedical research it is not clear which particle size is more effective against biofilms. The purpose of this study was to evaluate the efficacy of sustained release poly-lactic-co-glycolic acid(PLGA) micro- and nanoparticles containing ciprofloxacin against biofilms of Staphylococcus aureus and Pseudomonas aeruginosa The PLGA particles were prepared by the double emulsion solvent evaporation method. The resulting microparticles (12 μm) and nanoparticles (300 nm) contained drug loads of 7.3% and 4.5%(w/w) ciprofloxacin, respectively. Drug release was complete within one week following comparable release profiles for both particle sizes. Micro- and nanoparticles demonstrated a similar in vitro antibiofilm performance against mature P. aeruginosa and S. aureus with marked differences between the two strains. The sustained release of ciprofloxacin from micro- and nanoparticles over 6 days was equally effective as the continuous treatment with ciprofloxacin solution over the same period resulting in the eradication of culturable S. aureus suggesting that reformulation of ciprofloxacin as sustained release PLGA micro- and nanoparticles might be valuable formulation approaches for the treatment of biofilms. Refereed/Peer-reviewed

Within an hour, as little as one disseminated tumor cell (DTC) per lymph node can be quantitatively detected using an intraoperative biosensing platform based on silicon nanowire field-effect transistors (SiNW FET). It is also demonstrated that the integrated biosensing platform is able to detect the presence of circulating tumor cells (CTCs) in the blood of colorectal cancer patients. The presence of DTCs in lymph nodes and CTCs in peripheral blood is highly significant as it is strongly associated with poor patient prognosis. The SiNW FET sensing platform out-performed in both sensitivity and rapidity not only the current standard method based on pathological examination of tissue sections but also the emerging clinical gold standard based on molecular assays. The possibility to achieve accurate and highly sensitive analysis of the presence of DTCs in the lymphatics within the surgery time frame has the potential to spare cancer patients from an unnecessary secondary surgery, leading to reduced patient morbidity, improving their psychological wellbeing and reducing time spent in hospital. This study demonstrates the potential of nanoscale field-effect technology in clinical cancer diagnostics. Refereed/Peer-reviewed

Circulating tumor cells (CTC) may be defined as tumor- or metastasis-derived cells that are present in the bloodstream. The CTC pool in colorectal cancer (CRC) patients may include not only epithelial tumor cells, but also tumor cells undergoing epithelial-mesenchymal transition (EMT) and tumor stem cells. A significant number of patients diagnosed with early stage CRC subsequently relapse with recurrent or metastatic disease despite undergoing "curative" resection of their primary tumor. This suggests that an occult metastatic disease process was already underway, with viable tumor cells being shed from the primary tumor site, at least some of which have proliferative and metastatic potential and the ability to survive in the bloodstream. Such tumor cells are considered to be responsible for disease relapse in these patients. Their detection in peripheral blood at the time of diagnosis or after resection of the primary tumor may identify those early-stage patients who are at risk of developing recurrent or metastatic disease and who would benefit from adjuvant therapy. CTC may also be a useful adjunct to radiological assessment of tumor response to therapy. Over the last 20 years many approaches have been developed for the isolation and characterization of CTC. However, none of these methods can be considered the gold standard for detection of the entire pool of CTC. Recently our group has developed novel unbiased inertial microfluidics to enrich for CTC, followed by identification of CTC by imaging flow cytometry. Here, we provide a review of progress on CTC detection and clinical significance over the last 20 years. Refereed/Peer-reviewed

Using magnetic tunnelling junction sensors, a novel magnetometer probe for the identification of the sentinel lymph node using magnetic tracers was developed. Probe performance was characterised in vitro and validated in a preclinical swine model. Compared to conventional gamma probes, the magnetometer probe showed excellent spatial resolution of 4.0 mm and the potential to detect as few as 5 μg of magnetic tracer. Due to the high sensitivity of the magnetometer, all first-tier nodes were identified in the preclinical experiments and there were no instances of false positive or false negative detection. Furthermore, these preliminary data encourage the application of the magnetometer probe for use in more complex lymphatic environments, such as in gastrointestinal cancers, where the sentinel node is often in close proximity to other non-sentinel nodes and high spatial resolution detection is required.

