Highly Efficient Wavelength-Resolved Electrochemiluminescence of Carbon Nitride Films for Ultrasensitive Multiplex MicroRNA Detection.

The development of electrochemiluminescence (ECL) emitters of different colors with high ECL efficiency (ΦECL) is appealing yet challenging for ultrasensitive multiplexed bioassays. Herein, we report the synthesis of highly efficient polymeric carbon nitride (CN) films with fine-tuned ECL emission from blue to green (410, 450, 470, and 525 nm) using the precursor crystallization method. More importantly, naked eye-observable and significantly enhanced ECL emission was achieved, and the cathodic ΦECL values were ca. 112, 394, 353, and 251 times those of the aqueous Ru(bpy)3Cl2/K2S2O8 reference. Mechanism studies showed that the density of surface-trapped electrons, the associated nonradiative decay pathways, and electron-hole recombination kinetics were crucial factors for the high ΦECL of CN. Based on high ΦECL and different colors of ECL emission, the wavelength-resolved multiplexing ECL biosensor was constructed to simultaneously detect miRNA-21 and miRNA-141 with superior low detection limits of 0.13 fM and 25.17 aM, respectively. This work provides a facile method to synthesize wavelength-resolved ECL emitters based on metal-free CN polymers with high ΦECL for multiplexed bioassays.

Diagnostic accuracy of severe periodontitis for Ramfjord teeth based on different classifications.

OBJECTIVE: To evaluate the accuracy of Ramfjord teeth (RT) protocol for the diagnosis of severe periodontitis based on different classifications and explore the misclassification bias such as teeth loss. METHODS: Patients (n = 435) receiving full-mouth periodontal examination (FMPE) were included. Patients were classified as severe (stage III/IV) periodontitis and no/mild/moderate (no/stage I/II) periodontitis according to the case definition proposed by the Centers for Disease Control and Prevention (CDC) and the American Academy of Periodontology (AAP)-(CDC/AAP), a new classification introduced by AAP and the European Federation of Periodontology (EFP)-(AAP/EFP), and consensus of Chinese experts (CCE). Sensitivity, specificity, positive predictive value, negative predictive value, Youden's index, and area under the receiver operating characteristic curve (AUROC) compared with FMPE were evaluated. RESULTS: The specificity of RT was 86.8%, 92.2%, and 77.1% when compared with FMPE protocol based on CDC/AAP, AAP/EFP, and CCE classifications, while the AUROC value was 0.934, 0.961, and 0.886 specifically. The loss of the first molar leads to the greatest reduction in the detection rate of severe periodontitis. CONCLUSIONS: RT showed the highest specificity based on the new AAP/EFP classification. The loss of the first molar leads to the greatest reduction in the detection rate of severe periodontitis.

Electrochemically Switchable Circularly Polarized Photoluminescence within Self-Assembled Conducting Polymer Helical Microfibers.

Achieving electrically and/or electrochemically controlled circularly polarized photoluminescence (CPL) is challenging due to the non-electroactive characteristics of most chiral materials and the non-electrosensitive feature of materials' chiroptical signals. Here we found that the CPL of self-assembled conducting polyaniline (PANI) helical microfibers could be reversibly switched by applying an alternating electrical bias. The conducting polymer is not the fluorophore but can transfer its chirality to the coassembled aggregation-induced emission (AIE) fluorescent molecules. The electrochemically switchable CPL is derived from the reversible transformation of the chirality of the polyaniline microfibers, which is probably due to the change in the molecular interchain distance upon doping/dedoping. Subsequently, we have demonstrated double-layer information encryption based on the electrochemically reversible CPL and conductance.

Pneumatic microvalve-based hydrodynamic sample injection for high-throughput, quantitative zone electrophoresis in capillaries.

