Faculty of Medicine, School of Pharmacy, The Hebrew University of Jerusalem, P.O. Box 12065, Jerusalem 91120, Israel.
Pharm Res. 2004 Mar;21(3):447-53. doi: 10.1023/B:PHAM.0000019298.29561.cd.
To study the adhesion properties of charged liposomes to the healthy and inflamed (colitis-induced) rat intestinal epithelium.
Neutral, positively charged, and negatively charged liposomes were prepared and tagged. The cationic or anionic liposomes contained increasing amounts (13, 22, or 36 mol%) of either the cationic lipid dimethyl-dioctadecylammoniumbromide (DODAB) or the anionic lipid 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DSPG). Colitis was induced in rats by DNBS. Adhesion of the various types of liposomes was assessed in rat colon sacs. The effects of charge type, charge density (mol%), liposome size, and incubation time on the adhesion of the liposomes were compared in the inflamed and healthy epithelial tissues.
Three times as many cationic liposomes adhered to the healthy colonic mucosa than neutral or anionic liposomes. However, anionic liposome adherence to the inflamed colonic mucosa was 2-fold that of either neutral or cationic liposomes (a finding that was verified by charged-dyes studies). Adherence was directly correlated with charge density. An inverse correlation was identified between cationic liposome size and healthy tissue adherence in short incubation periods. The adherence of cationic liposomes, which was also found to be time-dependent, decreased in healthy mucosa in the presence of high concentrations of aqueous Mg2+ rinse.
Anionic liposomes could be useful for the topical delivery of anti-inflammatory drugs in inflammatory bowel disease therapy.
研究荷电脂质体与健康和炎症（结肠炎诱导）大鼠肠上皮的黏附特性。
制备并标记中性、正电荷和负电荷脂质体。阳离子或阴离子脂质体分别包含越来越多（13、22 或 36mol%）的阳离子脂质二甲基-双十八烷基溴化铵（DODAB）或阴离子脂质 1,2-二肉豆蔻酰基-sn-甘油-3-[磷酸-rac-（1-甘油）]（DSPG）。通过 DNBS 在大鼠中诱导结肠炎。在大鼠结肠囊中评估各种类型脂质体的黏附情况。在健康和炎症上皮组织中比较了电荷类型、电荷密度（mol%）、脂质体大小和孵育时间对脂质体黏附的影响。
与中性或阴离子脂质体相比，三倍数量的阳离子脂质体黏附在健康的结肠黏膜上。然而，阴离子脂质体对炎症性结肠黏膜的黏附是中性或阳离子脂质体的两倍（通过带电荷染料研究证实了这一发现）。黏附与电荷密度直接相关。在短孵育时间内，阳离子脂质体大小与健康组织黏附呈反比关系。阳离子脂质体的黏附也是时间依赖性的，在高浓度的水镁冲洗液存在下，健康黏膜中的黏附减少。
阴离子脂质体可能有助于在炎症性肠病治疗中局部递抗炎药物。
