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Poly(2-hydroxylethyl methacrylate-co-methyl methacrylate)/poly(styrene-co-glycidyl methacrylate) (P(HEMA−MMA))/P(St−GMA)) composite polymer particles were prepared by soap-free seeded emulsion polymerization. The P(HEMA−MMA) seed latexes cross-linked by 0, 10, and 20 wt % ethylene glycol dimethacrylate (EGDMA) were prepared by soap-free emulsion polymerization with different HEMA/MMA monomer composition at 80 °C. 2,2‘-Azobis(2-amidinopropane) dihydrochloride (V-50) was used as an initiator in the two stages. The morphologies of composite particles were investigated by using seed particles with various HEMA content and cross-link degree, and the effects of solvent addition, preswelling of seed particles by monomers and solvent, and the weight ratio of secondary monomer to seed particles (M/P) on the particle morphology were discussed. Un-cross-linked P(HEMA−MMA) seed latex showed the property of gel particles capable of being swollen by water, which led to the instability of seed particles and a specific morphology variation. In principle, the addition of solvent favors to form thermodynamically stable morphology, but the preswelling process by monomers and toluene did not affect the particle morphology, possibly because the equilibrium swelling might be already attained during the nitrogen purge and heating intervals under lower M/P ratio. Various spherical and anomalous particle morphologies were obtained by controlling polymerization conditions; that is, sandwich-like, hemispherical, and microphase-separated spherical particles were formed when the seed particles with lower HEMA content and lower cross-link degree were employed under smaller M/P ratio. On the other hand, dumbbell, popcorn, and bunch of grapes like anomalous particles were formed under some specific conditions. When the cross-linker, divinylbenzene (DVB), was charged into the seed stage, the anomalous particles were changed to spherical particles due to the reduction of polymer chain mobility.

Mouse sarcoma 180 cell with a 25-fold higher cisplatin (CDDP) resistance, termed S-180cisR, is newly established. S-180cisR cells grow quite slowly in the presence of CDDP with high concentration. This may show that S-180cisR cells modulate the cell cycle to acquire CDDP resistance. P-Glycoprotein is selectively expressed on the surface of S-180cisR, which is not on CDDP-sensitive S-180 parent cells. In an experiment using an inhibitor (verapamil) of P-glycoprotein, cytotoxicity of CDDP against S-180cisR is significantly increased (viz., IC50 value is decreased) and accumulation of CDDP in S-180cisR cells is also increased. These results indicate that enhanced pumping-out of CDDP by P-glycoprotein should be one of the reasons for the CDDP resistance of S-180cisR. A platinum(II) complex with a cyclometalated 2-phenylpyridine ligand and a nonchelated one (complex 5) is synthesized, and its structure is determined by X-ray structural analysis. Complex 5 has a cyctotoxicity against S-180cisR higher than that of CDDP and its derivatives with 2- or 3-substituted pyridine ligands (complexes 2−4, 6, 7). Complex 5 is incorporated in S-180cisR to an enormously greater extent than CDDP; that is, the ratio of accumulated platinum amount after 3 h is 61.9. In S-180 parent cells, on the other hand, the ratio remains 8.1. This high accumulation of complex 5 into S-180cisR must account for the higher activity of complex 5 against S-180cisR compared to CDDP.

We synthesized five platinum(II) dinuclear complexes containing 1-alkylated thymines. Two of the 1-alkylated thymine, 1-MeThy and 1-EtThy, complexes afforded good crystals. The X-ray structures of these complexes were determined. The 1-MeThy complex has a head-to-head (H-H) arrangement, while the 1-EtThy complex has a head-to-tail (H-T) arrangement. The 1-MeThy complex (H-H) shows high electrophilicity against chloride anion (Cl^-) and high cytotoxicity against mouse sarcoma 180 (S-180) cells in vitro. The 1-EtThy complex (H-T) is inactive. The other 1-MeThy complex does not produce CDDP in the reaction with chloride ion and is inactive against the S-180 cell line. This complex is assumed to have an H-T arrangement. Similarly, two different 1-PrⁿThy complexes, one with high electrophilicity and cytotoxicity and the other without, must have an H-H and H-T arrangement, respectively. For comparison, we investigated six complexes, 1-methyluracil (1-MeUra) (H-H) dimer, α-pyridone (H-T) dimer, α-pyridone blue tetramer (PPB), 1-methylcytosine (1-MeCyt) (H-T) dimer, acetate dimer, and 1-MeUra monomer complexes. The α-pyridone (H-T), PPB, 1-MeCyt (H-T) dimer, and 1-MeUra monomer complexes are inert to chloride ion and inactive against mouse sarcoma S-180. The 1-MeUra (H-H) dimer and acetate dimer complexes show high electrophilicity and high cytotoxicity. Cellular accumulation of the platinum complexes phenomenally shows that all are incorporated to cancer cells to a lesser extent than CDDP. The relationships between the accumulation, the electrophilicity, and the interaction of these complexes with proteins are discussed.

Mesogenic behaviors of 4,4‘-di-n-alkoxybenzalazine (1) and 3-phenyl-4H-4-[one]-benzopyran (2) derivatives are analyzed using theoretical models. A general phase diagram including smectic and nematic phases is explained by McMillan's model which is the extension of the model of Maier and Saupe. Some of the fundamental features of 1 and 2 are reproduced by the model, while there are also some discrepancies between the experimental and theoretical results. This may be ascribed to the lack of ordering caused by rigid-body repulsive interaction in the model. In order to investigate the nematic phases in more detail, Kimura's model is applied. The electronic properties of 1 and 2 are calculated by a semiempirical molecular orbital method (AM1). It has turned out that 1 has high polarizability and small permanent dipole moments, while 2 has low polarizability and large permanent dipole moments. The higher temperature for nematic−isotropic transition (TNI) of 2 than 1 must be due to more flexibility of 1 or larger permanent dipole moment of 2.

Hydrophobicity is considered to be a phenomenon that nonpolar solutes have a poor solubility in water, which plays fundamental roles in many chemical and biological systems. On the basis of the scaled particle theory, it has been shown in the present study that hydrophobicity is not caused by the small size of water molecules but by their high packing density generated from strong molecular interaction. Solvophobicity, observed in some organic solvents such as ethylene glycol, can be also explained consistently by the present method.

A general rule, previously derived for a complex between an achiral guest compound and a chiral macrocyclic host compound, can explain the inversion of circular dichroism (CD) signs observed in the complexation of 2-substituted naphthalenes (2-naphthol, 2-methylnaphthalene, 2-chloronaphthalene, 6-bromo-2-naphthol) with α- and β-cyclodextrins, where the substrates are included deeply in the cavity of β-cyclodextrin but only partly included in the cavity of α-cyclodextrin. The present success of the general rule supports its validity and usefulness.