Preparation and release characteristics of protein-loaded polyanion/gelatin complex.
OBJECTIVE
This paper describes preparation of polymethacrylic acid/gelatin complex and Myoglobin release characteristics in order to evaluate the polyanion/gelatin complexes as matrices that can release proteins at a near zero-order kinetics over a long period of time.


METHODS
Mb-loaded PMAA/gelatin complex was prepared by two different titration methods. Mb entrapment efficiency and PMAA/gelatin ratio in the complex were determined by HPLC. The release of Mb and gelatin from the complex was followed by HPLC. Mb conformation was detected by UV-vis spectrophotometer and capillary electrophoresis apparatus.


RESULTS
Polyanion/gelatin feed ratio of the polyanion/gelatin/Mb mixed solution has great effects on complex yield and protein entrapment efficiency when "Type I" titration method is adopted, while for the colloid titration method the complex yield and protein entrapment efficiency are hardly influenced by preparative conditions (ca. 100%). Mb release rate could be adjusted by the complex composition (e.g., PMAA MW, hydrophobilization of PMAA, Mb loading and PMAA/gelatin ratio, etc.). Moreover, by coating of high MW PMAA/gelatin complex cylinder in a hydrophobic membrane with one open-end left, the period of protein release can extend to ca. 20 days and the release displays a near zero-order pattern. The protein release profiles can be described by the dissociation/erosion mechanism. The entrapment process has little effect on Mb conformation.


CONCLUSIONS
The studied polyanion/gelatin complex is promising to be used as protein carriers to release proteins at a near zero-order kinetics over a long period of time by selecting suitable polyanions and designing the device structure.
Jiang
H L
HL
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Zhu
K J
KJ
D005780:Gelatin / Q000008:administration & dosage*; D008970:Molecular Weight; D009211:Myoglobin / Q000008:administration & dosage*; D011109:Polymethacrylic Acids / Q000008:administration & dosage*; D012995:Solubility
D009211:Myoglobin; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D005780:Gelatin