【正文】
有Lf,且每個(gè)LfNP表面的Lf數(shù)約為55。 Biodegradable nanoparticle。然而,脂質(zhì)體的穩(wěn)定性差及單克隆抗體效果的不穩(wěn)定限制了其進(jìn)一步應(yīng)用[810]。此外,聚乙二醇和聚乳酸都是FDA已批準(zhǔn)的輔料,將使載藥系統(tǒng)具有較好的生物相容性和安全性[17,18]。采用透射電鏡技術(shù)(TEM)和動(dòng)態(tài)光散射分析(DLS)對(duì)LfNP和NP的形態(tài),粒徑進(jìn)行表征。將載有香豆素6的LfNP和NP稀釋成含1-60 μg/ml的納米粒供試液,按不同濃度每孔加入1 ml(空白孔加1 ml HBSS),分別放入37℃及4℃孵育1 h,考察細(xì)胞在4℃和37℃下對(duì)LfNP和NP的攝取情況。用酶標(biāo)儀在450 nm處讀數(shù)。以SPSS軟件進(jìn)行統(tǒng)計(jì)學(xué)分析。圖1納米粒的透射電子顯微鏡照片,標(biāo)尺均為100 nmANP;BLfNP;C加入抗Lf一抗和連接有10nm膠體金兔抗羊IgG二抗后的LfNP;D僅加入連接有10nm膠體金兔抗羊IgG二抗的LfNP;E加入抗Lf一抗和連接有10nm膠體金兔抗羊IgG二抗后的NPFig. 1 Transmission electron micrograph of different nanoparticles negatively stained with phosphotungstic acid solution. Bar on each photo was 100 nm.A NP。37 186。2h后,LfNP廣泛分布在整個(gè)細(xì)胞且進(jìn)入細(xì)胞核(圖3H)而NP則主要分布于胞漿。C incubation for 1h, respectively。C. The magnification bar is 100 181。給予LfNP和NP后,血中的香豆素6濃度沒(méi)有顯著差異,說(shuō)明少量Lf連接在納米粒表面并不影響PEG的長(zhǎng)循環(huán)功能。本文采用Lf構(gòu)建的新型生物可降解腦內(nèi)遞藥系統(tǒng)LfNP粒徑在150nm以下,適宜用于腦內(nèi)遞藥。的研究表明被K562髓性白血病細(xì)胞攝取后的Lf可以進(jìn)入細(xì)胞核并與DNA結(jié)合,Nuijens等人的研究也表明Lf可能具有調(diào)節(jié)基因表達(dá)的功能,這與我們觀察到LfNP在細(xì)胞核中的分布相一致。然而,其體內(nèi)毒性和長(zhǎng)期毒性還有待進(jìn)一步考察。NEIL R G. Tight junction protein expression and barrier properties of immortalized mouse brain microvessel endothelial cells [J]. Brain Res, 2007, 1130:1730.[22] DESAI M P, LABHASETWAR V, WALTER E, et al. The mechanism of uptake of biodegradable microparticles in Caco2 cells is size dependent [J]. Pharm Res, 1997, 14:15681573.[23] GRAU A J, WILLG V, FOGEL W, et al. Assessment of Plasma Lactoferrin in Parkinson’s Disease [J]. Movement Disord, 2001, 16(1):131134.[24] FAUCHEUX B A, NILLESSE N, DAMIER P, et al. Expression of lactoferrin receptors is increased in the mesencephalon of patients with Parkinson disease [J]. Proc Natl Acad Sci USA Neurobiology, 1995, 92:96039607. [25] KAWAMATA T, TOOYAMA I, YAMADA T, et al. Lactotransferrin immunocytochemistry in Alzheimer and normal human brain [J] Am J Pathol, 1993, 142(5):15741585.[26] PLARD J P, BAZILE D. Comparison of the safety profiles of PLA50 and –PLA50 nanoparticles after single dose intravenous administration to rats [J]. Colloid Surface B, 1999, 16:173183.[27] MATSUSUE Y, HANAFUSA S, YAMANURO T, et al. Tissue reaction of bioabsorbable ultra high strength poly (l–lactide) rod. A longterm study in rabbits [J]. Clin Orthop, 1995, 317:246253.[28] ZAMBAUX M F, BONNEAUX F, GREF R, et al. Protein Cloaded monomethoxypoly (ethylene oxide) –poly(lactic acid) nanoparticles [J]. Int J Pharm, 2001, 212:19.[29] THOTATHIL Z, JAMESON M B. Early experience with novel immunomodulators for cancer treatment [J]. Expert Opin Inv Drug, 2007, 16(9):13911403.[30] TOMITA M, WAKABAYASHI H, YAMAUCHI K, et al. Bovine lactoferrin and lactoferricin derived from milk: production and applications [J]. Biochem Cell Biol, 2002, 80(1) :109112.16 / 16。臨床研究證實(shí)了Lf的安全性[29, 30]。因此,我們認(rèn)為測(cè)得細(xì)胞中的香豆素6主要反應(yīng)了包載其的納米粒的分布情況。 D cortex after LfNP administration。通過(guò)測(cè)定香豆素6在血和腦中的濃度評(píng)價(jià)兩種納米粒在血和腦中的分布,結(jié)果表明,兩種納米粒在腦內(nèi)的藥時(shí)曲線相似,約在1h時(shí)達(dá)峰(圖6),LfNP腦內(nèi)的AUC(0–t)。m,其余標(biāo)尺為100 181。C孵育30 min后的攝取情況Fig. 2 uptake quantitative results, n=3 *p< A 160 μg/ml Lf–NP and NP at 37 186。由熒光顯微鏡照片可看出,在37 186。C的攝取量均高于4 186。13)個(gè)Lf。將各樣品的峰面積比代入相應(yīng)的標(biāo)準(zhǔn)曲線求得腦組織及血樣中的藥物濃度。104個(gè)細(xì)胞的密度接種于96孔培養(yǎng)板中培養(yǎng)過(guò)夜。棄去納米粒溶液,細(xì)胞用PBS沖洗三次,取出玻片放入4%多聚甲醛中于室溫固定20 min,用PBS漂洗3次后,用熒光封片劑封片,用相差及熒光顯微鏡觀察。巰基化