COSMOS

The crystal structures and electronic and magnetic properties of conducting molecular magnets developed by our group are reviewed from the viewpoints of our two current strategies for increasing the efficiency of the π–d interaction. (EDTDM)₂FeBr₄ is composed of quasi-one-dimensional donor sheets sandwiched between magnetic anion sheets. The ground state of the donor layer changes from the insulator state to the metallic state by the application of pressure. When it is near to the insulator–metal phase boundary pressure, the magnetic order of the anion spins considerably affects the transport properties of the donor layer. The crystal structure of (EDO–TTFBr₂)₂FeX₄ (X = Cl, Br) is characterized by strong intermolecular halogen–halogen contacts between the organic donor and FeX₄ anion molecules. The presence of the magnetic order of the Fe₃₊ spins and relatively high magnetic order transition temperature proves the role of the halogen–halogen contacts as exchange interaction paths.

The porphyrin macrocycle is one of the most frequently investigated functional molecular entities and can be incorporated into advanced functional nanomaterials upon formation of organized nanostructures. Thus, study of the science and technology of porphyrin assemblies has attracted many organic, biological and supramolecular chemists. A wide variety of nanostructures can be obtained by supramolecular self-assembly because the porphyrin moiety is amenable to chemical modifications through thoughtful synthetic design and moderate preparative effort. Some recent developments in porphyrin assembly, obtained through various supramolecular approaches, are briefly summarized. Topics described in this review are classified into four categories: (i) non-specific assemblies; (ii) specific assemblies; (iii) assemblies in organized films; (iv) molecular-level arrangement. We present examples in the order of structural precision of assemblies.

The present article reviews the self-assembly of oligopeptides to form nanostructures, both in solution and in solid state. The solution structures of the peptides were examined using circular dichroism and dynamic light scattering. The solid state assembly was examined by adsorbing the peptides onto a mica surface and analyzing it using atomic force microscopy. The role of pH and salt concentration on the peptide self-assembly was also examined. Nanostructures within a size range of 3–10 nm were obtained under different conditions.

Nanomedicine is to apply and further develop nanotechnology to solve problems in medicine, i.e. to diagnose, treat and prevent diseases at the cellular and molecular level. This article demonstrates through a full spectrum of proof-of-concept research, from nanoparticle preparation and characterization, in vitro drug release and cytotoxicity, to in vivo pharmacokinetics and xenograft model, how nanoparticles of biodegradable polymers could provide an ideal solution for the problems encountered in the current regimen of chemotherapy. A system of vitamin E TPGS coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles is used as an example for paclitaxel formulation as a model drug. In vitro HT-29 cancer cell viability experiment demonstrated that the paclitaxel formulated in the nanoparticles could be 5.64 times more effective than Taxol^® after 24 hr of treatment. In vivo pharmacokinetics showed that the drug formulated in the nanoparticles could achieve 3.9 times higher therapeutic effects judged by area-under-the curve (AUC). One shot can realize sustainable chemotherapy of 168 hr compared with 22 hr for Taxol^® at a single 10 mg/kg dose. Xenograft tumor model further confirmed the advantages of the nanoparticle formulation versus Taxol^®.

Diamond-like carbon (DLC) is a form of amorphous carbon which has high fraction of sp³ hybridization. Due to its nature of sp³ bonding, diamond-like carbon has been shown to have excellent properties similar to that of diamond. This includes high hardness, excellent wear-resistance, large modulus and chemically inert. Traditional applications include wear resistant coatings and protective film. This article intends to review the synthesis and material properties of diamond-like carbon as well as its potential as a novel material for applications in nano-architecture and nano-mechanical devices. An introduction into metal-dopants in diamond-like carbon film will be briefly mentioned as well as techniques on the design and fabrication of this material.

As an efficient and cost-effective method to synthesize nanomaterials, the hotplate technique has been reviewed in this article. Systematic studies have been carried out on the characterizations of the materials synthesized. In addition to the direct preparation of nanomaterials on metals, this method has been extended to the substrate-friendly and plasma-assisted hotplate synthesis. Apart from chemically pure nanostructures, a few nanohybrids were synthesized, further demonstrating the flexibility of this technique. The investigations on their applications indicate that they are promising material systems with potential applications in field emission devices, gas sensors, Li-ion batteries and ultrafast optical devices.