RESUMO
Enhancing blood flow to tumors is a prominent strategy for improving the tumor accumulation of macromolecular drugs through the enhanced permeability and retention (EPR) effect. IRL-1620 is an agonist of the endothelin B receptor, and is a promising molecule to enhance tumor blood flow by activating endothelial nitric oxide synthase. However, contradictory effects on tumor blood flow modulation have been reported because the effects of IRL-1620 may differ in different animal models. Here, we examined for the first time the effect of IRL-1620 on the EPR effect for PEGylated liposomes in a CT-26 murine colon cancer model. Co-injection of IRL-1620 at an optimum dose (3 nmol/kg) nearly doubled the tumor accumulation of liposomes compared with controls, indicating that IRL-1620 enhanced the EPR effect in the present colon cancer model. Co-injection of IRL-1620 is a promising strategy to improve the therapeutic effects of macromolecular drugs while reducing their side effects.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Neoplasias do Colo/tratamento farmacológico , Antagonistas do Receptor de Endotelina B/administração & dosagem , Endotelinas/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Linhagem Celular Tumoral/transplante , Colo/patologia , Neoplasias do Colo/irrigação sanguínea , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Lipossomos , Masculino , Camundongos , Permeabilidade/efeitos dos fármacos , Receptor de Endotelina B/metabolismoRESUMO
Development of highly effective approaches to desirable photothermal conversion agents is particularly valuable. Herein, we report a concept, namely, bond stretching vibration-induced photothermy, that serves as a mechanism to construct advanced photothermal conversion agents. As a proof-of-concept, two compounds (DCP-TPA and DCP-PTPA) with donor-acceptor (D-A) structures were synthesized. The bond stretching vibration of the pyrazine-containing unit in these molecules is vigorous and insensitive to the external environmental restraint, which efficiently transforms the absorbed photons to dark-state heat energy. The nanoparticles (NPs) of DCP-TPA and DCP-PTPA show rather high photothermal conversion efficiency (52% and 59%) and stronger photoacoustic (PA) signal than commercial methylene blue and reported high-performance semiconducting polymer nanoparticles. The DCP-PTPA NPs perform better than DCP-TPA NPs in terms of photothermal conversion, PA signal production, and in vivo PA tumor imaging because of the increased bond stretching vibration in the former molecule.
Assuntos
Nanopartículas , Técnicas Fotoacústicas , Fototerapia , Polímeros , VibraçãoRESUMO
The modulation of blood flow to tumors is a prominent strategy for improving the tumor accumulation of nanomedicines, resulting from the enhanced permeability and retention (EPR) effect. We previously reported a promising EPR enhancer-a nitric oxide (NO) donor-containing liposome (NO-LP)-which showed enhanced accumulation in tumor tissue. Herein, we study NO-LP in greater detail to clarify its practical use as an EPR enhancer. NO-LP was found to have advantages as a NO donor, including the ability to maintain NO donation over long periods of time, and a constant rate of NO-release irrespective of the environmental pH. NO-LP showed rapid accumulation in tumor tissue after injection (1â¯h), and then accumulation was continuously enhanced until 48â¯h. Enhanced NO-LP accumulation was observed specifically in tumor, while the accumulation in other organs remained relatively unchanged. The results obtained show the promising features of NO-LP as an EPR enhancer.