Recently, ultrasmall gadolinium oxide (Gd2O3) nanoparticles with high longitudinal relaxation rate have received enormous attention. However, it can't be concentrated in tumor site through intravenous administration due to its ultrasmall size. In this project, we coated ultrasmall Gd2O3 nanoparticles with a near-infrared (NIR) light-absorbing polymer polypyrrole (PPy), modifying with hyaluronic acid (HA) and loaded aluminum phthalocyanine (AlPc), the Gd2O3@PPy/AlPc-HA nanoparticles could be used for fluorescence (FL)/magnetic resonance (MR)/photoacoustic (PA) imaging guided as well as remotely controlled PTT/PDT combined anti-tumor therapy. Polymerized PPy with high photothermal conversion efficiency was introduced to assemble the ultrasmall Gd2O3 nanoparticles which have high longitudinal relaxation rate and signal-to-noise ratio, thus obtaining Gd2O3@PPy nanoparticles which possess a larger particle size and can be more suitable for tumor targeting based on the EPR effect. HA and AlPc were adsorbed on PPy for HA-mediated tumor targeting and photodynamic therapy respectively. The in vivo triple-modal imaging revealed that Gd2O3@PPy/AlPc-HA nanoparticles possess enhanced tumor uptake effect after intravenous injection. More importantly, the nanoparticles exhibited an obvious photothermal effect, which can trigger the release and de-quench of AlPc. The anti-tumor efficiency further corroborated that the combined therapy achieved an excellent tumor inhibition therapeutic effect which was much better than any other mono-therapy. Consequently, our work encouraged further exploration of polymer-based multifunctional theranostic nanoparticles for cancer combination therapy under remote near-infrared (NIR) light controls.

Early detection and therapy of esophageal cancer is very important for improving the prognosis and survival rate of the patient. A theranostic agent that combines multimodal imaging with cancer therapy may be used for augmenting the visualization and treatment of the cancer. Herein, we report the synthesis of a hollow tantalum oxide (TaOx) nanoparticle that was successfully engineered by encapsulation of polypyrrole (PPy) and doxorubicin (DOX) in the core and conjugation with a near infrared fluorescence dye (NIRDye800) on the shell of the hollow TaOx nanoparticles. The as-prepared core/shell nanoparticles showed multimodal imaging features including computed tomography (CT) (for the preliminary location of the tumor), photoacoustic (for the anatomical localization of the tumor), and fluorescence imaging (for real-time monitoring of the tumor margin) and pH- and thermal-sensitive drug release. Because the early esophageal carcinoma is a type of superficial cancer, a subcutaneous model in the thigh was used for the in vivo study. The core/shell nanoparticles shows high imaging contrast between the tumor and the adjacent tissues and controllable photothermal therapy (PTT) and chemotherapy. Our results indicated that the obtained core/shell nanoparticles had significant potential in the triple-modality imaging guided precisely chemo-thermal synergetic therapy of esophageal cancer. In addition, after aerosol administration, our nanoparticles also exhibited comparable therapeutic efficacy with the intravenous administration, which is more suitable for clinical therapy of esophageal carcinoma.

In current work highly sensitive and stable electrochemical sensor for simultaneous non-enzymatic detection of epinephrine (EP), L-tyrosine (L-Tyr) is constructed based on Electron beam irradiated Polypyrrole (EB-Ppy) nanospheres (Zeta potential 33.69 mV at pH 7) embedded over bovine serum albumin (BSA) (Zeta potential - 11.54 mV at pH 7) porous structure, fabricated by simple chemical routes. The BSA structure has the advantages of large surface area, excellent structure stability, rich pore channels and redox mediator role. The constructed sensor exhibited excellent sensor performances by the combination of protein with NH group and recorded the linear response of EP, L-Tyr individual in the concentration range of 100 nM-1 mM, 100 nM-800 μM, with detection limit 7.1 nM, 8.8 nM (S/N = 3σ/b). The EB-Ppy-BSA/GCE electrochemical sensor manifests intriguing application with good sensitivity, selectivity and reproducibility towards the EP, L-Tyr detection. The practical analytical utility provides great promise by selective measurements in tea, and chicken extract which has a promising future for biological and healthcare applications.

