Niosomes containing paclitaxel and gold nanoparticles with different coating agents for efficient chemo/photothermal therapy of breast cancer.

Breast cancer (BC) is one of the most common cancers in women, and chemotherapy is usually used to overcome this cancer. To improve drug delivery to cancer sites and reduce their side effects, nanocarriers such as niosomes (NIOs) are used. Moreover, a combination of other therapeutic methods like photothermal therapy (PTT) can help to enhance the chemotherapy effect. The aim of this research is the design a nanocarrier that simultaneously delivers chemotherapy and PTT agents. To achieve this goal, NIOs containing paclitaxel (PTX) as a chemotherapeutic agent and spherical gold nanoparticles (AuNPs) coated with citrate, chitosan (CS), and polyamidoamine (PAMAM) as a PTT agent were synthesized by thin hydration methods. Their physicochemical properties were determined by dynamic light scattering, UV-Vis, Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis. Cellular uptake, cell cytotoxicity, hyperthermia, and apoptosis effects of the proposed system were investigated in the MCF-7 BC cell line. The cellular uptake of NIOs/AuNPs-PAMAM (99.21%) and NIOs/AuNPs-CS (98.93%) by MCF-7 cells was higher than that of NIOs/AuNPs (79.55%), demonstrating that surface charge plays a key role in the cellular uptake of NPs. The MTT assay showed the cell viability of 45.48% for NIOs/AuNPs/PTX, 34.24% for NIOs/AuNPs-CS/PTX, and 37.67% for NIOs/AuNPs-PAMAM/PTX after 48 h of treatment. However, the application of hyperthermia significantly decreased the viability of cells treated with NIOs/AuNPs/PTX (37.72%), NIOs/AuNPs-CS/PTX (10.49%), and NIOs/AuNPs-PAMAM/PTX (4.1%) after 48 h. The apoptosis rate was high in NIOs/AuNPs-PAMAM/PTX (53.24%) and NIOs/AuNPs-CS/PTX (55.4%) confirming the data from MTT. In conclusion, the result revealed that combined PTT with chemotherapy increased cell cytotoxicity effects against the MCF-7 cells, and the AuNPs with various coating agents affected cellular uptake and hyperthermia which can be considered for efficient BC therapy.

Astaxanthin Binding Affinity to DNA: Studied By Fluorescence, Surface Plasmon Resonance and Molecular Docking Methods.

Carotenoid astaxanthin (Ax), a pink-red pigment, with its anti-oxidative feature, is useful as a therapeutic element for numerous diseases. The purpose of this study is to investigate the binding affinity of Ax to double strand (ds) DNA evaluated by using the fluorescence spectroscopy, surface plasmon resonance (SPR) and docking approaches. The fluorescence results show that Ax can quench the intensity of DNA fluorescence via a static quenching way. In the SPR method, for affinity evaluation, DNA molecules were attached on a gold sensor surface. Using different amounts of ds DNA, the kinetic values KD, KA, and Ka were calculated. The Van't Hoff equation was used to estimate thermodynamic parameters including enthalpy (∆H), entropy (∆S) and Gibbs free energy (∆G) changes. The obtained results for KD in SPR (6.89×10-5 M) and fluorescence (KD=0.76×10-5 M) methods were in line with each other. Thermodynamic studies were carried out at four different temperatures, and the resulted negative data for ΔH and ΔS displayed that the main binding strength in the interaction of Ax with DNA was hydrogen bonding. ΔG value calculated by fluorescence method was near -38 kJ. mol-1 and using the docking method, estimated -9.95 kcal. mol-1 (-41.63 kJ. mol-1) which shows the binding behavior has an exothermic and spontaneous mechanism. Molecular docking results confirmed that the side chains of Ax interact specifically with base pairs and the DNA backbone.

Electrochemical microfluidic paper-based analytical devices for cancer biomarker detection: From 2D to 3D sensing systems.

