Metallic Inverse Opals: An Electrochemiluminescence enhanced Substrate for Sensitive Bioanalysis.

Here, we proposed a novel local surface plasmon resonance (LSPR) enhanced ECL strategy based on the metallic inverse opals and Ru(bpy)32+-doped silica nanoparticles (RuSi NPs). Gold inverse opals (GIOs), as a plasmonic array, could interact with the ECL of RuSi NPs and excite the electromagnetic (EM) field at the gold surface. The triggered EM field could enhance the ECL emission of RuSi NPs. We compared the electrochemical and ECL performances of RuSi NPs modified on the gold electrodes with different surface morphologies and found that the ECL emission of RuSi NPs patterned at the inner surface of GIOs exhibited the highest intensity. The finite-difference time-domain (FDTD) simulations indicated that the EM field was related to the surface morphology of the metallic nanostructure, and the highest EM field was observed at the inner surface of the GIOs. Because of the superior ECL performances, the inner surfaces of GIOs were developed for nucleic acid detection with a detection limit of 3.3 fM (S/N = 3), which shows great promise for bioanalysis.

Recent advances of ratiometric electrochemiluminescence biosensors.

Ratiometric electrochemiluminescence (ECL) assays have been widely applied in biosensing because of eliminated outside interferences and improved reliability in detection. In order to construct ratiometric ECL biosensors with high sensitivity and reliability, it is critical to find two signal emitters with suitable applied potentials or emission wavelengths. This review aims to discuss recent advances and trends of ratiometric ECL biosensors in terms of ECL materials and corresponding ratiometric sensing approaches. We focus on four types of ratiometric ECL biosensors based on particular ECL materials and ratiometric sensing strategies.

Three-level spaser for next-generation luminescent nanoprobe.

The development of modern biological and medical science highly depends on advanced luminescent probes. Current probes typically have wide emission spectra of 30 to 100 nm, which limits the number of resolvable colors that are simultaneously labeled on samples. Spasers, the abbreviation for surface plasmon lasers, have ultranarrow lasing spectra by stimulated light amplification in the plasmon nanocavity. However, high threshold (>102 mJ cm-2) and short lasing lifetime (approximately picoseconds to nanoseconds) still remain obstacles for current two-level spaser systems. We demonstrated a new type of a three-level spaser using triplet-state electrons. By prolonging the upper state lifetime and controlling the energy transfer, high gain compensation was generated. This probe, named delayed spasing dots (dsDs), about 50 to 60 nm in size, exhibited a spectral linewidth of ~3 nm, an ultralow threshold of ~1 mJ cm-2, and a delayed lasing lifetime of ~102 µs. As the first experimental realization of the three-level spaser system, our results suggested a general strategy to tune the spasing threshold and dynamics by engineering the energy level of the gain medium and the energy transfer process. These dsDs have the potential to become new-generation luminescent probes for super-multiplex biological analysis without disturbance from short lifetime background emission.

Ultrasmall Nanopipette: Toward Continuous Monitoring of Redox Metabolism at Subcellular Level.

Ionic current rectification (ICR) based nanopipettes allow accurate monitoring of cellular behavior in single living cells. Herein, we proposed a 30 nm nanopipette functionalized with G-quadruplex DNAzyme as an efficient biomimetic recognizer for ROS generation at subcellular level via the changes of current-voltage relationship. Taking advantages of the ultra-small tip, the nanopipette could penetrate into a single living cell repeatedly or keep measuring for a long time without compromising the cellular functions. Coupled with precision nanopositioning system, generation of ROS in mitochondria in response to cell inflammation was determined with high spatial resolution. Meanwhile, the changes of aerobic metabolism in different cell lines under drug-induced oxidative stress were monitored continuously. We believe that the ICR-nanopipette could be developed as a powerful approach for the study of cellular activities via electrochemical imaging in living cells.

