Background: The lack of smart and controllable gene vectors with high safety and efficiency
is still a main obstruction for clinical applications of gene therapy. Recently, the external physical stimuli,
such as near infrared light induced temperature elevation, have been applied to enhance the gene
transfection efficiency and specificity. The aim of this paper is to fabricate chitosan functionalized CuS
nanoparticles (CuS@CS NPs) with small size and higher biocompatibility for enhanced gene delivery
by photothermal effect.
Methods: CuS@CS NPs were successfully prepared by simple hydrothermal method. The biocompatibility
was detected by MTT method and hymolytic analysis. pEGFP-C1was used as gene model, and its
expression efficiency was detected by fluorescence microscopy and flow cytometry to investigate the
effect of photothermal effect on the transfection efficiency.
Results: The CuS@CS NPs around 15 nm were successfully engineered. The modification of CuS
nanoparticles with chitosan conduced to higher physiological stability and biocompatibility. The utilization
of CuS@CS NPs in combination with external near infrared (NIR) laser irradiation could enhance
gene transfection efficiency due to photothermal effect. The gene transfection efficiency of CuS@CS
NPs found to increase from 5.05±0.54% (0 min) to 23.47±1.27% (10 min), significantly higher than the
free polyethylenimine (18.15±1.03%).
Conclusion: CuS@CS NPs showed great capability to control gene delivery by an external NIR laser
irradiation and enhance the gene transfection efficiency and specificity because of convenient preparation,
stabilized optical properties, excellent photothermal effect and good biocompatibility. It encourages
further exploration of the CuS@CS NPs as a photocontrollable nanovector for combined photothermal
and gene therapy, as well as image guided therapy.