Electrochemical Detection of Dopamine Release from Living Neurons Using Graphene Oxide-Incorporated Polypyrrole/Gold Nanocluster Hybrid Nanopattern Arrays.

Stem-cell-based therapeutics have shown immense potential in treating various diseases that are currently incurable. In particular, partial recovery of Parkinson's disease, which occurs due to massive loss or abnormal functionality of dopaminergic (DAnergic) neurons, through the engraftment of stem-cell-derived neurons ex vivo is reported. However, precise assessment of the functionality and maturity of DAnergic neurons is still challenging for their enhanced clinical efficacy. Here, a novel conductive cell cultivation platform, a graphene oxide (GO)-incorporated metallic polymer nanopillar array (GOMPON), that can electrochemically detect dopamine (DA) exocytosis from living DAnergic neurons, is reported. In the cell-free configuration, the linear range is 0.5-100 µm, with a limit of detection of 33.4 nm. Owing to its excellent biocompatibility, a model DAnergic neuron (SH-SY5Y cell) can be cultivated and differentiated on the platform while their DA release can be quantitatively measured in a real-time and nondestructive manner. Finally, it is showed that the functionality of the DAnergic neurons derived from stem cells can be precisely assessed via electrochemical detection of their DA exocytosis. The developed GOMPON is highly promising for a wide range of applications, including real-time monitoring of stem cell differentiation into neuronal lineages, evaluating differentiation protocols, and finding practical stem cell therapies.

Effect of Semi-Fluorinated Alkyl Side Chains on Conjugated Polymers with Planar Backbone in Organic Field-Effect Transistors.

Newly synthesized donor-acceptor (D-A) type of conjugated copolymer (PCTV-BTzF) with semi-fluorinated alkyl side chains, which has good solubility in common organic solvents, is described. Unlike polymers with hydrocarbon-based alkyl side chains, semi-fluorocabonated polymer leads to intriguing results. First, the self-organization behavior of the semi-fluoroalkyl side chains by the self-aggregate propensity between hydrocarbon and fluorocarbon induces patterned microstructural morphology in polymer films; second, it dominates the molecular orientation of polymers with planar back structure. Such unusual properties of the polymer with semi-fluoroalkyl side chains compared to that with the hydrocarbon ones are verified and characterized though various systematic characterizations, including temperature-dependent UV-Vis absorption spectroscopy, atomic force microscopy, and 2D-grazing incident X-ray diffraction measurement. As a result, PCTV-BTzF-based OFETs show the maximum p-type field-effect mobility of 1.02 cm2  V-1  s-1 in the 200 °C annealed films.

Comparison of the effect of endodontic-periodontal combined lesion on the outcome of endodontic microsurgery with that of isolated endodontic lesion: survival analysis using propensity score analysis.

OBJECTIVES: The purpose of this retrospective clinical study was to evaluate the effect of lesion types related to endodontic microsurgery on the clinical outcome. MATERIALS AND METHODS: Patients who underwent endodontic microsurgery between March 2001 and March 2014 with a postoperative follow-up period of at least 1 year were included in the study. Survival analyses were conducted to compare the clinical outcomes between isolated endodontic lesion group (endo group) and endodontic-periodontal combined lesion group (endo-perio group) and to evaluate other clinical variables. To reduce the effect of selection bias in this study, the estimated propensity scores were used to match the cases of the endo group with those of the endo-perio group. RESULTS: Among the 414 eligible cases, the 83 cases in the endo-perio group were matched to 166 out of the 331 cases in the endo group based on propensity score matching (PSM). The cumulated success rates of the endo and endo-perio groups were 87.3 and 72.3%, respectively. The median success period of the endo-perio group was 12 years (95% CI: 5.507, 18.498). Lesion type was found to be significant according to both Log-rank test (P = 0.002) and Cox proportional hazard regression analysis (P = 0.001). Among the other clinical variables, sex (female or male), age, and tooth type (anterior, premolar, or molar) were determined to be significant in Cox regression analysis (P < 0.05). CONCLUSION: Endodontic-periodontal combined lesions had a negative effect on the clinical outcome based on an analysis that utilized PSM, a useful statistical matching method for observational studies. CLINICAL RELEVANCE: Lesion type is a significant predictor of the outcome of endodontic microsurgery.