Electrochemiluminescence Energy Resonance Transfer System between RuSi Nanoparticles and Hollow Au Nanocages for Nucleic Acid Detection.

This paper describes an electrochemiluminescence resonance energy transfer (ECL-RET) system using Ru(bpy)32+-doped silica nanoparticles (RuSi NPs) as the ECL donor and hollow Au nanocages as the ECL acceptor. Tetrahedron DNA (TD) was used to construct the biosensing interface and control the distance (4.8 nm) between the ECL donor-acceptor pairs. The surface plasmon resonance (SPR) nanostructures, Au nanocages were assembled via the hairpin based sandwich assay. Due to the well overlap between the plasmon absorption spectrum of Au nanocages (628 nm) and the ECL emission spectrum of RuSi NPs (620 nm), high efficient energy transfer could occur. Subsequent cyclic DNA amplification further increased the binding amount of Au nanocages. Since the ECL inhibition is closely related with the binding amount of Au nanocages, a general "signal-off" ECL bioassay could thus be tailored with high sensitivity. At the optimized conditions, this ECL-RET system performed well with great stability and repeatability for nucleic acid detection in the range from 1.0 fM to 10 pM. This work manifested the great promise of hollow Au nanocages for an ECL-RET biosensor that to the best of our knowledge has not been reported. We believe that it could inspire more interest in the design and development of numerous other SPR nanostructures for advanced ECL-RET biosensors.

Visual electrochemiluminescence ratiometry on bipolar electrode for bioanalysis.

In this work, we developed a visual ECL ratiometry on a closed bipolar electrode (BPE) for the detection of prostate specific antigen (PSA), prostate cancer biomarker. High efficient CdTe QDs was synthesized which emitted visualized red light at BPE cathode. Integrating with the anodic ECL emitters, luminol, visual emission of red-blue ratiometric ECL was achieved in BPE array chips. As a sensing probe, Au NRs nanocomposite was assembled on the surface of the cathode and acted as both the quencher of the CdTe QDs ECL and the promoter of the luminol ECL. After incubated with PSA, the Au NRs nanocomposite was peeled off from the electrode surface due to the specific recognition between PSA and aptamer. Consequently, the cathode ECL partly recovered and the anode ECL turned off. By measuring the ratio of visual ECL intensity at two poles of BPE, sensitive detection of PSA was achieved with a linear range from 1.0ng/mL to 1.0µg/mL and detection limit of 0.5ng/mL (S/N=3). This strategy combining the BPE-ECL and visual ratiometry provided an accurate and intrinsic way for the sensing of PSA and showed good perspective in the clinical diagnosis.

Effect of CyberKnife stereotactic body radiation therapy for hepatocellular carcinoma on hepatic toxicity.

OBJECTIVE: To evaluate the safety of CyberKnife stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) patients and identify the treatment-related risk factors of hepatic toxicity. MATERIALS AND METHODS: One hundred and four HCC patients treated with CyberKnife SBRT were included in this study between August 2009 and December 2012. The average dose of prescribed radiation was 42.81±4.78 Gy (28-55 Gy) with the average fraction size of 8-16 Gy to the planning target volume. The average fractions were 3.31±0.81 (2-6 fractions). Response rates were determined, and the Child-Pugh (CP) score and class following CyberKnife SBRT were obtained to evaluate hepatic toxicity. RESULTS: Seventeen patients experienced progression in CP class and 24 patients experienced CTCAE V. 4.0 grade 2-3 hepatic toxicity during the five-month follow-up period, while no patient experienced grade 4 liver toxicity. Multivariate analysis indicated that only V25 was an independent factor in grade 2-3 hepatic toxicity (P=0.029, <0.05). Radiation-induced hepatic toxicity (RIHT), defined as an increase of at least two points within three months following CyberKnife SBRT, occurred in 13 of the 104 patients (13/104, 12.5%), and only the normal liver tissue was found to be associated with RIHT (P=0.008, <0.05). CONCLUSION: CyberKnife SBRT is a feasible and safe treatment for HCC with regard to hepatic toxicity, while V25 and normal liver volume may be an independent factor of grade 2-3 hepatic toxicity and RIHT, respectively.

