Synthesis And Biological Applications Of GNR@LDH Core-shell Nanocomposite

Enlarging the aspect ratio or forming the core-shell structure for gold nanorods(GNRs)can adjust their photothermal conversion efficiency(?).Herein,we developed a simple synthesis method to form GNR@LDH core-shell nanostructure with GNR and layered double hydroxide(LDH).The interaction between GNRs and LDHs causes the change of surrounding media refractive index and the increase of electron deficiency on the surface of Au.More electrons induce more thermal energy conversion.The ? of GNR@LDH rise to 60%under 808 nm irradiation,which is the highest efficiency compared with reported GNR-based photothermal materials.Besides,cetyltrimethyl ammonium bromide(CTAB)can be eliminated totally after synthesis,and GNRs keep a good dispersion in LDHs.The GNR@LDH can be applied in photothermal antibacterial,biological imaging and tumor therapy with low dosage and nontoxicity.The main contents of this paper are listed below:1.The GNRs were synthesized by seeds mediated method.And GNR@LDH is synthesized by using GNRs as seeds to promote the formation of LDH crystallization surround GNRs.Characterized by TEM,SEM,XRD,XAFS,UV-vis,MTT assay,hemolysis assay and some other characterizations,it could be found that the photothermal conversion efficiency was increased from 9%to 60%.At the meantime,the cytotoxicity of the nanomaterials had been reduced significantly.2.This work also studied about antibacterial properties of GNR@LDH.In vitro experiment,GNR@LDH exhibited a strong ability to kill both Gram-negative bacteria and Gram positive bacteria in the concentration of 300?g/mL with 5 min 808 nm irradiation.In the wound healing experiment on mice,GNR@LDH killed the bacteria on wound effectively and promoted the healing process of wound.There were no side effects on mice.3.The tumor imaging and therapy of GNR@LDH was also studied in this work.In the cell experiment in vitro,GNR@LDH was nontoxicity for HeLa without 808 nm laser.But it expressed great ability to kill HeLa under 808 nm irradiation in the concentration of 300 ?g/mL(death rate of cell>90%).GNR@LDH had an excellent properties as a photoregilated antitumor namomaterial.In vivo,the GNR@LDH had a good performance on photoacoustic imaging and computed tomography imaging.Besides,it could ablate the tumor under 808 nm irradiation and had no side effects on other major organs.GNR@LDH can be used as a good tumor guidance and therapeutic agent.