Background: Staphylococcus aureus and Pseudomonas aeruginosa are major pathogens in chronic rhinosinusitis (CRS) and their biofilms have been associated with poorer post surgical outcomes. This study investigated the distribution and anti-biofilm effect of cationic (+) and anionic (-) phospholipid liposomes with different sizes (unilamellar and multilamellar vesicle, ULV and MLV respectively) on S. aureus and P. aeruginosa biofilms. Method: Specific biofilm models for S. aureus ATCC 25923 and P. aeruginosa ATCC 15692 were established. Liposomal distribution was determined by observing SYTO9 stained biofilm exposed to DiI labeled liposomes using confocal scanning laser microscopy, followed by quantitative image analysis. The anti-biofilm efficacy study was carried out by using the alamarBlue assay to test the relative viability of biofilm treated with various liposomes for 24 hours and five minutes. Results: The smaller ULVs penetrated better than larger MLVs in both S. aureus and P. aeruginosa biofilm. Except that +ULV and –ULV displayed similar distribution in S. aureus biofilm, the cationic liposomes adhered better than their anionic counterparts. Biofilm growth was inhibited at 24-hour and five-minute exposure time, although the decrease of viability for P. aeruginosa biofilm after liposomal treatment did not reach statistical significance. Conclusion: The distribution and anti-biofilm effects of cationic and anionic liposomes of different sizes differed in S. aureus and P. aeruginosa biofilms. Reducing the liposome size and formulating liposomes as positively charged enhanced the penetration and inhibition of S. aureus and P. aeruginosa biofilms. Refereed/Peer-reviewed

Membrane-covered devices could help treat disease of the vasculature such as aneurysm, rupture, and fistulas. They are also investigated to reduce embolic complication associated with revascularization of saphenous vein graft. The aim of this study is to design a clinically applicable biodegradable membrane-covered stent based on the natural polysaccharide chitosan, which has been developed. The mechanical properties of the membrane is optimized through blending with polyethylene oxide (70:30% Wt CH:PEO). The membrane was able to sustain the mechanical deformation of the supporting self-expandable metallic stents during its deployment. The membrane was demonstrated to resist physiological transmural pressure (burst pressure resistance >500 mm Hg) and presented a high-water permeation resistance (1 mL/cm(2) min(-1) at 120 mmHg). The CH-PEO membrane showed a good hemocompatibility in an ex vivo assay. Heparin and hyaluronan surface complexation with the membrane further reduced platelet adhesion by 50.1 and 63% (p = 0.05). The ability of the membrane-covered devices to be used as a drug reservoir was investigated using the nitric oxide donor sodium nitroprusside (SNP). SNP-loaded membranes displayed significantly reduced platelet adhesion.

The burden of drug resistance emerges in the wake of chronic and repeated antibiotic use. This underpins the importance of discovering alternatives to current antibiotic regimens. In chronic rhinosinusitis (CRS), topical therapy such as nasal douches and steroid sprays is the mainstay of treatment. However, bacterial sinusitis such as those with Staphylococcus aureus biofilm infection point to more recalcitrant CRS subtypes, focusing research efforts into topical antimicrobial therapies. In the sinuses, both local mucosal and systemic effects must be considered in designing any new topical medication. Nitric oxide (NO), an endogenous antimicrobial agent, is found at extremely low levels in CRS sinuses and high levels in healthy sinuses. As a novel treatment modality, we have designed a liposomal formulation of an NO donor (LFNO) using isosorbide mononitrate, as a topical sinus wash in a sheep model of S. aureus biofilm rhinosinusitis. Heart rate (HR), blood pressure, mean arterial pressure (MAP), and histologic and ciliary analyses were assessed in the safety component. Efficacy was assessed by quantifying biofilm biomass post-treatment. LFNO-treated sheep had lesser inflammation (P = 0.02), and comparable ciliary preservation (P = 0.86) than the control group. A transient increase in HR and decrease in MAP were observed in the LFNO group (P < 0.05), but this was not accompanied by observable side effects. LFNO sheep had significantly lower biofilm biomass vs controls (P = 0.044). Our findings demonstrate the localized and systemic safety of LFNO in an animal model despite using high NO concentrations, thus warranting further investigation for its possible therapeutic role in CRS. Refereed/Peer-reviewed

