| The objective of this study is to establish a protein encapsulation model and identify the influencing factors that might affect the protein release pattern. The study includes screening and selection of polymer/amine; determination of the size of capsules; selection of model proteins for protein encapsulation; protein encapsulation and determination of effects of ion strength, releasing buffers, protein concentrations and protein molecular weights on the protein-encapsulated capsule structure and protein release pattern. A lab-scale screening technique was used and a reagent pair of carboxymethylcellulose (CMC)/decylamine was selected from a pool of 135 candidate reagents.; The variation in size of capsule varying with both polymer concentration and injection speed of polymer solution into amine solution was examined. In the study to evaluate the factors which affected protein release behaviors, a constant injection speed and concentration of polymer solution were used. The kinetic process of capsule formation, which begins in the outer layer and progresses toward its center, was evaluated.; Model proteins for encapsulation were determined based on following requirements: soluble in CMC polymer solution, stable during encapsulation and release study, analytically useful ultraviolet absorbance, and minimum effect on physical properties of capsules. Gelatin, trypsin inhibitor, bovine serum albumin, and fibrinogen were finally determined as model proteins for this study.; Physical stability of the protein-containing capsules was significantly affected by the molecular weight and concentration of proteins as well as pH and ion strength in the release buffers. Capsules containing a large protein (e.g., fibrinogen, 320 kDa) were disrupted faster than capsules containing smaller size proteins.; Protein initial release rates and release behaviors were significantly affected by ionic strength and pH in the release buffer. Protein with lower molecular weights showed high initial release rates. High ionic strength and pH in the release buffer caused a more rapid initial protein initial release rate. |