Ring Opening Metathesis Polymerization of Bicyclic α,ß-Unsaturated Anhydrides for Ready-to-be-grafted Polymers Having Tailored pH-Responsive Degradability.

Polymers having α,ß-unsaturated anhydrides as repeating units were synthesized by ring opening metathesis polymerization (ROMP). The anhydride moieties were ready-to-be-grafted with amines to form acid-labile cis-α,ß-unsaturated acid amide linkages. The pH-responsive reversible de-grafting can be controlled by changing the intramolecular accessibility between acid and amide groups. The alendronate-grafted ROMP polymers showed distinct pH-dependent cytotoxicity according to the anhydride structures.

Outcome of nonsurgical retreatment and endodontic microsurgery: a meta-analysis.

OBJECTIVES: The purpose of this study was to evaluate and compare the clinical and radiographic outcomes of nonsurgical endodontic retreatment and endodontic microsurgery by a meta-analysis. MATERIALS AND METHODS: Electronic databases including PubMed, Embase, Medline, and The Cochrane Library were searched, and the references of related articles were manually searched to identify all the clinical studies that evaluated the clinical and radiographic outcomes after retreatment or microsurgery. The first and second screening processes were conducted by three reviewers independently. The final studies were selected after strict application of the inclusion and exclusion criteria. The random effects meta-analysis model with the DerSimonian-Laird pooling method was performed. The weighted pooled success rates and 95 % confidence interval estimates of the outcome were calculated. Additionally, the effects of the follow-up period and study quality were investigated by a subgroup analysis. RESULTS: Endodontic microsurgery and nonsurgical retreatment have stable outcomes presenting 92 and 80 % of overall pooled success rates, respectively. The microsurgery group had a significantly higher success rate than the retreatment group. When the data were organized and analyzed according to their follow-up periods, a significantly higher success rate was found for the microsurgery group in the short-term follow-up (less than 4 years), whereas no significant difference was observed in the long-term follow-up (more than 4 years). CONCLUSIONS: Endodontic microsurgery was confirmed as a reliable treatment option with favorable initial healing and a predictable outcome. CLINICAL RELEVANCE: Clinicians may consider the microsurgery as an effective way of retreatment as well as nonsurgical retreatment depending on the clinical situations.

Hybrid nanoparticles with cell membrane and dexamethasone-conjugated polymer for gene delivery into the lungs as therapy for acute lung injury.

Gene therapy has been suggested as a new treatment for acute lung injury (ALI), which is a severe inflammatory disease. Previously, amphiphilic polymeric carriers such as dexamethasone-conjugated polyethylenimine (PEI) (DP) have been used to transport plasmid DNA (pDNA) into the lungs. In the current study, hybrid nanoparticles comprising DP and cell membrane (CM) from LA-4 lung epithelial cells were developed for enhanced delivery of pDNA into the lungs. The CM components of the hybrid nanoparticles may interact with plasma membranes of target cells and facilitate intracellular uptake of pDNA. DP/CM/pDNA nanoparticles had the highest transfection efficiency into LA-4 cells at a weight ratio of 8 : 3 : 1. In vitro transfection assays showed that DP/CM/pDNA nanoparticles improved the cellular uptake and transfection efficiency of pDNA compared with PEI (25 kDa, PEI25k)/pDNA and DP/pDNA nanoparticles. The DP/CM/pDNA nanoparticles were approximately 80 nm in diameter with a zeta potential of +25 mV. To evaluate the therapeutic effects, heme oxygenase-1 pDNA (pHO-1) was administered to ALI animal models by intratracheal instillation. DP/CM/pHO-1 nanoparticles improved gene delivery efficiency compared with PEI25k/pHO-1 and DP/pHO-1 nanoparticles. As a result, inflammation in the lungs was alleviated by DP/CM/pHO-1 nanoparticles more effectively than by other nanoparticles. The results suggest that DP/CM/pDNA hybrid nanoparticles may be useful gene carriers for the treatment of ALI.