Acute and subacute stents thrombosis along with thrombus mediating neointimal proliferation within the stent struts remain major concerns in coronary stenting. Up to date, there is an obvious lack of data on the thrombogenicity of stent materials in physiological conditions. This study was performed to compare the relative thrombogenicity of nitinol versus stainless steel stents. Nitinol stents were laser cut to reproduce the exact geometry of the stainless steel Palmaz stents and tested in an ex vivo AV shunt porcine model under controlled conditions. Nitinol stents presented only small amounts of white and/or red thrombus principally located at the strut intersections while Palmaz stents clearly exhibited more thrombus. As a result, 125I-fibrin(ogen) adsorption and (111)I-platelets adhesion were significantly lower on nitinol than on stainless steel devices (36%, p = 0.03 for fibrin(ogen) and 63%, p = 0.01 for platelet). These results were confirmed by scanning electron observations showing different thrombus morphologies for nitinol and stainless steel. Along with the unique mechanical properties of nitinol, its promising haemocompatibility demonstrated in our study may promote their increasing use for both peripheral and coronary revascularization procedures.

Aim: To evaluate the potential of newly-developed, biocompatible iron oxide magnetic nanoparticles (MNPs) conjugated with J591, an antibody to an extracellular epitope of PSMA, to enhance MRI of prostate cancer. Materials & methods: Specific binding to PSMA by J591-MNP was investigated in vitro. MRI studies were performed on orthotopic tumor-bearing NOD.SCID mice 2 h and 24 h after intravenous injection of J591-MNPs, or non-targeting MNPs. Results & conclusion: In vitro, MNPs did not affect prostate cancer cell viability, and conjugation to J591 did not compromise antibody specificity and enhanced cellular iron uptake. Magnetic resonance contrast of tumors was increased in vivo using PSMA-targeting MNPs, but not by non-targeting MNPs. This provides proof-of-concept that PSMA-targeting MNPs have potential to enhance magnetic resonance detection/localization of prostate cancer.

Bone marrow-derived mesenchymal stem cells (MSC) have unique immunomodulatory and reparative properties beneficial for allotransplantation cellular therapy. The clinical administration of autologous or allogeneic MSC with immunosuppressive drugs is able to prevent and treat allograft rejection in kidney transplant recipients, thus supporting the immunomodulatory role of MSC. Interferon-gamma (IFN-γ) is known to enhance the immunosuppressive properties of MSC. IFN-γ preactivated MSC (MSC-γ) directly or indirectly modulates T cell responses by enhancing or inducing MSC inhibitory factors. These factors are known to downregulate T cell activation, enhance T cell negative signalling, alter T cells from a proinflammatory to an anti-inflammatory phenotype, interact with antigen-presenting cells and increase or induce regulatory cells. Highly immunosuppressive MSC-γ with increased migratory and reparative capacities may aid tissue repair, prolong allograft survival and induce allotransplant tolerance in experimental models. Nevertheless, there are contradictory in vivo observations related to allogeneic MSC-γ therapy. Many studies report that allogeneic MSC are immunogenic due to their inherent expression of major histocompatibility (MHC) molecules. Enhanced expression of MHC in allogeneic MSC-γ may increase their immunogenicity and this can negatively impact allograft survival. Therefore, strategies to reduce MSC-γ immunogenicity would facilitate "off-the-shelf" MSC therapy to efficiently inhibit alloimmune rejection and promote tissue repair in allotransplantation. In this review, we examine the potential benefits of MSC therapy in the context of allotransplantation. We also discuss the use of autologous and allogeneic MSC and the issues associated with their immunogenicity in vivo, with particular focus on the use of enhanced MSC-γ cellular therapy. Refereed/Peer-reviewed

A novel approach based on advanced micromachining is demonstrated to fabricate concave microwell arrays for the formation of high quality multicellular tumor spheroids. Microfabricated molds were prepared using a state-of-the-art CNCmachining center, containing arrays of 3D convex micropillars withsize ranging from 150 μm to 600 μm. Microscopic imaging of themicropillars machined on the mold showed smooth, curved microfeatures of a dramatic 3D shape. Agarose microwells could be easily replicated from the metallic molds. EMT-6 tumor cells seeded in the primary macrowell sedimented efficiently to the bottom of the concave microwells and formed multicellular spheroidswithin 48 h. Dense and homogeneous multicellular spheroids were obtained after 10 days of culture, confirming the suitability ofthe proposed approach. To facilitate long term spheroid culture and reliable on-chip drug assay, polydimethylsiloxane microwells were also replicated from the metallic molds. A solvent swelling method was adapted and optimized to Pluronic F127 towardsphysically entrapping the block copolymer molecules within the polydimethylsiloxane network and in turn to improve long termcell-binding resistance. Homogeneous multicellular spheroids were efficiently formed in the concave microwells and on-chip drug assays could be reliably carried out using curcumin as a model anti-cancer drug. Advanced micromachining provides an excellent technological solution to the fabrication of high quality concave microwells. Refereed/Peer-reviewed

