Layer-by-layer nanocarriers for highly efficient solubilization of insoluble drug

描述（由申请人提供）：通过结合多功能药物纳米载体工程的最新发展，以及使用层层（LbL）技术制备新型聚合物涂层，我们期望获得低溶性药物的新剂型，并满足此类药物对适合亲代给药的稳定纳米胶体的未满足需求。目前用于难溶性药物的胶束载体存在严重问题：(a)药物的载药效率低（通常低于5% wt）；(b)不可能对不同的药物采用相同的方案；(c)难以控制药物释放速度；(d)扩大技术规模；(e)稳定性不足。另一方面，存在一种通过LbL工艺在不同颗粒上组装聚电解质多层壳的方法，该方法基于对带相反电荷的聚电解质的交替吸附。我们计划用LbL涂层制备稳定性高、释放速率可控、活性药物含量极高（高达90% wt）的难溶性药物的稳定水性胶体。为此，将具有微米级颗粒的难溶性药物水溶液悬浮液经超声处理使其尺寸达到纳米级，并通过施加LbL涂层在溶液中形成稳定的药物纳米颗粒。我们推测，在药物纳米颗粒周围形成LbL壳层，可以获得稳定的高含量活性药物制剂。通过改变聚合物上的电荷密度和/或包覆循环次数，可以制备具有不同表面电荷和不同包覆成分的颗粒，以控制药物释放速率。使用反应性聚合物形成“外”表面层将允许将特定的配体或报告基团以及其他感兴趣的部分附着到药物纳米颗粒上。本课题的具体目标是：(1)利用LbL技术制备紫杉醇（PCT）、喜树碱（CPT）等难溶性药物的纳米胶体，制备尺寸为100 ~ 200nm、药物含量在75% wt以上、药物释放率可控的稳定纳米胶体；(2)制备药物LbL纳米胶体，附着聚乙二醇（延长寿命）、肿瘤特异性单克隆抗体2C5或TAT肽（TATp），用于肿瘤靶向或细胞内渗透；(3)体外研究PCT和CPT的非靶向和靶向LbL纳米胶体在癌细胞中的性质、细胞毒性、与细胞的相互作用、细胞摄取和细胞内分布；(4)研究非靶向和靶向LbL药物纳米胶体在实验性肿瘤小鼠体内的特性；(5)制备tatp修饰的PCT和CPT的LbL纳米胶体，研究tatp介导的药物纳米胶体细胞内递送对体内和体外药物效率的影响。该提案将开发一个新的平台，用于制备稳定的高药物含量和提高药物生物利用度的难溶性药物靶向和非靶向纳米胶体。

DESCRIPTION (provided by applicant): By combining the recent developments in engineering of multifunctional pharmaceutical nanocarriers and in preparing novel types of polymeric coatings using the layer-by-layer (LbL) technology, we expect to obtain new dosage forms of poorly soluble drugs and meet the unmet need for stable nanocolloids of such drugs suitable for parental administration. There exist serious problems with currently used micellar carriers for poorly soluble drugs: (a) low loading efficacy of the drug (usually below 5% wt); (b) impossibility to apply the same protocol for different drugs; (c) difficulties in controlling the drug release rate; (d) scaling up the technology; (e) insufficient stability. On the other hand, there exists an approach to assemble polyelectrolyte multilayer shells on various particles through the LbL process based on an alternate adsorption of oppositely charged polyelectrolytes. We plan LbL coatings to make stable aqueous colloids of poorly soluble drugs with high stability, controllable release rate, and very high content (up to 90% wt) of the active drug. For this, aqueous suspensions of poorly soluble drugs with micron range particles are subjected to ultrasonication to bring their size to the nano level, and stabilized drug nanoparticles in solution are formed by applying the LbL coating. We hypothesize that the formation of LbL shell around drug nanoparticles will result in stable drug preparations with high content of an active drug. By varying the charge density on polymers and/or the number of coating cycles, particles with a different surface charge and different composition of the coat can be prepared to control drug release rate. The use of a reactive polymer to form the "outer" surface layer will allow for the attachment of specific ligands or reporter groups and other moieties of interest to drug nanoparticles. The proposal pursues the following specific aims: (1) To prepare stable nanocolloids of poorly soluble drugs - paclitaxel (PCT), and camptothecin (CPT) - with a size of 100-to-200 nm, drug content of above 75% wt, and controllable drug release rate by using the LbL technology; (2) To prepare drug LbL nanocolloids with attached polyethylene glycol (for increased longevity), cancer-specific monoclonal antibody 2C5 or TAT peptide (TATp), for cancer targeting or intracellular penetration; (3) To investigate the properties, cytoxicity, interaction with cells, and cellular uptake and intracellular distribution of non-targeted and targeted LbL nanocolloids of PCT, and CPT in cancer cells in vitro; (4) To investigate the properties of non-targeted and targeted LbL drug nanocolloids in vivo in mice with experimental tumors; and (5) To prepare TATp-modified LbL nanocolloids of PCT, and CPT and study the effect of TATp-mediated intracellular delivery of drug nanocolloids on drug efficiency both in vitro and in vivo. This proposal will develop a novel platform for making stable targeted and non-targeted nanocolloids of poorly soluble drugs with high drug content and enhanced drug bioavailability. PUBLIC HEALTH RELEVANCE: We plan to obtain new dosage forms of poorly soluble drugs suitable for parenteral administration by applying the layer-by-layer (LbL) technology by assembling polyelectrolyte multilayer shells on various particles through the process of an alternate adsorption of oppositely charged polyelectrolytes. This will result in stable aqueous colloids of poorly soluble drugs with high stability, controllable release rate, and very high content (up to 90% wt) of the active drug. By varying the charge density on polymers and/or the number of coating cycles, particles with a controlled surface charge and different composition of the coat can be prepared to control drug release rate. The use of a reactive polymer to form the "outer" surface layer will allow for the attachment of specific ligands or reporter groups and other moieties of interest to drug nanoparticles. The approach will be applied to several poorly soluble anticancer drugs, and the nanocolloids obtained will be additionally modified by various ligands to make them long-circulating, targeted, and capable of intracellular penetration.