Infrared emitting and absorbing conjugated polymer nanoparticles as biological imaging probes

Abstract

We discuss the synthesis of infrared-emitting conjugated polymer nanoparticles and their use in biological imaging. The image shows the vasculature of a mouse brain imaged with conjugated polymer nanoparticles (M. Liu et al., Angew. Chem., Int. Ed., 2021, 60, 983–989).

π-Conjugated Polymer Nanoparticles from Design, Synthesis to Biomedical Applications: Sensing, Imaging, and Therapy

“…It is widely used in a broad variety of preclinical investigations for the visualization of biological processes and provides cellular and subcellular resolution and image enhancement in 3D and real time in a non-destructive way. As a result, fluorescence-based diagnosis of diseases and fluorescence-image-guided surgery found many real applications in human disease diagnosis [ 3 , 83 ]. Nevertheless, the future search for improved cost-effective, time-dependent and safe bioimaging techniques with excellent resolution is still ongoing.…”

“…In the last decade, CPNs have surpassed conventional organic dyes and become a new class of probe materials for bioimaging due to their excellent photostability and high fluorescence brightness. Alongside with their applications in imaging, CPNs are appealing for cell culture research because of their beneficial intrinsic properties such as low cytotoxicity, inertness to intracellular processes, and their high resistance to bleaching and easy chemical functionalization [ 83 , 86 ]. For potential in vivo applications, CPNs should meet certain requirements including an ideal size range, as they are small enough to allow access to smaller capillary blood vessels and large enough to not be cleared immediately, which impacts therapeutic strategies, surface charges, cell viability and the associated pharmacokinetics.…”

Far-Red to Near-Infrared Emission from Conjugated Polymers with High Density of Excited States Based on a Boron Tropolonate Complex as an Electron Acceptor

“…Conjugated polymers are known to have fruitful photophysical and electronic properties derived from the π-conjugation over their main chains. , Particularly, donor–acceptor-conjugated systems are attractive to developing narrow energy gap materials − and semiconducting polymers with high charge mobility. , The direct connection of an electron donor and acceptor leads to the narrow energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of polymers and to the strong interchain interactions originating from its alternately polarized feature. , These polymers can be applied to FR and NIR emissive materials, − organic solar cells, and other electronic devices. , FR/NIR emission is highly important for biological and optoelectronic applications. For example, FR light promotes extension growth in plants, , and NIR-emitting materials are needed for bioimaging and phototheranostics because of its intrinsic high biopermeability. , To improve and tune the properties of these polymers, the developments of novel donors and acceptors are extremely significant.…”

Dansyl‐tagged xanthate ester as a capping agent to synthesize fluorescent silver nanoparticles with binding affinity toward serum albumin

“…[1][2][3][4] Nanoparticles with multifunctional properties are crucial for applications in imaging, drug delivery, and early diagnosis of disease. [5][6][7][8][9][10][11] Although the properties of nanoparticles depend on various factors, most of the significant properties, for example, stability, surface area, size, and shape are contributed by the capping agent, therefore selection of capping agent is important. [12][13][14] AgNPs are significantly more important than other metal nanoparticles due to interesting characteristics like relatively low manufacturing costs, high stability, better bio-combability, high antibacterial, and anticancer properties, and most importantly, high versatility over shapes like sphere, rod, and triangle and size.…”

“…The properties of nanoparticles change based on their composition, shape, size, and surface characteristics 1–4 . Nanoparticles with multifunctional properties are crucial for applications in imaging, drug delivery, and early diagnosis of disease 5–11 . Although the properties of nanoparticles depend on various factors, most of the significant properties, for example, stability, surface area, size, and shape are contributed by the capping agent, therefore selection of capping agent is important 12–14 .…”