An integrated translational biosensing technology based on arrays of silicon nanowire field-effect transistors (SiNW FETs) is described and has been preclinically validated for the ultrasensitive detection of the cancer biomarker ALCAM in serum. High quality SiNW arrays have been rationally designed toward their implementation as molecular biosensors. The FET sensing platform has been fabricated using a complementary metal oxide semiconductor (CMOS)-compatible process. Reliable and reproducible electrical performance has been demonstrated via electrical characterization using a custom-designed portable readout device. Using this platform, the cancer prognostic marker ALCAM could be detected in serum with a detection limit of 15.5 pg/mL. Importantly, the detection could be completed in less than 30 min and span a wide dynamic detection range (∼105). The SiNW-on-a-chip biosensing technology paves the way to the translational clinical application of FET in the detection of cancer protein markers. Refereed/Peer-reviewed

This study was designed to demonstrate the potential of small nanoparticulate lymphotropic contrast agents designed to bind with high affinity to lymphoid cells overexpressing the CD45 antigen. To this end, small gold nanoparticles used as model were conjugated to anti-CD45 antibodies and injected in mice in the dorsal toe of the fore/hind paw. Chemical analysis demonstrated rapid uptake and transport of the nanoparticles in the lymphatic as well as significant retention of the nanoparticles with high bind- ing affinity to lymphoid cells in the popliteal and axillary lymph nodes in comparison to non-targeted nanoparticles. Refereed/Peer-reviewed

Diatom silica microcapsules prepared by purification of diatomaceous earth (DE) were functionalised by dopamine modified iron-oxide nanoparticles, in order to introduce diatoms with magnetic properties. The application of magnetised diatomsas magnetically guided drug delivery microcarriers has been demonstrated. Refereed/Peer-reviewed

Extending on recent progress in control of matter at the nanoscale, functional nanoparticles and drug nanocarriers are being actively developed with the promise of improved delivery of therapeutic agents. Nanotechnology-enabled drug delivery approaches usually aim at reducing the systemic distribution and associated side-effects typically observed with conventional chemotherapeutic molecules as well as increasing the therapeutic index of the active agents. The enhanced permeation and retention effect has been exploited with notable success to passively deliver nanostructured drug carriers and therapeutic nanoparticles in vivo. Strategies aimed at further enhancing the nanocarriers accumulation within tumor tissues are under intensive investigation and could enable, in a not too distant future, the realization of the long sought after goal of chemotherapy without - or with reduced - side-effects. In particular, immunotargeted approaches are widely predicted to offer much greater specificity towards the target cells and tissues. Advancement in molecular biology has indeed made a wealth of information available in biological processes and application of this new knowledge to nanostructured agents, has also generated unprecedented hope of novel molecular diagnostic and therapeutic strategies. Focusing on oncological applications, this review aims to discuss the recent developments in immunotargeting of functional nanoparticles and drug nanocarriers and the integration of these systems into clinically relevant therapeutic applications. Refereed/Peer-reviewed

