1.Comparison of impedimetric detection of DNA hybridization on the various biosensors based on modified glassy carbon electrodes with PANHS and nanomaterials of RGO and MWCNTs.
Benvidi A1, Tezerjani MD2, Jahanbani S2, Mazloum Ardakani M2, Moshtaghioun SM3. Talanta. 2016 Jan 15;147:621-7. doi: 10.1016/j.talanta.2015.10.043. Epub 2015 Oct 17.
In this research, we have developed lable free DNA biosensors based on modified glassy carbon electrodes (GCE) with reduced graphene oxide (RGO) and carbon nanotubes (MWCNTs) for detection of DNA sequences. This paper compares the detection of BRCA1 5382insC mutation using independent glassy carbon electrodes (GCE) modified with RGO and MWCNTs. A probe (BRCA1 5382insC mutation detection (ssDNA)) was then immobilized on the modified electrodes for a specific time. The immobilization of the probe and its hybridization with the target DNA (Complementary DNA) were performed under optimum conditions using different electrochemical techniques such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed biosensors were used for determination of complementary DNA sequences. The non-modified DNA biosensor (1-pyrenebutyric acid-N- hydroxysuccinimide ester (PANHS)/GCE), revealed a linear relationship between ∆Rct and logarithm of the complementary target DNA concentration ranging from 1.
2.Antimicrobial peptide melimine coating for titanium and its in vivo antibacterial activity in rodent subcutaneous infection models.
Chen R1, Willcox MD2, Ho KK3, Smyth D4, Kumar N5. Biomaterials. 2016 Apr;85:142-51. doi: 10.1016/j.biomaterials.2016.01.063. Epub 2016 Jan 29.
Implant-associated infections represent a significant health problem and financial burden on healthcare systems. Current strategies for the treatment or prevention of such infections are still inadequate and new strategies are needed in this era of antibiotic resistance. Melimine, a synthetic antimicrobial peptide with broad spectrum activity against bacteria, fungi and protozoa, has been shown to be a promising candidate for development as antimicrobial coating for biomedical devices and implants. In this study, the in vitro and in vivo antimicrobial activity of melimine-coated titanium was tested. The titanium surface was amine-functionalised with 3-aminopropyltriethoxysilane (APTES) followed by reaction with a bifunctional linker 4-(N-maleimidomethyl)cyclohexane-1-carboxylic 3-sulfo-n-hydroxysuccinimide ester (Sulfo-SMCC) to yield a maleimide functionalised surface. Melimine was then tethered to the surface via a thioether linkage through a Michael addition reaction of the cysteine at its N-terminus with the maleimide moiety.
3.Controllable layer-by-layer assembly of PVA and phenylboronic acid-derivatized chitosan.
Zhang D1, Yu G2, Long Z2, Yang G3, Wang B4. Carbohydr Polym. 2016 Apr 20;140:228-32. doi: 10.1016/j.carbpol.2015.12.032. Epub 2015 Dec 17.
Phenylboronic acid-derivatized chitosan (chitosan-PBA) were prepared by grafting small molecules bearing phenylboronic acid groups onto chitosan with N-hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) as a coupling reagent pair. Self-assembly multilayer thin films of chitosan-PBA and poly(vinyl alcohol) were subsequently produced under pH control on supporting surfaces, either a silicon wafer or polystyrene latex particles. The driving force of the self-assembly was the ester formation of phenylboronic acid containing polymers with PVA, which can be "turned off" by simple pH control.
4.Luminescent Nanocellulose Platform: From Controlled Graft Block Copolymerization to Biomarker Sensing.
Navarro JR1, Wennmalm S2, Godfrey J1, Breitholtz M3, Edlund U1. Biomacromolecules. 2016 Mar 14;17(3):1101-9. doi: 10.1021/acs.biomac.5b01716. Epub 2016 Jan 29.
A strategy is devised for the conversion of cellulose nanofibrils (CNF) into fluorescently labeled probes involving the synthesis of CNF-based macroinitiators that initiate radical polymerization of methyl acrylate and acrylic acid N-hydroxysuccinimide ester producing a graft block copolymer modified CNF. Finally, a luminescent probe (Lucifer yellow derivative) was labeled onto the modified CNF through an amidation reaction. The surface modification steps were verified with solid-state (13)C nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy. Fluorescence correlation spectroscopy (FCS) confirmed the successful labeling of the CNF; the CNF have a hydrodynamic radius of about 700 nm with an average number of dye molecules per fibril of at least 6600. The modified CNF was also imaged with confocal laser scanning microscopy. Luminescent CNF proved to be viable biomarkers and allow for fluorescence-based optical detection of CNF uptake and distribution in organisms such as crustaceans.
