Thiol-PEG6-acid

Huang, Chun-Jen, et al. Colloids and Surfaces B: Biointerfaces 145 (2016): 291-300.

For targeted hyperthermia applications of nanoshells, anti-HER2 mouse monoclonal antibody was used to conjugate to nanoshells for delivery to HER2-positive MDA-MB-453 cell lines. MDA-MB-453 cells were maintained in DMEM supplemented with 10% FBS at 37°C in a humidified CO incubator. Initially, nanoshells were modified to terminate carboxyl groups by mixing Thiol-PEG6-acid with Cys-b or OEG-thiol at a molar ratio of 1:4, respectively. Nanoshells prepared in DI H2O at a concentration of approximately 2x10 nanoshells/mL were treated with mixed thiol solutions at a total concentration of 5 μM for 48 hours at room temperature. After ligand exchange, COOH-functionalized nanoshells were collected by centrifugation at 20,000 rpm for 10 minutes and then redispersed in PBS. The carboxyl groups were chemically activated by EDC/NHS amine coupling. The activation solution was prepared by dissolving 18 mg EDC and 1.2 mg NHS in 1 mL PBS. A 1 mL aliquot of the activation solution was transferred to a solution of modified nanoshells at a concentration of approximately 2x10 nanoshells/mL in PBS at 4°C for 2 hours. Afterwards, the activated nanoshells were collected by centrifugation at 20,000 rpm for 10 min and removed by washing 3 times with fresh PBS.