목적: Various methods to increase the target-specificity of nanoshells (NS) have been studied. Among them, one is the use of macrophage as cellular vector for nanoshells. The aim of the present study is to evaluate viability and mobility of NS-loaded macrophage in vivo situation and to prove the ability of macrophage to invade into tumor. 방법:For the uptake of nanoshells in peritoneal macrophages, the nanoshell suspension was co-incubated with peritoneal macrophages. Immunohistochemical studies were performed for identification of nanoshell-loaded macrophage migration into tumor. The nanoshell-loaded macrophages were applied on xenograft nude mouse by two types of local injection intratumorally or peritumorally. A NIR laser with a wavelength of 960nm at irradiance of 1 W/cm2 for 2 minutes was illuminated to tumor 48 hours after injection of the nanoshell-loaded macrophages. The irradiated xenograft tumor masses were resected and then examined via hematoxylin and eosin staining. 결과:The macrophages injected on the center of xenograft tumor (intratumoral injection group) showed minimal migration of few macrophages from the injection site at even 48 hours after injection.The peritumoral-injected macrophages penetrated into tumor at 48 hours after injection of them. After nanoshell-loaded macrophages were injected around xenograft tumor and then photothermal treatment was performed, the nanoshell within macrophages were aggregated and become coarse particles on injection site. In peritumoral injection group, extensive cellular destruction evenly occurred on all portions of tumor. The thermally induced death of cancer cells were induced by using NIR laser light at irradiation of 1W for 2 minutes 결론:Nanoshell-loaded macrophage functioned as a cellular vector and photothermal effect of NS was effective to kill cancer cells in vivo situation.