Conjugation To ELPs: Chromophors For Hydrodynamic Property Determination and Improved Drug Delivery
Anna N. Thigpen1, Andy T. Cassity1, Rachel D. Bravenec1, Parth R. Patel1, Deandrea (DJ) C. Hawkins1, Saihou Ceesay1, Valeria Zai-Rose2, Jacob Pruett2, John J. Correia2, Wolfgang H. Kramer*
1Department of Chemistry and Biochemistry, Millsaps College, Jackson, MS
2Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, MS
ELPs (Elastin-like Polypeptides) are synthetic biopolymers that have unique properties. They are known to undergo liquid-liquid phase separation reversibly above a concentration-dependent transition temperature. Thus they are thermo-responsive and can be equipped with cell-penetrating peptides and loaded with other molecules via cysteine-maleimide crosslinking. Consequently, compounds such as cancer drugs like doxorubicin, can be delivered with ELPs by hyperthermia to target cancer cells.
The transition-temperature is influenced by the conjugated drug and this study aims to investigate the effect of various parameters on the thermodynamic functions responsible for the phase separation.
The influence of the connective spacer and the chromophore is investigated in this study. For this, various amino acids are converted into their maleimides and p-nitroaniline amides. p-Nitroaniline absorbs at 365 nm as a free amine, while the amide absorbs at 325 nm. The conjugation to ELP is determined by the ratio of the 280 nm and 325 nm absorptions.
Acknowledgement: This work was supported by the Mississippi INBRE, funded by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103476.