The Influence And Mechanism Of Gold Nanoparticles Morphology On Its Sonodynamic Activity

Sonodynamic therapy（SDT）has attracted more and more attention due to its high tissue penetration and low side effects.However,due to the limitation of sonosensitizers,the development of efficient and stable sonosensitizers will be still an important research topic to improve the therapeutic effect of SDT.Gold nanoparticles（GNPs）are particularly well-suited for biomedical applications because of their superior biocompatibility and stability.In the early stage,the sound sensitivity of new fluoroquinolone compounds was verified by ultrasonic damage of serum proteins.At the same time,GNPs were used as carriers to load the fluoroquinolone drug ciprofloxacin,and the promotion effect of GNPs-loaded ciprofloxacin combined with ultrasonic bacteriostasis was studied.In summary,the effect of morphology on the sonodynamic activity of GNPs was further investigated and the related mechanism was investigated.It is expected to provide a theoretical reference for the screening and development of sonosensitizers.Firstly,three morphologies of GNPs were prepared by sodium citrate reduction method and seed growth method.And they were characterized by UV-vis spectrophotometer,laser granulometer and scanning electron microscopy.The results showed that the three morphologies of GNPs were successfully prepared and their sizes followed the experimental requirements.Secondly,the damage of combined ultrasound on serum proteins were investigated by UV-vis spectrophotometer and fluorescence spectrophotometer for the three morphological GNPs.Then,the effects of GNPs concentration,GNPs shape,and ultrasonic parameters on protein sonodynamic damage were investigated further.The results revealed that all three types of GNPs combined with ultrasound could severely damage serum proteins,and the degree of damage was greater than that of ultrasound alone;upon contrasting the destructive effect of combined ultrasound on serum proteins induced by three distinct GNPs shapes,it was discovered that the sonodynamic activity of the three shapes varied.Based on the results,it was determined that the sonodynamic activity of gold nanospheres（GNSs）was comparable to that of gold nanoflowers（GNFs）and superior to that of gold nanorods（GNRs）.It was also found that more GNPs concentration,higher ultrasonic power and longer ultrasonic time were beneficial to improve the sonodynamic damage effect of GNPs with different shapes.Finally,the physical damage mechanism of sonodynamic damage to serum proteins by different GNPs was investigated by simultaneous fluorescence spectrophotometer and circular dichroism spectrophotometer.The results demonstrated that the secondary and tertiary structures of serum proteins were compromised by the combined ultrasound of GNPs with various morphologies,so that the conformation of serum proteins was altered.However,the degree of damage to the conformation of serum proteins by the combined ultrasound of GNPs with three morphologies was different.Further,the chemical damage mechanism of sonodynamic damage to serum proteins by different shapes of GNPs was investigated using singlet oxygen（¹O₂）fluorescence probe,and the results revealed that the yield of ¹O₂ in the system was significantly higher after adding different shapes of GNPs combined with ultrasound than the effect of ultrasound alone.The yield of ¹O₂ increased as the concentration of GNPs increased in various systems,reflecting the difference in shape-dependent sonodynamic activity.In the meantime,an increase in ultrasound intensity and ultrasound time can promote the accumulation of ¹O₂ in the system.In summary,all three morphological GNPs showed excellent sonodynamic activities.The ranking of the sonodynamic activities was GNSs≈GNFs>GNRs.Therefore,spherical GNPs are more suitable for use as a sonosensitizer or a sonosensitizer carrier.And the concentration of GNPs,ultrasonic power and ultrasonic time all influenced the sonodynamic effects.The ultrasonic activation of distinct morphological GNPs causes both chemical and physical damage to serum proteins.The development of this study provides a theoretical reference for the further development of nanomaterials sonosensitizers.