Spatial-resolved electrochemiluminescence ratiometry based on bipolar electrode for bioanalysis.

Herein, a spatial-resolved electrochemiluminescene (ECL) ratiometry based on a closed biopolar electrode (BPE) is reported for the highly sensitive detection of prostate specific antigen (PSA). Au@g-C3N4 NCs as one ECL emitter were firstly coated on the cathode of BPE, while the anode of the BPE served for calibration via another ECL substance, Ru(bpy)3(2+). The electroneutrality across the BPE makes the reactions on each pole of BPE electrically coupled. Thus one electrochemical sensing reaction at one pole of BPE could be quantified at both ends. A composite, Pt-PAMAM-DNAzyme was assembled on the surface of cathode via DNA hybridization between probe DNA and PSA aptamer. It acted as an ECL quencher of g-C3N4 via resonance energy transfer (RET) and catalyzing the reduction of O2, the co-reactant of g-C3N4. Meanwhile, it could promote the ECL of Ru(bpy)3(2+) at anode, since the catalytic reduction of O2 at the cathode increased the faradiac current flowing through the BPE. Based on this signal composite, an ECL "off-on" phenomenon was observed at the cathode, after Pt-PAMAM-DNAzyme was "peeled off" by PSA. Conversely, at the anode, an "on-off" ECL changing was obtained. Therefore, a sensitive ratiometry for PSA detection was achieved with a linear range from 0.10 to 200ng/mL. Since the two ECL emitters were physically separated, the ratiometric system was relatively simple and neither optical filters nor spectrometer were required. The strategy combining the ECL ratiometry and BPE broadens the applications of BPE-ECL and shows good perspective in clinical application.

Efficacy and toxicity of nimotuzumab combined with radiotherapy in elderly patients with esophageal squamous cell carcinoma.

This study was conducted to assess the efficacy and toxicity of nimotuzumab combined with radiotherapy (RT) in elderly patients with esophageal squamous cell carcinoma. The clinical data of 16 esophageal squamous cell carcinoma patients, aged >70 years, who were initially treated with nimotuzumab combined with RT, were collected and retrospectively reviewed. The overall response and treatment toxicity were analyzed using SPSS software. All the patients completed the treatment schedule. The response to treatment was assessed at treatment completion and reassessed after 1-2 months: 1 patient achieved complete response (CR), 10 patients achieved partial response (PR), 4 patients exhibited stable disease and 1 patient developed disease progression and succumbed to radiation pneumonitis (RP) 1 month later. The overall response rate (CR+PR) was 68.8%. All 16 patients experienced grade 1-2 radiation esophagitis; no grade 3-4 toxicities were reported. There was one case of treatment-related mortality due to RP during the study. One patient developed a rash on the forearm. No hematological, gastrointestinal, hepatic or renal toxicities were observed. In conclusion, the toxicity of combined nimotuzumab with RT in elderly patients with esophageal cancer was tolerable. However, due to limitations associated with the retrospective nature of this study, the limited number of enrolled cases and the epidermal growth factor receptor expression determination prior to treatment, the efficacy of this treatment modality requires further investigation.

The efficacy and toxicities of combined lobaplatin with paclitaxel as a first-line chemotherapy for advanced esophageal squamous cell carcinoma.

