Micelles have been successfully used for the delivery of anticancer drugs. Amphiphilic polymers form core-shell structured micelles in an aqueous environment through self-assembly. The hydrophobic core of micelles functions as a drug reservoir and encapsulates hydrophobic drugs. The hydrophilic shell prevents the aggregation of micelles and also prolongs their systemic circulation in vivo. In this protocol, we describe a method to synthesize a doxorubicin lipophilic pro-drug, doxorubicin-palmitic acid (DOX-PA), which will enhance drug loading into micelles. A pH-sensitive hydrazone linker was used to conjugate doxorubicin with the lipid, which facilitates the release of free doxorubicin inside cancer cells. Synthesized DOX-PA was purified with a silica gel column using dichloromethane/methanol as the eluent. Purified DOX-PA was analyzed with thin layer chromatography (TLC) and 1H-Nuclear Magnetic Resonance Spectroscopy (1H-NMR). A film dispersion method was used to prepare DOX-PA loaded DSPE-PEG micelles. In addition, several methods for characterizing micelle formulations are described, including determination of DOX-PA concentration and encapsulation efficiency, measurement of particle size and distribution, and assessment of in vitro anticancer activities. This protocol provides useful information regarding the preparation and characterization of drug-loaded micelles and thus will facilitate the research and development of novel micelle-based cancer nanomedicines.

Tin Oxide (SnO 2 ) nanorods have been successfully grown on a p-type Si substrate by a low-temperature vapor-liquid-solid (VLS) technique. Tin chloride and zinc chloride powders were used as starting materials. Surface morphologies and structural properties of the SnO 2 nanorods were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM images shows distinct hierarchical growth of SnO 2 as well as the mixture with ZnO microstructures. The structural studies demonstrated rutile crystal structure SnO 2 nanorods with square-shaped facets of 40-60 nm in cross section size and 2 μm in length approximately and ZnO microrods of 10 μm diameter and 50 μm length. The fabrication of a gas sensor for acetone and ethanol vapors is also reported and its properties are discussed.

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