An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucl...An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.展开更多
Targeted drug delivery coupled with rapid drug release in cytoplasm is a powerful strategy to enhance efficacy and reduce off-target effects of anti-cancer drugs. Herein, we describe a dual-functional mixed micellar s...Targeted drug delivery coupled with rapid drug release in cytoplasm is a powerful strategy to enhance efficacy and reduce off-target effects of anti-cancer drugs. Herein, we describe a dual-functional mixed micellar system consisting of a pH-responsive copolymer D-α-tocopheryl polyethylene glycol 1000-block- poly-（β-amino ester） （TPGS-b-PBAE, TP） and AS1411 aptamer （Apt） decorated TPGS polymer （Apt-TPGS）, which recognizes the over-expressed nucleolin on the plasma membrane of cancer cells. The anti-cancer drug paclitaxel （PTX） was encapsulated in the Apt-mixed micelles, and these drug-loaded micelles had a suitable particle size and zeta potential of 116.3 nm ± 12.4 nm and -26.2 mV ±4.2 mV, respectively. PTX/Apt-mixed micelles were stable at pH 7.4, but they dissociated and quickly released the encapsulated PTX in a weakly acidic environment （pH 5.5）. Compared with non-Apt modified mixed micelles, more Apt-modified mixed micelles were internalized in SKOV3 ovarian cancer cells, whereas no significant difference in cellular uptake was observed in normal cells （LO2 cells）. The enhanced transmembrane ability of Apt-modified mixed micelles was achieved through Apt-nucleolin interaction. With a synergistic effect of cancer cell recognition and pH-sensitive drug release, we observed significantly increased cytotoxicity and G2/M phase arrest against SKOV3 cells by PTX/ Apt-mixed micelles. Intravenous administration of PTX/Apt-mixed micelles for 16 days significantly increased tumor accumulation of PTX, inhibited tumor growth, and reduced myelosuppression on tumor-bearing mice compared with free PTX injection. Therefore, this dual-functional Apt-mixed micellar system is a promising drug delivery system for targeted cancer therapy.展开更多
基金the Ministry of Science and Technology of China(Grant No.2012CB720604)National Natural Science Foundation of China(Grant No.21332010)
文摘An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi＇om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.
文摘Targeted drug delivery coupled with rapid drug release in cytoplasm is a powerful strategy to enhance efficacy and reduce off-target effects of anti-cancer drugs. Herein, we describe a dual-functional mixed micellar system consisting of a pH-responsive copolymer D-α-tocopheryl polyethylene glycol 1000-block- poly-（β-amino ester） （TPGS-b-PBAE, TP） and AS1411 aptamer （Apt） decorated TPGS polymer （Apt-TPGS）, which recognizes the over-expressed nucleolin on the plasma membrane of cancer cells. The anti-cancer drug paclitaxel （PTX） was encapsulated in the Apt-mixed micelles, and these drug-loaded micelles had a suitable particle size and zeta potential of 116.3 nm ± 12.4 nm and -26.2 mV ±4.2 mV, respectively. PTX/Apt-mixed micelles were stable at pH 7.4, but they dissociated and quickly released the encapsulated PTX in a weakly acidic environment （pH 5.5）. Compared with non-Apt modified mixed micelles, more Apt-modified mixed micelles were internalized in SKOV3 ovarian cancer cells, whereas no significant difference in cellular uptake was observed in normal cells （LO2 cells）. The enhanced transmembrane ability of Apt-modified mixed micelles was achieved through Apt-nucleolin interaction. With a synergistic effect of cancer cell recognition and pH-sensitive drug release, we observed significantly increased cytotoxicity and G2/M phase arrest against SKOV3 cells by PTX/ Apt-mixed micelles. Intravenous administration of PTX/Apt-mixed micelles for 16 days significantly increased tumor accumulation of PTX, inhibited tumor growth, and reduced myelosuppression on tumor-bearing mice compared with free PTX injection. Therefore, this dual-functional Apt-mixed micellar system is a promising drug delivery system for targeted cancer therapy.