A hybrid microchip/capillary electrophoresis (CE) system was developed to allow unbiased and lossless sample loading and high-throughput repeated injections. This new hybrid CE system consists of a poly(dimethylsiloxane) (PDMS) microchip sample injector featuring a pneumatic microvalve that separates a sample introduction channel from a short sample loading channel, and a fused-silica capillary separation column that connects seamlessly to the sample loading channel. The sample introduction channel is pressurized such that when the pneumatic microvalve opens briefly, a variable-volume sample plug is introduced into the loading channel. A high voltage for CE separation is continuously applied across the loading channel and the fused-silica capillary separation column. Analytes are rapidly separated in the fused-silica capillary, and following separation, high-sensitivity MS detection is accomplished via a sheathless CE/ESI-MS interface. The performance evaluation of the complete CE/ESI-MS platform demonstrated that reproducible sample injection with well controlled sample plug volumes could be achieved by using the PDMS microchip injector. The absence of band broadening from microchip to capillary indicated a minimum dead volume at the junction. The capabilities of the new CE/ESI-MS platform in performing high-throughput and quantitative sample analyses were demonstrated by the repeated sample injection without interrupting an ongoing separation and a linear dependence of the total analyte ion abundance on the sample plug volume using a mixture of peptide standards. The separation efficiency of the new platform was also evaluated systematically at different sample injection times, flow rates, and CE separation voltages.

Direct fiber comb stabilization to a gas-filled hollow-core photonic crystal fiber.

We have isolated a single tooth from a fiber laser-based optical frequency comb for nonlinear spectroscopy and thereby directly referenced the comb. An 89 MHz erbium fiber laser frequency comb is directly stabilized to the P(23) (1539.43 nm) overtone transition of (12)C(2)H(2) inside a hollow-core photonic crystal fiber. To do this, a single comb tooth is isolated and amplified from 20 nW to 40 mW with sufficient fidelity to perform saturated absorption spectroscopy. The fractional stability of the comb, ~7 nm away from the stabilized tooth, is shown to be 6 × 10(-12) at 100 ms gate time, which is over an order of magnitude better than that of a comb referenced to a GPS-disciplined Rb oscillator.

Targeted delivery of herpes simplex virus glycoprotein D to CD169+ macrophages using ganglioside liposomes alleviates herpes simplex keratitis in mice.

Herpes simplex keratitis (HSK) is a common blinding corneal disease caused by herpes simplex virus type 1 (HSV-1) infection. Antiviral drugs and corticosteroids haven't shown adequate therapeutic efficacy. During the early stage of HSV-1 infection, macrophages serve as the first line of defense. In particular, CD169+ macrophages play an important role in phagocytosis and antigen presentation. Therefore, we constructed GM-gD-lip, a ganglioside GM1 liposome vaccine encapsulating HSV-1 glycoprotein D and targeting CD169+ macrophages. After subconjunctival injection of the vaccine, we evaluated the survival rate and ocular surface lesions of the HSK mice, as well as the virus levels in the tear fluid, corneas, and trigeminal ganglia. We discovered that GM-gD-lip reduced HSV-1 viral load and alleviated the clinical severity of HSK. The GM-gD-lip also increased the number of corneal infiltrating macrophages, especially CD169+ macrophages, and polarized them toward M1. Furthermore, the number of dendritic cells (DCs) and CD8+ T cells in the ocular draining lymph nodes was significantly increased. These findings demonstrated that GM-gD-lip polarized CD169+ macrophages toward M1 to eliminate the virus while cross-presenting antigens to CD8+ T cells via DCs to activate adaptive immunity, ultimately attenuating the severity of HSK. The use of GM-gD-lip as an immunotherapeutic method for the treatment of HSK has significant implications.

[Research on the method of loading exosomes onto absorbable stents].

Objective: To explore a method of loading exosomes onto absorbable stents. Methods: By building a stent-(3-aminopropyl) triethoxysilane-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol) 5000]-exosomes connection, the exosomes were loaded onto absorbable stents to obtained the exosome-eluting absorbable stents. The surface conditions of the stents and absorption of exosomes were observed by scanning electron microscope and identified through the time-of-flight mass spectrometry; the roughness of the stents' surfaces was observed by atomic force microscope; the appearances and sizes of the stents were observed by stereomicroscope; and the radial force was tested by tensile test machine. The absorbable stents were used as control. Results: The scanning electron microscope observation showed that the exosome-eluting absorbable stents had some small irregular cracks on the surface where many exosomes could be seen. The atomic force microscopy observation showed that within the range of 5 µm 2, the surface roughness of the absorbable stents was ±20 nm, while the surface roughness of the exosome-eluting absorbable stents was ±70 nm. In the results of time-of-flight mass spectrometry, both the exosome-eluting absorbable stents and exosomes had a peak at the mass charge ratio of 81 (m/z 81), while the absorbable stents did not have this peak. The peak of exosome-eluting absorbable stents at m/z 73 showed a significant decrease compared to the absorbable stents. The stereomicroscope observation showed that the sizes of exosome-eluting absorbable stents met standards and the surfaces had no cracks, burrs, or depressions. The radial force results of the exosome-eluting absorbable stents met the strength standards of the original absorbable stent. Conclusion: By applying the chemical connection method, the exosomes successfully loaded onto the absorbable stents. And the sizes and radial forces of this exosome-eluting absorbable stents meet the standards of the original absorbable stents.

