Biocompatible Conjugated Polymer Nanoparticles for Efficient Photothermal Tumor Therapy

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2015-04, Vol.11 (13), p.1603-1610
• Main Authors: Geng, Junlong, Sun, Chunyang, Liu, Jie, Liao, Lun-De, Yuan, Youyong, Thakor, Nitish, Wang, Jun, Liu, Bin
• Format: Article
• Language: English
• Subjects: Absorption; Biocompatibility; Biocompatible Materials; Cancer; cancer therapy; conjugated polymers; Encapsulation; HeLa Cells; Humans; Nanoparticles; Nanoparticles - therapeutic use; Nanotechnology; near-infrared absorption; organic nanoparticles; Phototherapy; photothermal therapy; Polymers - therapeutic use; Spectrophotometry, Ultraviolet; Surgical implants; Therapy; Tumors
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201402092

Conjugated polymers (CPs) with strong near‐infrared (NIR) absorption and high heat conversion efficiency have emerged as a new generation of photothermal therapy (PTT) agents for cancer therapy. An efficient strategy to design NIR absorbing CPs with good water dispersibility is essential to achieve excellent therapeutic effect. In this work, poly[9,9‐bis(4‐(2‐ethylhexyl)phenyl)fluorene‐alt‐co‐6,7‐bis(4‐(hexyloxy)phenyl)‐4,9‐di(thiophen‐2‐yl)‐thiadiazoloquinoxaline] (PFTTQ) is synthesized through the combination of donor–acceptor moieties by Suzuki polymerization. PFTTQ nanoparticles (NPs) are fabricated through a precipitation approach using 1,2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethylene glycol)‐2000] (DSPE‐PEG2000) as the encapsulation matrix. Due to the large NIR absorption coefficient (3.6 L g‐1 cm‐1), the temperature of PFTTQ NP suspension (0.5 mg/mL) could be rapidly increased to more than 50 °C upon continuous 808 nm laser irradiation (0.75 W/cm2) for 5 min. The PFTTQ NPs show good biocompatibility to both MDA‐MB‐231 cells and Hela cells at 400 μg/mL of NPs, while upon laser irradiation, effective cancer cell killing is observed at a NP concentration of 50 μg/mL. Moreover, PFTTQ NPs could efficiently ablate tumor in in vivo study using a Hela tumor mouse model. Considering the large amount of NIR absorbing CPs available, the general encapsulation strategy will enable the development of more efficient PTT agents for cancer or tumor therapy. An efficient conjugated polymer based photothermal agent is developed by a facile precipitation apporach utilzing DSPE‐PEG2000 as the encapsulation matrix. The obtained nanoparticles exhibit strong NIR absorption, excellent photostability, superb biocompatibility, and high photothermal conversion efficiency, which show good cancer therapeutic effect in both in vitro and in vivo studies.