BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 Utility of polyeletrolyte gels in biomaterials/bioengineering Cell encapsulation: In situ formation with no additives, no change in pH, no change in temperature, in physiological solutions o Useful for safe encapsulation of cells o Drug delivery: lonic interactions for protein-polymer complexes prior to gel formation allow high protein entrapment o PEMs can form hollow capsules Drug release from PSS/PAMAM PEM capsules 0.154 M NaC Figure 4. Release profiles for encapsulated DOX in PSs tion of the their interior. The inset show Fluoresceno. tas used for release studies. The excitation waveteng rug-loaded PEM capsules o Enzyme immobilization: binding to ionic groups for biosensors or active biomaterials o Protein separations/recovery: some binding specificity can be achieved in certain situations to allow for selective sorption of a target protein o Addition of polycation or polyanion to solution of protein leads to protein-polyelectrolyte coacervate formation o bound proteins released by adjustment of ph/ionic strength AN减 YCAY p, 2l. wutu of a sampan. circe Fg. b The mechanisn of proein-polyelaetrohte complexes Lecture 9-polyelectrolyte hydrogels 9of17BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Utility of polyeletrolyte gels in biomaterials/bioengineering o Cell encapsulation: In situ formation with no ‘additives’, no change in pH, no change in temperature, in physiological solutions o Useful for safe encapsulation of cells o Drug delivery: Ionic interactions for protein-polymer complexes prior to gel formation allow high protein entrapment efficiencies o PEMs can form hollow capsules Drug release from PSS/PAMAM PEM capsules: Fluorescent drug-loaded PEM capsules o Enzyme immobilization: binding to ionic groups for biosensors or active biomaterials o Protein separations/recovery: 9 some binding specificity can be achieved in certain situations to allow for selective sorption of a target protein o Addition of polycation or polyanion to solution of protein leads to protein-polyelectrolyte coacervate formation o Bound proteins released by adjustment of pH/ionic strength Lecture 9 – polyelectrolyte hydrogels 9 of 17