posted on 2022-02-03, 16:10authored byZe Zhang, Yuyang Wu, Nan Lin, Shengyan Yin, Zihui Meng
MicroRNAs (miRNAs) are a class of
small, noncoding RNAs involved
in nearly all genetic central dogma processes and human biological
behavior, which also play a significant role in the pathological activity
of tumors, such as gene transcription, protein translation, and exosome
secretion. Therefore, through the navigation of certain specific miRNAs,
we can trace the specific physiological processes or image some specific
tissues. Designing and accurately positioning microRNA (miRNA)-sensitive
fluorescent nanoprobes with benign specificity and recognition in
cells or tissues are a challenging research field. To solve the difficulties,
we introduce four semiconducting polymer dots (Pdots) as nanoprobes
linked by specific miRNA antisense sequences for monitoring the pathological
grading by the variation in miRNA expression. Based on the base pairing
principle, these miRNA-sensitive Pdots could bind to specific miRNAs
within the cancerous cells. As impacted by the background of different
pathology gradings, the proportions of the four hepatocellular carcinoma
(HCC)-specific miRNAs within the cancerous cell are different, and
the pathological grading of the patient tissues can be determined
by comparing the palette combinations. The short single-stranded RNA-functionalized
Pdots, which have excellent microRNA sensitivity, are observed in
an experimental cell model and a series of tissue specimens from HCC
patients for the first time. Using the Förster (or fluorescence)
resonance energy transfer (FRET) model of Pdots and Cy3dt tag to simulate
in vivo miRNA detection, the superior sensitivity and specificity
of these nanoprobes are verified. The interference of subjective factors
in traditional single/bis-dye emission intensity detection is abandoned,
and multiple label staining is used to enhance sensitivity further
and reduce the false-positive rate. The feasibility exhibited by this
novel staining method is verified in normal hepatocellular HCC cell
lines and 16 frozen ultrathin tissue sections, which are employed
to quantify pathological grading-related color presentation systems
for clinical doctors and pathologists’ use. The intelligently
designed miRNA-guided Pdots will emerge as an ideal platform with
promising biological imaging.