ABSTRACT
The regioselective, orthogonal functionalisation of 4,10-dichlorochrysene enables the synthesis of a variety of 2,8,4,10-"A2B2"-tetrasubstituted chrysenes. Such compounds exhibit broadened UV-vis absorption spectra, decreased band gap and higher HOMO levels compared to the parent chrysene.
ABSTRACT
The new paradigm of heterostructures based on two-dimensional (2D) atomic crystals has already led to the observation of exciting physical phenomena and creation of novel devices. The possibility of combining layers of different 2D materials in one stack allows unprecedented control over the electronic and optical properties of the resulting material. Still, the current method of mechanical transfer of individual 2D crystals, though allowing exceptional control over the quality of such structures and interfaces, is not scalable. Here we show that such heterostructures can be assembled from chemically exfoliated 2D crystals, allowing for low-cost and scalable methods to be used in device fabrication.
Subject(s)
Graphite/chemistry , Ink , Nanoparticles/chemistry , Nanostructures/chemistry , Electronics/instrumentation , Equipment Design , Nanoparticles/ultrastructure , Nanostructures/ultrastructure , Nanotechnology/instrumentation , Printing/instrumentationABSTRACT
Two poly(styrene oxide)-poly(ethylene oxide) (PSO-PEO) triblock copolymers with different chain lengths were analyzed as potential chemotherapeutic nanocarriers, and their ability to inhibit the P-glycoprotein (P-gp) efflux pump in a multidrug resistant (MDR) cell line were measured in order to establish possible cell-responses induced by the presence of the copolymer molecules. Thus, EO33SO14EO33 and EO38SO10EO38 polymeric micelles were tested regarding doxorubicin (DOXO) entrapment efficiency (solubilization test), physical stability (DLS), cytocompatibility (fibroblasts), release profiles at various pHs (in vitro tests), as well as P-gp inhibition and evasion and cytotoxicity of the DOXO-loaded micelles in an ovarian MDR NCI-ADR/RES cell line and in DOXO-sensitive MCF-7 cells. EO33SO14EO33 and EO38SO10EO38 formed spherical micelles (~13nm) at lower concentration than other copolymers under clinical evaluation (e.g. Pluronic®), exhibited 0.2% to 1.8% loading capacity, enhancing more than 60 times drug apparent solubility, and retained the cargo for long time. The copolymer unimers inhibited P-gp ATPase activity in a similar way as Pluronic P85, favoring DOXO accumulation in the resistant cell line, but not in the sensitive cell line. DOXO loaded in the micelles accumulated more slowly inside the cells, but caused greater cytotoxicity than free drug solutions in the NCI-ADR-RES cell line, which overexpressed P-gp. Hence, PSO-PEO block copolymers offer interesting features as new biological response modifiers to be used in the design of efficient nanocarriers for cancer chemotherapy.
Subject(s)
Antibiotics, Antineoplastic/administration & dosage , Doxorubicin/administration & dosage , Drug Carriers/administration & dosage , Nanoparticles/administration & dosage , Polyethylene Glycols/administration & dosage , Polystyrenes/administration & dosage , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Adenosine Triphosphatases/metabolism , Antibiotics, Antineoplastic/chemistry , Cell Line, Tumor , Doxorubicin/chemistry , Drug Carriers/chemistry , Drug Resistance, Neoplasm , Drug Stability , Humans , Micelles , Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Polystyrenes/chemistryABSTRACT
A new fabrication process for the patterning of organic semiconductors at the nanoscale has been developed using low temperature thermal nanoimprint lithography and the details of this process are discussed. Novel planar nanotransistors have been fabricated and characterized from poly(3-hexylthiophene) (P3HT) and we demonstrate the feasibility of using such devices as highly sensitive chemical sensors.
