pH-Responsive globular poly(ethylene glycol) for photodynamic tumor therapy.
In this study, we report the development of extremely small-sized globular poly(ethylene glycol) (gPEG) that can specifically recognize tumor acidic pH. gPEG coupled with chlorin e6 (Ce6, a photosensitizing drug) and 2,3-dimethylmaleic acid (DMA, as a pH-responsive moiety) (gPEG-Ce6-DMA, particle size: 3-4nm in diameter) was easily dispersed in phosphate buffered saline (PBS) without any of the nanoparticle fabrication steps. We observed that gPEG-Ce6-DMA displayed pH-dependent zeta-potential changes due to coupling (at pH 7.4) or decoupling (at pH 6.8-6.0) of DMA. As a result, the uptake of gPEG-Ce6-DMA was significantly increased in tumors at acidic pH, likely due to the decoupling of DMA (backing cationic primary amines). As a result, the preferential cellular uptake of gPEG-Ce6-DMA at acidic pH allowed for a significant enhancement of in vitro/in vivo photodynamic tumor cell ablation under light illumination.
Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
Eun Bi
EB
Ku
Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
Dong Jin
DJ
Lee
Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
Kun
K
Na
Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
Sung-Wook
SW
Choi
School of Pharmacy, Sungkyunkwan University, 300 Chonchon-dong, Jangan-ku, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Yu Seok
YS
Youn
College of Pharmacy, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea.
Soo Kyung
SK
Bae
College of Pharmacy, Chung-Ang University, 221 Heukseok dong, Dongjak-gu, Seoul 155-756, Republic of Korea. Electronic address: kyungoh@cau.ac.kr.
Kyung Taek
KT
Oh
Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro Wonmi-gu, Bucheon-si, Gyeonggi-do 420-743, Republic of Korea. Electronic address: eslee@catholic.ac.kr.
Eun Seong
ES
Lee
D000818:Animals; D045744:Cell Line, Tumor; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy*; D010778:Photochemotherapy; D011092:Polyethylene Glycols / Q000737:chemistry*
D011092:Polyethylene Glycols
2,3-dimethylmaleic acid; Chlorin e6; Globular poly(ethylene glycol); Photodynamic tumor therapy