Characteristics of corn starch/polyvinyl alcohol composite film with improved flexibility and UV shielding ability by novel approach combining chemical cross-linking and physical blending.

With the aim of effectively improving the performance of bio-friendly food packaging and circumventing the hazards associated with petroleum-based plastic food packaging, composite films of corn starch and polyvinyl alcohol were prepared using a new method that involved chemical cross-linking of glutaraldehyde and blending with cinnamon essential oil nanoemulsion (CNE). Glutaraldehyde and CNE enhance the film's network structure by chemical bonding and hydrogen bonding, respectively. This results in improved surface smoothness, mechanical properties, and UV shielding ability of the film. However, the films' surface hydrophilicity increased as a result of CNE, which is harmful for food preservation in high humidity. Overall, glutaraldehyde and CNE have a synergistic effect on some of the properties of the film which is mainly attributed to the films' structure improvement. The films have great potential for preparing flexible and UV-shielding films and offer new ideas for developing biodegradable films.

Electrochemical deposition multi-walled carbon nanotube coatings on the surface of Ti6Al4V alloy for enhancing its biotribological properties.

Ti6Al4V alloys have potential applications as bone implants. However, their poor biotribological performances affected the service life. In this work, carboxylic multi-walled carbon nanotubes (CMWNT) coatings were grafted on the surface of Ti6Al4V alloys by electrochemical deposition for enhancing the biotribological properties. The CMWNT coatings showed lower coefficient of friction and wear rates, with the reduction of wear rates of 6% in dry condition and 90% under simulated body fluid (SBF) lubrication. This result might be ascribed to the transfer of friction behavior from sliding friction to rolling friction. In addition, the tribological regularity of CMWNT coating with the frequency and load were discussed. Under dry friction, with the increase of frequency and the decrease of normal load, the COF of the CMWNT coating decreased. In SBF lubrication, the COF decreased and the wear rate increased with the increase of frequency. Moreover, the excellent anti-wear properties were observed at the below of 10 N. These findings indicate that the CMWNT coating has an excellent protective effect on titanium alloy, and has a certain application potential in the biomedical field.

Surface acoustic wave sensor based on Au/TiO2/PEDOT with dual response to carbon dioxide and humidity.

A surface acoustic wave (SAW) gas sensor with an Au/TiO2/poly(3,4-ethylenedioxythiophene) (PEDOT, which is a conductive polymer with photoelectric conversion function) sensing film was constructed for the quantitative detection of water vapor and CO2. The Au/TiO2/PEDOT sensing film was assembled on the delayed region of the 204 MHz SAW delay line, which was used as the base device for the gas sensor. The center frequency of the sensor decreases with an increase in relative humidity (RH), and the center frequency increases with increasing CO2 concentration, so that not only can the two gases be identified, but quantitative analysis can also be performed. The SAW sensor has a response range of 5%-90% for RH and a response range of 500-2000 ppm for CO2 gas. The shifts in center frequency varied linearly with the concentrations, giving rise to the sensitivities of -0.0068 and -0.1880 kHz %-1 for RH and ∼0.003 kHz ppm-1 CO2. The response/recovery time is 9 s/9.2 s for 700 ppm CO2 and 15 s/14 s for 70% RH. The experimental results show that the SAW sensor offers excellent selectivity, wide response range, rapid response, and good stability and repeatability. The mechanism of humidity and CO2 sensing is attributed to the hydrophilic porous structure of the Au/TiO2/PEDOT sensing film, and also to the reversible variation of its viscoelasticity under illumination conditions. The sensor, combined with the communication function of its own SAW device, has several prospective applications in the monitoring of atmospheric conditions.

