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Neonatal hypoxic-ischemic encephalopathy is the leading cause of permanent brain injury in term newborns and currently has no cure. Catalase, an antioxidant enzyme, is a promising therapeutic due to its ability to scavenge toxic reactive oxygen species and improve tissue oxygen status. However, upon in vivo administration, catalase is subject to a short half-life, rapid proteolytic degradation, immunogenicity, and an inability to penetrate the brain. Polymeric nanoparticles can improve pharmacokinetic properties of therapeutic cargo, although encapsulation of large proteins has been challenging. In this paper, we investigated hydrophobic ion pairing as a technique for increasing the hydrophobicity of catalase and driving its subsequent loading into a poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticle. We found improved formation of catalase-hydrophobic ion complexes with dextran sulfate (DS) compared to sodium dodecyl sulfate (SDS) or taurocholic acid (TA). Molecular dynamics simulations in a model system demonstrated retention of native protein structure after complexation with DS, but not SDS or TA. Using DS-catalase complexes, we developed catalase-loaded PLGA-PEG nanoparticles and evaluated their efficacy in the Vannucci model of unilateral hypoxic-ischemic brain injury in postnatal day 10 rats. Catalase-loaded nanoparticles retained enzymatic activity for at least 24 h in serum-like conditions, distributed through injured brain tissue, and delivered a significant neuroprotective effect compared to saline and blank nanoparticle controls. These results encourage further investigation of catalase and PLGA-PEG nanoparticle-mediated drug delivery for the treatment of neonatal brain injury. View Full-Text
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PEGylated Multimeric RNA Nanoparticles for siRNA Delivery in Traumatic Brain Injury
Abstract Traumatic brain injury (TBI) impacts millions of people globally, however currently there are no approved therapeutics that address long‐term brain health. In order to create a technology that is relevant for siRNA delivery in TBI after systemic administration, sub‐100 nm nanoparticles with rolling circle transcription (RCT) are synthesized and isolated in order improve payload delivery into the injured brain. Unlike conventional RCT‐based RNA particles, in this method, sub‐100 nm RNA nanoparticles (RNPs) are isolated. To enhance RNP pharmacokinetics, RNPs are synthesized with modified bases in order to graft polyethylene glycol (PEG) to the RNPs. PEGylated RNPs (PEG‐RNPs) do not significantly impact their knockdown activity in vitro and lead to longer blood half‐life after systemic administration and greater accumulation into the injured brain in a mouse model of TBI. In order to demonstrate RNA interference (RNAi) activity of RNPs, knockdown of the inflammatory cytokine TNF‐α in injured brain tissue after systemic administration of RNPs in a mouse model of TBI is demonstrated. In summary, small sub‐100 nm multimeric RNA nanoparticles are synthesized and isolated that can be modified using accessible chemistry in order to create a technology suitable for systemic RNAi therapy for TBI.
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- Award ID(s):
- 2011924
- PAR ID:
- 10576934
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 21
- Issue:
- 10
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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