Engineering Effective Polymers to Enable Gene Based Therapies

与传统药物相比，利用核酸进行分子治疗提供了一种令人兴奋的方法。使用从核酸中提取的基于基因的药物，可以更好地将患病的器官恢复到正常状态。然而，成功完全依赖于核酸载体的使用，因为核酸本身不能被细胞内化，因为它们的大小和阴离子性质。阳离子聚合物是安全的载体，它们可以很容易地中和核酸，并将它们浓缩成适合摄取的纳米颗粒。然而，它们的转染率低，活性持续时间短，毒性高。我研究的总体目标是创造能够与核酸自组装的工程聚合物，从而创造出理想的细胞递送纳米颗粒。*我们一直在用脂质取代的阳离子聚合物设计一类基因载体。这种聚合物被发现可以产生稳定的、自组装的纳米颗粒，将货物输送到细胞的能力提高了100倍。我们确定了几种有希望的脂质替代，并绘制了它们在特定类型的细胞中运送特定类型的核酸的有益图表。在我们过去的工作中没有出现通用的载体设计，但我们为不同类型的细胞确定了有效的载体。我们的总体假设是：两亲性聚合物可以由阳离子聚合物和脂类制成，用于控制特定细胞的核酸输送和释放，最终以安全的方式改善功能结果。下一代运营商将追求三个目标：*AIM-1。以创造三级纳米颗粒，以实现更好的核酸输送。我们最近发现，在纳米颗粒中添加一个叔基多阴离子可以改善功能传递。我们将使用内部制备的具有定制功能的聚阴离子分子来设计优质的三级纳米粒子。*AIM-2。创造多种载脂聚合物，用于将核酸输送到更广泛的细胞群体。我们确定了在不同患者细胞中对核酸输送有效的关键类脂取代基。我们建议创造杂化的‘脂聚合物，其中不同的脂质取代基将在聚合物主干上有条不紊地变化，以创建能够作用于更广泛的细胞来源的通用’载体。目的：确定用于核酸输送的聚合物的功能性能。利用几种体外模型，我们将研究AIM-1和AIM-2改进后的递送系统的功能性能。将对现有系统和新系统以及商业试剂进行系统的比较。*我的目标是为聚合物引导的遗传剂输送奠定基础，并开发有效和安全输送核酸的功能材料。我们设想该载体将作为生物医学研究企业的研发试剂和功能载体，实现对人类疾病的安全分子治疗。**

Molecular therapy utilizing nucleic acids offers an exciting approach over conventional drugs. Diseased organs can be better restored to normal state with the use of gene-based medicines derived from nucleic acids. The success, however, is absolutely dependent on the use of nucleic acid carriers, since nucleic acids alone cannot be internalized by cells due to their large size and anionic nature. Cationic polymers are safe carriers and they can readily neutralize nucleic acids and condense them into nanoparticles suitable for uptake. However, they suffer from low transfection efficiencies, short duration of activity and high toxicities. Overall goal of my research to create engineered' polymers that can self-assemble with nucleic acids to create nanoparticles ideal for cellular delivery. ******We have been engineering a class of gene carriers from lipid-substituted cationic polymers. Such polymers were found to create stable, self-assembled nanoparticles, enhancing delivery of the cargo into cells by as much as 100-fold. We identified several promising lipid substitutions and charted their beneficial in the delivery of particular types of nucleic acids in particular types of cells. No universal carrier design emerged in our past work, but we identified effective carriers for different types of cells. Our overall hypothesis is: amphiphilic polymers can be engineered from cationic polymers and lipids for controlled delivery and release of nucleic acids for specific cells, ultimately leading to improved functional outcomes in a safe manner. Three aims will be pursued for next generation carriers:******Aim-1. To create tertiary' nanoparticles for superior delivery of nucleic acids. We recently discovered that adding a tertiary polyanion into nanoparticles improved the functional delivery. We will design superior tertiary nanoparticles by using in-house prepared polyanionic molecules with tailored features. ******Aim-2. To create multiple lipid-bearing polymers for delivery of nucleic acids to broader population of cells. We identified key lipid substituents effective for nucleic acid delivery in different patient cells. We propose to create hybrid' lipopolymers, where different lipid substituents will be methodically varied on the polymer backbone, to create universal' carriers capable of acting on wider source of cells.******Aim-3. To determine functional performance of polymers for nucleic acid delivery. Using several in vitro models, we will investigate the functional performance of improved delivery systems from Aim-1 and -2. Systematic comparisons between current and new systems, and commercial reagents will be undertaken.******My goal is to establish a foundation for polymer-guided delivery of genetic agents and develop functional materials for effective and safe delivery of nucleic acids. We envision the carriers to serve as R&D reagents in biomedical research enterprise as well as functional carriers to implement safe molecular therapies for human diseases.**