Nanocarrier with metal bridge for affinity based delivery of metal binding peptid

描述（由申请人提供）：溶葡萄球菌素是一种金属内肽酶，对金黄色葡萄球菌具有溶菌作用，是治疗耐多药金黄色葡萄球菌介导感染的潜在全身疗法。然而，这种酶在体内的半衰期短，阻碍了它作为一种全身疗法的发展。我们的公司PharmaIN提出了一种新的药物递送纳米技术（药物纳米载体），称为保护接枝共聚物（PGC）与PharmaIN的可逆结合（PRB）相结合，这是一种新的技术，用于将含有金属结合位点的肽和/或蛋白质可逆地结合到药物纳米载体上。重要的是，纳米载体集中在血管通透性增加的部位，这一事实提供了在感染部位集中相关药物的能力。我们的长期目标是开发溶葡萄球菌蛋白的递送系统，考虑到它的锌结合结构域，它似乎特别适合与我们的载体结合。设想的配方不仅能够延长酶的循环时间，而且还能将药物集中在感染部位，潜在地提高疗效，降低整个治疗期间的总剂量，并抑制耐药性的出现。在一期项目中，我们提出以下建议：目标1：用PRB设计、合成、纯化和表征PGC。目的2：用PGC/PRB配制溶葡萄蛋白，并测定(i) PGC/PRB溶葡萄蛋白复合物的形成效率，（ii）在血清存在和不存在的情况下，PGC/PRB溶葡萄蛋白的解离常数，（iii）在体外，在咪唑和底物存在的情况下，从载体释放溶葡萄蛋白并保持其活性而不变性的能力。目的3:PGC/PRB：溶葡萄球菌蛋白复合物与溶葡萄球菌蛋白体内药动学参数的比较。II期研究将包括对配方溶葡萄球菌蛋白的综合评估，包括生物分布（感染部位的积累）和在葡萄球菌感染动物模型中的疗效。这些研究旨在为设想的产品-溶葡萄球菌蛋白在治疗侵袭性葡萄球菌感染的最佳感染部位定向递送系统中申请IND。

DESCRIPTION (provided by applicant): Lysostaphin, a metalloendopeptidase that is bacteriolytic for Staphylococcus aureus, is a potential systemic therapy for treating multidrug-resistant S. aureus mediated infections. However, the short half life of this enzyme in vivo has precluded its development thus far as a systemic therapy. Our company, PharmaIN proposes to apply a novel drug delivery nanotechnology (drug nanocarrier) called Protected Graft Copolymers (PGC) coupled with PharmaIN's Reversible Binding (PRB), a new technology for the reversible formulation of peptides and/or proteins containing a metal binding site to the drug nanocarrier. Importantly, the fact that the nanocarrier concentrates at sites of increased vascular permeability affords the ability to concentrate associated agents at the site of infection. Our long-term goal is to develop this delivery system for lysostaphin that, considering its Zn-binding domain, appears to be particularly well suited for association with our carrier. The envisioned formulation would not only offer the ability to prolong the circulation time of the enzyme but also concentrate the agent at sites of infection, potentially increasing efficacy, decreasing overall dose over the entire treatment period and suppressing the emergence of resistance. In the Phase I project, we propose the following: Aim 1: Design, synthesis, purification and characterization of PGC with PRB. Aim 2: Formulation of lysostaphin with PGC/PRB and determination of (i) formation efficiency of PGC/PRB:lysostaphin complex, (ii) dissociation constant of lysostaphin from the PGC/PRB in the presence and absence of serum, (iii) the ability, in vitro, to release lysostaphin from carrier in the presence of imidazole and substrate and maintain its activity without denaturation. Aim 3: Comparison of in vivo pharmacokinetic parameters of PGC/PRB:lysostaphin complex and lysostaphin. The Phase II studies will involve a comprehensive evaluation of formulated lysostaphin including biodistribution (accumulation at sites of infection) and efficacy in an animal model of staphylococcal infection. The studies are aimed toward filing an IND for the envisioned product - lysostaphin in an optimal infection site-directed delivery system for the treatment of invasive staphylococcal infections. Public Health Relevance: The available therapies for antibiotic resistant S. aureus bacteria are limited and the emergence of numerous high-level vancomycin resistant bacteria predicts a dire public health situation if new treatments aren't developed. This Phase I application is aimed toward developing a life-saving product for use in life threatening emergency caused by invasive and systemic staphylococcal infections with the eventual goal of FDA filing of an IND application. The product will contain an enzyme (lysostaphin) to digest bacterial cell walls and a nanocarrier drug delivery system that would make the enzyme stable to clear infections in blood and tissue of the patients.