KBG syndrome: Clinical features and molecular findings in seven unrelated Korean families with a review of the literature.

BACKGROUND: KBG syndrome is a rare genetic disorder involving macrodontia of the upper central incisors, craniofacial, skeletal, and neurologic symptoms, caused either by a heterozygous variant in ANKRD11 or deletion of 16q24.3, including ANKRD11. Diagnostic criteria were proposed in 2007 based on 50 cases, but KBG syndrome remains underdiagnosed. METHODS: Whole exome sequencing (WES) and array comparative genomic hybridization (array CGH) were conducted for genetic analysis and patient phenotypes were characterized based on medical records. RESULTS: Eight patients from seven unrelated families were confirmed with KBG syndrome. All patients (8/8, 100%) had some degree of craniofacial dysmorphism and developmental delay or intellectual disabilities. Triangular face, synophrys, anteverted nostril, prominent ears, long philtrum, and tented upper lip, which are typical facial dysmorphism findings in patients with KBG syndrome, were uniformly identified in the eight patients participating in this study, with co-occurrence rates of 4/8 (50%), 4/8 (50%), 4/8 (50%), 4/8 (50%), 5/8 (62.5%), and 5/8 (62.5%), respectively. Various clinical manifestations not included in the diagnostic criteria were observed. Six patients had point mutations in ANKRD11, one had an exonic deletion of ANKRD11, and one had a 16q24.3 microdeletion. According to the ACMG guidelines, all mutations were classified as pathogenic. The c.2454dup (p.Asn819fs*1) mutation in Pt 4 was reported previously. The remaining variants (c.397 + 1G>A, c.226 + 1G>A, c.2647del (p.Glu883Argfs*94), and c.4093C>T (p.Arg1365Ter)) were novel. CONCLUSION: The clinical and molecular features of eight patients from seven unrelated Korean families with KBG syndrome described here will assist physicians in understanding this rare genetic condition.

Microbial Contamination of Preservative-Free Artificial Tears Based on Instillation Techniques.

Preservative-free artificial tears eliminate the side effects of preservatives but are prone to microbial contamination. This study evaluates the incidence of microbial contaminations in single-use vials of preservative-free 0.1% hyaluronate artificial tears. Based on what touched the vial tip during its first use, 60 unit-dose vials (0.5 mL) were divided into groups A (no touch, n = 20), B (fingertip, n = 20), and C (lid margin, n = 20). The vials were recapped after the first use, and the residual solution was cultured 24 h later. The solution from 20 aseptically opened and unused vials was also cultured (group D). Microbial contamination rates were compared between the groups using the Fisher's exact test. Groups B and C contained 45% (9/20) and 10% (2/20) contaminations while groups A and D contained undetected microbial growth. The culture positivity rates were significantly different between groups A and B (p = 0.001) and groups B and C (p = 0.013) but not between groups A and C (p = 0.487). We demonstrate a significantly higher risk of contamination when fingertips touch the vial mouth. Therefore, users should avoid the vial tip touching the fingers or eyelid during instillation to prevent contamination of the eye drops.

Lactobacillus plantarum lipoteichoic acid disrupts mature Enterococcus faecalis biofilm.

Apical periodontitis is caused by biofilm-mediated root canal infection. Early phase oral bacterial biofilms are inhibited by Lactobacillus plantarum lipoteichoic acid (Lp.LTA). However, mature biofilms that develop over 3 weeks are more resistant to traditional endodontic medicaments. Therefore, this study examined the effectiveness of Lp.LTA on disrupting mature Enterococcus faecalis biofilms, and on enhancing the effects of endodontic medicaments. LTA was purified from L. plantarum through butanol extraction followed by hydrophobic and ion-exchange chromatography. E. faecalis biofilms were formed over 3 weeks on glass bottom dishes and in dentin blocks obtained from human single-rooted premolars. These mature biofilms were treated with or without Lp.LTA for 1 h, followed by additional treatment with either chlorhexidine digluconate (CHX), calcium hydroxide (CH), or triple antibiotics for 24 h. Biofilms on glass were live/dead stained and quantified by ZEN through confocal laser microscopy. Bio-films in dentin were fixed, sputter coated and analyzed by ImageJ with scanning electron microscopy. Preformed E. faecalis mature biofilms on the culture dishes were dose-dependently disrupted by Lp.LTA. Lp.LTA potentiated the effects of CHX or CH on the disruption of mature biofilm. Interestingly, CHX-induced disruption of preformed E. faecalis mature biofilms was synergistically enhanced only when pre-treated with Lp.LTA. Furthermore, in the dentin block model, Lp.LTA alone reduced E. faecalis mature biofilm and pre-treatment with Lp.LTA promoted the anti-biofilm activity of CHX. Lp.LTA could be an anti-biofilm or supplementary agent that can be effective for E. faecalis-biofilm-induced diseases.

