Table of Contents

Abstract: In this paper, we investigated the self-assembly and fractal feature of chitosan andAg (I), Cu (II)-chitosan due to the theoretical and practical importance of chitosan inbiomedical engineering, biomaterials and environmental sciences etc. The self-assembly andfractal structures of chitosan and Ag (I), Cu (II)-chitosan were observed using atomic forcemicroscope (AFM), and the fractal dimensions of chitosan and Ag (I)-chitosan werecalculated. The results indicate that their fractal dimension is approximate 2 and relates withthe accumulation degree: the fractal dimension decreases with the accumulation degreeincreases. In addition, a new self-assembly strategy was presented to study the lyotropicliquid crystals (LLC) of chitosan and the formation mechanism of LLC was primarilyanalyzed and discussed. All of these results are valuable for the structure/functionrelationship study of chitosan and useful for application in biomedical materials.

Abstract: A practical approach for addressing the computer simulation of protein-carbohydrate interactions is described here. An articulated computational protocol was setup and validated by checking its ability to predict experimental data, available in theliterature, and concerning the selectivity shown by the Carbohydrate Recognition Domain(CRD) of the human asialoglycoprotein receptor (ASGP-R) toward Gal-type ligands. Somerequired features responsible for the interactions were identified. Subsequently the sameprotocol was applied to monomer sugar molecules that constitute the building blocks foralginates and ulvans. Such sugar polymers may supply a low-cost source of rare sugars witha potential impact on several industrial applications, from pharmaceutical to fine chemicalindustry. An example of their applicative exploitation could be given by their use indeveloping biomaterial with adhesion properties toward hepatocytes, through interactionwith the ASGP-R. Such a receptor has been already proposed as a target for exogenousmolecules, specifically in the case of hepatocytes, for diagnostic and therapeutic purposes.The DOCK5.2 program was used to search optimal locations of the above ligands of interestinto CRD binding site and to roughly estimate interaction energies. Finally, the binding ∆G oftheoretical protein-ligand complexes was estimated by using the DelPhi program in which thesolvation free energy is accounted for with a continuum solvent model, by solving the Poisson-Boltzmann equation. The structure analysis of the obtained complexes and their ∆G values suggest that one of the sugar monomers of interest shows the desired characteristics.

Abstract: Two supramolecular coordination polymers, [HgI₂(L¹)·0.5H₂O]_∞ (1) and[HgI₂(L²)·0.4CH₃OH]_∞ (2), have been prepared by ligands L¹ (L¹ = bis[4-(4-pyridylmethyleneamino)phenyl] ether) and L² (L² = N,N′-bis(3-pyridylmethyl)-diphthalicdiimide) with HgI₂, respectively. 1 formed an interestingly infinite cross-linked doublehelical structure, whereas 2 formed the one-dimensional zigzag chains, which are parallelwith each other.

Abstract: Camptothecin, an anticancer component from Camptotheca acuminate, mayinteract with human serum albumin (HSA) at the subdomain IIA (site I), and then convert toits inactive form(carboxylate form). In this paper, the detailed electrochemical behaviors ofcamptothecin at a pyrolytic graphite electrode is presented. The interaction betweencamptothecin and HSA is also studied by electrochemical technique. By comparing withbovine serum albumin (BSA), which is highly homologous to HSA, we prove thatcamptothecin can specifically bind to HSA. Meanwhile, the inhibitory influence of sodiumsalicylate to this binding is also discussed.

Abstract: Hyperphosphorylation of tau leading to aggregated tau and tangle formation is acommon pathological feature of tauopathies, including Alzheimer's disease. Abnormalphosphorylation of tau by kinases, in particular GSK3β, has been proposed as a pathogenicmechanism in these diseases. In this study we demonstrate that the heat shock protein 90(Hsp90) maintains the stability and function of the GSK3β. By using both rat primarycortical neurons and COS-7 cells, we show that Hsp90 inhibitors lead to a reduction of theprotein level of GSK3β, and that this effect is associated with both a decrease in tauphosphorylation at putative GSK3β sites and an induction in heat shock protein 70 (Hsp70)levels. We further show that Hsp90 associates with the GSK3β regulating its stability andfunction and preventing its degradation by the proteasome.

Abstract: This study was designed to evaluate the inhibitory effect of endostatin onchoroidal neovascularization (CNV) in laser-induced rat model. Choroidalneovascularization was induced in Brown Norway (BN) rats by diode-laserphotocoagulation. Rats were randomly divided into five groups (10 animals in each group):endostatin 20mg/kg group, endostatin 10mg/kg group, laser injury group, normal salinegroup and blank control group. The animals were treated with endostatin, normal saline,laser injury or without treatment on day 0 to day 13 after laser photocoagulation. On day 7and 14 after laser photocoagulation, the CNV formation was assessed by fluoresceinangiography and histopathological analysis. VEGF expression in retina was determined byimmunohistochemical assay. In two endostatin groups, the incidence of CNV formation andthe intensity of fluorescein leakage were reduced compared with the two control groups. Nosignificant difference was found between laser injury group and normal saline group. Theexpression of VEGF reached peak at day 7 and then decreased from day 14 afterphotocoagulation. The expression of VEGF was significantly reduced in the two endostaingroups than laser injury group in a dose-dependent way. Endostatin can inhibit the formationof experimental CNV in the rat. Down-regulation of VEGF expression could be one of themechanisms underlying the inhibition of CNV by endostatin.