Mast cells are found in connective or mucosal tissues of the body, and play an important role in allergic reactions as well as the inflammatory and immune responses. Because mast cells produce and secrete a large number of mediators, as their functions and mechanisms are complex. Mast cells possess a unique feature of presenting diverse phenotypes that are dependent on the tissue microenvironments during their maturation in vivo. Therefore we advocate that non-tumor cells are more desirable than tumor cells such as Rat Basophilic Leukemia cells (RBL-2H3) and Human Mast Cells (HMC-1) for determining the changes in the character of mast cells in vivo. We previously reported a new non-tumor mast cell line, NCL-2, and described the morphological and proliferative changes occurring in mast cells growing on Honeycomb-like Films (HCF) using NCL-2 cells. In the present study, we compared the changes in the proliferation pattern and morphology between NCL-2 and RBL-2H3 cells as well as in the spontaneous release of histamine and Leukotriene B4 (LTB4) from these cells cultured on HCF as the surrounding micro environment. Compared with RBL-2H3 cells, which have been most frequently used for mast cell research, NCL-2 cells displayed increasing floating cells, multinuclear formation, and no changing of histamine release but decreasing LTB4 release, on the HCFs. Hence, we are convinced that HCF plays different roles as physical stimuli for the spontaneous release of histamine and LTB4 from NCL-2 and RBL-2H3 cells. HCF has huge potential for use in the new therapeutic treatment of allergy and inflammation by inhibiting the function of mast cells.

Preparation and colloidal dispersion of highly concentrated biocompatible nanoparticles suspensions are vital for fabrication of dense bioceramic nanocomposites with improved mechanical and microstructural properties for biomedicine applications. This paper presents formation and rheological characterization of highly concentrated biocompatible aqueous ZrO2 nanosuspensions for such applications. The rheological properties including viscosity (η), shear rate (γ), and shear stress (τ) were investigated in relation to a wide range of solid loading (ϕ, by weight = 75 - 78 mass%). Maximum solid loading (ϕmax) was estimated with a constant 0.9 mass% concentration of a new type of anionic polyelectrolyte Dolapix CE64, suitable for casting of materials. A colloidal model was proposed to visualize the effect of solid loading on colloidal stability, rheological behavior and green microstructure of samples after casting. The maximum solid loading (ϕmax) was estimated to be 77 mass% based on the dependence of both viscosity (η) and yield stress (τ0) on solid loading (ϕ). For further validation, the maximum solid loading was compared and fittedby different rheological flow models with a correlation factor r = 0.998 for Herschel-Bulkley model, r = 0.999 forPower law model and r = 0.920 for Bingham model at shear rate γ (50 s-1). All concentrated ZrO2 nanosuspensions exhibited shear-thinning behaviour. The results obtained from rheological measurements, scanning electron microscopy imaging and flow models validate our proposed hypothesis for prediction of maximum solid loading and visualization of quality of green microstructures after casting. These results contribute to preparation, characterization, and processing of highly concentrated bio/nanoparticles suspensions; aiming to fabricate highly dense bio/nanocomposite materials with specific functionality.