Tailored siRNA delivery to human endothelium to inhibit and reverse inflammatory damage following ischemia reperfusion injury in the kidney

Abstract
Ischemia reperfusion injury (IRI) causes endothelial inflammation and microvascular rarefaction that leads to
adverse kidney graft outcomes in organ transplant. Direct treatment of endothelial cells (EC) can reduce the
impact of IRI on the health of the graft, but there is a lack of EC targeted therapies that can effectively
intervene and alleviate the various modes of dysfunctional endothelial response. The goal of this work is to
develop a therapeutic strategy that addresses the two key modes of endothelial damage in response to IRI:
dysfunctional inflammation in ECs and damage to capillary networks, in a site-specific and temporary manner.
We propose that therapeutic siRNA can be delivered directly to endothelial cells using polymeric nanoparticles
(NPs), which provide a customizable platform to enhance the cell penetration and to sustain the delivery of
nucleic acids. In Aim 1, we will determine the NP characteristics utilizing a novel family of PACE polymers that
enable maximum and sustained siRNA to endothelial cells in order to reduce adhesion molecule expression
upon inflammatory activation. In Aim 2, we will translate this knowledge of structure/function relationship of the
NP to rationally design siRNA-mediated knockdown of adhesion molecules in relevant models of 3D human
vasculature and evaluate the long-term effect after transplantation in vivo. In the R00 phase of the award, the
principles determined in Aim 1 and 2 to impact endothelial-NP interaction will be applied to polymer NPs
delivered within a hydrogel delivery vehicle to the renal cortex. Aim 3 will investigate the potential of
endothelial-tailored siRNA-NPs to locally deliver anti-fibrotic siRNAs within an ECM-derived hydrogel to IRI-
damaged renal cortex in vivo.
Dr. Laura Bracaglia has earned her PhD in Bioengineering and is currently a postdoctoral fellow in the
Department of Biomedical Engineering at Yale University. In her training so far, she has studied NP and drug
delivery methods in human tissue models that provide translatable insights into vascular inflammation. To
successfully accomplish the specific aims of this proposal, Dr. Bracaglia has identified that she will need
additional training in the 1) chemical and polymer science aspects involved in the development of NPs. In
addition, the impact of the proposed work would be enhanced with training and expertise in 2) vascular
immune biology, 3) renal pathology and response to injury, and 4) translation to human immunology. To train in
these areas, Dr. Bracaglia has assembled a team of expert mentors who can provide clinical perspective and
technical expertise. In addition, she has planned key course work and set milestones for progress in scientific
and professional goals. This proposed training in the K99 mentored phase will support meeting the initial goals
of this work. NP treatment strategies developed during the mentored phase, together with her expertise in the
development of ECM-based biomaterials, will support the final aim of this proposal (R00).

Grant Number: 5R00HL157552-05
NIH Institute/Center: NIH
Principal Investigator: Laura Bracaglia