pH-Responsive P(MAA-co-EGMA) hydrogel microparticles were prepared and their feasibility as intelligent delivery carriers was evaluated. P(MAA-co-EGMA) hydrogel microparticles were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-EGMA) microparticles at a pH of ~ 5 and, as the amount of MAA in the hydrogel increased, the swelling ratio increased at a pH above 5. The loading efficiency of the ascorbic acid into the hydrogel was affected more by the degree of swelling of the hydrogel than the electrostatic interaction between the hydrogel and the loaded ascorbic acid. The P(MAA-co-EGMA) hydrogel microparticles showed a pH-sensitive release behavior. Thus, at pH 4 almost none of the ascorbic acid permeated through the skin while at pH 6 relatively high skin permeability was obtained. The ascorbic acid loaded in the hydrogel particles was hardly degraded and its stability was maintained at high temperature.

Atopic dermatitis is a common chronic inflammatory skin disease, associated with marked inflammatory cells (of mast cells and eosinophils) and severe itching, which leads to clinical problems in the pediatric population. This study was designed to investigate the inhibitory effects of luteolin liposome solution, that is entrapped the hydrophobic luteolin (one of the flavonoids) into ethosome to improve its stability, by using hapten-induced atopic dermatitis animal model (NC/Nga mice).The luteolin liposome treated mice showed anti-inflammatory effect as evidenced by the lowering of erythema and edema in clinical observation, reduction of inflammatory cell infiltration and epidermal thickness in histopathological examination, when compared with TNCB induced controls. Luteolin liposome solution also reduced the serum IgE level which played important roles in the atopic dermatitis model. These results suggest that luteolin liposome solution has some merit in this formulation showing inhibitory effects for the atopic dermatitis.

Facilitated transport of oxygen through Co(II) and Mn(II) chelate membranes from poly(vinyl alcohol)/poly(N-salicylidene allyl amine) was investigated. As the membranes became chelated, oxygen diffusivity decreased and the solubility toward oxygen was enhanced. The oxygen permeability of the base poly(vinyl alcohol)/poly(Nsalicylidene allyl amine) membrane was 2.6 1 10 03 cm 3 (STP)cm/cm 2 cm Hg sec (barrer), and the selectivity toward oxygen was 2.2. As Co(II) was introduced into this membrane, oxygen permeability and oxygen selectivity increased to 2.82 1 10 02 barrer and 8.5, respectively. The permeability and selectivity of Mn(II) chelate membrane were 3.28 1 10 02 and 5, respectively. A major reason for the increased selectivity was the enhanced solubility of oxygen in chelate membrane upon chelation. The transport behavior of chelate membranes followed a dual-mode transport, and the parameters were estimated and compared between Co(II) and Mn(II) membranes.