The Investigation For Conjugation Of Perylene Imide Derivatives And Human Serum Albumin

Biological conjugated system with bifunctional properties has been widely used in biomedical sciences, which attracts more and more attentions. In this paper, a series of pentafluorophenol (PFP) ester based on perylene imides and their derivatives were synthesized and applied to interact with human serum albumin (HSA). The main contents were stated as follow.1. By adjusting the reactant ratio and reaction time, the penylene imide derivatives (PDIs) with one or four carboxylic acid groups in the bay region were synthesized, and further modification was perfromed by treated with PFP to form the uniform active esters (PDI-b-1-PFP, PDI-b-4-PFP). The esters reacted with the amino groups of the lysine (Lys) residues in HSA resulting in the uniform conjugations (PDI-b-1-HSA, PDI-b-4-HSA). Because of the electrostatic interaction between the HSA and PDI, the fluorescence of PDIs in the bioconjugation was quenched. However, HSA can be degraded by glutathione (GSH). The fluorescence of PDIs could be recovered, when the HSA was degraded and removed by GSH. Thus, the conjugations may have potential applications in GSH detection.2. To obtain the PDI-HSA NPs combining through the covalent bond, three types of PFP esters modified PDI derivatives were designed and synthesized. They reacted with HSA to form the bioconjugations (PDI-N-1-HSA, PDI-N-2-HSA, and PDI-N-4-HSA, N:imide position). The bioconjugations were assembled to uniform nanoparticles (PDI-N-1-HSA NPs, PDI-N-2-HSA NPs, PDI-N-4-HSA NPs). The SEM characterization results indicated that, compared to the other two types of nanoparticles, PDI-N-1-HSA NPs were very stable and well-dispersed in aqueous solution with the particle diameter around 200 nm. In addition, the PDI-N-1-HSA NPs could successfully be uptaken into HeLa cell, indicating their potential applications in label and diagnosis for cancer cell.3. To obtain the PDIs HSA NPs conjugating through the noncovalent bond, synthetic water-soluble PDIs were used to interact with HSA and the process was investigated by UV absorption, fluorescence spectroscopy, three-dimensional fluorescence spectroscopy and isothermal titration calorimetry (ITC). As a result, one kind of the PDIs HSA conjugations combining through hydrophobic interaction was fabricated to nanoparticles and had internalized into HeLa cell.