Gold Nanoparticle-Based Gene Delivery

11-MUA, 11-MUOH, 6-MHA, 25 kDa branched PEI, Tween 20, generation four PAMAM dendrimers with EDA core, DAH core, cystamine core or hydroxyl termini were purchased from Sigma Aldrich (St. Lewis, MO). EDC and Sulfo-NHS were purchased from Thermo Scientific (Waltham, MA). 5 nm citrate stabilized colloidal AuNPs were purchased from Ted Pella (Redding, CA). Plasmid DNA with cytomegalovirus (CMV) promoter and enhanced green fluorescent protein (eGFP) as the reporter gene (pCMV-eGFP, 4.7 kb) were obtained from Clark Needham at Rice University [38 (link)]. SK-BR-3 cell line, cell culture medium and PBS were purchased from ATCC (Manassas, VA). MES buffered saline and CT(PEG)₁₂ were purchased from Pierce (Rockford, IL). Amicon Ultra-15 10 and 50 kDa Centrifuge Concentrators were purchased from Millipore (Billerica, MA). Hydroxylamine was purchased from Alfa Aesar (Ward Hill, MA). Propidium iodide (PI) Staining Solution was purchased from eBiosSciences (San Diego, CA). All other chemicals were purchased from Sigma Aldrich (St. Lewis, MO) or Fisher Scientific (Waltham, MA) unless otherwise stated.