A novel tumor targeting drug carrier for optical imaging and therapy.
Human serum albumin (HSA), a naturally abundant protein in blood plasma and tissue fluids, has an extraordinary ligand-binding capacity and is advocated as a drug carrier to facilitate drug delivery. To render it tumor targeting specificity, we generated a recombinant HSA fused with the amino-terminal fragment (ATF) of urokinase, allowing the fusion protein to bind to urokinase receptor (uPAR), which is shown to have a high expression level in many tumors, but not in normal tissues. To test the efficacy of this bifunctional protein (ATF-HSA), a hydrophobic photosensitizer (mono-substituted β-carboxy phthalocyanine zinc, CPZ) was chosen as a cytotoxic agent. A dilution-incubation-purification (DIP) strategy was developed to load the ATF-HSA with this CPZ, forming a 1:1 molecular complex (ATF-HSA:CPZ). We demonstrated that CPZ was indeed embedded inside ATF-HSA at the fatty acid binding site 1 (FA1) of HSA, giving a hydrodynamic radius of 7.5 nm, close to HSA's (6.5 nm). ATF-HSA:CPZ showed high stability and remarkable optical and photophysical properties in aqueous solution. In addition, the molecular complex ATF-HSA:CPZ can bind to recombinant uPAR in vitro and uPAR on tumor cell surfaces, and was efficient in photodynamic killing of tumor cells. The tumor-killing potency of this molecular complex was further demonstrated in a tumor-bearing mouse model at a dose of 0.080 μmol / kg, or 0.050 mg CPZ / kg of mouse body weight. Using fluorescent molecular tomography (FMT), ATF-HSA:CPZ was shown to accumulate specifically in tumors, and importantly, such tumor retention was higher than that of HSA:CPZ. Together, these results indicate that ATF-HSA:CPZ is not only an efficient tumor-specific cytotoxic agent, but also an useful tumor-specific imaging probe. This bifunctional protein ATF-HSA can also be used as a drug carrier for other types of cytotoxic or imaging agents to render them specificity for uPAR-expressing tumors.
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China; ; 4. University of Chinese Academy of Sciences, Beijing, 100049, China.
Rui
R
Li
3. College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian, 350002, China;
Ke
K
Zheng
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
Ping
P
Hu
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China; ; 4. University of Chinese Academy of Sciences, Beijing, 100049, China.
Zhuo
Z
Chen
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
Shanyong
S
Zhou
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
Jincan
J
Chen
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
Cai
C
Yuan
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China; ; 4. University of Chinese Academy of Sciences, Beijing, 100049, China.
Song
S
Chen
2. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
Wei
W
Zheng
2. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China;
En
E
Ma
3. College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian, 350002, China;
Fengling
F
Zhang
3. College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou, Fujian, 350002, China;
Jinping
J
Xue
2. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China; ; 4. University of Chinese Academy of Sciences, Beijing, 100049, China.
Xueyuan
X
Chen
1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China; ; 4. University of Chinese Academy of Sciences, Beijing, 100049, China.
Mingdong
M
Huang
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000737:chemistry* / Q000493:pharmacokinetics / Q000627:therapeutic use; D006801:Humans; D007211:Indoles / Q000737:chemistry; D054833:Isoindoles; D008297:Male; D051379:Mice; D009374:Neoplasms, Experimental / Q000175:diagnosis / Q000188:drug therapy*; D009942:Organometallic Compounds / Q000737:chemistry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D012709:Serum Albumin / Q000737:chemistry / Q000235:genetics; D041622:Tomography, Optical; D014568:Urokinase-Type Plasminogen Activator / Q000737:chemistry / Q000235:genetics; D017967:Zinc Compounds
D000970:Antineoplastic Agents; D004337:Drug Carriers; D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D011994:Recombinant Proteins; D012709:Serum Albumin; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine; D014568:Urokinase-Type Plasminogen Activator
amino-terminal fragment of urokinase; fluorescent molecular tomography.; human serum albumin; phthalocyanine zinc; tumor targeting; urokinase receptor