Calcium-Binding Polymer-Coated Poly(lactide- co-glycolide) Microparticles for Sustained Release of Quorum Sensing Inhibitors to Prevent Biofilm Formation on Hydroxyapatite Surfaces.

Quorum sensing (QS) inhibitor-based therapy is an attractive strategy to inhibit bacterial biofilm formation without excessive induction of antibiotic resistance. Thus, we designed Ca2+-binding poly(lactide- co-glycolide) (PLGA) microparticles that can maintain a sufficient concentration of QS inhibitors around hydroxyapatite (HA) surfaces in order to prevent biofilm formation on HA-based dental or bone tissues or implants and, therefore, subsequent pathogenesis. Poly(butyl methacrylate- co-methacryloyloxyethyl phosphate) (PBMP) contains both Ca2+-binding phosphomonoester groups and PLGA-interacting butyl groups. The PBMP-coated PLGA (PLGA/PBMP) microparticles exhibited superior adhesion to HA surfaces without altering the sustained release properties of uncoated PLGA microparticles. PLGA/PBMP microparticle-encapsulating furanone C-30, a representative QS inhibitor, effectively inhibited the growth of Streptococcus mutans and its ability to form biofilms on HA surface for prolonged periods of up to 100 h, which was much longer than either furanone C-30 in its free form or when encapsulated in noncoated PLGA microparticles.

Comparison of DNA extraction methods for drug susceptibility testing by allele-specific primer extension on a microsphere-based platform: Chelex-100 (in-house and commercialized) and MagPurix TB DNA Extraction Kit.

Tuberculosis (TB), caused by infections of the Mycobacterium tuberculosis (MTB) complex, is the ninth leading cause of death worldwide, and several molecular approaches for MTB species identification and the detection of mutations associated with drug resistance have been developed to date. We previously developed a diagnostic assay for drug susceptibility testing that can detect mutations conferring resistance to anti-TB drugs using allele-specific primer extension on a microsphere-based platform for multiplex polymerase chain reaction. The aim of the present study was to optimize this diagnostic assay based on the evaluation of three methods for extracting mycobacterial DNA from clinical samples. Mycobacterial DNA of 81 samples was digested and decontaminated by N-acetyl-l-cysteine-2% NaOH and then extracted using three methods: "in-house" 5% Chelex-100 chelating resin, InstaGene Matrix, and MagPurix TB DNA Extraction Kit. The former two methods are manual extraction methods, whereas the MagPurix TB DNA Extraction Kit is an automated extraction method used with the MagPurix 12 s automated nucleic acid purification system. The extracted DNA was then subjected to our diagnostic assay, and the results were compared among methods. The magnetic bead method exhibited a higher extraction efficiency and resulted in greater diagnostic efficacy than the two resin-based methods with respect to both target gene detection and acid-fast bacilli smear grades. Therefore, the MagPurix TB DNA Extraction Kit is the optimal MTB DNA extraction method for our diagnostic assay of TB drug susceptibility testing.

Development of anti-biofouling interface on hydroxyapatite surface by coating zwitterionic MPC polymer containing calcium-binding moieties to prevent oral bacterial adhesion.