BACKGROUND: To assess the efficacy and toxicities of combined lobaplatin with paclitaxel (LP) as a first line chemotherapy in esophageal cancer. METHODS: The clinical data of 45 patients with esophageal squamous cell carcinoma treated initially with lobaplatin-paclitaxel chemotherapy were collected and reviewed retrospectively. The overall response, treatment toxicities and dysphagia relief were analyzed with SPSS software. RESULTS: The overall response rate was 42.2%, with 1 patient (2.2%) showing complete remission, 18 patients (40.0%) with partial remission, 19 (42.2%) with stable disease (SD), and 7 (15.6%) with progressive disease, respectively. The most common hematological toxicity was leucopenia with grade 0, I, II, III and IV in 16 (35.6%), 10 (22.2%), 11 (24.4%), 7 (15.6%), and 1 patient (2.2%), respectively. Thirty-seven patients (82.2%) experienced grade I-II nausea/vomiting without grade III-IV instances occurring. Four patients (8.9%) experienced grade I hepatotoxicity. No nephrotoxicity was observed. Five in thirteen patients treated with concurrent chemoradiotherapy (CRT) suffered severe radiation pneumonitis. The dysphagia resolved or improved in 32 patients (71%). CONCLUSIONS: Lobaplatin-paclitaxel showed a significant antitumor effect to squamous esophageal cancer with manageable toxicities. Limitation of the surveillance time and the retrospective nature, the effect that based on these data formal prospective trials appear warranted and are needed prior to routine first line use of this regimen.

Radiation-induced liver disease in three-dimensional conformal radiation therapy for primary liver carcinoma: the risk factors and hepatic radiation tolerance.

PURPOSE: To identify risk factors relevant to radiation-induced liver disease (RILD) and to determine the hepatic tolerance to radiation. METHODS AND MATERIALS: The data of 109 primary liver carcinomas (PLC) treated with hypofractionated three-dimensional conformal radiation therapy (3D-CRT) were analyzed. Seventeen patients were diagnosed with RILD and 13 of 17 died of it. RESULTS: The risk factors for RILD were late T stage, large gross tumor volume, presence of portal vein thrombosis, association with Child-Pugh Grade B cirrhosis, and acute hepatic toxicity. Multivariate analyses demonstrated that the severity of hepatic cirrhosis was a unique independent predictor. For Child-Pugh Grade A patients, the hepatic radiation tolerance was as follows: (1) Mean dose to normal liver (MDTNL) of 23 Gy was tolerable. (2) For cumulative dose-volume histogram, the tolerable volume percentages would be less than: V5 of 86%, V10 of 68%, V15 of 59%, V20 of 49%, V25 of 35%, V30 of 28%, V35 of 25%, and V40 of 20%. (3) Tolerable MDTNL could be estimated by MDTNL (Gy) = -1.686 + 0.023 * normal liver volume (cm3). CONCLUSION: The predominant risk factor for RILD was the severity of hepatic cirrhosis. The hepatic tolerance to radiation could be estimated by dosimetric parameters.

Prediction of radiation-induced liver disease by Lyman normal-tissue complication probability model in three-dimensional conformal radiation therapy for primary liver carcinoma.

PURPOSE: To describe the probability of RILD by application of the Lyman-Kutcher-Burman normal-tissue complication (NTCP) model for primary liver carcinoma (PLC) treated with hypofractionated three-dimensional conformal radiotherapy (3D-CRT). METHODS AND MATERIALS: A total of 109 PLC patients treated by 3D-CRT were followed for RILD. Of these patients, 93 were in liver cirrhosis of Child-Pugh Grade A, and 16 were in Child-Pugh Grade B. The Michigan NTCP model was used to predict the probability of RILD, and then the modified Lyman NTCP model was generated for Child-Pugh A and Child-Pugh B patients by maximum-likelihood analysis. RESULTS: Of all patients, 17 developed RILD in which 8 were of Child-Pugh Grade A, and 9 were of Child-Pugh Grade B. The prediction of RILD by the Michigan model was underestimated for PLC patients. The modified n, m, TD50 (1) were 1.1, 0.28, and 40.5 Gy and 0.7, 0.43, and 23 Gy for patients with Child-Pugh A and B, respectively, which yielded better estimations of RILD probability. The hepatic tolerable doses (TD5) would be MDTNL of 21 Gy and 6 Gy, respectively, for Child-Pugh A and B patients. CONCLUSIONS: The Michigan model was probably not fit to predict RILD in PLC patients. A modified Lyman NTCP model for RILD was recommended.

