【正文】 P的攝取及它們?cè)谛∈竽X內(nèi)的分布,并通過(guò)細(xì)胞活力試驗(yàn)進(jìn)行了該系統(tǒng)體外毒性的評(píng)價(jià)。同時(shí)將載香豆素6的LfNP和NP分別以10 μg/ml的濃度加入培養(yǎng)孔中，放入37℃、2和4 h，考察在37℃下、。3. 結(jié)果 NP和LfNP的表征透射電鏡下觀察，制得的NP和LfNP大小均勻、外觀圓整，粒徑分別為（ 177。C時(shí)，兩種納米粒攝取量隨濃度的升高呈線性升高（圖2A），具有濃度依賴性，在60 μg/ml時(shí)。 B 10 μg/ml Lf–NP and NP at 37 186。圖5 尾靜脈注射60 mg/kg LfNP和NP1h后的腦內(nèi)分布，標(biāo)尺為50 181。Lf的這種進(jìn)入細(xì)胞核的能力可能會(huì)利于基因藥物的遞送。, 2005, 2:108119.[17] LANGER R. Tissue engineering: a new field and its challenges [J]. Pharm Res, 1997, 14 (7):840–841.[18] ADAMS M L, LAVASANIFAR A, KWON G S. Amphiphilic block copolymers for drug delivery [J]. J Pharm Sci, 2003, 92(7):13431355.[19] LU W, ZHANG Y, TAN Y Z, et al. Cationic albuminconjugated pegylated nanoparticles as novel drug carrier for brain delivery [J]. J Control Release, 2005, 107:428448.[20] PEPPER M S, TACCHINICOTTIER F, SABAPATHY T K, MONTESANO R, WAGNER E F. Tumour Angiogenesis [M]. Oxford, UK: Oxford University Press, 1997:309331.[21] BROWN R C, MORRIS A P, O39。文獻(xiàn)報(bào)道載香豆素6的PLGA納米粒與細(xì)胞孵育2h后，游離香豆素6僅占細(xì)胞攝取香豆素6總量的3%[22]，我們進(jìn)行的體外泄露試驗(yàn)也證實(shí)了24h內(nèi)香豆素6主要位于納米粒內(nèi)部。LfNP特定的濃集于紋狀體和第三腦室室周區(qū)，這一特點(diǎn)可以用于治療帕金森病，肥胖等靶點(diǎn)位于此部位的疾病。C孵育不同時(shí)間后的攝取情況；C10 μg/ml NP, Lf–NP和加入10 mg/ml Lf的Lf–NP在37 186。兩種納米粒37 186。樣品處理后以HPLC法分析血中和腦中的香豆素6含量。細(xì)胞用HBSS預(yù)先孵育15 min后，分別加入載香豆素6 LfNP和NP的HBSS溶液（15 μg/ml），37℃ h、1 h和2 h。最近, Ji等人比較了Tf，OX26和Lf的入腦性能，結(jié)果證實(shí)Lf的入腦能力顯著高于前兩者[15]。關(guān)鍵詞：乳鐵蛋白；血腦屏障；香豆素6；生物可降解納米粒；腦內(nèi)遞送中圖分類號(hào)：R9 Lactoferrinconjugated PEG–PLA nanoparticles with improved brain delivery: in vitro and in vivo evaluationsHU Kaili, LI Jingwei, SHEN Yehong, LU Wei, GAO Xiaoling, Jiang Xinguo (Department of Pharmaceutics, School of Pharmacy, Fudan University, Shanghai 200032)ABSTRACT：OBJECTIVE To construct the lactoferrin (Lf) conjugated poly (ethyleneglycol) –poly (lactide) (PEG–PLA) nanoparticle (Lf–NP) as a novel biodegradable brain drug delivery system and evaluate its in vitro and in vivo delivery properties. METHODS Lf was thiolated and conjugated to the distal maleimide functions surrounding on the pegylated nanoparticles prepared by double emulsion and solvent evaporation procedure to form the Lf–NP. Dynamic light scattering analysis, transmission electron micrograph (TEM), Xray photoelectron spectrometry analysis and ELISA were used to characterize the LfNP. A fluorescent probe, coumarin6 was incorporated into Lf–NP and its uptake by a mouse brain capillary endothelial cell line, were pared to that of unconjugated nanoparticle (NP). The brain distribution of LfNP following an intravenous administration was evaluated quantitatively by pharmacokinetic studies and qualitatively by fluorescent microscopy. The influence of LfNP on cell viability was also evaluated. RESULTS Dynamic light scattering analysis and transmission electron micrograph (TEM) showed that the Lf–NP had a round and regular shape with an average diameter of around 110 nm. The existence of Lf on the surface of Lf–NP was verified by TEM observation and Xray photoelectron spectrometry analysis. The Lf ELISA results confirmed the biorecognitive activity of Lf after the covalent coupling procedure and suggested the average number of Lf conjugated on each nanoparticle was around 55. The uptake of Lf–NP by was