ABSTRACT
Objective To prepare a kind of superparamagnetic iron oxide (SPIO) and doxorubicin loaded multifunctional polymer microbubbles (MPMBs),and to explore its potential application as an ultrasound(US)/magnetic resonance (MR) imaging contrast agent in vitro.Methods The MPMBs and normal polymer microbubbles (PMBs) were made by double emulsion and freeze-drying methods.The physical property,drug encapsulation efficiency and the drug-loading efficiency of MPMBs were determined,and the release property and US/MR imaging enhancement of MPMBs were observed.Results The MPMBs had a regular shape and narrow size distribution.The drug encapsulation efficiency was (60.20±2.69) ％,and the drug-loading efficiency was (6.02 ± 0.27) ％.The in vitro release experiment showed that ultrasound can promote the release of doxorubicin in MPMBs.US imaging in vitro showed that the enhancement of MPMBs was better than PMBs,and MR imaging in vitro conformed that MPMBs could well enhance MR imaging.Conclusions The MPMBs is a multifunctional contrast agent with the treatment function as well as US/MR dual-mode imaging enhancement effect.
ABSTRACT
Objective To prepare polyclactic-co-glycolic acid(PLGA) polymer ultrasound contrast agent loading sudan black dye (SB-PLGA) and study the enhancement effect of it on rabbit lymph nodes imaging and as a sentinel lymph node (SLN) biopsy in the feasibility and value of the indicator.Methods SB-PLGA ultrasound contrast agent was made by double emulsion and freeze-drying methods.Thigh subcutaneous rabbit VX2 tumor model of eight lymph nodes were set up with the foot pad subcutaneous injection of contrast agents to get contrast-enhanced ultrasound imaging of the popliteal lymph node and the second inguinal lymph node stations.Then the blue stained lymph nodes were resected by popliteal lymph node dissection and the second station lymph nodes were also observed after 30 mins respectively,lymph nodes were examined by frozen sections HE staining in parallel.Results SB-PLGA microbubbles had a tight size distribution.Ultrasound imaging can be significantly enhanced lymph node imaging,the second station lymph node imaging was not obvious.Popliteal lymph node dissection for lymph node staining,30minutes later,frozen sections HE staining were seen within the lymph node contrast agent present in the lymphatic sinus and a large entry of macrophages.Inguinal lymph node dissection showed the second station of lymph nodes no blue staining.Conclusions SB-PLGA ultrasound contrast agent is good for sentinel lymph node imaging and biopsy indicator.Contrast agent retention and accumulation in the lymph nodes by the uptake of macrophages may be associated with the mechanisms of lymph node enhanced imaging.
