Conjugated polymer nanoparticles, considered as a class of promising nanomaterials for biomedical application, are extensively employed in bioimaging, anti‐microorganism and antitumor, gene and drug ...delivery/release in the past decade. By virtue of unique photoelectric properties, such as strong light absorbing quality, high brightness, good photostability, tunable spectra property, and favorable compatibility, conjugated polymer nanoparticles attract increasing attention and are used in more emerging aspects in biological and biomedical fields. This review summarizes the recent (2014–2018) development of conjugated polymer nanoparticles, including design, synthesis, and biomedical applications. Especially, their abilities of bioimaging, cell activity regulation, anti‐microorganism and antitumor therapy are discussed in detail. Finally, the challenges and outlooks in the field are highlighted.
The development of conjugated polymer nanoparticles is flourishing and fast ranging from molecular design to novel function and biological application. This review summarizes the recent application progress of conjugated polymer nanoparticles, including bioimaging (optical, photoacoustic, Raman), activity regulation (gene expression, ion channel, enzyme activity, photosynthesis), and phototherapy (photodynamic therapy, photothermal therapy, combination therapy), and also gives some outlooks.
In the past few years, conjugated polymer nanoparticles (CPNs) have been successfully prepared and applied in the biological field because of their unique opto-electronic properties. The rapid ...development of CPNs is mainly attributed to their simple synthesis procedures and easy separation steps. The advantages of CPNs include high brightness, excellent photostability, low cytotoxicity, high quantum yield and versatile surface modification. The functionalization of CPNs with specific recognition elements imparts them good ability for targeted recognition and imaging
in vitro
and
in vivo
. CPNs can be applied to deliver drug and gene, and simultaneously to real-time monitor the release process due to their self-luminous characteristics. Moreover, CPNs can sensitize oxygen molecules to generate reactive oxygen species (ROS) which can kill adjacent bacteria and tumor cells. In this
tutorial review
, we provide a recent development of the preparation methods, properties, and functionalization strategies of CPNs, especially discussing their biological applications in targeted imaging, drug/gene delivery and biomedicine. The challenges and outlooks in this field will also be discussed.
This review provides an overview of the latest advancement in preparation, properties, functionalization and biological applications of conjugated polymer nanoparticles.
A couple of fluorescent enantiomers, which are suitable for the emitters of high‐efficiency TADF‐sensitized CP‐OLEDs, have been developed. The enantiomers show configurational stability, high PLQY of ...98 %, large kr of 7.8×107 s−1, and intense CPL activities with |glum| values of about 2.5×10−3. Notably, by using matchable TADF sensitizer, the enantiomers were then exploited as emitter to fabricate CP‐OLEDs. The TADF‐sensitized CP‐OLEDs not only show mirror‐image CPEL activities with gEL values of +1.8×10−3 and −1.4×10−3, but also display fast start‐up featuring with low VT of 3.0 V as well as driving voltage of 4.8 V at 10 000 cd m−2. Meaningfully, the TADF‐sensitized fluorescent devices show high EQEmax of 21.5 % and extremely low efficiency roll‐off, whose EQEs are 21.2 % and 15.3 % at 1000 and 10 000 cd m−2, respectively. The obtained EQEs are comparable to those of CP‐TADF emitters, which provides a promising perspective to break through the EL efficiency limit of CP‐FL emitters.
A couple of fluorescent enantiomers with high PLQY of 98 % and mirror‐imaged CPL activities have been developed to fabricate TADF‐sensitized CP‐OLEDs. The resulting devices not only display intense CPEL with |gEL| of about 1.8×10−3, but also show high EQEmax of 21.5 % with remarkably low efficiency roll‐off, whose EQE is 15.3 % even at 10 000 cd m−2.
