Elastic biodegradable ureteral stent

描述（由申请人提供）：本I期研究的目的是开发弹性、可生物降解的输尿管支架，该支架在手术后2周内可在体内降解。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去除，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切除。有许多外科手术需要放置输尿管支架。输尿管是允许尿液从肾脏流向膀胱的管道。输尿管支架置入术用于治疗肾脏感染或肾结石等疾病的外科手术。通常，支架用于为输尿管提供临时支撑，并允许尿液流动，直到输尿管愈合足以维持其自身的完整性和流动或绕过输尿管梗阻。这个过程大约需要2周，之后必须通过第二次手术去除不可降解的支架。该支架将在两周内降解，无需第二次手术。本研究中要优化的两个主要性能是弹性和降解性。具体目标1是合成具有良好弹性和降解动力学的可生物降解聚合物，与输尿管支架的应用相匹配。这些聚合物将由含有一定量的可生物降解部分和水溶性部分的大单体配制而成，以便最大限度地提高弹性，并在大约2周内发生降解。具体目标2是设计输尿管支架结构，以确保降解成小块，例如小于2mm，以便于从输尿管取出。这种支架将通过电喷涂或通过超声波喷嘴将聚合物溶液喷涂到旋转芯轴上逐层制造。最内层将是一种快速降解的配方，中间层将是生物聚合物的混合物，如壳聚糖或海藻酸盐在微珠中配制，最外层将是一种缓慢降解的配方，能够在降解过程中提供机械支持。尾辫线圈将在两端形成，以确保支架保持在适当的位置。I期研究的成功完成将证明这种新型的、有弹性的、可生物降解的支架的可行性，这种支架能够在2周后降解，无需进行第二次移除手术。这些支架将保留，直到完全愈合，不再需要它们。该支架将被设计成与现有支架具有相同的尺寸和性能，以便现有的导管导丝和技术可用于其放置。第二阶段的开发将侧重于创造可销售的原型和动物研究。公共卫生相关性：本研究的目的是制造用于输尿管手术的弹性、可生物降解的聚合物输尿管支架。这些支架将克服与当前技术相关的问题，不再需要第二次手术来移除支架。这项技术将提高患者的便利性，减少与第二次移除手术相关的并发症，并消除支架移除手术的成本。

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.