PEGylated Polyester Nanoparticles Trigger Adverse Events in a Large Animal Model of Trauma and in Naı̈ve Animals: Understanding Cytokine and Cellular Correlations with These Events

Abstract

Intravenously infusible nanoparticles to control bleeding have shown promise in rodents, but translation into preclinical models has been challenging as many of these nanoparticle approaches have resulted in infusion responses and adverse outcomes in large animal trauma models. We developed a hemostatic nanoparticle technology that was screened to avoid one component of the infusion response: complement activation. We administered these hemostatic nanoparticles, control nanoparticles, or saline volume controls in a porcine polytrauma model. While the hemostatic nanoparticles promoted clotting as marked by a decrease in prothrombin time and both the hemostatic nanoparticles and controls did not active complement, in a subset of the animals, hard thrombi were found in uninjured tissues in both the hemostatic and control nanoparticle groups. Using data science methods that allow one to work across heterogeneous data sets, we found that the presence of these thrombi correlated with changes in IL-6, INF-alpha, lymphocytes, and neutrophils. While these findings might suggest that this formulation would not be a safe one for translation for trauma, they provide guidance for developing screening tools to make nanoparticle formulations in the complex milieux of trauma as well as for therapeutic interventions more broadly. This is important as we look to translate intravenously administered nanoparticle formulations for therapies, particularly considering the vascular changes seen in a subset of patients following COVID-19. We need to understand adverse events like thrombi more completely and screen for these events early to make nanomaterials as safe and effective as possible.

Perspectives on complement and phagocytic cell responses to nanoparticles: From fundamentals to adverse reactions

“…Later, demonstration of complement activation by Doxil ® (a long-circulating liposome formulation with encapsulated doxorubicin) [ 34 ] generated much interest in studying complement activation properties of different nano- and micro-particles (reviewed in [ 9 , 22 , 35 , 36 ]). Since then, this trend has continued with a diverse range of organic and inorganic materials [ 37 – 43 ]. Our own efforts in complement mapping have included lipid nanoparticles (including liposomes of different phospholipid composition and bilayer characteristics, and a wide range of non-lamellar liquid crystalline aqueous nanodispersions such as cubosomes and hexosomes), tumour cell-derived exosomes, polymeric nanoparticles, micelles, metallic (e.g., iron oxide) nanoparticles, dendrimers, hydrogels, carbon nanotubes, graphene oxide, and archaeal viruses (reviewed in [ 9 , 22 , 36 ]).…”

“…These observations, strongly suggest an important role for PIMs as effector cells in directing cardiopulmonary distress, particularly on robust nanoparticle clearance from the systemic circulation. Collectively, these observations have generated controversy regarding pig as a valid model for studying human infusion-reactions to nanopharmaceuticals [ 22 , 26 , 43 , 109 , 110 , 121 – 125 ].…”

In situ forming biomaterials as muscle void fillers for the provisional treatment of volumetric muscle loss injuries

“…For scanning electron microscopy (SEM), crosslinked samples were swollen overnight as described above and then lyophilized for 24 h before coating with Au/Pd (60:40) using a Cressington 108 (Cressington) before imaging. Imaging was performed via FEI NovaNano SEM 450 (HV: 5 kV, magnification: 2000×) [ 16 , 17 ].…”

Intravenous Hemostats: Foundation, Targeting, and Controlled-Release

“…However, after these PLGA nanoparticles were applied in a porcine model of trauma, the results showed that these nanoparticles would trigger complement activation and vasodilation, leading to a rapid drop in blood pressure, blood gas changes, and ultimately, increased bleeding. 103 So Nuzhat Maisha et al 76 developed another block copolymer based on poly(lactic acid) (PLA)-PEG nanoparticles (hNPs) with two molecular weights of PEG that led to no measurable complement activation in vitro. The porcine polytrauma model indicated that hNPs could promote clotting and would not activate complement.…”