Multifunctional siRNA/ferrocene/cyclodextrin nanoparticles for enhanced chemodynamic cancer therapy

The therapeutic outcome of chemodynamic therapy (CDT) is greatly hindered by the presence of oxidative damage repair proteins (MTH1) inside cancer cells. These oxidative damage repair proteins detoxify the action of radicals generated by Fenton or Fenton-like reactions. Hence, it is extremely important to develop a simple strategy for the downregulation of MTH1 protein inside cancer cells along with the delivery of metal ions into cancer cells. A one-pot host-guest supramolecular approach for the codelivery of MTH1 siRNA and metal ions into a cancer cell is reported. Our approach involves the fabrication of an inclusion complex between cationic β-cyclodextrin and a ferrocene prodrug, which spontaneously undergoes amphiphilicity-driven self-assembly to form spherical nanoparticles (NPs) having a positively charged surface. The cationic surface of the NPs was then explored for the loading of MTH1 siRNA through electrostatic interactions. Using HeLa cells as a representative example, efficient uptake of the NPs, delivery of MTH1 siRNA and the enhanced CDT of the nanoformulation are demonstrated. This work highlights the potential of the supramolecular approach as a simple yet efficient method for the delivery of siRNA across the cell membrane for enhanced chemodynamic therapy.

Effectiveness of platelet inhibition on major adverse cardiac events in non-cardiac surgery after percutaneous coronary intervention: a prospective cohort study

BACKGROUND

Platelet inhibition is mandatory therapy after percutaneous coronary intervention (PCI). Withdrawal of oral antiplatelet agents has been linked to increased incidence of postoperative adverse cardiac events in post-PCI patients having non-cardiac surgery (NCS). There is limited knowledge of temporal changes in platelet inhibition in this high-risk surgical population. We therefore performed a multicentre prospective cohort study evaluating perioperative platelet function and its association with postoperative major adverse cardiac events (MACE).

METHODS

In 201 post-PCI patients having NCS, we assessed the association between platelet function and postoperative MACE. We performed perioperative platelet function testing using a platelet mapping assay (PMA). Troponin-I was measured every 8 h for 2 days, then daily until day 5. Myocardial infarction was assessed using the third universal definition. We used multivariable logistic regression to assess the association between platelet inhibition and MACE.

RESULTS

Major adverse cardiac events occurred in 40 patients within 30 days of surgery. Thirty-two of these events were non-ST-elevation myocardial infarction, four ST-elevation myocardial infarction, and four exacerbation of congestive heart failure. We were unable to show an association between platelet inhibition and MACE. The PMA showed declining levels of platelet inhibition the longer the antiplatelet therapy was withheld before surgery. Logistic regression did not show an association between preoperative platelet function or the type of stent and MACE. We found an increased cardiac risk of MACE after surgery within 6 weeks of PCI.

CONCLUSIONS

The incidence of MACE in patients undergoing NCS after previous PCI is high in spite of adequate perioperative antiplatelet therapy.

CLINICAL TRIAL REGISTRATION

NCT 01707459 (registered at http://www.clinicaltrials.gov).

Development of simple, rapid and sensitive detection assay for grouper nervous necrosis virus using real-time loop-mediated isothermal amplification

A quantitative rapid detection method based on loop-mediated isothermal amplification has been developed for red-spotted grouper nervous necrosis virus (RGNNV). The nested polymerase chain reaction (PCR) assay is the mainstream inspection of the brooder in the hatchery. In this study, a real-time loop-mediated isothermal amplification (LAMP) method has been applied for RGNNV detection, known as a high-speed gene amplification procedure. Of the three temperatures (60 °C, 63 °C and 65 °C) attempted, it has been found that 63 °C is giving higher amplification from 11th minute onwards. Sensitivity analysis performed in comparison with real-time polymerase chain reaction, reverse transcriptase PCR and nested RT-PCR using various concentrations of template revealed that real-time LAMP method is efficient in terms of cost and time consumption. Specificity analysis revealed that the method developed is specific to RGNNV, whereas it has sequence cross-match with tiger puffer NNV giving advantage in detecting both the viruses. This method could be much efficient in analysing RGNNV in combination with TPNNV.