Aptamer-Based Targeting of Cancer: A Powerful Tool for Diagnostic and Therapeutic Aims.

Cancer is known as one of the most significant causes of death worldwide, and, in spite of novel therapeutic methods, continues to cause a considerable number of deaths. Targeted molecular diagnosis and therapy using aptamers with high affinity have become popular techniques for pathological angiogenesis and cancer therapy scientists. In this paper, several aptamer-based diagnostic and therapeutic techniques such as aptamer-nanomaterial conjugation, aptamer-drug conjugation (physically or covalently), and biosensors, which have been successfully designed for biomarkers, were critically reviewed. The results demonstrated that aptamers can potentially be incorporated with targeted delivery systems and biosensors for the detection of biomarkers expressed by cancer cells. Aptamer-based therapeutic and diagnostic methods, representing the main field of medical sciences, possess high potential for use in cancer therapy, pathological angiogenesis, and improvement of community health. The clinical use of aptamers is limited due to target impurities, inaccuracy in the systematic evolution of ligands via exponential enrichment (SELEX)stage process, and in vitro synthesis, making them unreliable and leading to lower selectivity for in vivo targets. Moreover, size, behavior, probable toxicity, low distribution, and the unpredictable behavior of nanomaterials in in vivo media make their usage in clinical assays critical. This review is helpful for the implementation of aptamer-based therapies which are effective and applicable for clinical use and the design of future studies.

A new molecularly imprinted polymer electrochemical sensor based on CuCo2 O4 /N-doped CNTs/P-doped GO nanocomposite for detection of 25-hydroxyvitamin D3 in serum samples.

25-Hydroxyvitamin D3 as a main circulating metabolite of vitamin D is usually measured in serum to evaluate the vitamin D status of humans. So, developing an accessible, fast response, sensitive, and selective detection method for 25-hydroxyvitamin D3 is highly important. In this study, we designed a sensitive and selective electrochemical sensor based on the modification of glassy carbon electrode by nanocomposite of CuCo2 O4 /nitrogen-doped carbon nanotubes and phosphorus-doped graphene oxide. Then 25-hydroxyvitamin D3 -imprinted polypyrrole was coated on the electrode surface through electropolymerization. Moreover, ferricyanide was used as a mediator for the creation of a readable signal, which was considerably decreased after rebinding of 25-hydroxyvitamin D3 on the electrode. The proposed sensor successfully detected 25-hydroxyvitamin D3 in the range of 0.002-10 µM, with a detection limit of 0.38 nM, which was highly lower than deficiency concentration (20 ng/ml; 49.92 nM). Finally, the proposed sensor was checked for detection of 25-hydroxyvitamin D3 in serum samples with recovery in the range of 80%-106.42%. The results demonstrated the applicability of the designed sensor for the detection of 25-hydroxyvitamin D3 in biological samples.

Application of a transition metal oxide/carbon-based nanocomposite for designing a molecularly imprinted poly (l-cysteine) electrochemical sensor for curcumin.

In this study an electrochemical sensor was fabricated for detection of curcumin, as a functional herbal food, using molecularly imprinted polymer and highly conductive transition metal oxide/carbon-based nanocomposite. In this way, CuCo2O4/nitrogen-doped carbon nanotubes/phosphorus-doped graphene oxide nanocomposite was dropped on the electrode. This nanocomposite synergically possesses conductivity features of copper and phosphorus-doping sites, specific surface area of carbon nanotubes, and carbons Fermi level of graphene oxide. In the following, l-Cystein electropolymerized on the electrode in presence of curcumin. The sensor was produced by removing curcumin from poly (L- cystein) matrix. The sensor was successfully used for detection of curcumin in the ranges of 0.1-1 µmol L-1 and 1-30 µmol L-1, with acceptable detection limit (30 nmol L-1). Finally, the proposed method was used for detection of curcumin in serum samples with recoveries of 80-110.87%. The results demonstrated that aforementioned method can be used for detection of curcumin in biological samples.

Ellagic acid as a potent anticancer drug: A comprehensive review on in vitro, in vivo, in silico, and drug delivery studies.

Ellagic acid as a polyphenol or micronutrient, which can be naturally found in different vegetables and fruits, has gained considerable attention for cancer therapy due to considerable biological activities and different molecular targets. Ellagic acid with low hydrolysis and lipophilic and hydrophobic nature is not able to be absorbed in circulation. So, accumulation inside the intestinal epithelial cells or metabolization to other urolithins leads to the limitation of direct evaluation of EA effects in clinical studies. This review focuses on the studies which supported anticancer activity of pure or fruit-extracted ellagic acid through in vitro, in vivo, in silico, and drug delivery methods. The results demonstrate ellagic acid modulates the expression of various genes incorporated in the cancer-related process of apoptosis and proliferation, inflammation related-gens, and oxidative-related genes. Moreover, the ellagic acid formulation in carriers composed of lipid, silica, chitosan, iron- bovine serum albumin nanoparticles obviously enhanced the stable release and confident delivery with minimum loss. Also, in silico analysis proved that ellagic acid was able to be placed at a position of cocrystal ADP, in the deep cavity of the protein target, and tightly interact with binding pocket residues leading to suppression of substrate availability of protein and its activation inhibition.

Biosensors based on aptamer-conjugated gold nanoparticles: A review.

Simply synthetized gold nanoparticles have been highly used in medicine and biotechnology as a result of their biocompatibility, conductivity, and being easily functionalized with biomolecules such as aptamer. Aptamer-conjugated gold nanoparticle structures synergically possess characteristics of both aptamer and gold nanoparticles including high binding affinity, high biocompatibility, enhanced target selectivity, and long circulatory half-life. Aptamer-conjugated gold nanoparticles have extensively gained considerable attention for designing of biosensing systems due to their interesting optical and electrochemical features. Moreover, biosensors based on aptamer-gold nanoparticles are easy to use, with fast response, and inexpensive which make them ideal in individualized medicine, disease markers detection, food safety, and so forth. Moreover, due to high selectivity and biocompatibility of aptamer-gold nanoparticles, these biosensing platforms are ideal tools for targeted drug delivery systems. The application of this nanostructure as diagnostic and therapeutic tool has been developed for detection of cancer in the early stage by detecting cancer biomarkers, pathogens, proteins, toxins, antibiotics, adenosine triphosphate, and other small molecules. This review obviously demonstrates that this nanostructure effectively is applicable in the field of biomedicine and possesses potential of commercialization aims.