Hypofractionated three-dimensional conformal radiation therapy for primary liver carcinoma.

BACKGROUND: The purpose of the current study was to evaluate the tolerance and efficacy of hypofractionated three-dimensional conformal radiotherapy (3DCRT) with or without transarterial chemoembolization (TACE) for technically unresectable or medically inoperable primary liver carcinoma (PLC). METHODS: Between April 1999 and August 2003, 128 patients with a clinical diagnosis of PLC received hypofractionated 3DCRT at Cancer Hospital, Guangxi Medical University. Both hypofractionated 3DCRT and TACE were used to treat 48 of these 128 patients. Liver cirrhosis of Child-Pugh Grade A was found in 108 patients, and Grade B was found in 20 patients. The mean gross tumor volume (GTV) was 459 +/- 430 cm3. A mean total irradiation dose of 53.6 +/- 6.6 Gy was delivered at an average fraction of 4.88 +/- 0.47 Gy, 3 times a week using 8-MV photons. RESULTS: The median follow-up time after 3DCRT was 12 months (range, 2-56 mos.). The immediate response rate was 55%. The overall survival rates at 1, 2, and 3 years were 65%, 43%, and 33%, respectively, with a median survival of 20 months (range, 7-31 mos.). Radiation Therapy Oncology Group (RTOG) Grade 2 acute gastrointestinal complications developed in 8 patients, whereas 4 patients developed Grade 3 late gastrointestinal complications. Radiation-induced liver disease (RILD) developed in 19 (15%) patients, of which 12 had Child-Pugh Grade B liver cirrhosis, and 7 had Grade A. GTV and associated liver cirrhosis were identified by Cox regression analysis as independent predictors for survival (P = 0.044 and 0.015). CONCLUSIONS: Hypofractionated 3DCRT is effective in carefully selected patients with PLC. Gastrointestinal complications and RILD were the most distinct complications.

[Prognostic factor of primary liver cancer treated by hypofractionated three-dimensional conformal radiotherapy].

OBJECTIVE: To evaluate the toxicity and efficacy of primary liver cancer (PLC) treated by hypofractionated three-dimensional conformal radiotherapy (3DCRT) and investigate the prognostic factors. METHODS: Between April 1999 and August 2003, 128 PLC patients received hypofractionated 3DCRT. According to UICC/AJCC staging system, there were 83 T3 patients, 45 T4, with none of them having lymph node metastasis. The mean value of gross tumor volume (GTV) was (458.92 +/- 429.8) cm(3) (6.2-2097 cm(3)). Thirty-four patients had portal vein tumor thrombosis (PVTT). 108 patients had Child-Pugh Grade A liver cirrhosis and 20 Child-Pugh Grade B liver cirrhosis. All patients received a total dose of (53.6 +/- 6.6) Gy/4-8 Gy per fraction/3 fractions per week. Forty-eight of these patients received 3DCRT combined with transarterial chemoembolization (TACE). RESULTS: Seven patients died within 3 months after the treatment were dismissed from the series. The response rate (CR + PR) was 55% (67/121). The overall 1-, 2-, and 3-year survival rate was 65.0%, 43.3%, and 33.1%, respectively. T stage (P = 0.001), GTV (P = 0.0001), PVTT (P = 0.0001) and Child-Pugh Grade (P = 0.0001) had significant impact on the overall survival. However, only GTV and Child-Pugh Grade were independent significant prognostic factors by Cox-regression analysis, (P = 0.044 and P = 0.015). CONCLUSION: T stage, GTV, PVTT and Child-Pugh Grade have significant impact on the overall survival in primary liver cancer patients treated by three-dimensional conformal radiotherapy. But only GTV and Child-Pugh Grade are independent prognostic factors.