Effective recruitment strategies in an exercise trial for patients with fibromyalgia.

BACKGROUND: Recruitment of fibromyalgia populations into long-term clinical trials involving exercise interventions is a challenge. We evaluated the cost and randomization yields of various recruitment methods used for a fibromyalgia trial in an urban setting. We also investigated differences in participant characteristics and exercise intervention adherence based on recruitment source. METHODS: We recruited individuals with fibromyalgia in the greater Boston area to a randomized controlled trial (RCT) using six recruitment strategies: newspaper advertisements, web advertisements, flyers, clinic referrals, direct mailing to patients in a clinic database, and word of mouth. We used the American College of Rheumatology 1990 and 2010 diagnostic criteria to screen and enroll participants. During an initial phone call to an interested participant, the study staff asked how they heard about the study. In this study, we compared the cost and yield of the six recruitment strategies as well as baseline characteristics, adherence, and attendance rates of participants across strategies. RESULTS: Our recruitment resulted in 651 prescreens, 272 screening visits, and 226 randomized participants. Advertisements in a local commuter newspaper were most effective, providing 113 of 226 randomizations, albeit high cost ($212 per randomized participant). Low-cost recruitment strategies included clinical referrals and web advertisements, but they only provided 32 and 16 randomizations. Community-based strategies including advertisement and flyers recruited a more racially diverse participant sample than clinic referrals and mailing or calling patients. There was no evidence of difference in adherence among participants recruited from various strategies. CONCLUSIONS: Newspaper advertisement was the most effective and most expensive method per randomized participant for recruiting large numbers of individuals with fibromyalgia in an urban setting. Community-based strategies recruited a more racially diverse cohort than clinic-based strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT01420640 . Registered on 19 August 2011.

Friction stability and cellular behaviors on laser textured Ti-6Al-4V alloy implants with bioinspired micro-overlapping structures.

The grain structure and surface morphology of bio-implants act as a pivotal part in altering cell behavior. Titanium alloy bone screws, as common implants, are prone to screws loosening and complications threat in the physiological environment due to their inferior anti-wear and surface inertia. Manufacturing bone screws with high wear resistance and ideal biocompatibility has always been a challenge. In this study, a series of overlapping morphologies inspired by the hierarchical structure of fish scales and micro bulges of shrimp were structured on Ti-6Al-4V implant by laser texturing. The results indicate that the textured patterns could improve cell attachment, proliferation, and osteogenic differentiation. The short-term response of human bone marrow-derived mesenchymal stem cells (hBMSCs) on the textured surface are more sensitive to the microstructure than the surface roughness, wettability, grain size and surface chemical elements of the textured surfaces. More importantly, the friction-increasing and friction-reducing type overlapping structures exhibit excellent friction stability at different stages of modified simulated body fluid (m-SBF) soaking. The overlapping structure (Micro-smooth stacked ring: MSSR) is more beneficial to promote the formation of apatite. Deposited spherical-like apatite particles can act as a "lubricant" on the MSSR surface during the friction process to alleviate the adhesion wear of the surface. Meanwhile, apatite particles participate in the formation of friction film, which plays an effective role in reducing friction and antiwear in corrosion solution (m-SBF) for a long time. These features show that the combination of soaking treatment in m-SBF solution with laser-textured MSSR structure is expected to be an efficient and environmentally friendly strategy to prolong the service life of bone screws and reducing the complications of mildly osteoporotic implants.

Ir-Ho bimetallic complex-mediated low-dose radiotherapy/radiodynamic therapy in vivo.

We report a bimetallic complex [Ir4Ho2(pq)8(H2dcbpy)4(OAc)2] (denoted as Ir4Ho2, pq = 2-phenylquinoline, H2dcppy = 2,2'-bipyridine-3,3'-dicarboxylic acid) and its application for radiotherapy/radiodynamic therapy (RT/RDT). In a tumor xenograft mouse model, Ir4Ho2 exerted a tumor-suppressive effect through efficient low-dose RT/RDT.

