Conjugated Polymer Nanoparticles toward In Vivo Theranostics – Focus on Targeting, Imaging, Therapy, and the Importance of Clearance

Abstract

Conjugated polymer nanoparticles are highly fluorescent colloids with tunable emission colors ranging from the visible deep into the near infrared spectrum. Conjugated polymer nanoparticles are easy to prepare, tunable in their size, and virtually nonbleachable. Conjugated polymer particles can also be designed to give off heat upon irradiation. All these properties make conjugated polymer particles ideal materials for biomedical fluorescence and photoacoustic imaging as well as for theranostic applications. Here, different examples of surface functionalization to attach pathological homing devices, imaging modalities, as well as the emerging possibilities for therapeutic measures are discussed. Furthermore, clearance of the particles is considered, which is important to ultimately apply the materials for in vivo theranostics. Due to the conjugated backbone of the conjugated polymers, established degradation strategies, as known from hydrophilic nonconjugated polymer carriers, cannot be applied. Bioinspired strategies and potential pathways for degradation and clearance via structural changes upon triggers such as pH, oxidation, and temperature are also discussed in this progress report.

Molecular Engineering of Photoacoustic Performance by Chalcogenide Variation in Conjugated Polymer Nanoparticles for Brain Vascular Imaging

“…PDTPBD, PDTPBT, and PDTPBSe NPs showed 74%, 50%, and 43% higher PA intensity than those obtained before NP injection, indicating the strong PA generation ability of the NPs. Then, the PA signals decreased to the value equal to the background because of the accumulation of CPNs in liver and spleen tissues through the reticuloendothelial system uptake . The results obtained at 800 nm exhibited similar trends as that obtained at 700 nm (Figure b).…”

“…Then, the PA signals decreased to the value equal to the background because of the accumulation of CPNs in liver and spleen tissues through the reticuloendothelial system uptake. [39,[57][58][59] The results obtained at 800 nm exhibited similar trends as that obtained at 700 nm (Figure 6b). Among these three NPs, PDTPBD NPs showed the best performance, which is in accordance with the in vitro PA signal measurement.…”

π-Conjugated nanostructured materials: preparation, properties and photonic applications

“…Because of these features, these materials have been used in a wide range of optoelectronic and biomedical applications. [15][16][17][18][19][20][21][22] Accordingly, this review provides an overview of recent works on p-conjugated oligomer-and polymer-based nanostructured materials and focuses on their preparation, properties, light harvesting and energy transfer properties, and their photonic applications. A brief section on their applications in bionanotechnology is also included.…”

Unity Makes Strength: How Aggregation‐Induced Emission Luminogens Advance the Biomedical Field

“…During the past decades, there has been a surge in biomedical research employing state‐of‐the‐art imaging techniques to monitor complicated biological processes and understand the mechanism of diseases for promoting breakthrough theranostic approaches . Fluorescence imaging has become one of the most popular bioimaging techniques due to its native merits of superb sensitivity, simplicity, high temporal resolution, rapid responsiveness, and maneuverability . As a key component in fluorescence imaging, the development of advanced fluorescent theranostic agents has emerged as one of the most exciting research fields to provide new opportunities for precise and personalized medical treatment of patients .…”