Spatial Resolution Of Mass Spectrometry Imaging And Application Of Inkjet Printing Technology In Single-cell Quantification

Droplets are an important applied technological tool in scientific research in fields such as biology and chemistry.At the same time,the generation of droplets is technically challenging.Therefore,it is an important task to develop a technology that can generate droplets quickly,conveniently and with high throughput.At present,there are two main ways to generate droplets.One is that microfluidic technology has been widely used in various fields.However,due to the complex production process,high cost and strict requirements on the experimental environment,its application is limited.Another widely used inkjet printing technology is simple,repeatable and cost-effective.This paper mainly studies the application of inkjet printing technology in the quantitative analysis of single cells and in the determination of the spatial resolution of mass spectrometry imaging.The main research results are as follows:In this paper,a uniform and uniform sample for the determination of the spatial resolution of aerodynamic-assisted desorption electrospray ionization mass spectrometry imaging(AFADESI-MSI)was fabricated by inkjet printing technology,and the spatial resolution and scanning conditions of AFADESI-MSI were explored.Firstly,uniform samples were prepared using a commercial inkjet printer,and the printing conditions were explored.Uniform samples printed on photo paper with different line spacing and uniform edges were obtained,which could be used to verify the spatial resolution of AFADESI-MSI.Then,using the obtained uniform sample,the scanning conditions such as the step size and scanning speed of the imaging system were optimized,and the optimized conditions were used to measure the spatial resolution of mass spectrometry.The results show that the longitudinal spatial resolution of the system can reach 153.9±3.2 ?m when the needle with a diameter of 100 ?m is used,and the longitudinal spatial resolution of the system can be improved to 65.1±1.5 ?m after using the needle of 20 ?m.This technique can provide new insights into pharmacological and toxicological mechanisms,facilitating clinical diagnosis of complex diseases.Using laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS),a method for quantitative analysis of boron content in single cells was established.Picoliter droplets similar to cell matrices were prepared using a commercial inkjet printer as a singlecell quantification standard.Human glioma cells and mouse microglioma cells exposed to the two drugs used for boron neutron capture therapy(BPA-F and BCDs)were subsequently quantitatively analyzed using LA-ICP-MS.The results showed that the intracellular boron content of the two cells basically met the requirements of BNCT treatment after being exposed to 17.5 ppm(calculated as boron)for 4 h and 6 h.