Poly membranes capture

As mentioned above, HPMA copolymers containing approximately 2% oligopeptidyl side-chains have no affinity for the plasma membrane and enter cells by fluid-phase pinocytosis. Increasing the hydrophobicity of macromolecules appears to enhance, non-specifically, their rate of capture by rat visceral yolk sacs and we have shown that incorporation of 20% tyramine residues into the synthetic polymer poly-a-3"N(2-hydroxyethyl) -D,-L- aspartamide greatly enhances its rate of uptake by this tissue.More recently we have found that incorporation of tyrosine residues (approximately 18%) into HPMA oligopeptidyl side-chains produces the same results (Table 4). The existence of a correlation between the percentage tyrosine in the molecule and the rate of pinocytic uptake indicates that synthetic polymers can be designed in such a way as to control their non-specific affinity for membranes. 

Biodegradable poly-gamma-glutamic acid (y-PGA), a linear biopolymer, and its cross-linked nanoparticles were used to capture the metal ions by forming nanosized particles. The polymer-metal ion particles, with sizes in the range of 80-350 nm, were then removed by UF membrane separation. The method is named the combined nano-membrane separation technique (Hajdu... 

Interesting advances in the field of GS membrane materials are polymers with high-free volumes, such as poly(l-trimethylsilyl-l-propyne), poly(4-methyl-2-pentyne), and polymers of intrinsic microporosity [108]. Regarding the emerging application of CO2 capture, the copolymer class Pebax (Arkema) showed promising results. For instance, Bondar et al. [109] reported interesting values of CO2/N2 and CO2/H2 selectivity for different grades of Pebax membranes. 

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