UNLABELLED: The purpose of the present study is to synthesize a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer capable of being immobilized on the tooth surface to prevent oral bacterial adhesion. The strategy is to develop an MPC-based polymer with Ca(2+)-binding moieties, i.e., phosphomonoester groups, for stronger binding with hydroxyapatite (HA) of the tooth surface. To this end, a 2-methacryloyloxyethyl phosphate (MOEP) monomer was synthesized and copolymerized with MPC by free radical polymerization. The coating efficiency of the synthesized polymer, MPC-ran-MOEP (abbreviated as PMP) with varied composition, onto a HA surface was estimated by means of contact angle measurement and X-ray photoelectron spectroscopy. The anti-biofouling nature of PMP-coated HA surfaces was estimated by analyzing protein adsorption, cell adhesion, and Streptococcus mutans adhesion. As a result, HA surface coated with a copolymer containing around 50% MPC (PMP50) showed the best performance in preventing protein adsorption and the downstream cell and bacterial adhesion. STATEMENT OF SIGNIFICANCE: Preparation of anti-biofouling surface on the tooth enamel is the key technique to prevent dental and periodontal diseases, which are closely related with the biofilm formation that induced by the adsorption of salivary proteins and the adhesion of oral bacteria on the tooth surface. In this research, a PMP copolymer with an optimized ratio of zwitterionic and Ca(2+)-binding moieties could form a highly effective and robust anti-biofouling surface on HA surfaces by a simple coating method. The PMP-coated surface with high stability can provide a new strategy for an anti-adsorptive and anti-bacterial platform in dentistry and related fields.

A randomized controlled study of the use of ProRoot mineral trioxide aggregate and Endocem as direct pulp capping materials.

INTRODUCTION: The purpose of the present study was to evaluate and compare the short-term clinical outcomes of direct pulp capping using ProRoot MTA (Dentsply, Tulsa, OK) or Endocem (Maruchi, Wonju, Korea) as capping materials in a prospective randomized controlled study. MATERIALS AND METHODS: This study was conducted with subjects who were recruited from the pool of patients from the Department of Conservative Dentistry at the Dental College of Yonsei University, Seoul, Korea, between January and May 2013. Of the 48 teeth confirmed to be eligible for direct pulp capping, a total of 46 teeth were randomly assigned to either the ProRoot MTA or the Endocem group (23 teeth per group). Direct pulp capping was performed using these 2 materials, and clinical and radiographic evaluations were performed at 1, 2, 4, and 12 weeks after the treatments. Teeth with no response to pulp vitality test and those exhibiting clinical or radiographic signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered to be failures. RESULTS: Thirty-two patients (43 teeth) were examined at the 3-month follow-up (patient recall rate = 91.4%); 22 of these teeth were in the ProRoot MTA group, and 21 were in the Endocem group. The overall success rate was 93%, and the success rates in the ProRoot MTA and Endocem groups were 95.5% (21/22 teeth) and 90.5% (19/21 teeth), respectively. Statistical analyses of these success rates did not reveal any significant difference between the groups (P = .522). CONCLUSIONS: In this randomized controlled study, no significant difference in the short-term clinical outcomes of direct pulp capping using ProRoot MTA or Endocem as the capping material was found. Furthermore, the favorable short-term outcome success rate of 93% indicates that direct pulp capping may be a reliable treatment for pulp exposure in adult teeth.

Unusual morphology of permanent tooth related to traumatic injury: a case report.

INTRODUCTION: Root duplication, or multiple roots, is a very rare anatomy of the maxillary central incisor. METHODS: This case report describes a permanent central incisor having 2 distinct roots as an assumed sequela of the avulsion and replantation of a primary incisor. RESULTS: The permanent successor might have had a disturbance of development because of the traumatic injury and discontinuity in the treatment after replantation. Conventional endodontic treatment followed by esthetic restoration was performed on the tooth. CONCLUSIONS: Clinicians should consider the potential prognoses and complications of traumatic injuries to primary teeth.

Tooth discoloration after the use of new pozzolan cement (Endocem) and mineral trioxide aggregate and the effects of internal bleaching.

