Cell Culture models, targeted drug delivery

The control of inverse transition temperatures by sequence manipulation and biocompatibility of ELPs make them useful polymers for drug delivery. Cultured cancer cells and solid tumors in animal models uptake fluorescently labeled ELPs in a thermally responsive manner (48,49). Two major limitations in cancer therapy have been the inability of therapeutic molecules to cross the cell membrane and the target-specificity of the compounds. To overcome these limitations cell-penetrating, peptides (CPP) have been fused with ELPs (CPP-ELP) to develop thermally responsive therapeutics with the ability to translocate the cell membrane (Figure 3B). CPPs can assist in the transportation of hydrophilic compounds (small molecules, oglionucleotides and peptides) across the cell membrane (50). Fusing ELPs to a variety of CPPs have revealed that the peptide sequence of penetratin demonstrates the most efficient cellular uptake (51). Further, these CPP-ELPs have been fused to a c-Myc inhibitory peptide known to target and inhibit cancer. As proof of principle, these fusion proteins inhibits proliferation of cultured cancer cell lines in a thermally responsive manner (52). 

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