Purpose: To develop a first trimester prediction model for gestational diabetes mellitus (GDM) using obesity, placental, and inflammatory biomarkers.

Methods: We used a first trimester dataset of the ASPRE study to evaluate clinical and biochemical biomarkers. All biomarkers levels (except insulin) were transformed to gestational week-specific medians (MoMs), adjusted for maternal body mass index (BMI), maternal age, and parity. The MoM values of each biomarker in the GDM and normal groups were compared and used for the development of a prediction model assessed by area under the curve (AUC).

Results: The study included 185 normal and 20 GDM cases. In the GDM group, compared to the normal group BMI and insulin (P = 0.003) were higher (both P < 0.003). The MoM values of uterine artery pulsatility index (UtA-PI) and soluble (s)CD163 were higher (both P < 0.01) while pregnancy associated plasma protein A (PAPP-A), placental protein 13 (PP13), and tumor-necrosis factor alpha (TNFα) were lower (all P < 0.005). There was no significant difference between the groups in placental growth factor, interleukin 6, leptin, peptide YY, or soluble mannose receptor (sMR/CD206). In screening for GDM in obese women the combination of high BMI, insulin, sCD163, and TNFα yielded an AUC of 0.95, with detection rate of 89% at 10% false positive rate (FPR). In non-obese women, the combination of sCD163, TNFα, PP13 and PAPP-A yielded an AUC of 0.94 with detection rate of 83% at 10% FPR.

Conclusion: A new model for first trimester prediction of the risk to develop GDM was developed that warrants further validation.

Keywords: Gestational diabetes; Insulin; Leptin; MAP; Maternal serum biomarkers; Obesity; PAPP-A; PP13; PPY; Singleton pregnancy; TNFα; UtA-PI; sCD163.

We report the conducting nature of carbon dots (Cdots) synthesized from citric acid and ethylene diamine. Chemically synthesized conducting nanocomposite consisting of Cdots and polypyrrole (PPy) is further reported, which showed higher electrical conductiviy in comparison to the components i.e., Cdots or PPy. The conductive film of the composite material was used for highly sensitive and selective detection of picric acid in water as well as in soil. To the best of our knowledge, this is the first report on the conductivity based sensing application of Cdot nanocomposite contrary to the traditional fluorescence based sensing approaches.

A magnetic chitosan-polypyrrole-magnetite (Cs-PPy-Fe3O4) nanocomposite is prepared in a simple one-step method via in situ chemical polymerization of pyrrole using anhydrous FeCl3 as an oxidant in the presence of Cs. Magnetic Fe3O4 nanoparticles of size in the range of 10-20 nm are successfully introduced into the Cs-PPy matrix. Adsorption of an anionic dye (acid green 25, AG) from aqueous solution into the Cs-PPy-Fe3O4 nanocomposite is investigated. The nanocomposite exhibits high adsorption capacity compared to PPy and Cs themselves. After the adsorption, the Cs-PPy-Fe3O4 nanocomposite is easily separated from the reaction solution using an external magnet, which is very useful for practical applications.

Electrical stimulation (ES) with conductive polymers can dramatically enhance neurite outgrowth and promote neural regeneration. However, besides ES, the practical applications of neural repair is also highly dependent on the nerve cell functionality and response to substrate conductivity. Therefore, the combination of the ES and suitable materials, such as tissue scaffolds, has been applied to facilitate treatment of neural injuries and demonstrated great potential in peripheral nerve regeneration. In this study, polypyrrole/silk fibroin (PPy/SF) conductive composite scaffold was fabricated by 3D bioprinting and electrospinning. Schwann cells seeded on these scaffolds were electrically stimulated and hence demonstrated enhanced viability, proliferation and migration, as well as upregulated expression of neurotrophic factors. Furthermore, the constructed PPy/SF conductive nerve guidance conduits accompanying with ES could effectively promote axonal regeneration and remyelination in vivo. Moreover, we found that the MAPKs signal transduction pathway was activated by ES at the conductive conduit. Our findings demonstrate that the PPy/SF conductive composite scaffolds with longitudinal guidance exhibit favorable properties for clinical use and promotes nerve regeneration and functional recovery.

