Construction Of Dual Photo-magnetic Responsive Porous Silicon-based Nanocomposite Carriers For Biomedical Applications

Stimulation-responsive nanocomposites used as nanocarriers can selectively respond to external physical stimuli,such as light irradiation,magnetic field or ultrasound,to trigger and control the release of their cargoes.Under the irradiation of NIR light NIR light-responsive nanocarriers can efficiently kill the cancer cells and ablate tumor tissues,due tothe heating generation caused by their photothermal effect,meanwhile they also can control the release of their cargo drugs.As for the magnetic field-responsive nanocarriers,they can be also used as carriers to deliver the the cargoes to the targeted region under the external magnetic field.Here,porous silicon-based nanocomposites which can be responsed to NIR light and magnetic field were constructed,and the details as followed:（1）Firstly,Si-H bonds on the surfaces of PSiNP were used to reduce chloroauric acid in situ to prepare PSiNPs@Au nanocomposites,and then they were subsequently dispersed in chiston（CS）solution to fabricate temperature-sensitive CS/PSiNPs@Au hydrogel.Afterwards,the hydrogel formation/degradation in situ,and the anticancer drug（doxorubicin hydrochloride,DOX）loading/release of CS/PSiNPs@Au hydrogels were characterized in detail in vitro and in vivo.On this basis,we further injected CS/PSiNPs@Au loaded with drug and intratumorally inject them into the 4T1 tumor-bearing mice,adopted NIR light irradiation to induce the anti-tumor drug release from the hydrogel,and explored the anticacner effects.（2）With the PSiNPs as host matrices,magnetic PSiNPs@Fe₃O₄ nanocomposites were fabricated via the hydrophobic interaction between the porous silicon nanoparticles and ferroferric oxide nanoparticles.Then by the modification of the biocompatible polydopamine（PDA）,magnetic and photothermal nanocomposites were constructed.Finally,the performance of as-preapred PSiNPs@Fe₃O₄@PDA nanocomposites for the exogenous gene transfection was studied with the help of NIR laser irradiation and external magnetic field.