Versatile Polymer Nanoparticles as Two‐Photon‐Triggered Photosensitizers for Simultaneous Cellular, Deep‐Tissue Imaging, and Photodynamic Therapy

Abstract

Clinical applications of current photodynamic therapy (PDT) photosensitizers (PSs) are often limited by their absorption in the UV-vis range that possesses limited tissue penetration ability, leading to ineffective therapeutic response for deep-seated tumors. Alternatively, two-photon excited PS (TPE-PS) using NIR light triggered is one the most promising candidates for PDT improvement. Herein, multimodal polymer nanoparticles (PNPs) from polythiophene derivative as two-photon fluorescence imaging as well as two-photon-excited PDT agent are developed. The prepared PNPs exhibit excellent water dispersibility, high photostability and pH stability, strong fluorescence brightness, and low dark toxicity. More importantly, the PNPs also possess other outstanding features including: (1) the high O quantum yield; (2) the strong two-photon-induced fluorescence and efficient O generation; (3) the specific accumulation in lysosomes of HeLa cells; and (4) the imaging detection depth up to 2100 µm in the mock tissue under two-photon. The multifunctional PNPs are promising candidates as TPE-PDT agent for simultaneous cellular, deep-tissue imaging, and highly efficient in vivo PDT of cancer.

Two‐Photon‐Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment

“…The potential of 3D‐resolved two‐photon‐actuated nanomedicine has been exploited via various nanomaterials such as semiconductor and carbon nanodots, polymeric, organic, silicon, gold, graphene and graphene oxide, silica hybrid, and other inorganic nanomaterials. What are the advantages of silica‐based nanoparticles?…”

Polymer Dots as Effective Phototheranostic Agents

“…These photosensitizer-CPs exhibited relatively high cross section, low dark 2000] (DSPE-PEG2000) as an encapsulation matrix via one-step nanoprecipitation in our group (Fig. 11a) (90). The Pdots exhibited diameters of 10.2-14.8 nm with a narrow size distribution obtained by dynamic light scatter (DLS) measurement.…”

“…To develop individual nanoparticles rather than hybrids as two‐photon photosensitizer, novel Pdots with intrinsic two‐photon fluorescence and 1 O 2 generation were developed using polythiophene derivatives (PT2) and 2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine N ‐[methoxy(polyethyleneglycol)‐2000] (DSPE‐PEG2000) as an encapsulation matrix via one‐step nanoprecipitation in our group (Fig. a) . The Pdots exhibited diameters of 10.2–14.8 nm with a narrow size distribution obtained by dynamic light scatter (DLS) measurement.…”

“…Scale bar: 100 μm. Reproduced with permission from ref . Copyright 2017 Wiley‐VCH Verlag GmbH & Co. KGaA.…”

Therapeutic Considerations and Conjugated Polymer‐Based Photosensitizers for Photodynamic Therapy

“…Hydrophobic conjugated polymers can form small nanoparticle in the aqueous solutions . Hydrophobic photosensitizers can be doped inside the conjugated polymer nanoparticles for amplified singlet oxygen generation by energy transfer . In these systems, the conjugated polymer efficiently absorbs and transfers the excitation energy to the photosensitizer units, resulting in singlet oxygen generation under both one‐photon or two‐photon excitations.…”