Scientific REPORTs | (2018) 8:4393 | DOI:10.1038/s41598-018-22828-2
nanoparticles as a probe for
zebrash sensory hair cells targeted
in vivo imaging
Gyo Eun Gu
, Chul Soon Park
, Hyun-Ju Cho
, Tai Hwan Ha
, Joonwon Bae
, Oh Seok
, Jeong-Soo Lee
& Chang-Soo Lee
Fluorescent polydopamine nanoparticles (FPNPs) are prepared via the ethylenediamine (EDA)-induced
degradation of as-prepared non-uorescent polydopamine (PDA) and used for targeted bioimaging.
The reductive treatment of PDA in the presence of EDA yields uorescent precipitates, inspiring us
to seek various biological approaches to preparing FPNPs with excellent optical and biocompatible
properties. Moreover, we rstly found that FPNPs selectively label neuromast hair cells in the lateral
line of zebrash, their applications as a reliable uorescent indicator to investigate the neuromast
hair cells, to in turn determine the viability of hair cells, was demonstrated. FPNPs also provided a
minimal toxicity enable to assay the number of functional hair cells per neuromast in live animals as
development proceeds. Upon combined incubation with TO-PRO-3, a well-established hair cell marker,
all hair cells that were rapidly labeled with FPNPs were observed to be also completely labeled with
the TO-PRO-3, labeling hair cells in neuromasts positioned in the supraorbital, otic and occipital lateral
line as well as in posterior lateral line of living zebrash larvae. Their potential ecacy for biological
applications was demonstrated by their excellent optical and biocompatible properties, oering new
opportunities in cancer research, real-time monitoring of stem cell transplantation and other cell-based
e use of self-assembled monodisperse π-conjugated oligomers is regarded as one of the most useful strate-
gies for the preparation of uorescent nanoparticles
. However, their structures are unstable, and the strong
hydrophobic interactions of uorescent nanoparticles in water oen decreases their uorescence quantum yield,
severely restricting their use in practical biomedical applications
. ere is therefore still a requirement for new
approaches to the development of novel uorescent nanoparticles to overcome these limitations
Dopamine (DA) fulls several important functions as a neurotransmitter in the brain, and can self-polymerize
from the oxidation of catechol under alkaline conditions to generate polydopamine (PDA)
, forming a hydro-
philic coating that strongly adheres to bulk materials with various shapes and surface properties
the excellent physicochemical and biocompatible properties of PDA particles make this molecule suitable for
investigation of various applications, including surface modication, bio-inspired hydrogels, metal deposition
and drug delivery, besides being used as a coating material
. Although uorescent polydopamine nanopar-
ticles (FPNPs) have similar biocompatibility and uorescence properties, few studies on PDA particles-based
uorescent nanoparticles have been reported thus far, compared to other uorescent nanoparticles.
Hazards Monitoring BNT Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125
Gwahak-ro, Yuseong-gu, Daejeon, 34141, South Korea.
Disease Target Structure Research Center, Korea Research
Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon, 34141, South Korea.
Department of Biotechnology, University of Science & Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon,
34113, South Korea.
Department of Polymer Engineering, Graduate School, Chonnam National University,
Gwangju, 61186, South Korea.
Department of Applied Chemistry, Dongduk Women’s University, 60 Hwarang-ro
13-gil, Seongbuk-gu, Seoul, 02748, South Korea. Gyo Eun Gu, Chul Soon Park and Hyun-Ju Cho contributed equally
to this work. Correspondence and requests for materials should be addressed to J.-S.L. (email: jeongsoo@kribb.
re.kr) or C.-S.L. (email: firstname.lastname@example.org)
Received: 16 November 2017
Accepted: 1 March 2018
Published: xx xx xxxx