Introduction: Antibodies covalently conjugated with chelators such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) are required for radioimmunoscintigraphy and radioimmunotherapy, which are of growing importance in cancer medicine. Method: Here, we report a suite of simple methods that provide a preclinical assessment package for evaluating the effects of DOTA conjugation on the in vitro and in vivo performance of monoclonal antibodies. We exemplify the use of these methods by investigating the effects of DOTA conjugation on the biochemical properties of the DAB4 clone of the La/SSB-specific murine monoclonal autoantibody, APOMAB®, which is a novel malignant cell death ligand. Results: We have developed a 96-well microtiter-plate assay to measure directly the concentration of DOTA and other chelators in antibody-chelator conjugate solutions. Coupled with a commercial assay for measuring protein concentration, the dual microtiter-plate method can rapidly determine chelator/antibody ratios in the same plate. The biochemical properties of DAB4 immunoconjugates were altered as the DOTA/Ab ratio increased so that: (i) mass/charge ratio decreased; (ii) hydrodynamic radius increased; (iii) antibody immunoactivity decreased; (iv) rate of chelation of metal ions and specific radioactivity both increased and in vivo, (v) tumor uptake decreased as nonspecific uptake by liver and spleen increased. Conclusion: This simplified suite of methods readily identifies biochemical characteristics of the DOTA-immunoconjugates such as hydrodynamic diameter and decreased mass/charge ratio associated with compromised immunotargeting efficiency and, thus, may prove useful for optimizing conjugation procedures in order to maximize immunoconjugate-mediated radioimmunoscintigraphy and radioimmunotherapy.

This work was partly supported by the Natural Science and Engineering Research Council (NSERC) of Canada. More than a million metallic endovascular devices are implanted each year, but the quest for the perfect material continues. The importance of interfacial properties in the overall biocompatibility of metals and alloys has been recognized for a long time. In particular, these properties modulate the hemocompatibility of devices in contact with blood and, in turn, strongly influence implantation outcomes. In this article, the relative properties of metallic materials commonly used in endovascular applications are reviewed. Particular emphasis is given to the corrosion behavior of metallic endovascular materials and the specific surface treatments used in the production processes. Issues relative to corrosion assays will also be reviewed in terms of their relevance to in vivo applications. The potential adverse effects of degradation products with respect to endovascular applications will be described. Finally, this review addresses future perspectives of metallic devices in endovascular procedures in view of the recent promises of antiproliferative strategies that are likely to profoundly modify current procedures.

Catheter-based brachytherapy is one of the most effective modalities to inhibit hyperplasia following revascularization procedures. Radioactive stents have failed, however, to prevent clinical hyperplasia due to excessive late lumen loss on the edge of the devices. Numerous strategies have been proposed to circumvent the drawbacks of irradiation therapies, such as the use of more appropriate radionuclides or the "hot-end" stents approach. This paper describes versatile radioactive devices obtained by coating plasma functionalized surfaces-stents or catheters-with a hyaluronan (HA)-diethylenetriamine pentaacetic acid (DTPA) conjugate (HA-DTPA) complexed with a gamma or beta radionuclide. Yttrium and indium were used as radionuclide models, due to their suitability for endovascular radiotherapy. X-ray photoelectron microscopy and time-of-flight secondary ions mass spectrometry analyses confirmed the successful immobilization of the HA-DTPA conjugate on both the metallic (NiTi) and polymeric (Teflon) plasma functionalized surfaces. HA-DTPA-coated surfaces were significantly more hydrophilic than bare surfaces (39.5 degrees vs. 67 degrees on NiTi substrate and 29 degrees vs. 128 degrees on Teflon substrate). Therapeutic doses of yttrium and indium were easily loaded onto the surfaces and remained stable over 2 weeks with a radionuclide loss of about 6%. The HA-DTPA-coated Teflon surfaces presented significantly less fibrinogen adsorption than uncoated materials in an in vitro flow model. This approach, which combines the hemocompatibility of HA-coated surfaces and the anti-proliferative effects of an appropriate radiotherapy, constitutes a promising methodology to alleviate the restenosis induced by existing devices.

Background: Staphylococcus aureus in its biofilm form has been associated with recalcitrant chronic rhinosinusitis with significant resistance to conventional therapies. This study aims to determine if liposomal-encapsulation of a precursor ofthe naturally occurring antimicrobial nitric oxide (NO) enhances its desired anti-biofilm effects against S. aureus, in the hope that improving its efficacy can provide an effective topical agent for future clinical use. Methodology: S. aureus ATCC 25923 biofilms were grown in-vitro using the Minimum Biofilm Eradication Concentration(MBEC) device and exposed to 3 and 60 mg/mL of the NO donor isosorbide mononitrate (ISMN) encapsulated into different anionic liposomal formulations based on particle size (unilamellar ULV, multilamellar MLV) and lipid content (5 and 25 mM) at 24 h and 5 min exposure times. Biofilms were viewed using Live-Dead Baclight stain and confocal scanning laser microscopy and quantified using the software COMSTAT2. Results: At 3 and 60 mg/mL, ISMN-ULV liposomes had comparable and significant anti-biofilm effects compared to untreated control at 24 h exposure (p = 0.012 and 0.02 respectively). ULV blanks also had significant anti-biofilm effects at both 24 h and 5 min exposure (p = 0.02 and 0.047 respectively). At 5 min exposure, 60 mg/mL ISMN-MLV liposomes appeared to have greater anti-biofilm effects compared to pure ISMN or ULV particles. Increasing liposomal lipid content improved the anti-biofilm efficacy of both MLV and ULVs at 5 min exposure. Conclusion: Liposome-encapsulated ‘‘nitric oxide’’ is highly effective in eradicating S. aureus biofilms in-vitro, giving great promise for use in the clinical setting to treat this burdensome infection. Further studies however are needed to assess its safety and efficacy in-vivo before clinical translation is attempted. Refereed/Peer-reviewed

