OC 23.1 - Transfusion of RNA-Edited Platelets in a Rodent Model of Polytrauma: A Pilot Study

Sunday, June 25, 2023

14:45 – 15:00 ET

Room: 710B

Session Available As: On-Demand

Presenting Author(s)

Jerry Leung (he/him/his)

PhD Candidate
The University of British Columbia
Vancouver, British Columbia, Canada

Co-Author(s)

Katherine Badior, PhD

Post-doctoral Research Fellow
Versiti Blood Research Institute
Wauwatosa, Wisconsin, United States
Colton Strong (he/him/his)

PhD Candidate
The University of British Columbia
Vancouver, British Columbia, Canada
XW

Xiaowu Wu

Science Lead
U.S. Army Institute of Surgical Research
San Antonio, Texas, United States
MM

Michael Meledeo

Science Lead, Blood and Shock Resuscitation CRT1
U.S. Army Institute of Surgical Research
San Antonio, Texas, United States
EJ

Eric Jan

Professor
University of British Columbia
Vancouver, British Columbia, Canada
DD

Dana Devine

Professor
The University of British Columbia
Vancouver, British Columbia, Canada
PC

Pieter Cullis

Professor
The University of British Columbia
Vancouver, British Columbia, Canada
Christian Kastrup, PhD

Senior Investigator
Versiti Blood Research Institute
Wauwatosa, Wisconsin, United States

Background: Platelets transfusions are one of the most common cell therapies and hold potential to be expanded for other therapeutic indications. We demonstrated that human platelets can be engineered using lipid nanoparticles (LNPs) to express exogenous protein. In this presentation, we tested whether LNP-engineered platelets retain their function once transfused, using an in vivo transfusion model of severe hemorrhage.

Aims: To (1) determine an optimal LNP that enables exogenous protein production in rodent platelets, and (2) evaluate if LNP-engineered rat platelets can be transfused and contribute to hemostasis in a rat model of polytrauma and hemorrhage.

Methods: Platelets, isolated from rat whole blood, were washed and incubated with varying LNPs encapsulating mRNA encoding for nanoluciferase. After identifying the formulation yielding the highest nanoluciferase expression, washed rat platelets were transfected with the optimized LNP and transfused into injured rats following polytrauma. Kidney bleeding time, blood loss, and various ROTEM parameters were determined. Histological analyses was used to assess if LNP-treated platelets localized to the wound.

Results: Rat platelets expressed nanoluciferase (Fig. 1A), with the optimal LNP (Formulation D) yielding three-fold higher expression relative to the pre-optimized LNP (Formulation A). After transfusion, LNP-treated platelets displayed comparable ROTEM parameters relative to control platelets, and rats transfused with LNP-treated platelets had no significant differences in bleeding times and blood loss compared to controls (Fig. 1B,C). Histological analyses demonstrated localization of the LNP-treated platelets to the wound site.

Conclusion(s): Rat platelets can be transfected with LNPs to express exogenous protein without loss of efficacy, can be transfused, and appear safe in this pilot study. Future studies using this pre-clinical model will evaluate the transfusion efficacy of platelets engineered to express therapeutically relevant proteins to develop more effective platelet products. This study was supported by the US Department of Defense Investigator-Initiated Research Award.

Learning Objectives:

Describe the use of a rodent model of polytrauma to assess platelet function
Evaluate whether RNA-edited platelets retain hemostatic function and are safe for transfusion in a bleeding model
Discuss the potential of RNA-edited platelets as a future therapeutic