After removal of pressure, the obtained PVA/HAp/DNA complexes were observed by SEM. Figure 1 shows typical SEM images of PVA/DNA (PVA: 1.0%) and PVA/HAp/DNA complexes (PVA: 1.0%, HAp: 0.1%). Many particles less than 1μm were observed for the PVA/DNA complex. The surface of PVA/DNA particles was smooth. On the other hand, in the case of PVA/HAp/DNA complexes, irregular particle surfaces were

observed without any significant HAp absorption on the particles, showing that HAp particles were encapsulated in the PVA/HAp/DNA Inhibitors,research,lifescience,medical complexes. When excess HAps were mixed with PVA and DNA, many aggregates of HAps on the PVA/HAp/DNA particles obtained by the pressurization were clearly visible (data not shown). The particle size of PVA/DNA and PVA/HAp/DNA complexes at various concentrations of PVA and HAp were measured by DLS measurement (Figure 2, Table 1). The diameter of PVA/DNA particles without HAp increased with increased PVA concentration, which corresponds to our previous report [1–4]. This tendency was exhibited for Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical the particle size of PVA/HAp/DNA complexes, SB431542 cost irrespective of HAp concentration. At each

PVA concentration, the diameter of PVA/HAp/DNA particles increased with increased HAp concentration, indicating that HAp particles were significantly encapsulated in PVA/HAp/DNA complexes at these concentrations of PVA and HAp. From these results Inhibitors,research,lifescience,medical of SEM observation and DLS measurement, it was clear that nano-, microscaled composites of PVA, Hap, and DNA were obtained by high hydrostatic pressurization, and the size of PVA/HAp/DNA particles depended on PVA and HAp concentrations. To investigate the stability of DNA in the PVA/DNA particles on serum condition, PVA/DNA particles were incubated in medium containing 10% serum for 20h, and then subjected to in vitro transcription and translation (Figure 3). The high luciferase activity of DNA was showed on the condition

without serum, whereas the luciferase activity was remarkably reduced after incubation with serum. On the other hand, there is Inhibitors,research,lifescience,medical no difference in the luciferase activity of DNA in PVA/DNA particles before and after incubation with serum, indicating the high stability of tuclazepam DNA in PVA/DNA particles against serum. Figure 1 SEM images of (a) PVA/DNA complex (PVA: 1.0w/v%) and (b) PVA/HAp/DNA complex (PVA: 1.0w/v%, HAp: 0.1w/v%) obtained by high hydrostatic pressurization (980MPa, 10min, 40°C). DNA conc.: 0.0025w/v%. … Figure 2 DLS measurement of PVA/DNA and PVA/HAp/DNA complexes at various PVA and HAp concentrations. DNA conc.: 0.0025w/v%. Each value represents the mean ± SD (n = 5). Figure 3 Stability of DNA in PVA/DNA complexes in the presence of serum. Each value represents the mean ± SD (n = 3). *P < .05. Table 1 DLS measurement of PVA/DNA and PVA/HAp/DNA complexes at various PVA and HAp concentrations. DNA conc.: 0.0025w/v%.