Iridium complex nanoparticle mediated radiopharmaceutical-excited phosphorescence imaging.

We firstly perpared liposome coated [Ir(pq)2(bpy)]Cl (Ir@liposome) as a transducer for radiopharmaceutical (18F-FDG) excited phosphorescence imaging (REPI). Ir@liposome-based REPI exhibited deep tissue penetration and high signal-to-noise ratio in the tumor.

Tribological behavior of Ti-6Al-4V against cortical bone in different biolubricants.

Titanium alloys (Ti-6Al-4V) are promising materials as bone implants in clinical surgeries owing to their excellent performances. However, wear debris caused by the tribological behavior of the cortical bone and titanium alloy interface were found to be paramount for implant stability. The contact environment between the cortical bone and Ti-6Al-4V in vivo has been considered to affect the tribological behavior. Currently, the tribological behaviors of bone and Ti-6Al-4V in different biolubricants remain elusive. Therefore, in this work, the tribological behaviors of Ti-6Al-4V plates sliding against bovine cortical bone were investigated in dry sliding and in biolubricants of physiological saline (PS), simulated body fluids (SBF), and fetal bovine serum (FBS). Results show that the friction coefficient and wear rate of the bovine cortical bone and Ti-6Al-4V interface exhibit the same sequence as follows: FBS > SBF > PS > dry sliding. These results are attributed to bone hardness variation and corrosion of different biolubricants. Meanwhile, the effects of normal load and velocity on the tribological behavior of bone and Ti-6Al-4V interface were also investigated in dry sliding and three different biolubricants. Results show that as the normal load is increased and the sliding velocity is decreased, the friction coefficient decreases in dry condition, adhering to the Hertz contact theory. However, according to the boundary lubrication theory, the friction coefficient in three biolubricants correlates positively to the normal load and negatively to the sliding velocity. Moreover, the wear rates of the bone samples increase with the increase in normal load and sliding velocity under dry and biolubrication conditions. Finally, the characterization results indicate that the wear mechanisms of the cortical bone and Ti-6Al-4V interface in dry friction are primarily adhesive and abrasive wear. Further, corrosive wear occurs in biolubrications, apart from adhesive and abrasive wear.

Enhanced Osseointegration of Titanium Alloy Implants with Laser Microgrooved Surfaces and Graphene Oxide Coating.

Rapid and effective osseointegration, as a critical factor in affecting the success rate of titanium (Ti) implants in orthopedic applications, is significantly affected by their surface microstructure and chemical composition. In this work, surface microgrooved Ti-6Al-4V alloys with graphene oxide coating (Ti-G-GO) were fabricated by a combination of laser processing and chemical assembly techniques. The osteogenic capability in vitro and new bone formation in vivo of the implants were systematically investigated, and biomechanical pull-out tests of the screws were also performed. First, in vitro studies indicated that the optimal microgroove width of the titanium alloy surface was 45 µm (Ti-G), and the optimum GO concentration was 1 mg/mL. Furthermore, the effects of the surface microstructure and GO coating on the in vitro bioactivity were investigated through culturing bone marrow mesenchymal stem cells (BMSCs) on the surface of titanium alloy plates. The results showed that the BMSCs cultured on the Ti-G-GO group exhibited the best adhesion, proliferation, and differentiation, compared with that on the Ti-G and Ti groups. Micro-computed tomography evaluation, histological analysis, and pull-out testing demonstrated that both Ti-G and Ti-G-GO implants had the higher osseointegration than the untreated Ti implant. Moreover, the osteogenic capability of the Ti-G-GO group appeared to be superior to that of the Ti-G group, which could be attributed to the improvement of surface wettability and apatite formation by the GO coatings. These results suggest that the combination of the microgroove structure and GO coatings exhibits considerable potential for enhancing the surface bioactivation of materials, and the combination modification is expected to be used on engineered titanium alloy surfaces to enhance osseointegration for orthopedic applications.

Controlling pre-tilt angles of liquid crystal using mixed polyimide alignment layer.

