title: Binding and Uptake into Human Hepatocellular Carcinoma Cells of Peptide-Functionalized Gold Nanoparticles.
abstract: One of the most daunting challenges of nanomedicine is the finding of appropriate targeting agents to deliver suitable payloads precisely to cells affected by malignancies. Even more complex is the ability to ensure that the nanosystems enter those cells. Here, we use 2 nm (metal core) gold nanoparticles to target human hepatocellular carcinoma (HepG2) cells stably transfected with the SERPINB3 (SB3) protein. The nanoparticles were coated with a 85:15 mixture of thiols featuring, respectively, a phosphoryl choline (to ensure water solubility and biocompatibility) and a 28-mer peptide corresponding to the amino acid sequence 21-47 of the hepatitis B virus-PreS1 protein (PreS1(21-47)). Conjugation of the peptide was performed via the maleimide-thiol reaction in methanol, allowing the use of a limited amount of the targeting molecule. This is an efficient procedure also in the perspective of selecting libraries of new targeting agents. The rationale behind the selection of the peptide is that SB3, which is undetectable in normal hepatocytes, is overexpressed in hepatocellular carcinoma and in hepatoblastoma and has been proposed as a target of the hepatitis B virus (HBV). For the latter, the key recognition element is the PreS1(21-47) peptide, which is a fragment of one of the proteins composing the viral envelope. The ability of the conjugated nanoparticles to bind the target protein SB3, expressed in liver cancer cells, was investigated by surface plasmon resonance analysis and in vitro via cellular uptake analysis followed by atomic absorption analysis of digested samples. The results showed that the PreS1(21-47) peptide is a suitable targeting agent for cells overexpressing the SB3 protein. Even more important is the evidence that the gold nanoparticles are internalized by the cells. The comparison between the surface plasmon resonance analysis and the cellular uptake studies suggests that the presentation of the protein on the cell surface is critical for efficient recognition.
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Satadru
authors: S
authors: Jha
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Federico
authors: F
authors: Ramadori
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Santina
authors: S
authors: Quarta
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Alessandra
authors: A
authors: Biasiolo
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Enrica
authors: E
authors: Fabris
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Paola
authors: P
authors: Baldan
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Gaetano
authors: G
authors: Guarino
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Mariagrazia
authors: M
authors: Ruvoletto
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Gianmarco
authors: G
authors: Villano
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Cristian
authors: C
authors: Turato
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Angelo
authors: A
authors: Gatta
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Fabrizio
authors: F
authors: Mancin
authors: Dipartimento di Medicina, Univeristà di Padova , via Giustiniani, 2, 35128 Padova, Italy.
authors: Patrizia
authors: P
authors: Pontisso
authors: Dipartimento di Scienze Chimiche, Università di Padova , via Marzolo 1, 35131, Padova, Italy.
authors: Paolo
authors: P
authors: Scrimin
mesh_terms: D000595:Amino Acid Sequence; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D006046:Gold / Q000737:chemistry*; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010455:Peptides; D006046:Gold