Folate-PEG-CKK₂-DTPA, A Potential Carrier for Lymph-Metastasized Tumor Targeting

Gu, Bing
Xie, Cao
Zhu, Jianhua
He, Wei
Lu, Weiyue

¹School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China
²Department of Nuclear Medicine, Huadong Hospital, Shanghai 200040, China

Received: 15 October 2009/Accepted: 22 February 2010/Published online: 11 March 2010

ABBREVIATIONS BCS, Bull Calf Serum; CKK₂, cysteine-L-lysine-(L-lysine)₂; DIPEA, N,N-Diisopropylethylamine; DMSO, dimethyl sulfoxide; DTPA, diethylenetriaminepentaacetic acid; EDA, Ethylenediamine; EDC·HCl, 1-Ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride; FBS, Fetal bovine serum; FITC, Fluorescein-5-isothiocyanate; FR, Folate receptor; HBTU, O-Benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluorophosphate; HF, hydrogen fluoride; HOBT, Hydroxybenzotriazole; HPLC, high-performance liquid chromatography; KB, human oral epidermoid carcinoma; Mal-PEG-NHS, maleimide-polyethyl glycol-succinimidyl ester; ROI, Region of Interest; SPECT, Single-Photon-Emission Computed Tomography; TFA, trifluoacetic acid; ¹H NMR, ¹H nuclear magnetic resonance

Pharmaceutical Research 27(5):p 933-942, May 2010. | DOI: 10.1007/s11095-010-0100-3

ABSTRACT

Purpose

A novel conjugate, Folate-PEG-CKK₂-DTPA, was designed and prepared as a carrier for lymphatic metastasized tumor imaging diagnosis and targeting therapy.

Methods

Folate-PEG-CKK₂-DTPA was synthesized and characterized by analysis High Performance Liquid Chromatography, Size Exclusive Chromatography and ¹H-NMR. ^99mTc-labeled conjugation was prepared, and in vivo quantitative biodistribution and SPECT imaging were studied after subcutaneously injected into the rats and rabbits, respectively. Cell uptake study was carried in a KB cell line using fluorescent methods. In vivo and ex vivo fluorescent imaging study was carried in tumor-bearing nude mouse to evaluate its targeting ability.

Results

Folate-PEG-CKK₂-DTPA was synthesized with high purity. Both in vivo biodistribution study and SPECT imaging study show the rapid direction and high distribution of the conjugation to the lymph nodes. The uptake of fluorescence-labeled Folate-PEG-CKK₂-DTPA in human oral epidermis carcinoma cells was observed. In vivo and ex vivo fluorescent imaging study indicated it could accumulate in tumor region after vein tail injection in nude mouse.

Conclusions