Keywords: 3D bioprinting; Electrical stimulation; Electrospinning; Nerve; Polypyrrole; Silk fibroin.

Polypyrrole (PPy) was electropolymerized in xanthan hydrogels (XCA), resulting in electroactive XCAPPy scaffolds with (15 ± 3) wt.% PPy and (40 ± 10) μm thick. The physicochemical characterization of hybrid XCAPPy scaffolds was performed by means of cyclic voltammetry, swelling tests, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM) and tensile tests. XCAPPy swelled~80% less than XCA. FTIR spectra and thermal analyses did not evidence strong interaction between PPy and XCA matrix. XCAPPy presented a porous stratified structure resulting from the arrangement of PPy chains parallel to XCA surface. Under stress XCAPPy presented larger strain than neat XCA probably due to the sliding of planar PPy chains. The adhesion and proliferation of fibroblasts onto XCA and XCAPPy were evaluated in the absence and in the presence of external magnetic field (EMF) of 0.4T, after one day, 7 days, 14 days and 21 days. Fibroblast proliferation was more pronounced onto XCAPPy than onto XCA, due to its higher hydrophobicity and surface roughness. EMF stimulated cell proliferation onto both scaffolds.

This study aimed to distinguish the rhizomes of Paris polyphylla var. yunnanensis (Franch) Hand Mazz (PPY) and Paris veitnamensis (Takht.) H. Li (PV) using metabolomics-based ultra high-performance liquid chromatography coupled with quadrupole time-of-fligh mass spectrometry (UHPLC/Q-TOF MS). First, the UHPLC/Q-TOF MS approach was optimized for metabolite profiling. Then, the MS data were processed using UNIFI™ combined with an in-house library to automatically characterize the metabolites. Based on the exact mass information, the fragmentation characteristics, and the retention time of compounds, and the fragmentation mechanism and retention behavior of steroidal glycosides in the references, the structures identified by UNIFI were further verified. Overall, 146 metabolites, including 42 potential new compounds, were identified or tentatively identified. Pattern recognition analysis of the PPY and PV MS data revealed that they were clearly separated, and 15 potential biomarkers for differentiating between them were selected. These biomarkers were subsequently used to successfully predict the genus of PPY and PV samples. These results indicated that metabolite profiling by UHPLC/Q-TOF MS is an effective, robust approach for determining the characteristic biomarkers that differentiate between TCM species with multiple botanical origins.

The potential applications of aligned, conductive electrospun fibers have been widely studied in anisotropic tissue regeneration. In this study, aligned porous poly L-lactic acid fibers were obtained with electrospinning, then polypyrrole nanoparticles (PPy NPs) were coated onto the porous fibers with oxidation polymerization to prepare electrically conductive fibers with about 1.24 μm of diameter, and their surface conductivity was about 50 mS. The results of L929 cell test showed that more than 55% of cells grew along the aligned porous fiber axis, confirming that the cell guidance of aligned porous fibers was better than that of non-porous fibers. The results of differentiated PC12 cells on porous fibers showed that the alignment degree of neurite outgrowth and average neurite length of the cells were 84% and 111 μm, respectively, which were larger than those on the non-porous fibers. A primary mechanism was proposed to explain effect of these pores on cell/neurite adhesion and orientation along the aligned porous fibers.