Three approaches to controlling liquid crystal (LC) pre-tilt angle in a cell are demonstrated using a polyimide (PI) alignment layer on substrates, in the form of a mixture of horizontal (H) and vertical (V) polyimides. The concentration ratio of H- to V-PI, baking temperature, and rubbing strength influence the pre-tilt angle, and highlight parameters for controlling the pre-tilt angle of an LC cell. Finally, a variable polarization converter is demonstrated using this approach.

Pulmonary immunization of guinea pigs with diphtheria CRM-197 antigen as nanoparticle aggregate dry powders enhance local and systemic immune responses.

This study establishes the immune response elicited in guinea pigs after pulmonary and parenteral immunizations with diphtheria CRM-197 antigen (CrmAg). Several spray-dried powders of formalin-treated/untreated CrmAg nanoaggregates with L-leucine were delivered to the lungs of guinea pigs. A control group consisting of alum with adsorbed CrmAg in saline was administered by intramuscular injection. Animals received three doses of powder vaccines containing 20 or 40 µg of CrmAg. The serum IgG titers were measured for 16 weeks after the initial immunization; IgA titers were measured at the time of sacrifice in the broncho-alveolar lavage fluid. Further, toxin neutralization tests in naïve guinea pigs were performed for a few select serum samples. Histopathology of the lung tissues was conducted to evaluate inflammation or injury to the lung tissues. While the highest titer of serum IgG antibody was observed in guinea pigs immunized by the intramuscular route, those animals immunized with dry powder formulation by the pulmonary route, and without the adjuvant alum, exhibited high IgA titers. A pulmonary administered dry powder, compared to parenteral immunization, conferred complete protection in the toxin neutralization test. Mild inflammation was observed in lung tissues of animals receiving dry powder vaccines by the pulmonary route. Thus, administering novel CrmAg as dry powders to the lungs may be able to overcome some of the disadvantages observed with the existing diphtheria vaccine which is administered by the parenteral route. In addition, these powders will have the advantage of eliciting a high mucosal immune response in the lungs without using traditional adjuvants.

Screening for potential adjuvants administered by the pulmonary route for tuberculosis vaccines.

Tuberculosis (TB) infects one third of the world's population, and new infections occur at a rate of 1/s. Better vaccines are needed than the live mycobacterium Bacille Calmette-Guérin (BCG). Alveolar macrophages (AMPhis) play a central role in pulmonary manifestations of TB. Targeting immunomodulators to AMPhis, the first line of defense against Mycobacterium tuberculosis (Mtb), may initiate a potent cell-mediated immune response. Muramyl dipeptide (MDP) and trehalose dibehenate (TDB) have elicited strong immune response when delivered to the lungs as aerosols. AMPhis show toxicity in response to some immunomodulators. The objective of this work was to screen the immunomodulators MDP and/or TDB encapsulated in microparticles (MPs) and to evaluate certain indicators of toxicity in human AMPhi-like cells. Poly(lactide-co-glycolide) (PLGA) MPs containing MDP and/or TDB were prepared by spray-drying. The morphology, particle size distribution, and immunomodulator encapsulation efficiency of MPs were examined. THP-1 cells were exposed to these MPs for 24 h and characteristics of cell morphology, tumor necrosis factor-alpha (TNF-alpha) release, lactate dehydrogenase (LDH), N-acetyl-beta-D: -glucosaminidase (NAG) and alkaline phosphatase (ALP) activity in AMPhi culture supernatants were measured. MTT assay was used to assess the viability of cells. Spray-drying produced low-density MPs having volume median diameters between 4 and 6 microm as measured by laser diffraction and projected area diameter between 3 and 5 microm calculated by microscopy. More TNF-alpha was produced by THP-1 cells exposed to MPs composed of PLGA-MDP or PLGA alone than PLGA-TDB. LDH release following exposure to MPs of PLGA-MDP and PLGA alone was greater than controls. NAG release was higher following exposure to MPs of PLGA alone or PLGA-MDP 0.1% than PLGA-TDB (0.1% and 1.0%). Cells remained viable after exposure to MPs as per MTT assay. PLGA-MDP MPs demonstrated statistically elevated indicators of biochemical responses in cell culture compared to PLGA-TDB MPs, but the extent of their potential to elicit adverse effects in vivo must be studied independently.