Microfluidic paper-based analytical devices (µPADs) offer a unique possibility for a cost-effective portable and rapid detection of a wide range of small molecules and macromolecules and even microorganisms. In this line, electrochemical detection methods are key techniques for the qualitative analysis of different types of ligands. The electrochemical sensing µPADs have been devised for the rapid, accurate, and quantitative detection of oncomarkers through two-/three-dimensional (2D/3D) approaches. The 2D µPADs were first developed and then transformed into 3D systems via folding and/or twisting of paper. The microfluidic channels and connections were created within the layers of paper. Based on the fabrication methods, 3D µPADs can be classified into origami and stacking devices. Various fabrication methods and materials have been used to create hydrophilic channels in µPADs, among which the wax printing technique is the most common method in fabricating µPADs. In this review, we discuss the fabrication and design strategies of µPADs, elaborate on their detection modes, and highlight their applications in affinity-based electrochemical µPADs methods for the detection of oncomarkers.

Impacts of oxidants and antioxidants on the emergence and progression of Alzheimer's disease.

The brain shows a high sensitivity to oxidative stress (OS). Thus, the maintenance and homeostasis of the brain, in particular neural cells, regarding the reduction-oxidation (redox) situation is crucial for the regular function of the central nervous systems (CNS). The imbalance between the reactive oxygen species (ROS) and the cellular mechanism(s) might lead to the emergence of OS, resulting in possible cell death and tissue damages, and initiating neurodegenerative disorders (NDDs). Characterized by the cytoplasmic growth of neurofibrillary tangles and extracellular ß-amyloid plaques, Alzheimer's disease (AD) is a complex NDD that causes dementia in adult life with severe manifestations. Nuclear factor erythroid 2-related factor 2 (NRF2) is a key transcription factor that regulates the functional expression of OS-related genes and the functionality of endogenous antioxidants in response to ROS. In the case of oxidative damage, NRF2 is transferred to the nucleus and attached to the antioxidant response element (ARE), which can subsequently enhance the functional expression of the cell-protecting genes. In this review, we impart on the key mechanisms engaged in the generation of active and reactive species of endogenous and exogenous oxidants and discuss the antioxidants as the defense system of neural cells regarding the NRF2-ARE signaling path in the CNS.

Photonic crystal based biosensors: Emerging inverse opals for biomarker detection.

Photonic crystal (PC)-based inverse opal (IO) arrays are one of the substrates for label-free sensing mechanism. IO-based materials with their advanced and ordered three-dimensional microporous structures have recently found attractive optical sensor and biological applications in the detection of biomolecules like proteins, DNA, viruses, etc. The unique optical and structural properties of IO materials can simplify the improvements in non-destructive optical study capabilities for point of care testing (POCT) used within a wide variety of biosensor research. In this review, which is an interdisciplinary investigation among nanotechnology, biology, chemistry and medical sciences, the recent fabrication methodologies and the main challenges regarding the application of (inverse opals) IOs in terms of their bio-sensing capability are summarized.

Computational predictive approaches for interaction and structure of aptamers.

Aptamers are short single-strand sequences that can bind to their specific targets with high affinity and specificity. Usually, aptamers are selected experimentally via systematic evolution of ligands by exponential enrichment (SELEX), an evolutionary process that consists of multiple cycles of selection and amplification. The SELEX process is expensive, time-consuming, and its success rates are relatively low. To overcome these difficulties, in recent years, several computational techniques have been developed in aptamer sciences that bring together different disciplines and branches of technologies. In this paper, a complementary review on computational predictive approaches of the aptamer has been organized. Generally, the computational prediction approaches of aptamer have been proposed to carry out in two main categories: interaction-based prediction and structure-based predictions. Furthermore, the available software packages and toolkits in this scope were reviewed. The aim of describing computational methods and tools in aptamer science is that aptamer scientists might take advantage of these computational techniques to develop more accurate and more sensitive aptamers.