Self-assembly Of Noble Metal Nanomaterials Based On Vapreotide And Their Biological Properties Study

The noble metal nanomaterials have attracted increased attention owing to their special photology,biology and other properties.However,it is still a great challenge to prepare the green,non-toxic and uniform nanomaterials which possess the superior photothermal therapy property.In this study,the vapreotide acetate was utilized to prepare the noble metal nanomaterials with different morphologies,which was then characterized and tested for photothermal therapy.Vapreotide acetate is one kind of somatostatin analog,which includes eight amino acids and possesses antitumor activity.Due to the small molecular weight,when the vapreotide acetate was dissolved in the acid solution(pH 2.0),it was tend to self-assemble into biotemplate which owned the regular morphology and spatial conformation.The nanomaterials possessed the advantages of uniform sizes,excellent monodispersity and eco-friendly synthesis,which were fabricated by the biotemplate-induced method.The vapreotide acetate-silver nanoshells(Vap-AgNSs)and vapreotide acetate-gold nanoflowers(Vap-AuNFs)were prepared based on the vapreotide acetate biotemplate.The TEM images showed that the diameters of Vap-AgNSs and Vap-Au NFs were 100 nm and 150 nm,respectively.The elementary compositions and crystal natures were demonstrated by the EDS and XRD,and the good stabilities of solutions were proved by the Zeta potential analysis.In addition,the absorption peaks of Vap-AgNSs and Vap-AuNFs located at 670 nm and 620 nm respectively.The photothermal therapy tests showed that the temperatures of Vap-AgNSs and Vap-AuNFs rose to 40? rapidly at the irradiation of 808 nm near-infrared light.And the cell experiment indicated that the prepared nanomaterials could kill most of Hela cells.Through the replacement reactions,the vapreotide acetate-silver@gold nanoshells(Vap-Ag@AuNSs)with the diameter of 120 nm was synthesized based on the Vap-AgNSs,which was monodisperse and uniform.The different stages of Vap-Ag@AuNSs were observed by TEM.In addition,the absorption peak of Vap-Ag@AuNSs was at 826 nm.The photothermal therapy tests showed that the temperatures of prepared Vap-Ag@AuNSs could rise to 52? after 10 min.And the cell experiment indicated that the prepared nanomaterials also killed most of Hela cells,and the boundary line between irradiated region and unirradiated region was obvious.The above results showed that the vapreotide acetate can be employed as the excellent biotemplate which can control the special structure of nanomaterial and endow the nanomaterial with superior biological property.Thus,vapreotide acetate is the good candidate of synthesis of nano biological materials.