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新型大便失禁（FI）疗法推向市场。FI是粪便物质的反复不受控制的通过。肛门内括约肌（IAS）负责维持肛门直肠括约肌。IAS的功能取决于平滑肌和肠内神经系统（ENS）的神经肌肉完整性。目前，大便失禁的动物模型不能模拟在人类中观察到的被动FI症状。我们建议进一步开发一种新的手术技术，在实验室中开发的诱导大便失禁的兔子损伤IAS和利用这个模型来验证植入生物工程神经支配的IAS结构治疗FI的疗效。我们的外科手术不会导致肛门外括约肌（EAS）损伤，从而限制了IAS平滑肌层的损伤。通过肛门直肠测压检查表明IAS静息压的丧失以及IAS括约肌部分切除术后神经介导的直肠肛门抑制反射（RAIR）。我们的初步结果表明，接受部分IAS括约肌切除术的兔子失禁，粪便行为改变，类似于在人类中观察到的被动FI症状（目的1）。我们已经开发了基于组织培养的技术，从IAS中分离出环形平滑肌细胞，从空肠活检中分离出肠神经元祖细胞。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受神经支配的IAS构建体，包括识别对神经祖细胞分化重要的因素。我们建议扩大我们的生物工程设计，共培养这两种细胞类型，以产生生物工程自体内在神经支配的IAS结构。这些构建体具有生理学功能，并且将经受严格的质量控制以评价肌原性和神经原性特性。我们建议进行临床前随机兔子试验，从而我们将植入生物工程IAS结构在失禁兔子（目标2）。将使用肛门直肠测压法在体内评价这些结构的功能，并检查RAIR的恢复。我们的初步研究表明，这种神经介导的反射发生后，植入生物工程结构的恢复。最后，为了将该项目推向FDA的研究性新药（IND）申请并获得首次人体研究的资格，我们建议简化我们的生产和质量控制方案，以符合当前的良好生产工艺（CGMP）指南（Aim3）。我们的拨款建议是量身定制的，以直接补救潜在的病理FI，即损失的神经肌肉完整性的国际会计准则。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.