It is of great significance to develop effective antibacterial agents and methods to combat drug resistant bacterial infections due to its increasing threaten to human health and the ineffectiveness ...of antibiotics. Herein, a multifunctional hybrid nano-assembly (M1-Fe NPs) based on conjugated oligomer and ferrous ion was engineered with favorable bactericidal activity for synergetic antibacterial therapy. The chelation of ferrous ion not only enhances the photothermal conversion efficiency of M1 but also endows the nano-assembly with catalytic capability of transferring H2O2 into stronger oxidant hydroxyl radicals (•OH). Meanwhile, the generated heat can further promote the Fenton reaction activity. By generating cytotoxic heat and oxidative •OH, M1-Fe NPs can effectively kill Staphylococcus aureus in vitro and in vivo with the aid of low dosage of H2O2. The work provides a new multifunctional platform for combinational drug resistant antibacterial therapy and even antitumor therapy.
A hybrid nano-assembly comprised of conjugated oligomer and ferrous ion is engineered with enhanced photothermal effect and Fenton reaction activity for synergetic photothermal therapy and catalytic chemodynamic therapy of drug resistant bacterial infection.
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A series of amide anthraquinone derivatives, an important component of some traditional Chinese medicines, were structurally modified and the resulting antitumor activities were evaluated. The ...compounds showed potent anti-proliferative activities against eight human cancer cell lines, with no noticeable cytotoxicity towards normal cells. Among the candidate compounds, 1-nitro-2-acyl anthraquinone-leucine (
) showed the greatest inhibition of HCT116 cell activity with an IC
of 17.80 μg/mL. In addition, a correlation model was established in a three-dimensional quantitative structure-activity relationship (3D-QSAR) study using Comparative Molecular Field Analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA). Moreover, compound
effectively killed tumor cells by reactive oxygen species (ROS)-JNK activation, causing an increase in ROS levels, JNK phosphorylation, and mitochondrial stress. Cytochrome c was then released into cytoplasm, which, in turn activated the cysteine protease pathway and ultimately induced tumor cell apoptosis, suggesting a potential use of this compound for colon cancer treatment.
The development of biomolecular fiber materials with imaging ability has become more and more useful for biological applications. In this work, cationic conjugated polymers (CCPs) were used to ...construct inherent fluorescent microfibers with natural biological macromolecules (DNA and histone proteins) through the interfacial polyelectrolyte complexation (IPC) procedure. Isothermal titration microcalorimetry results show that the driving forces for fiber formation are electrostatic and hydrophobic interactions, as well as the release of counterions and bound water molecules. Color‐encoded IPC fibers were also obtained based on the co‐assembly of DNA, histone proteins, and blue‐, green‐, or red‐ (RGB‐) emissive CCPs by tuning the fluorescence resonance energy‐transfer among the CCPs at a single excitation wavelength. The fibers could encapsulate GFP‐coded Escherichia coli BL21, and the expression of GFP proteins was successfully regulated by the external environment of the fibers. These multi‐colored fibers show a great potential in biomedical applications, such as biosensor, delivery, and release of biological molecules and tissue engineering.
Artificial spider silk: Cationic conjugated polymers (CCPs) were used to construct inherent fluorescent microfibers (see picture) with DNA and histone proteins. The color of the fibers could be fine‐tuned by changing the molar ratio of the three different CCPs.
This study optimized the TADF feature of axial chiral enantiomers through precise donor engineering, and multicolor CP-TADF was achieved in the axial chiral framework. Three pairs of axial ...enantiomers with donor-regulated TADF feature, namely (
R/S
)-
TPCBD
, (
R/S
)-
DPCBD
, and (
R/S
)-
DPACBD
, were synthesized by introducing carbazole donors with different substituents onto biphenyl cyanide acceptors. As the electron-donating ability of donors increases, the emission of these axial enantiomers ranges from 455,476 to 552 nm, their singlet-triplet energy gaps (Δ
E
ST
) gradually decrease from 0.30,0.22 to 0.02 eV, accompanied by an increasement in the transition rate (
k
RISC
) of RISC process, and the
k
RISC
of
DPACBD
could reach up to 7.16 × 10
5
s
−1
. These axial enantiomers also exhibit mirror-image CD and circularly polarized luminescence (CPL) properties. Moreover, OLEDs based on
TPCBD, DPCBD
, and
DPACBD
as emitter were then fabricated, which displayed blue, green, and orange electroluminescence with EQE
max
of 13.0%, 16.4%, and 25.0%, respectively. The results also exhibited a phenomenon of device efficiency increasing with the enhancement of donor abilities. Notably, the CP-OLEDs using (
R/S
)-
TPCBD
, (
R/S
)-
DPCBD
and (
R/S
)-
DPACBD
as emitters displayed intense CPEL signals with
g
EL
values of 3.4 × 10
−3
/−4.1 × 10
−3
, 3.2 × 10
−3
/−3.1 × 10
−3
and 2.3 × 10
−3
/−2.1 × 10
−3
, respectively. By convenient molecular engineering of donor regulation in the same molecular skeleton, CP-TADF materials with multicolor CPEL and improved device performance could be conveniently achieved.