INTRODUCTION: The aim of this study was to evaluate tooth discoloration after the use of mineral trioxide aggregate (MTA) and to examine the effect of internal bleaching on discoloration associated with MTA. METHODS: Thirty-two teeth were endodontically treated. Three-millimeter plugs of MTA, ProRoot, Angelus, or Endocem were placed on the access cavities of 24 teeth. Eight teeth served as the control group. After 24 hours, the access cavities were restored, and the tooth color was recorded at baseline and at 1, 2, 4, 8, and 12 weeks. After 12 weeks, the MTA materials were removed under a microscope, and an internal bleaching treatment was performed. After removal of the MTA materials and after a 1-week bleaching treatment, the color changes were measured, and the MTA-dentin interfaces were observed under a microscope. RESULTS: The ProRoot and Angelus groups displayed increasing discoloration during a period of 12 weeks. The discoloration associated with ProRoot and Angelus was observed at the MTA-dentin interface and on the interior surface of the dentin. However, the Endocem groups demonstrated no significant discoloration (P < .05). No marginal discoloration was observed around the material in the Endocem group. Removal of the discolored MTA was effective for resolving the discoloration in all of the experimental groups (P < .05). However, a subsequent internal bleaching treatment was not significantly effective compared with the removal of MTA. CONCLUSIONS: ProRoot and Angelus caused tooth discoloration. However, Endocem did not affect the contacting dentin surface. Removing the discolored MTA materials contributed more to resolving the tooth discoloration than post-treatment internal bleaching.

Remarkable enhancement of hole transport in top-gated N-type polymer field-effect transistors by a high-k dielectric for ambipolar electronic circuits.

A remarkable enhancement of p-channel properties is achieved in initially n-channel dominant ambipolar P(NDI2OD-T2) organic field-effect transistors (OFETs) by the use of the fluorinated high-k dielectric P(VDF-TrFE). An almost two orders of magnitude increase in hole mobility (~0.11 cm(2) V(-1) s(-1) ) originates from a strong interface modification at the semiconductor/dielectric interface, which provides high-performance complementary-like inverters and ring oscillator circuits.

Biomimetic component coating on 3D scaffolds using high bioactivity of mesoporous bioactive ceramics.

BACKGROUND: Mesoporous bioactive glasses (MBGs) are very attractive materials for use in bone tissue regeneration because of their extraordinarily high bone-forming bioactivity in vitro. That is, MBGs may induce the rapid formation of hydroxy apatite (HA) in simulated body fluid (SBF), which is a major inorganic component of bone extracellular matrix (ECM) and comes with both good osteoconductivity and high affinity to adsorb proteins. Meanwhile, the high bioactivity of MBGs may lead to an abrupt initial local pH variation during the initial Ca ion-leaching from MBGs at the initial transplant stage, which may induce unexpected negative effects on using them in in vivo application. In this study we suggest a new way of using MBGs in bone tissue regeneration that can improve the strength and make up for the weakness of MBGs. We applied the outstanding bone-forming bioactivity of MBG to coat the main ECM components HA and collagen on the MBG-polycarplolactone (PCL) composite scaffolds for improving their function as bone scaffolds in tissue regeneration. This precoating process can also expect to reduce initial local pH variation of MBGs. METHODS AND MATERIALS: The MBG-PCL scaffolds were immersed in the mixed solution of the collagen and SBF at 37°C for 24 hours. The coating of ECM components on the MBG-PCL scaffolds and the effect of ECM coating on in vitro cell behaviors were confirmed. RESULTS: The ECM components were fully coated on MBG-PCL scaffolds after immersing in SBF containing dilute collagen-I solution only for 24 hours due to the high bone-forming bioactivity of MBG. Both cell affinity and osteoconductivity of MBG-PCL scaffolds were dramatically enhanced by this precoating process. CONCLUSION: The precoating process of ECM components on MBG-PCL scaffold using a high bioactivity of MBG was not only effective in enhancing the functionality of scaffolds but also effective in eliminating the unexpected side effect. The MBG-PCL scaffold-coated ECM components ideally satisfied the required conditions of scaffold in tissue engineering, including 3D well-interconnected pore structures with high porosity, good bioactivity, enhanced cell affinity, biocompatibility, osteoconductivity, and sufficient mechanical properties, and promise excellent potential application in the field of biomaterials.