Polymer phosphate buffer solution

FIGURE 1 Rate of polyanhydride degradation versus time. PCPP and SA copolymers were formulated into 1.4-cm-diameter disks 1 mm thick by compression molding, and placed into a 0.1 M pH 7.4 phosphate buffer solution at 37°C. The cumulative percentage of the polymer which degraded was measured by absorbance at 250 nm. 

The phase transition was traced by monitoring the transmittance of a 500 nm light beam on a Spectronic 20 spectrophotometer (Baush Lomb). The concentration of the aqueous polymer solution was 5 wt%, and the temperature was raised from 15 to 70°C in 2° increments every 10 min. To observe their pH/temperature dependence, the phase transitions of polymers in citric-phosphate buffer solution versus temperature at two pH values (4.0 and 7.4) were measured. 

Figure 10 Disintegration of the polymer matrix in phosphate buffer solution at two glucose concentrations. 

Fig. 10.4 Adhesive% of polymer-coated liposomes in rat intestine (taken from Takeuchi et al. 1996). Lipid composition DPPC DCP=8 2. Dispersion medium phosphate buffer solution...

Figure 2 shows the degree of hydrolysis of poly(MAOT-co-AA) (Sample no. 10 in Table 3), poly(AOT-co-AA) (No. 15), and poly(MAOA-co-AA) (No. 12) at 60 °C in a 0.1 M phosphate buffer solution (pH 7.8) as a function of time. Acryloyloxyethyltype copolymer (poly(AOT-co- AA)) was hydrolyzed rather easily, but no significant difference between the kinds of leaving group was observed. The flexibility of the polymer chain is supposed to be an important factor for the hydrolysis of the polymer side chain. 

FIG. 2 Bovine serum albumin adsorption to different polymer surfaces at 37°C in phosphate-buffered solution. The initial albumin concentration is 3 mg/ml. PVA poly(vinyl alcohol), PMMA poly(methyl methacrylate), PET polyethylene therephthalate), PP polypropylene, HDPE high-density polyethylene, PTFE polytetrafluoroethylene. (From Ref. 1.)... 

The dependence of viscosity on concentration is usually described through a nondimensional parameter c[r ], which, as a measure of volume occupancy of polymer molecules, may be used to evaluate the extent of overlapping of polymer domains. Chou and Kokini (1987) showed that pectins from citrus, apple and tomato in citrate phosphate buffer solution (pH 4.6) are characterized by overlapping concentrations (c ) that separate the dilute and concentrate regions at a c p value of about 6 (Figure 9.7). Up to c, viscosity depends on concentration to the power 1.4 and beyond c, to the power 3.3. 

In the case of coexistence of BSA with Na2Chs, the zeta potential changed stepwise in phosphate buffer solutions from 40 to -60 mV without reaching the iep. The results were explained as due to a complex formation on the kaolin surface via concurrent and/or cooperative adsorption of two polymers. 

Anion-exchange chromatography with a 30 mM sodium phosphate buffer solution at pH 6 was used for the separation of arsenous acid, DMA, MA, and arsenic acid on the polymer-based Hamilton PRP-XlOO anion-exchange column... 

A 72 hour incubation was used with 100,200 and 500 pi of polymer added per ml of Phosphate Buffer Solution. The numbers indicate the DNA content relative to that observed in the control (PBS). A vzJue over 100% signifies mitogenicity... 

For this study, 250 p-thick circular discs, each having a diameter of 15 mm, were prepared by pouring the cured cyanoacrylate into a plastic template submerged in a phosphate buffer solution at pH = 7.4 and 37°C. The cured discs were dried and their dry weight was determined. Weight was determined periodically after incubating in a phosphate buffer at 37°C and pH = 7.4. Using titis method, it was shown that MFC and V-200 lost 55 3% and 80 4% of their initial mass at 75 days. These results are consistent with the thesis that the oxalate polymer modifier accelerates the absorption rate of polymeric MFC. 

Comments pH values were prepared by phosphate buffer solutions. Polymer (B) ... 

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