A Sustained Release Anchored Biocide System Utilizing the Honeycomb Cellular Structure of Expanded Perlite.

The development of a sustained-release biocide system, involving an anchored quaternary ammonium salt (AQAS) embedded in expanded perlite (EP) substrate, is reported. Scanning electron microscopy (SEM) images reveal the well-defined honeycomb cells that are a feature of EP. These honeycomb cells exhibit a variety of polygon shapes, which are filled with the AQAS molecules as evidenced by SEM data.

Atomic Force Microscopy and Angular-Dependent X-ray Photoelectron Spectroscopy Studies of Anchored Quaternary Ammonium Salt Biocides on Quartz Surfaces.

A siloxane surface-anchored quaternary ammonium salt (AQAS: BIOSAFE HM4100 in this study) has been chemisorbed onto a quartz substrate. The aim of this study is to elucidate, using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), the structure of the chemisorbed AQAS layers. The AQAS biocide includes a C alkyl chain previously invoked in lysis potency.

Molecular Weight and Charge Density Effects of Guanidinylated Biodegradable Polycarbonates on Antimicrobial Activity and Selectivity.

Six guanidine functionalized aliphatic biodegradable polycarbonates with varying molecular weights and charge densities were synthesized via postsynthesis modification of alkyne containing polycarbonates using Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry. The concept of passive diluting group was to modify the cationic charge density of the polycarbonate without changing its hydrophilicity. Within the molecular weight range from 8000 to 30000 g mol, these guanidine polycarbonates exhibited broad-spectrum biocidal activity with low toxicity to red blood cells (RBCs).

Electrospun functionalized polyaniline copolymer-based nanofibers with potential application in tissue engineering.

Nanofibrous blends of HCl-doped poly(aniline-co-3-aminobenzoic acid) (3ABAPANI) copolymer and poly(lactic acid) (PLA) were fabricated by electrospinning solutions of the polymers, in varying relative proportions, in dimethyl sulfoxide/tetrahydrofuran mixture. The morphology, mechanical and electrical properties of the nanofibers were characterized and an assessment of their bioactivity performed. To assess cell morphology and biocompatibility, pure PLA and 3ABAPANI-PLA nanofibrous mats were deposited in the form of three-dimensional networks with a high degree of connectivity, on glass substrates, and their ability to promote proliferation of COS-1 fibroblast cells was determined.

Electrochemical detection of DNA hybridization amplified by nanoparticles.

Detection of specific oligonucleotide (ODN) fragments has become an important field in many areas of biomedicine. We describe a novel ODN sensor based on electropolymerization of a conducting polymer (polypyrrole) in the presence of a sample containing ODN(s). The resulting trapped ODN(s) are then probed by addition of complimentary sequence ODN.

Label-free electrochemical DNA sensor based on functionalised conducting copolymer.

A simple and label-free electrochemical sensor for recognition of the DNA hybridization event was prepared based on a new functionalised conducting copolymer, poly[pyrrole-co-4-(3-pyrrolyl) butanoic acid]. This precursor copolymer can be easily electrodeposited on the electrode surface and shows high electroactivity in an aqueous medium. An amino-substituted oligonucleotide (ODN) probe was covalently grafted onto the surface of the copolymer in a one step procedure and tested on hybridization with complementary ODN segments.

Vibrational Spectra and Molecular Association of Titanium Tetraisopropoxide.

The Fourier transform-infrared (FT-IR) and polarized FT-Raman spectra of titanium tetraisopropoxide (tetraisopropoxytitanium, TPT), in pure and diluted forms, and of 2-propanol have been investigated in conjunction with previous assignments for related compounds to obtain a comprehensive assignment of the vibrational spectra. Evidence was obtained for the presence of both monomeric and associated species of TPT. The latter are formed by coordination expansion through bridging isopropoxy ligands.

Electrospray Mass Spectrometry of Thiophenolate-Capped Clusters of CdS, CdSe, and ZnS and of Cadmium and Zinc Thiophenolate Complexes: Observation of Fragmentation and Metal, Chalcogenide, and Ligand Exchange Processes.

Electrospray mass spectrometry provides a rapid, convenient technique for characterizing and studying the chemistry of anionic metal sulfide thiolate clusters. Negative-ion electrospray mass spectra have been recorded for the thiophenolate-capped clusters [Me(4)N](4)[E(4)Cd(10)(SPh)(16)] (E = S, Se), [Me(4)N](4)[S(4)Zn(10)(SPh)(16)], and [Me(4)N](2)[S(4)Cd(17)(SPh)(28)] and of the metal thiophenolate complexes [Me(4)N](2)[M(SPh)(4)], [Me(4)N](2)[M(4)(SPh)(10)] (M = Cd, Zn), and [Et(4)N](2)[Cd(4)X(4)(SPh)(6)] (X= Cl, Br, I). The exchanges of M, E, and X which occur in various mixtures of these clusters and complexes and the fragmentation processes have been investigated.