The chemical structure of end groups influenced the phase transition temperature of thermoresponsive polymers. We demonstrated a strategy for the preparation of the pH/thermo-responsive polymeric nanoparticles via sub...The chemical structure of end groups influenced the phase transition temperature of thermoresponsive polymers. We demonstrated a strategy for the preparation of the pH/thermo-responsive polymeric nanoparticles via subtle modification of end groups of thermoresponsive polymer segments with a carboxyl group and revealed its potential application for enhanced intracellular drug delivery. By developing a polymeric nanoparticle composed of poly(aliphatic ester) as the inner core and thermoresponsive polyphosphoester as the outer shell, we showed that end groups of thermoresponsive polyphosphoester segments modified by carboxyl groups exhibited a pH/thermo-responsive behavior due to the hydrophilic to hydrophobic transitions of the end groups in response to the pH. Moreover, by encapsulating doxorubicin into the hydrophobic core of such pH/thermo-responsive polymer nanoparticles, their intracellular delivery and cytotoxicity to wild-type and drug-resistant tumor cells were significantly enhanced through the phase-transition-dependent drug release that was triggered by endosomal/lysosomal pH. This novel strategy and the multi-responsive polymer nanoparticles achieved by the subtle chain-terminal modification of thermoresponsive polymers provide a smart platform for biomedical applications.展开更多
Over the past years, significant efforts have been devoted to explore novel drug delivery and detection strategies for simultaneous therapy and diagnostics. The development of biotinylated polyurethane-urea nanopartic...Over the past years, significant efforts have been devoted to explore novel drug delivery and detection strategies for simultaneous therapy and diagnostics. The development of biotinylated polyurethane-urea nanoparticles as theranostic nanocarriers for targeted drug and plasmid delivery, for fluorescence detection of human hepatocellular carcinoma cells, is described herein. These targeted nanoparticles are specifically designed to incorporate biotin into the polymeric matrix, since many tumor types overexpress receptors for biotin as a mechanism to boost uncontrolled cell growth. The obtained nanoparticles were spherical, exhibited an average diameter ranging 110-145 nm, and showed no cytotoxicity in healthy endothelial cells. Biotinylated nanoparticles are selectively incorporated into the perinuclear and nuclear area of the human hepatocellular carcinoma cell line, HepG2, in division, but not into growing, healthy, human endothelial cells. Indeed, the simultaneous incorporation of the anticancer drugs, phenoxodiol or sunitinib, together with plasmid DNA encoding green fluorescent protein, into these nanoparticles allows a targeted pharmacological antitumor effect and furthermore, selective transfection of a reporter gene, to detect these cancer cells. The combined targeted therapy and detection strategy described here could be exploited for liver cancer therapy and diagnostics, with a moderate safety profile, and may also be a potential tool for other types of cancer.展开更多
基金supported by the Ministry of Science and Technology of China(2010CB934001)the National Natural Science Foundation of China(51125012,51203145)
文摘The chemical structure of end groups influenced the phase transition temperature of thermoresponsive polymers. We demonstrated a strategy for the preparation of the pH/thermo-responsive polymeric nanoparticles via subtle modification of end groups of thermoresponsive polymer segments with a carboxyl group and revealed its potential application for enhanced intracellular drug delivery. By developing a polymeric nanoparticle composed of poly(aliphatic ester) as the inner core and thermoresponsive polyphosphoester as the outer shell, we showed that end groups of thermoresponsive polyphosphoester segments modified by carboxyl groups exhibited a pH/thermo-responsive behavior due to the hydrophilic to hydrophobic transitions of the end groups in response to the pH. Moreover, by encapsulating doxorubicin into the hydrophobic core of such pH/thermo-responsive polymer nanoparticles, their intracellular delivery and cytotoxicity to wild-type and drug-resistant tumor cells were significantly enhanced through the phase-transition-dependent drug release that was triggered by endosomal/lysosomal pH. This novel strategy and the multi-responsive polymer nanoparticles achieved by the subtle chain-terminal modification of thermoresponsive polymers provide a smart platform for biomedical applications.
文摘Over the past years, significant efforts have been devoted to explore novel drug delivery and detection strategies for simultaneous therapy and diagnostics. The development of biotinylated polyurethane-urea nanoparticles as theranostic nanocarriers for targeted drug and plasmid delivery, for fluorescence detection of human hepatocellular carcinoma cells, is described herein. These targeted nanoparticles are specifically designed to incorporate biotin into the polymeric matrix, since many tumor types overexpress receptors for biotin as a mechanism to boost uncontrolled cell growth. The obtained nanoparticles were spherical, exhibited an average diameter ranging 110-145 nm, and showed no cytotoxicity in healthy endothelial cells. Biotinylated nanoparticles are selectively incorporated into the perinuclear and nuclear area of the human hepatocellular carcinoma cell line, HepG2, in division, but not into growing, healthy, human endothelial cells. Indeed, the simultaneous incorporation of the anticancer drugs, phenoxodiol or sunitinib, together with plasmid DNA encoding green fluorescent protein, into these nanoparticles allows a targeted pharmacological antitumor effect and furthermore, selective transfection of a reporter gene, to detect these cancer cells. The combined targeted therapy and detection strategy described here could be exploited for liver cancer therapy and diagnostics, with a moderate safety profile, and may also be a potential tool for other types of cancer.
