Microencapsulation polyelectrolyte complexation

Keywords Bio artificial pancreas, biomaterials, complex coacervation, immunoisolation, microencapsulation, polyelectrolytes, water soluble polymers. 

Several other investigators have reported microencapsulation methods based upon polyelectrolyte complexes [289, 343]. For example, oppositely-charged polyelectrolytes (Amberlite IR120-P (cationic) and Amberlite IR-400 (anionic)) were recently used along with acacia and albumin to form complex coacervates for controlled release microcapsule formations [343]. Tsai and Levy [344,345] produced submicron microcapsules by interfacial crosslinking of aqueous polyethylene imine) and an organic solution of poly(2,6 dimethyl... 

We have outlined the diversity and procedural flexibility afforded through the use of appropriately designed synthetic polymers for mammalian cell immobilization. Having selected the acrylate family of monomers because of their diversity, we have shown that mammalian cells may be microencapsulated in uncharged and polyelectrolyte polymer, in polyelectrolyte complexes and inside a cohesive precipitate from a destabilized emulsion all without significant loss of viability. Through this chemical diversity and inherent biocompatibility, these systems hold forth the possibility of improved transplantation therapies for a wide variety of cellular diseases. 

KCl by microencapsulation. In this chapter, a comprehensive attempt has beenmade to discuss the different aspects of ionotropic gelation and polyelectrolyte complexation approaches by considering these techniques as great promising tools for the development of encapsulation process. 

Examples of Microencapsulating Substances by Ionotropic Gelation and Polyelectrolyte Complexation... 

Complex coacervation is similar to simple coacervation where another complimentary polyelectrolyte is used. Gelatin and gum arabic is a well-estabHshed system for microencapsulation by complex coacervation. Mayya et al. have reported a two-layer encapsulation of paraffin oil, based on a primary layer of interface active polyelectrolyte-surfactant complex, followed by a second layer of the conjugate polyelectrolyte-polyelectrolyte complex [41]. The procedure involves the dispersion of paraffin oil in 1% gelatin solution (pH adjusted to 6.5) containing SDS having concentration less than its CMC, followed by drop-wise addition of the solution of the other polyelectrolyte (1% gum arabic) into the dispersion. The pH is then ad-... 

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