A water-soluble PEGylated RGD-functionalized bisbithiophenyl diketopyrrolopyrrole as a photoacoustic sonophore

Abstract

Photoacoustic imaging presents an innocuous imaging modality with good penetration depth and resolution. To use this modality for detection and imaging of pathological sites, new imaging probes need to be developed to enhance the contrast over endogenous sonophores. These contrast agents should specifically bind to the site of interest, be non-toxic and be cleared renally if applied intravenously. Small organic dyes with absorption in the near infrared spectrum often exhibit good photoacoustic response. However, such dyes are often not water soluble or they are cytotoxic. Here, we present a novel PEGylated sonophore based on diketopyrrolopyrrole (DPP), which overcomes these limitations and can be functionalized with desired biological recognition motifs using thiol-yne click chemistry. Proof of concept is demonstrated by functionalizing the DPP-based probe with an RGD peptide, resulting in specific binding to endothelial (HUVEC) cells and an efficient photoacoustic response.

A comparative analysis of symmetric diketopyrrolopyrrole‐cored small conjugated molecules with aromatic flanks: From geometry to charge transport

“…Although, there is no direct experimental confirmation that this network promotes the charge transport in the system, such molecular design allows for controlled self‐organization of the molecules in the bulk and in 2D. The latter could be especially promising for the construction of smart biomimetic surfaces …”

“…The latter could be especially promising for the construction of smart biomimetic surfaces. [74] For disubstituted Th-DPP-Th, [64,67,75] the trans-trans conformations are detected in experiments. The characteristic distances and dihedrals are similar for measured and predicted in the gas phase (Supporting Information Table SI.2).…”