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The monitoring of DNA and RNA biomarkers freely circulating in the blood constitutes the basis of innovative cancer detection methods based on liquid biopsy. Such methods are expected to provide new opportunities for a better understanding of cancer disease at the molecular level, thus contributing to improved patient outcomes. Advanced biosensors can advance possibilities for cancer-related nucleic acid biomarkers detection. In this context, peptide nucleic acids (PNAs) play an important role in the fabrication of highly sensitive biosensors. This review provides an overview of recently described PNA-based biosensors for cancer biomarker detection. One of the most striking features of the described detection approaches is represented by the possibility to detect target nucleic acids at the ultra-low concentration with the capability to identify single-base mutations. [ABSTRACT FROM AUTHOR]

Droplet microfluidics combined with the isothermal circular strand displacement polymerization (ICSDP) represents a powerful new technique to detect both single-stranded DNA and microRNA sequences. The method here described helps in overcoming some drawbacks of the lately introduced droplet polymerase chain reaction (PCR) amplification when implemented in microfluidic devices. The method also allows the detection of nanoliter droplets of nucleic acids sequences solutions, with a particular attention to microRNA sequences that are detected at the picomolar level. The integration of the ICSDP amplification protocol in droplet microfluidic devices reduces the time of analysis and the amount of sample required. In addition, there is also the possibility to design parallel analyses to be integrated in portable devices.

Three coumarins, scopoletin (1), esculetin (2), and esculin (3), were investigated by differential scanning calorimetry and Langmuir-Blodgett techniques to gain information about the interaction of these compounds with cellular membranes. Phospholipids assembled as multilamellar vesicles or monolayers (at the air-water interface) were used as biomembrane models. Differential scanning calorimetry was employed to study the interaction of these coumarins with multilamellar vesicles and to evaluate their absorption by multilamellar vesicles. These experiments indicated that 1-3 interact in this manner to different extents. The Langmuir-Blodgett technique was used to study the effect of these coumarins on the organization of phospholipids assembled as a monolayer. The data obtained were in agreement with those obtained in the calorimetric experiments.

E-3,5,4'-trimethoxystilbene (TMS) is a naturally occurring analog of resveratrol. The anti-neoplastic, antiallergic and anti-angiogenic activities of TMS have been recently reported. From the viewpoint of metabolism, TMS may be more favourable than resveratrol because all of its hydroxyl groups, which are subjected to extensive glucuronide or sulphate conjugation in the metabolic pathways of resveratrol, are protected by methylation. Moreover, methylation increases lipophilicity and may enhance cell membrane permeability, but it decreases its solubility in aqueous media. A way to increase TMS solubility can be represented by complexation with beta-cyclodextrins. In the present paper, the differential scanning calorimetry technique has been used to study the interaction of TMS with a biomembrane model constituted by dimyristoylphosphatidylcholine multilamellar vesicles. Furthermore, kinetic experiments have been carried out to follow the uptake of TMS by biomembranes in the presence of beta-cyclodextrins to gain information on the effect of beta-cyclodextrins on the uptake process. Our results indicate that opportune concentrations of beta-cyclodextrins greatly improve the uptake of TMS by biomembrane models., (Copyright (c) 2009 Elsevier B.V. All rights reserved.)