Antisense oligo control compounds and nanoparticle delivery systems for fire blight pathogen management

Overview

This research develops antisense oligonucleotides (ASOs) as a novel approach to controlling fire blight, a destructive bacterial disease caused by Erwinia amylovora that affects apple and pear orchards worldwide. ASOs work by silencing essential genes in the pathogen, functioning similarly to antibiotics but through a gene-silencing mechanism. Laboratory testing has demonstrated that the initial ASO compound controls E. amylovora as effectively as streptomycin, the conventional antibiotic treatment. The primary obstacle to commercial deployment is the high cost of current PNA-CPP chemistry used in ASO synthesis. This project addresses that limitation by exploring lower-cost alternative chemistries and nanoparticle-based delivery systems to make ASOs practical for agricultural field application.

Technical specifications

Core technology:

• Antisense oligonucleotides targeting Erwinia amylovora with demonstrated minimum inhibitory concentration (MIC) of 2.5 µM
• Comparable efficacy to streptomycin (MIC of 2 µM) in controlled laboratory assays

Alternative chemistries under evaluation:

• Double-stranded DNA (dsDNA) constructs
• DNA-RNA hybrid molecules (sihybrids)
• Single-stranded DNA (ssDNA) configurations
• L-DNA cycled enantiomers for enhanced stability

Nanoparticle delivery systems:

• Lipid nanoparticles for encapsulation and cellular uptake
• Anodic alumina structures for controlled release
• DNA nanostructures for targeted delivery and stability

Validation methodology: Bacterial cultures grown in LB broth, standardized to 5×10⁵ CFU/ml, tested in 96-well plate formats with optical density monitoring at 600 nm over 20 hours at 28°C.

Technology readiness level

The technology is currently at TRL 3-4 (analogous). The initial PNA-CPP ASO compound has been validated in laboratory settings against E. amylovora, confirming antibacterial efficacy comparable to streptomycin. The next phase requires approximately 1.5 years of testing to evaluate alternative chemistries and nanoparticle delivery systems for cost reduction and field readiness. This stage requires funding for synthesis and laboratory testing. Successful completion will advance the technology toward greenhouse trials and eventual commercial deployment for orchard disease management.