| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2003: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
The electrostatic effect of microcarrier's surface on fibroblastic cell growth was studied. Various aminated cellulose beads were prepared as cationic polymer microcarriers. The microcarriers were prepared by immobilization of 1,3Diamino-2-hydroxypropane, polyallylamine, or poly(ε-lysine), respectively, onto cellulose spherical beads. The amino-group content of the microcarriers was adjusted by changing the immobilization condition(amination time and temperature). The anion-exchange capacities of the microcarriers were estimated not only as total amino- group content but also functional(charged) amino- group content at pH 7.5(cell culture condition). When the growth of mouse L cell on the various microcarriers were determined by common cell culture methods, it strongly depended on the microcarrier's charged amino-group amount at pH 7.5, but not necessarily on their total amino-group content. The charged amino-group content was also drastically controlled by apparent pK_a of the ligand of the microcarriers. As a result, when the cellulose beads with charged amino-group content of 0.02-0.06 meq/g, under cell culture conditions, were used as microcarriers, they showed the excellent growth of mouse L cells.
The present results suggest that the optimum environment for the cell growth is controlled by microcarrier's functional amino-group content but not necessarily by their introduced amino-group content. Their functional amino-group contents were estimated as the charged amino-group content at pH 7.5, which is cell culture pH condition, and it is strongly influenced by their pK_<a,app> values originating from the original amines.
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