生物谷Bioon.com 訊 把超聲波與磁共振成像（MRI）磁場結(jié)合起來可能幫助科學(xué)家向大腦的特定區(qū)域供給攜帶藥物的顆粒,。Kuo-Chen Wei及其同事把涂敷了常見抗癌藥物的磁性納米顆粒導(dǎo)向了大鼠的癌性腦瘤,。此前的研究已經(jīng)證明了聚焦的超聲波可以臨時(shí)破壞局部血腦屏障（血腦屏障是通向大腦的毛細(xì)血管上的一系列保護(hù)性的“閘門”）,，讓大分子治療更多地進(jìn)入中樞神經(jīng)系統(tǒng)。
這組科學(xué)家在對大鼠注射攜帶藥物的磁性顆粒之后對其大腦施加了超聲波,，并且輔以磁共振成像（MRI）的強(qiáng)力磁場和實(shí)時(shí)成像,，把這些顆粒導(dǎo)向了腫瘤部位。測試顯示,，在把磁打靶和聚焦超聲波方法結(jié)合起來而非單獨(dú)使用其中任何一種的時(shí)候,，更多的攜帶藥物的顆粒聚集在了指定的腦部位，而且用聯(lián)合療法治療的大鼠比未經(jīng)治療的大鼠存活時(shí)間長了66%,。
目前靜脈注射給藥的大腦治療需要大劑量以確保受影響的區(qū)域達(dá)到足夠的濃度,。這組作者說，該研究可能有助于科學(xué)家開發(fā)出對患者副作用更少的非侵入性治療腦疾病的方法,。（生物谷Bioon.com）
生物谷推薦原文出處：
PNAS doi: 10.1073/pnas.1003388107
Magnetic resonance monitoring of focused ultrasound/magnetic nanoparticle targeting delivery of therapeutic agents to the brain
Hao-Li Liu a,b,1, Mu-Yi Hua c,1, Hung-Wei Yang c,1, Chiung-Yin Huang d, Po-Chun Chu a, Jia-Shin Wu a, I-Chou Tseng d, Jiun-Jie Wang e, Tzu-Chen Yen b,f, Pin-Yuan Chen d,g,2,3, and Kuo-Chen Weid,2,3
Departments of aElectrical Engineering, cChemical and Material Engineering, and eMedical Image and Radiological Sciences and gGraduate Institute of Clinical Medical Sciences, Chang-Gung University, Taoyuan 333, Taiwan; bMolecular Imaging Center and fDepartment of Nuclear Medicine, Chang-Gung Memorial Hospital, Taoyuan 333, Taiwan; and dDepartment of Neurosurgery, Chang-Gung University College of Medicine and Memorial Hospital, Taoyuan 333, Taiwan
The superparamagnetic properties of magnetic nanoparticles (MNPs) allow them to be guided by an externally positioned magnet and also provide contrast for MRI. However, their therapeutic use in treating CNS pathologies in vivo is limited by insufficient local accumulation and retention resulting from their inability to traverse biological barriers. The combined use of focused ultrasound and magnetic targeting synergistically delivers therapeutic MNPs across the blood–brain barrier to enter the brain both passively and actively. Therapeutic MNPs were characterized and evaluated both in vitro and in vivo, and MRI was used to monitor and quantify their distribution in vivo. The technique could be used in normal brains or in those with tumors, and significantly increased the deposition of therapeutic MNPs in brains with intact or compromised blood–brain barriers. Synergistic targeting and image monitoring are powerful techniques for the delivery of macromolecular chemotherapeutic agents into the CNS under the guidance of MRI.
