Tumor-associated macrophages and epithelial�mesenchymal transition in cancer: Nanotechnology comes into view

Tumor-associated macrophages (TAMs) are an important component of the leukocytic infiltrate of the tumor microenvironment. There is persuasive preclinical and clinical evidence that TAMs induce cancer inanition and malignant progression of primary tumors toward a metastatic state through a highly conserved and fundamental process known as epithelial�mesenchymal transition (EMT). Tumor cells undergoing EMT are distinguished by increased motility and invasiveness, which enable them to spread to distant sites and form metastases. In addition, besides becoming resistant to apoptosis and antitumor drugs, they also contribute to immunosuppression and get a cancer stem-cell like phenotype. Here, we will focus on selected molecular pathways underlying EMT�in particular, the role of TAMs in the induction and maintenance of EMT�and further discuss how the targeting of TAMs through the application of nanotechnology tools allows the development of a whole new range of therapeutics. © 2018 Wiley Periodicals, Inc

Concurrent application of conductive biopolymeric chitosan/ polyvinyl alcohol/ MWCNTs nanofibers, intracellular signaling manipulating molecules and electrical stimulation for more effective cardiac tissue engineering

Fabrication of appropriate electro-conductive scaffold, application of small molecules (SMs), electrical stimulation (ES), and stem cells are steps forward in cardiac tissue engineering. Herein, for the first time, all mentioned factors have been taken into account concurrently regarding the differentiation of unrestricted somatic stem cells (USSCs) into cardiac cells. To accomplish this goal, electrospun composite scaffolds made of chitosan (CS) and polyvinyl alcohol (PVA) with multi-wall carbon nanotubes (MWCNTs; ranged from 0 to 2.5 w/w) were fabricated. After analyzing mechanical, electrical, and biological properties, the best MWCNTs portion was selected. Of note, the addition of 2w/w MWCNTs to the CS/PVA samples reduced average fiber diameter from 225 to 110 nm, increasing electrical conductivity from 8 � 10�5 S/m to 9 � 10�3 S/m and trebling tensile strength. Then, by using a 10-day differentiation protocol (including CHIR99021, IWP2, SB431542, and purmorphamine SMs) and ES, USSCs were induced into cardiomyocytes. Overexpression of some cardiac-associated genes, including troponin I, CX43, and β-MHC, along with proper phenotypic alteration, were observed. (Scaffold + SM + ES) show a significant increase in the expression of these genes, 172, 5.3, and 64-times as normalized to undifferentiated cells, respectively. Our findings confirmed the importance of the simultaneous implementation of different factors for the developing functionality of the cardiac tissue. Altogether, it is recommended to deploy all mentioned features to obtain effective cardiac tissue engineering. © 2020 Elsevier B.V

Photoluminescent carbon quantum dot/poly-L-Lysine core-shell nanoparticles: A novel candidate for gene delivery

Cationic polymers such as poly-L-lysine (PLL) are able to interact electrostatically with DNA to produce polymeric systems with nanometric diameters due to the neutralization and accumulation of DNA. This study integrates the outstanding properties of carbon quantum dots (CQDs) with PLL to develop a novel gene delivery vehicle with a core-shell hybrid nanostructure. The CQD/PLL core-shell nanoparticles (NPs) were, therefore, synthesized in such a way that they had narrow size distribution and an average diameter under 10 nm, both of which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy exhibited that the PLL passivation agents were formed on the CQDs through releasing amine groups on their surface. The positive charge of the CQD/PLL core-shell NPs reduced from +15 to nearly zero mV after being loaded with DNA at the weight ratio of 2:1. These traceable, water-soluble, biocompatible, and tunable photoluminescent NPs demonstrated a quantum yield of around 12 and a cellular uptake of nearly 70. The NPs also showed no considerable toxicity to the human embryonic kidney (HEK)-293T cells. Hence, these novel CQD/PLL core-shell NPs hold great promise as a non-toxic and efficient gene delivery vector. © 2020 Elsevier B.V