A medical nanoplatform with small size, low cost, biocompatibility, good biodegradability, and, in particular, multifunctionality has attracted much attention in the exploration of novel therapeutic methodologies. As an emerging material of self-assembled porous structure, metal-organic frameworks (MOFs) have high expectations because of their special properties compared to traditional porous materials. Therefore, integration of MOFs and functional materials is leading to the creation of new multifunctional composites/hybrids. Photothermal therapy (PTT), using near-IR (NIR) laser-absorbing nanomaterials as PTT agents, has shown encouraging therapeutic effects to photothermally ablate tumors. However, the most of widely used PTT agents are inorganic materials and nonbiodegradable. Herein, uniform polypyrrole (PPy) nanoparticles (NPs) with good biodegradability were synthesized by a microemulsion method. The PPy NPs were further coated with the mesoporous iron-based MOF structure MIL-100 by interaction between PPy NPs and MIL-100 precursors at room temperature. As a multifunctional nanoplatform, an anticancer drug could easily be loaded into the mesopores of the MIL-100 shell. The PPy core, as an organic photothermal agent, is able to photothermally ablate cancer cells and improve the efficacy of chemotherapy under NIR irradiation. The composites showed an outstanding in vivo synergistic anticancer capacity. Our work could encourage further study in the construction of a synergetic system using MOFs and organic PTT agents.

We developed a new electrochemical sensor based on TiO₂ and polypyrrole (PPy) molecularly imprinted polymer (MIP) nanocomposites for the high selective detection of p-nonylphenol in food samples, which is considered as a kind of endocrine disrupting chemical and harmful to human health. With p-nonylphenol as template molecules, the molecularly imprinted polymer was synthesized by the chemical oxidative polymerization of pyrrole and deposited on the surface of TiO₂ nanoparticles to form partially encapsulated PPy@TiO₂ nanocomposites, denoted as NP-PPy@TiO₂ MIP. p-Nonylphenol was bound in the PPy matrix through hydrogen bond and π-π interaction between p-nonylphenol and PPy skeleton. NP-PPy@TiO₂ MIP nanocomposites were modified onto glassy carbon electrode (GCE) and p-nonylphenol molecules were excluded from PPy layers by potentiostatic sweeping at the potential of 1.3 V. The as-prepared electrochemical sensor obtained a large amount of micro cavities in PPy layer which could specially recognize and combine target molecules p-nonylphenol. After special adsorption of p-nonylphenol from samples, p-nonylphenol embedded in the PPy layer exhibited a strong differential pulse voltammetry (DPV) response at 0.56 V, which can be used for the detection of p-nonylphenol with a linearly proportional concentration range of 1.0 × 10^-8 to 8 × 10^-5 mol/L and a detection limit of 3.91 × 10^-9 mol/L. The good stability, reproducibility and specificity of the resulting MIP electrochemical sensor are demonstrated. It might open a new window for investigation of selectively electrochemical sensing of small organic molecules from their analogues with the molecular imprinting technique.

Over the past decade, tissue engineering strategies, mainly involving injectable hydrogels and epicardial biomaterial patches, have been pursued to treat myocardial infarction. However, only limited therapeutic efficacy is achieved with one single means. Here, a combined therapy approach is proposed, that is, the co-administration of a conductive hydrogel patch and injectable hydrogel to the infarcted myocardium. The self-adhesive conductive hydrogel patch is fabricated based on Fe3+-induced ionic coordination between dopamine-gelatin (GelDA) conjugates and dopamine-functionalized polypyrrole (DA-PPy), which forms a homogenous network. The injectable and cleavable hydrogel is formed in situ via Schiff base reaction between oxidized sodium hyaluronic acid (HA-CHO) and hydrazided hyaluronic acid (HHA). Compared with single mode system (SMS), injecting HA-CHO/HHA hydrogel intramyocardially followed by painting conductive GelDA/DA-PPy hydrogel patch on the heart surface results in more pronounced improvement of cardiac function in terms of echocardiographical, histological and angiogenic outcomes.

