Elastic biodegradable ureteral stent

描述（由申请人提供）：这项I期研究的目的是开发弹性、可生物降解的输尿管支架，该支架将在手术后2周内在体内降解。目前的输尿管支架是由不可降解的聚合物制成的，除非它们是永久性的，否则必须通过第二次手术移除，这需要对患者进行进一步的干预。可生物降解输尿管支架不需要第二次手术取出。有许多外科手术需要放置输尿管支架。输尿管是一个允许尿液从肾脏流向膀胱的管道。输尿管支架置入用于疾病的外科手术，例如肾感染或肾结石。通常，支架用于为输尿管提供临时支撑并允许尿液流动，直到输尿管充分愈合以保持其自身的完整性和流动或绕过输尿管阻塞。这个过程大约需要2周，之后必须通过第二个程序取出不可降解的支架。申报支架将在2周内降解，无需进行第二次手术。在这项研究中要优化的两个主要性能是弹性和降解。具体目标1是合成与输尿管支架应用相匹配的具有良好弹性和降解动力学的可生物降解聚合物。这些聚合物将由含有可控量的可生物降解部分和水溶性部分的大分子单体配制，以使弹性最大化，并在约2周内发生降解。具体目标2是设计输尿管支架构型，以确保降解成小碎片，例如，小于2 mm，便于从输尿管中取出。该支架将通过电喷涂或通过超声喷嘴将聚合物溶液喷涂到旋转芯轴上逐层制造。最内层将是快速降解制剂，中间层将是生物聚合物的混合物，例如配制在微珠中的壳聚糖或藻酸盐，最外层将是能够在降解期间提供机械支撑的缓慢降解制剂。将在每一端形成猪尾线圈，以确保支架保持在原位。这项I期研究的成功完成将证明新型弹性可生物降解支架的可行性，该支架能够在2周后降解，无需进行第二次取出手术。这些支架将保留，直到发生充分愈合，不再需要。支架的尺寸和特性将与现有支架相同，因此现有导管导丝和技术可用于其置入。第二阶段的开发将集中在创造一个可销售的原型和动物研究。公共卫生相关性：本研究的目的是产生弹性，可生物降解的聚合物为基础的输尿管支架用于输尿管手术。这些支架将克服与当前技术相关的问题，消除了第二次手术取出支架的需要。该技术将提高患者的便利性，减少与第二次取出手术相关的并发症，并消除支架取出手术的成本。

DESCRIPTION (provided by applicant): The objective of this Phase I study is to develop elastic, biodegradable ureteral stents that will degrade in the body within 2 weeks after a procedure. Current ureteral stents are made of non-degradable polymers and, unless they are permanent, have to be removed by second procedure, which requires further intervention on the patients. Biodegradable ureteral stents will not require a second surgical removal procedure. There are many surgical procedures that require the emplacement of a ureteral stent. The ureter is a tube that allows urine to flow from the kidney to the bladder. Ureteral stent emplacement is utilized in surgical procedures for ailments, such as kidney infections, or kidney stones. Commonly, the stent is used to provide temporary support for the ureter and to allow urine flow until the ureter heals sufficiently to maintain its own integrity and flow or to bypass ureteral obstruction. This process takes approximately 2 weeks, after which non-degradable stents must be removed by a second procedure. The proposed stent will degrade in 2 weeks eliminating the need for a second procedure. The two main properties to be optimized in this study are elasticity and degradation. Specific Aim 1 is to synthesize biodegradable polymers with good elasticity and degradation kinetics matching the applications of ureteral stents. These polymers will be formulated from macromonomers containing biodegradable portions and water-soluble portions in controlled amounts so as to maximize elasticity and have degradation occur with approximately 2 weeks. Specific Aim 2 is to design ureteral stent configuration to ensure degradation into small pieces, e.g., less than 2 mm, for easy removal from the ureter. This stent will be manufactured layer-by-layer by either electrospraying or spraying through an ultrasonic nozzle polymer solution onto a rotating mandrel. The innermost layer will be a rapidly degrading formulation, the middle layer will be a mixture of biological polymers, such as chitosan or alginate formulated in microbeads, and the outermost layer will be a slow degrading formulation capable of providing mechanical support during degradation. Pigtail coils will be formed on each end to ensure the stent remains in place. Successful completion of this Phase I study will demonstrate the feasibility of novel, elastic, biodegradable stents capable of degrading after 2 weeks eliminating the need for a second removal procedure. These stents will remain until sufficient healing has occurred and they are no longer necessary. The stent will be designed to have the same size and properties as currently existing stents so that currently existing catheter guide wires and techniques may be used for their emplacement. Phase II development will focus on creating a marketable prototype and animal studies. PUBLIC HEALTH RELEVANCE: The objective of this research is to generate elastic, biodegradable polymer-based ureteral stents for use in ureteral surgery. These stents will overcome problems associated with current technology by eliminating the need for a second surgery to remove the stent. This technology will improve patient convenience, reduce complications associated with a second removal procedure, and eliminate the cost for the stent removal procedure.