Effect of chiral poly(acryloyl-valine) capped on AuNPs on protein adsorption and cellular uptake

Abstract

Event Abstract Back to Event Effect of chiral poly(acryloyl-valine) capped on AuNPs on protein adsorption and cellular uptake Changyou Gao1, Jun Deng1, Sai Wu1 and Mengyun Yao1 1 Zhejiang University, Department of Polymer Science and Engineering, China Introduction: Understanding and use of the effects of nanoparticles (NPs) on living cells are now the principal aims and most challenging aspects of nanobiotechnology and nanomedicine[1]. The surface of NPs is covered by proteins upon contacting with biological systems (e.g. serum), resulting in the formation of a protein “corona” that is strongly associated with the NPs' surface and defines how cells “see” the NPs in a biological medium[2],[3]. Although many studies have demonstrated that surface modification of AuNPs with biomolecules endows them with various biological functionalities, the impact on living organisms of the chirality of the surface molecules at nanoscale has not been disclosed. Herein the effects of AuNPs capped with different chiral forms of poly(acryloyl-L(D)-valine) (L(D)-PAV) on uptake by A549 cells are examined. Experiment Section: The 15nm AuNPs were incubated with 1 mg/mL L(D)-PAV at room temperature overnight. The obtained solution was centrifuged and followed by dialysis in water for 4 d. Then the protein adsorption, cellular uptake amount and intracellular distribution of PAV-AuNPs were studied by µBCA, ICP-MS and laser scanning confocal microscopy, respectively. Results and Discussion: The diameter of the PAV-AuNPs was about 16 nm. The only difference between L-PAV-AuNPs and D-PAV-AuNPs was their chirality. The PAV-AuNPs were mainly distributed in cytoplasm, regardless of chirality. With the concentration of FBS increasing, the adsorbed amount of proteins on the PAV-AuNPs increased, and the internalized amount of PAV-AuNPs by A549 cells was decreased. In DMEM and 10% FBS/DMEM, A549 cells took up higher amount of D-PAV-AuNPs. However, in 50% FBS/DMEM and 20 mg/mL BSA/DMEM, the internalized amount of L-PAV-AuNPs and D-PAV-AuNPs was chirality-independent. This finding discloses the importance of molecular chirality on the protein adsorption and thereby the cellular uptake of nanomaterials. Conclusion: The molecular chirality on AuNPs acts as a direct regulator of cellular uptake, but the effect of chirality on cellular uptake disappears when the NPs are covered by proteins, especially BSA. Identification of this chirality-dependent cellular uptake of NPs provides a new idea that chiral effect can act as a novel strategy for designing bio-interface materials and may open a new avenue for further development of gold nanoparticles for biomedical applications. The NSFC (51120135001, 21374097), and Zhejiang Province (2013TD02).