Fiber supercapacitors are promising energy storage devices for wearable applications. However, the fiber supercapacitors are currently limited by the mediocre capacitance performances due to the use of typical carbon materials as the anode, sacrificing the volumetric energy density of the whole device. In addition, the inability to undergo washable cycles and poor self-discharge rate prevents the fiber-shaped supercapacitors from being a true energy textile and affects their practicability. Hence, the porous anode electrode FeOOH/PPy@CF has been firstly prepared with a high volumetric capacitance of 30.17 F cm-3, contributing to a high volumetric energy density of 2 mWh cm-3 (based on the whole encapsulated device) for a fiber asymmetric supercapacitor MnO2@CF//FeOOH/PPy@CF in PVA/LiCl. Good flexibility could be exhibited when it was woven into a glove. Desired working voltage and capacity output could be easily obtained when connecting devices in series and parallel. The encapsulated device could work stably even after it was dipped for multiple cycles in different solutions and with intensive stirring in water that simulates washing cycles. The self-discharge rate could be mitigated when an ionogel electrolyte ([EMIM][TFSI]/FS) was incorporated and this further enhanced the energy density to 3.7 mWh cm-3. The outstanding properties of our assembled asymmetric fiber supercapacitor device render it a good candidate for practical wearable energy storage devices.

Multifunctional nanocomposites for image-guided cancer therapy are highly desired in clinical application. Herein, a novel theranostic agent based on gold and ferroferric oxide nanoparticles coating polypyrrole particles (PPy@Fe3O4/Au nanocomposites) for computed tomography (CT) and magnetic resonance (MR) imaging guided photothermal therapy was successfully assembled by a very facile electrostatic adsorption method. PPy@Fe3O4/Au nanocomposites exhibit good biocompatibility in vitro and in vivo. Because of high r2 relaxivity of Fe3O4 and high X-ray attenuation ability of Au, the PPy@Fe3O4/Au nanocomposites exhibited desirable CT and MR imaging performance, which provide more comprehensive and accurate diagnostic information. Moreover, PPy@Fe3O4/Au nanocomposites can efficiently kill cancer cells by hyperthermia with the guiding of CT and MR imaging, even completely ablate tumours. Hence, the electrostatic adsorption assembled PPy@Fe3O4/Au nanocomposites have great potential in clinical application for diagnosing and treating tumour in the future.

Electrical stimulation (ES) via electrodes is promising for treating chronic wounds, but this electrode-based strategy is unable to stimulate the whole wound area and the therapeutic outcome may be compromised. In this study, a conductive poly(2-hydroxyethyl methacrylate) (polyHEMA)/polypyrrole (PPY) hydrogel was developed, and 3-sulfopropyl methacrylate was covalently incorporated in the hydrogel's network to in-situ dope the PPY and maintain the hydrogel's conductivity in the weak alkaline physiological environment. The obtained hydrogel was superior to the commercial Hydrosorb® dressing for preventing bacterial adhesion and protein absorption, and this is helpful to reduce the possibilities of infection and secondary damage during dressing replacement. The in vitro scratch assay demonstrates that ES through the hydrogel enhanced fibroblast migration, and this enhancement effect remained even after the ES was ended. The in vivo assay using diabetic rats shows that when ES was conducted with this polyHEMA/PPY hydrogel, the healing rate was faster than that achieved by the electrode-based ES strategy. Therefore, this polyHEMA/PPY hydrogel shows a great potential for developing the next generation of ES treatment for chronic wounds. STATEMENT OF SIGNIFICANCE: Electrical stimulation (ES) via separated electrodes is promising for treating chronic wounds, but this electrode-based strategy is unable to stimulate the whole wound area, compromising the therapeutic outcome. Herein, a hydrogel was developed with stable electrical conductivity in the physiological environment and strong resistance to protein absorption and bacterial adhesion. The in vitro and in vivo tests proved that ES applied through the flexible and conductive hydrogel that covered the wound was superior to ES through electrodes for promoting the healing of the chronic wound. This hydrogel-based ES strategy combines the advantages of ES and hydrogel dressing and will pave the way for the next generation of ES treatment for chronic wounds.

