Highly Magnetized Encoded Hydrogel Microparticles with Enhanced Rinsing Capabilities for Efficient microRNA Detection.

Wookyoung Jang,Ki Wan Bong,Seok Joon Mun,Jiwoo Kim,Sun Min Kim

doi:10.3390/biomedicines9070848

Abstract

Encoded hydrogel microparticles mounting DNA probes are powerful tools for high-performance microRNA (miRNA) detection in terms of sensitivity, specificity, and multiplex detection capability. However, several particle rinsing steps in the assay procedure present challenges for rapid and efficient detection. To overcome this limitation, we encapsulated dense magnetic nanoparticles to reduce the rinsing steps and duration via magnetic separation. A large number of magnetic nanoparticles were encapsulated into hydrogel microparticles based on a discontinuous dewetting technique combined with degassed micromolding lithography. In addition, we attached DNA probes targeting three types of miRNAs related to preeclampsia to magnetically encoded hydrogel microparticles by post-synthesis conjugation and achieved sensitivity comparable to that of conventional nonmagnetic encoded hydrogel microparticles. To demonstrate the multiplex capability of magnetically encoded hydrogel microparticles while maintaining the advantages of the simplified rinsing process when addressing multiple samples, we conducted a triplex detection of preeclampsia-related miRNAs. In conclusion, the introduction of magnetically encoded hydrogel microparticles not only allowed efficient miRNA detection but also provided comparable sensitivity and multiplexed detectability to conventional nonmagnetic encoded hydrogel microparticles.

Highlights

MicroRNAs are endogenous small fragments of noncoding RNAs that regulate gene expression by decreasing the accessibility of translation modules to mRNAs or through the degradation of mRNAs [1,2]
We demonstrated that the detection limit was comparable to that in previous miRNA detection studies based on nonmagnetic hydrogel microparticles
To synthesize graphically encoded magnetic hydrogel microparticles, magnetic nanoparticles (MNPs) were incorporated into the precursor liquid comprising photoinitiator Darocur 1173 and the crosslinker PEGDA

Summary

Introduction

MicroRNAs (miRNAs) are endogenous small fragments of noncoding RNAs that regulate gene expression by decreasing the accessibility of translation modules to mRNAs or through the degradation of mRNAs [1,2]. Considering the importance of miRNA detection for the diagnosis of various diseases, diverse techniques such as microarray detection [8], quantitative reverse transcription polymerase chain reaction (qRT-PCR) [9], northern blotting [10], and next-generation sequencing (NGS) [11,12] have been developed. These techniques have shortcomings in high-performance miRNA detection. The detection of short-length miRNAs is challenging with the microarray technique, which may be limited in the specific detection of multiple miRNA targets with similar sequences [13]. qRT-PCR lacks multiplex capability, owing to complicated primer design, and requires expensive costs [8,13]

Methods

Results

Conclusion