A highly selective switch for
d-fructose was formed by water-soluble conjugated polymer PP-
S-BINOL and tetraboronic acid functionalized benzyl viologen T
oBV. The two-component system showed a high ...selectivity and sensitivity only for
d-fructose in familiar
d-monosaccharides. The high selectivity of the sensing system for
d-fructose may be depended on stable pyranose ester form of
d-fructose with T
oBV. A desirable linear response of the sensing system to low concentrations of
d-fructose (<10.0 mM) was observed with 0.9936 linear dependent coefficient at pH 7.4.
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Diseases induced by bacterial infections increasingly threaten the health of people all over the world; thus, it is urgent and significant to early diagnose and effectively eliminate infections to ...save people’s lives. To this end, we synthesized an intelligent hydrogel that integrated in situ visualized diagnosis and photothermal therapy of bacterial infections. By simply and subtly incorporating pH-sensitive bromothymol blue (BTB) and near-infrared (NIR)-absorbing conjugated polymer (termed as PTDBD) into thermosensitive chitosan (CS)-based hydrogel, the synthesized BTB/PTDBD/CS hydrogel can diagnose the acidic microenvironment of Staphylococcus aureus (S. aureus) biofilm and infected wounds by showing visualized color change. After rapid diagnosis, the hydrogel can immediately treat the infection site by local hyperthermia under irradiation of NIR laser (808 nm) and even the stubborn biofilm that is difficult to eradicate. Since the dominating antibacterial mechanism is hyperthermia, the hybrid hydrogel shows broad-spectrum antibacterial activity against Gram-positive, Gram-negative, and drug-resistant bacteria. In addition, it has low cytotoxicity to normal cells and no effect on the main organs of mice. It paves a brand new avenue to develop smart and facile diagnosis and a treatment platform for bacterial infections.
The trade‐off between the open‐circuit voltage (Voc) and short‐circuit current density (Jsc) has become the core of current organic photovoltaic research, and realizing the minimum energy offsets ...that can guarantee effective charge generation is strongly desired for high‐performance systems. Herein, a high‐performance ternary solar cell with a power conversion efficiency of over 18% using a large‐bandgap polymer donor, PM6, and a small‐bandgap alloy acceptor containing two structurally similar nonfullerene acceptors (Y6 and AQx‐3) is reported. This system can take full advantage of solar irradiation and forms a favorable morphology. By varying the ratio of the two acceptors, delicate regulation of the energy levels of the alloy acceptor is achieved, thereby affecting the charge dynamics in the devices. The optimal ternary device exhibits more efficient hole transfer and exciton separation than the PM6:AQx‐3‐based system and reduced energy loss compared with the PM6:Y6‐based system, contributing to better performance. Such a “two‐in‐one” alloy strategy, which synergizes two highly compatible acceptors, provides a promising path for boosting the photovoltaic performance of devices.
A “two‐in‐one” strategy is applied to form an acceptor alloy for fine‐tuning the donor/acceptor energy alignment and blend morphology. Enhanced hole transfer and suppressed charge recombination in the alloy acceptor consisting of AQx‐3 and Y6 enable a power conversion efficiency of over 18%, which is the highest documented for ternary organic solar cells utilizing two nonfullerene acceptors.