Engineering Nanoparticle And Nanoring Patterns For The Study Of Molecular Crystallization Under Nanoconfinement

This dissertation focuses on generating the inorganic nanoparticle/organic nanorod hybrid nanostructures by the strategy of nanoparticle induced molecular crystallization developed by us and the new electrochemical method. We synthesize the gold nanoparticles with different sizes and functional groups and then fabricate the nanohybrids with fatty acid nanorods by spin coating method. Atomic force microscope monitors the topography of the hybrid nanostructures to help understand the underlying mechanism of the crystallization process. This successful self-assembled method could be used to fabricate nanohybrids based on seed-mediated nucleation. Also the novel nano-flasks have been generated by particle lithography method, which could be served for nanoconfining drug crystals and be used in high throughput screening applications

Cyclodextrin-erythromycin complexes as a drug delivery device for orthopedic application

Wei Song1, Xiaowei Yu2, Sunxi Wang5, Ralph Blasier4, David C Markel3, Guangzhao Mao5, Tong Shi1, Weiping Ren1,31Department of Biomedical Engineering, Wayne State University, Detroit, MI, USA; 2Department of Orthopedic Surgery, Second Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China; 3Detroit Medical Center and Providence Hospital Orthopedic Residency, Detroit, 4Orthopedic Section, St Francis Hospital, Escanaba, 5Department of Chemical Engineering, Wayne State University, Detroit, MI, USABackground: Erythromycin, a hydrophobic antibiotic used to treat infectious diseases, is now gaining attention because of its anti-inflammatory effects and ability to inhibit osteoclasts formation. The aim of this study was to explore a cyclodextrin-erythromycin (CD-EM) complex for sustained treatment of orthopedic inflammation.Methods and results: Erythromycin was reacted with ß-cyclodextrin to form a nonhost-guest CD-EM complex using both kneading and stirring approaches. Physiochemical measurement data indicated that erythromycin and cyclodextrin formed a packing complex driven by intermolecular forces instead of a host-guest structure due to the limited space in the inner cavity of ß-cyclodextrin. The CD-EM complex improved the stability of erythromycin in aqueous solution and had a longer duration of bactericidal activity than free erythromycin. Cytotoxicity and cell differentiation were evaluated in both murine MC3T3 preosteoblast cells and RAW 264.7 murine macrophage cells. The CD-EM complex was noncytotoxic and showed significant inhibition of osteoclast formation but had little effect on osteoblast viability and differentiation.Conclusion: These attributes are especially important for the delivery of an adequate amount of erythromycin to the site of periprosthetic inflammation and reducing local inflammation in a sustained manner.Keywords: erythromycin, cyclodextrin, drug stability, bactericidal activity, osteoclastogenesi

Surfactaut-free synthesis of hyperbranched monoclinic bismuth vanadate and its applications in photocatalysis, gas sensing, and lithium-ion batteries

Hyperbranched monoclinic BiVO4 (h-BiVO4) has been synthesized on a large scale and with good uniformity by a surfactant-free hydrothermal route. h-BiVO4 consists of four trunks with branches distributed on opposite sides. From observation of the intermediates at an early stage of the reaction process, it can be seen that during formation h-BiVO4 has different growth rates along the a, b, and c axes. Based on crystal structure analysis and experimental results, h-BiVO4 Shows preferential growth along the [100] direction, and subsequently, along the [010] and [001] directions. As-synthesized h-BiVO4 exhibits excellent photocatalytic ability in the photodegradation reaction of an aqueous solution of RB under visible light. Electrochemical measurements predict that h-BiVO4 possesses high sensitivity to formaldehyde and ethanol gases, favorable discharge capacity, and capacity retention, which indicate potential applications in the fields of sensing devices and lithium-ion batteries

A Supra-monolayer Nanopattern for Organic Nanoparticle Array Deposition

Nanopatterns have applications in many areas including sensors, optoelectronics, and crystallization screening. Particle lithography is a convenient method to manufacture nanoring nanopatterns based on organosilane surface chemistry. The pattern thickness is generally limited to the monolayer thickness. This work is focused on the chemical vapor deposition conditions that yield nanopatterns with multilayer thickness. The supra-monolayer n-octadecyltrichlorosilane (OTS) nanoring patterns are made using polystyrene particle lithography. The supra-monolayer nanopatterns are used as “nano-flasks” to deposit and nucleate nanoparticles of small organic molecules including <i>n</i>-docosane, aspirin, and clarithromycin. The supra-monolayer OTS nanopattern is an effective template for nanoparticle array deposition of all three chemicals with high degree of fidelity to the substrate pattern. The nanoparticle size is varied by solution concentration. The preferential deposition of the organic molecules inside the nanoring is attributed to the dewetting of the liquid film on the nanopattern. The dewetting process effectively distributes the liquid film among the “nano-flasks” so that millions of solution experiments can be carried out in isolated droplets with droplet volume as small as 1 × 10^–10 nL. The research demonstrates a method to manufacture “nano-flask” arrays for high-throughput nanoparticle deposition trials and manufacture of monodisperse organic/drug nanoparticles through self-assembly