Chengzhi Cai

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Poly(amidoamine) (PAMAM) dendrimer derivatives have been investigated for their biological applications, especially for delivery of drugs, including antimicrobial drugs to eukaryotic cells, but their effects on bacterial cells are largely unexplored. Herein we report that amino-terminated PAMAM dendrimers are highly toxic to the common Gram-negative(More)
We have investigated the antibacterial activity and cytotoxicity of a series of amino-terminated poly(amidoamine) (PAMAM) dendrimers modified with poly(ethylene glycol) (PEG) groups. The antibacterial activity of the PAMAM dendrimers and their derivatives against the common ocular pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, was evaluated by(More)
Protein-resistant films derived from the fifth-generation poly(amidoamine) dendrimers (PAMAM G5) functionalized with oligo(ethylene glycol) (OEG) derivatives consisting of various ethylene glycol units (EG(n), n = 3, 4, and 6) were prepared on the self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) on gold substrates. The resulting films(More)
A versatile and stable liposomal platform is developed for rapid optimization of its peripheral composition. The platform is based on polydiacetylene lipids terminated with alkynyl groups. Conditions for copper-catalyzed azide-alkyne cycloaddition (a "click" reaction) are optimized for rapid attachment of azides with controlled composition onto the(More)
Metal-organic coordination networks (MOCNs) have attracted wide interest because they provide a novel route towards porous materials that may find applications in molecular recognition, catalysis, gas storage and separation. The so-called rational design principle-synthesis of materials with predictable structures and properties-has been explored using(More)
Copper-catalyzed azide-alkyne cycloaddition (CuAAC), combined with the chemical stability of the Si-C-bound organic layer, serves as an efficient tool for the modification of silicon substrates, particularly for the immobilization of complex biomolecules. This review covers recent advances in the preparation of alkynyl- or azido-terminated "clickable"(More)
In this article, we present the first report on the antibacterial activity and cytotoxicity of poly(amidoamine) (PAMAM) dendrimers immobilized on three types of titanium-based substrates with and without calcium phosphate coating. We show that the amino-terminated PAMAM dendrimers modified with various percentages (0-60%) of poly(ethylene glycol) (PEG)(More)
We present investigations on noncovalent bonding and supramolecular self-assembly of two related molecular building blocks at a noble metal surface: 4-[trans-2-(pyrid-4-yl-vinyl)]benzoic acid (PVBA) and 4-[(pyrid-4-yl-ethynyl)]benzoic acid (PEBA). These rigid, rodlike molecules comprising the same complementary moieties for hydrogen bond formation are(More)
We present a general approach for preparing well-defined AFM tips for probing single target molecules. We demonstrated that carboxylic acid groups could be generated by electrochemical oxidation selectively at the apex of an AFM tip that is coated with a monolayer of oligo(ethylene glycol) derivatives for resisting nonspecific interactions. These carboxylic(More)
In this work, laser coating of biphasic calcium phosphate/titanium (BCP/Ti) nanocomposite on Ti-6Al-4 V substrates was developed. A continuous wave neodymium-doped yttrium aluminium garnet (Nd:YAG) laser was used to form a robust multilayer of BCP/Ti nanocomposite starting from hydroxyapatite and titanium nanoparticles. In this process, low power coating is(More)