One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemi-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemi-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to "self-delithiation" or "self-discharging" at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ∼150 nm for bare SiNPs to ∼380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries.

An inseparable part of ionic actuator characterization is a set of adequate measurement devices. Due to significant limitations of available commercial systems, in-house setups are often employed. The main objective of this work was to develop a software solution for running isotonic and isometric experiments on a hardware setup consisting of a potentiostat, a linear displacement actuator, a force sensor, and a voltmeter for measuring the force signal. A set of functions, hardware drivers, and measurement automation algorithms were developed in the National Instruments LabVIEW 2015 system. The result is a software called isotonic (displacement) and isometric (force) electro-chemo-measurement software (IIECMS), that enables the user to control isotonic and isometric experiments over a single compact graphical user interface. The linear ionic actuators chosen as sample systems included different materials with different force and displacement characteristics, namely free-standing polypyrrole films doped with dodecylbenzene sulfonate (PPy/DBS) and multiwall carbon nanotube/carbide-derived carbon (MWCNT-CDC) fibers. The developed software was thoroughly tested with numerous test samples of linear ionic actuators, meaning over 200 h of experimenting time where over 90% of the time the software handled the experiment process autonomously. The uncertainty of isotonic measurements was estimated to be 0.6 µm (0.06%). With the integrated correction algorithms, samples with as low as 0 dB signal-to-noise ratio (SNR) can be adequately described.

This paper presents risk-based enteric pathogen log reduction targets for non-potable and potable uses of a variety of alternative source waters (i.e., locally-collected greywater, roof runoff, and stormwater). A probabilistic Quantitative Microbial Risk Assessment (QMRA) was used to derive the pathogen log₁₀ reduction targets (LRTs) that corresponded with an infection risk of either 10^-4 per person per year (ppy) or 10^-2 ppy. The QMRA accounted for variation in pathogen concentration and sporadic pathogen occurrence (when data were available) in source waters for reference pathogens in the genera Rotavirus, Mastadenovirus(human adenoviruses), Norovirus, Campylobacter, Salmonella, Giardia and Cryptosporidium. Non-potable uses included indoor use (for toilet flushing and clothes washing) with occasional accidental ingestion of treated non-potable water (or cross-connection with potable water), and unrestricted irrigation for outdoor use. Various exposure scenarios captured the uncertainty from key inputs, i.e., the pathogen concentration in source water; the volume of water ingested; and for the indoor use, the frequency of and the fraction of the population exposed to accidental ingestion. Both potable and non-potable uses required pathogen treatment for the selected waters and the LRT was generally greater for potable use than non-potable indoor use and unrestricted irrigation. The difference in treatment requirements among source waters was driven by the microbial quality of the water - both the density and occurrence of reference pathogens. Greywater from collection systems with 1000 people had the highest LRTs; however, those for greywater collected from a smaller population (~ 5 people), which have less frequent pathogen occurrences, were lower. Stormwater had highly variable microbial quality, which resulted in a range of possible treatment requirements. The microbial quality of roof runoff, and thus the resulting LRTs, remains uncertain due to lack of relevant pathogen data.

