Implantation of Bioengineered Intrinsically Innervated Internal Anal Sphincter (BioSphincter) to Treat Fecal Incontinence

 描述(由申请人提供)：我们建议将一种基于再生医学的治疗大便失禁(FI)的新方法推向市场。FI是一种反复出现的不受控制的排泄物。肛门内括约肌(IAS)负责维持肛门直肠节制。IAS的功能依赖于平滑肌和肠道固有神经系统(ENS)的神经肌肉完整性。目前，大便失禁的动物模型并不能模拟在人类身上观察到的被动大便失禁症状。我们建议进一步开发一种在实验室中开发的新的外科技术，通过破坏IAS来诱导兔的大便失禁，并利用该模型来验证植入生物工程神经IAS结构治疗FI的有效性。我们的手术不会对肛门外括约肌(EAS)造成损害，从而将损伤限制在IAS的平滑肌层。肛门直肠测压检查显示，部分IAS括约肌切除后，IAS静息压力和神经介导的直肠肛门抑制反射(RAIR)丢失。我们的初步结果表明，接受部分IAS括约肌切除术的兔出现大小便失禁，粪便行为改变，类似于在人类中观察到的被动FI症状(目标1)。我们开发了基于组织培养的技术，从IAS分离环状平滑肌细胞，从空肠活检组织中分离肠神经前体细胞。我们已经优化了我们的生物工程技术，以产生具有神经肌肉完整性的神经IAS结构，包括识别对神经前体细胞分化至关重要的因素。我们建议扩展我们的生物工程设计，以共培养这两种细胞类型，以产生生物工程的自体固有神经支配的IAS结构。这些结构具有生理功能，并将接受严格的质量控制，以评估肌源性和神经源性属性。我们建议进行一项临床前随机兔试验，在失禁兔体内植入生物工程IAS结构(目标2)。这些结构的功能将使用肛门直肠测压技术在体内进行评估，并检查RAIR的恢复情况。我们的初步研究表明，植入生物工程结构后，这种神经介导的反射发生了恢复。最后，为了推动该项目向FDA申请研究新药(IND)，并有资格进行首例人体研究，我们建议简化我们的制造和质量控制协议，以适应当前的良好制造过程(CGMP)指南(AIM3)。我们的拨款建议是为直接补救FI的潜在病理，即IAS神经肌肉完整性的丧失而量身定做的。我们的初步结果为这种再生医学方法治疗FI的成功提供了概念证明。

 DESCRIPTION (provided by applicant): We propose to bring to market, a novel regenerative medicine based therapy for fecal incontinence (FI). FI is the recurrent uncontrolled passage of fecal material. The Internal Anal Sphincter (IAS) is responsible for maintaining anorectal continence. Function of the IAS is dependent upon the neuromuscular integrity of both the smooth muscle and the intrinsic enteric nervous system (ENS). Currently, animal models of fecal incontinence do not mimic symptoms of passive FI observed in humans. We propose to further develop a novel surgical technique developed in lab to induce fecal incontinence in rabbits by damaging the IAS and utilize this model to validate the efficacy of implantation of bioengineered innervated IAS constructs for the treatment of FI. Our surgical procedure does not result in damage to the external anal sphincter (EAS), thereby limiting the injury to the smooth muscle layer of the IAS. Examination through anorectal manometry indicates the loss of IAS resting pressure as well as the neurally mediated rectoanal inhibitory reflex (RAIR) following partial IAS sphincterectomy. Our preliminary results indicate that rabbits undergoing partial IAS sphincterectomy are incontinent, with altered fecal behavior similar to symptoms of passive FI observed in humans (Aim 1). We have developed tissue culture based techniques to isolate circular smooth muscle cells from the IAS, and enteric neuronal progenitor cells from jejunal biopsies. We have optimized our bioengineering technique to generate innervated IAS constructs with neuromuscular integrity, including identifying factors important for neural progenitor cell differentiation. We propose to expand our bioengineering design to co-culture these two cell types to generate bioengineered autologous intrinsically innervated IAS constructs. These constructs are physiologically functional, and will be subject to intensive quality control to evaluate myogenic and neurogenic properties. We propose to conduct a pre-clinical randomized rabbit trial, whereby we will implant bioengineered IAS constructs in incontinent rabbits (Aim 2). The functionality of these constructs will be evaluated in vivo using anorectal manometry, and examine the reinstatement of the RAIR. Our preliminary studies indicate that reinstatement of this neurally mediated reflex occurs following implantation of bioengineered constructs. Lastly, in order to move this project towards an Investigative New Drug (IND) application to the FDA and qualify for First-in-Human studies, we propose to streamline our manufacturing and quality control protocols to fit Current Good Manufacturing Processes (CGMP) guidelines (Aim3). Our grant proposal is tailored to directly remedy the underlying pathology of FI, namely the loss of the neuromuscular integrity of the IAS. Our preliminary results provide proof of concept for the success of this regenerative medicine approach for treatment of FI.