Based on promising reports from international randomized trials such as BENESTENT, vascular stent implantation has been increasingly used - with more than 500,000 implantations per year worldwide - and has become a procedure of choice in the treatment of atherosclerotic vascular disease [1,2]. Since the first implantation in 1986, many devices, mostly balloon expandable stainless steel stents, have been approved by regulatory agencies, for both peripheral and coronary revascularization. In the early 90’s, many studies have reported experimental temporary or permanent use of NiTi stents [3,4]. Due to the thermoelastic properties of the alloy, optimal deployment of NiTi self expanding stents can be easily achieved with high expansion ratio and less longitudinal shortening than most common stainless steel devices. In addition, their flexibility and radiopacity along with their good biocompatibility and resistance to corrosion have contributed to their increasing use in cardiovascular applications [5-7]. Despite its good biocompatibility, like all metallic materials NiTi is prone to adsorption of plasma protein such as fibrinogen, which is a potent promoter of platelet adhesion [8]. In a recent study, Makkar et al. have shown that surface topography significantly affects the thrombogenicity of NiTi stents, which may in turn have an effect on complications observed much after implantation [9]. Indeed, platelets adhesion is the first step of thrombus formation which may lead to acute and sub-acute thrombosis. Stent thrombosis still represents a major complication after stent implantation, especially for small vessels, thrombus containing lesions and bifurcation stenoses [10]. Moreover, through the release of growth factor by activated platelets, thrombus formation is expected to participate to the restenosis process initiation [11]. Many strategies have been developed to reduce stents thrombogenicity such as improvement of surface characteristics or coating with pharmacological drugs and polymers [9,12,13].

The deposition of polysaccharide-based self-assembled nanocoatings onto damaged arteries is described as a means not only to protect a damaged artery against thrombogenesis, but also to control the healing processes by incorporating biologically active components within the multilayer. As shown by confocal microscopy, the polysaccharide multilayer was retained on the artery in physiological condition and prevented platelet adhesion. Diffusion of the polysaccharides within the artery was also observed and may be used to efficiently target the vascular wall. The NO-precursor l-arginine was used a drug model and incorporated within the self-assembled layers.

Building on recent breakthroughs in the field of microfluidic-based capture of rare cancer cells circulating in the blood, the present article reports on the use of Herceptin functionalized PDMS devices designed to efficiently capture from blood cancer cells, overexpressing the tyrosine kinase human epidermal growth factor receptor HER2. The identification of patients overexpressing HER2 is critical as it typically associates with an aggressive disease course in breast cancer and poor prognosis. Importantly, HER2 positive patients have been found to significantly benefit from Herceptin Trastuzumab, a humanized monoclonal antibody MAb against HER2. Disposable PDMS devices prepared using standard soft lithography were functionalized by the plasma polymerization of an epoxy-containing monomer. The epoxy-rich thin film AGEpp thus created could be conjugated with Herceptin either directly or through a polyethylene glycol interlayer. The properties and reactivity toward the monoclonal antibody conjugation of these coatings were determined using x-ray photoelectron spectroscopy; direct conjugation provided a good compromise in reactivity and resistance to biologically nonspecific fouling and was selected. Using the breast cancer cell line SKBR3 as a model for cells overexpressing HER2, the immunocapture efficacy of the Herceptin functionalized PDMS was demonstrated in model studies. Validation studies confirmed the ability of the device to efficiently capture 80 capture yield HER2 positive cells from full blood. Refereed/Peer-reviewed