Protein-polymer interactions

A neutron scattering investigation of the polymer solution structure and protein-polymer interactions, Macromolecules 1992b, 25, 3932-3941. N. L. Abbott,... 

Protein. At the same solution conditions, different proteins display distinct solubilities with polyelectrolytes. The strength of the protein-polymer interaction depends on both the number and distribution of charged sites on the protein surface (11). At pH 3.4 and ionic strength of... 

Adhesion forces recorded by a fibronectin-coated AFM probe correlated with fluorescence measurements of protein adhesion on the polymer array, and both methods proved useful in characterizing protein-polymer interactions on a polymer array (Figure 27). ° While only a demonstration, the ability to discover relationships between surface chemistry and surface properties using this combined multiprong analysis with polymeric microarrays is notably powerful. 

The development of a stable protein formulation for microencapsulation also includes consideration of the potential for protein-polymer interactions. For example, proteins that are very basic (high PI) may interact with the free acid groups generated by the degradation of polylactides. In this case, it may be necessary to add excipients such as polyionic compounds (anionic for protein binding, cationic for polymer binding) that prevent or reduce the interaction between the protein and the polymer. For polylactides, it may be unlikely that the protein will form a covalent adduct with... 

Jiang, G. et al.. Assessment of protein release kinetics, stability and protein polymer interaction of lysozyme encapsulated poly(D,L-lactide-co-glycolide) microspheres,/. Control. Release,79,137, 2002. 

Nevertheless, it has been proved that the addition of PEG to the system produces a reduction of encapsulation efficiency for drugs and proteins, even when the appropriate fabrication technique is used. That reduced drug inclusion could be related to steric interference of drug/protein-polymer interaction by the PEG chains, but until now, the precise mechanism for this effect was not elucidated. Improved release kinetics... 

Another interesting featiu e issued from this work is the generalisation of the rapidity with which protein-polymer interaction set up since one minute of protein-polymer contact was sufficient to result in the protective effect of protein. The collection of a white pellet by centrifugation of plasma and Q-P(TDAE)ii or PLL in the absence of RBC appeared as another support to the occxurence protein-polycation complexation. 

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