In Vivo Plain X‐Ray Imaging of Cancer Using Perovskite Quantum Dot Scintillators

Abstract

Real‐time in vivo detection of cancer via attenuation‐based plain X‐ray imaging is proposed to fundamentally overcome the penetration depth limits of current fluorescence‐based imaging techniques. Using cesium lead bromide (CsPbBr3, CPB) quantum dot (QD) scintillators, real‐time X‐ray detection of 5 mm‐sized Panc‐1 cell tumors grown in a mouse is successfully performed. The QDs are rapidly co‐synthesized and double‐encapsulated with silicon dioxide (SiO2) to completely prevent them from being aggregated, decomposed, or released; they are then conjugated with antibodies to target pancreatic cancer. Due to the dramatic X‐ray attenuation, the X‐ray signal from the CPB QDs placed under the 2 cm‐thick tissue is clearly observed, while their fluorescence signal is not detected at all. In in vivo mouse experiments, the injection of a tiny amount (2.8 μg on a QD basis) of the CPB–SiO2@SiO2–Ab nanoparticles gives rise to a bright spot at the location of the tumor. Cell viability assay and histological analysis confirm the biocompatibility and nontoxicity of the nanoparticles.

Enhanced X-ray Attenuating Efficiency of Silicon Dioxide Nanoparticles with Cesium Lead Bromide and 2,5-Diphenyloxazole Co-Embedded Therein

“…Comparing these spectra, any detectable PPO signal was not observed for the solution, in which the CPB/SiO 2 NPs were dispersed for 30 days, indicating the high stability of PPO molecules in the NPs. Furthermore, based on the report that most SiO 2 NPs of this size intravenously injected into mice are excreted within 7 days [9], the accumulated PPO or SiO 2 in the body would be much less. Of course, further in-depth evaluation will be required to safely apply this material to in vivo imaging.…”

“…SiO 2 NPs containing CPB QDs and PPO molecules, denoted as CPB-PPO/SiO 2 NPs, were synthesized using a modified "rapid co-synthesis and double-encapsulation method", which was described elsewhere [9]. Briefly, 2 mL CPB precursor solution prepared by adding 0.3 g lead bromide (99.999%; Sigma-Aldrich, Seoul, Korea), 0.17 g cesium bromide (99.999%; Sigma-Aldrich, Seoul, Korea), 1.2 mL oleylamine (70%; Sigma-Aldrich, Seoul, Korea), 3.6 mL oleic acid (90%; Sigma-Aldrich, Seoul, Korea), and catalytic amount of ammonium hydroxide (28%; Deajung, Seoul, Korea) in 20 mL N,N-dimethylformamide (99.5%, Deajung, Seoul, Korea) were rapidly injected into a SiO 2 precursor solution containing 1600 µL tetramethyl orthosilicate (98%; Sigma-Aldrich, Seoul, Korea) and 200 mg PPO (grade for spectrometry; Sigma-Aldrich, Seoul, Korea) in 100 mL toluene (99.7%; Deajung, Seoul, Korea), followed by stirring at room temperature for 2 h. The synthesized CPB-PPO/SiO 2 NPs were collected using centrifugation and washed with ethanol three times, followed by annealing at 150 • C for 2 h to remove surface hydroxyl groups.…”

“…Although fluorophores emitting the wavelength, λ, of longer tissue penetration, especially near-infrared-II (λ of 900-1700 nm), have extensively been investigated in recent years, they also have intrinsically limited penetration depth and a trade-off between the depth and the resolution [7,8]. To overcome the limitations of such emission-based imaging technologies, we have recently proposed an X-ray-attenuation-based imaging technique using cesium lead bromide (CPB; CsPbBr 3 ) quantum dot (QD)-embedded silicon dioxide (SiO 2 ) nanoparticles (NPs) that effectively attenuate incident X-rays [9]. Because X-rays have almost unlimited depth of tissue penetration, the X-ray-based imaging can be a plausible candidate for real-time in vivo detection of cancer wherever it is located in a body.…”

Mn-derived Cs4PbX6 nanocrystals with stable and tunable wide luminescence for white light-emitting diodes

“…7–10 These characteristics afford metal halide perovskites NCs broad applications in light-emitting diodes (LEDs), solar cells, photodetectors, lasers and biological imaging. 11–20 However, three-dimensional (3D) perovskites have the characteristics of ionic crystals wherein wet and hot conditions lead to phase transition and decomposition of the NCs, which greatly limit their applications in optoelectronics. Therefore, researchers have focused on the development of low-dimensional perovskite derivatives.…”

Whole‐genome bisulfite sequencing analysis of circulating tumour DNA for the detection and molecular classification of cancer

“…Notably, screening requires the collection of samples from a large population, whereas early diagnosis requires periodic testing, which is only feasible using non‐invasive methods. Clinical methods for the non‐invasive detection of cancer include medical imaging technologies (such as X‐ray imaging, 2 computed tomography, 3 magnetic resonance imaging, 4 ultrasonic testing 5 and positron emission tomography‐computed tomography 6 ) and serum antigen protein markers. 7 These methods have their strengths; for example medical imaging reveals the location and morphology of tumours, whereas serum antigen protein markers have broad applications.…”