A label-free electrochemical miRNA biosensor was developed based on a pyrrolidinyl peptide nucleic acid (acpcPNA)/polypyrrole (PPy)/silver nanofoam (AgNF) modified electrode. The AgNF was electrodeposited as redox indicator on a gold electrode, which was then functionalized with an electropolymerized layer of PPy, a conducting polymer, to immobilize the PNA probes. The fabrication process was investigated by electrochemical impedance spectroscopy. The biosensor was used to detect miRNA-21, a biomarker abnormally expressed in most cancers. The signal was monitored by the change in current of the AgNF redox reaction before and after hybridization using cyclic voltammetry. Two PNA probe lengths were investigated and the longer probe exhibited a better performance. Nucleotide overhangs on the electrode side affected the signal more than overhangs on the solution side due to the greater insulation of the sensing surface. Under optimal conditions, the electrochemical signal was proportional to miRNA-21 concentrations between 0.20fM and 1.0nM, with a very low detection limit of 0.20fM. The biosensor showed a high specificity which could discriminate between complementary, single-, doubled-base mismatched, and non-complementary targets. Three out of the seven tested plasma samples provided detectable concentrations (63 ± 4, 111 ± 4 and 164 ± 7fM). The sensor also showed good recoveries (81-119%). The results indicated the possibilities of this biosensor for analysis without RNA extraction and/or amplification, making the sensor potentially useful for both the prognosis and diagnosis of cancer in clinical application.

In the proposed study, for the first time, sensitive electrochemical detection of a breast cancer biomarker microRNA (miRNA), mir-21 was achieved via electropolymerized polypyrrole (PPy) modified pencil graphite electrodes (PPy/PGE). The detection of hybridization of electrochemically doped probe miRNA, antimir-21, with its complementary target, mir-21 was monitored by either electrochemical impedance spectroscopy (EIS) via comparison of charge transfer resistance (Rct) values before and after hybridization or by electrochemical reduction signal of an hybridization indicator, Meldola's blue (MDB). The study covers all the optimization steps for hybridization procedure and electropolymerization of pyrrole as well as detection from real samples of breast cancer cell line, MCF-7. The designed sensor shows a high selectivity and a low detection limit of 0.17nM thanks to electrical conductivity and porous structure of PPy.

The delivery of drugs in a controllable fashion is a topic of intense research activity in both academia and industry because of its impact in healthcare. Implantable electronic interfaces for the body have great potential for positive economic, health, and societal impacts; however, the implantation of such interfaces results in inflammatory responses due to a mechanical mismatch between the inorganic substrate and soft tissue, and also results in the potential for microbial infection during complex surgical procedures. Here, we report the use of conducting polypyrrole (PPY)-based coatings loaded with clinically relevant drugs (either an anti-inflammatory, dexamethasone phosphate (DMP), or an antibiotic, meropenem (MER)). The films were characterized and were shown to enhance the delivery of the drugs upon the application of an electrochemical stimulus in vitro, by circa (ca.) 10⁻30% relative to the passive release from non-stimulated samples. Interestingly, the loading and release of the drugs was correlated with the physical descriptors of the drugs. In the long term, such materials have the potential for application to the surfaces of medical devices to diminish adverse reactions to their implantation in vivo.

Conductive polymer composites (CPCs) containing nanoscale conductive fillers have been widely studied for their potential use in various applications. In this paper, polypyrrole (PPy)/polydopamine (PDA)/silver nanowire (AgNW) composites with high electromagnetic interference (EMI) shielding performance, good adhesion ability and light weight are successfully fabricated via a simple in situ polymerization method followed by a mixture process. Benefiting from the intrinsic adhesion properties of PDA, the adhesion ability and mechanical properties of the PPy/PDA/AgNW composites are significantly improved. The incorporation of AgNWs endows the functionalized PPy with tunable electrical conductivity and enhanced EMI shielding effectiveness (SE). By adjusting the AgNW loading degree in the PPy/PDA/AgNW composites from 0 to 50 wt%, the electrical conductivity of the composites greatly increases from 0.01 to 1206.72 S cm-1, and the EMI SE of the composites changes from 6.5 to 48.4 dB accordingly (8.0-12.0 GHz, X-band). Moreover, due to the extremely low density of PPy, the PPy/PDA/AgNW (20 wt%) composites show a superior light weight of 0.28 g cm-3. In general, it can be concluded that the PPy/PDA/AgNW composites with tunable electrical conductivity, good adhesion properties and light weight can be used as excellent EMI shielding materials.