Circular Non-Viral DNA Vectors for Persistent Low-Immunogenic Expression
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Solution Overview
Problem
Viral gene therapy vectors pose risks such as inflammation, immune response, cytotoxicity, mutagenesis, and carcinogenesis, limiting their clinical use, necessitating the development of safer non-viral alternatives for therapeutic gene delivery.
Innovation Solution
Circular, non-viral DNA vectors are designed with specific structural features, including inverted repeat sequences and a non-repeating nucleotide sequence, to facilitate persistent gene expression and minimize immunogenicity, devoid of CpG sequences and drug resistance genes, and incorporating bacterial origins of replication for efficient delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If viral vectors are used for gene delivery, then delivery efficiency is improved, but immune response and safety risks worsen
Solution Approach 1:
The patent extracts and eliminates the viral component from the gene delivery system, using purely non-viral DNA vectors (plasmids or circular DNA) that lack viral genomes and proteins. This removes the source of immune response while maintaining delivery capability through alternative mechanisms such as lipid nanoparticles or electroporation.
Solution Approach 2:
The patent modifies the chemical and structural parameters of the DNA vector, including using circular rather than linear topology, removing CpG sequences, and optimizing base composition. These parameter changes reduce immunogenicity while maintaining or improving delivery efficiency through enhanced cellular uptake and nuclear translocation.
2Productivity
If viral vectors are used for gene delivery, then delivery efficiency is improved, but cytotoxicity and mutagenesis worsen
Solution Approach 1:
The patent removes the viral replication machinery and proteins that cause cytotoxicity and mutagenesis, relying instead on the cell's own replication machinery to process and maintain the non-viral DNA vector. This eliminates the harmful effects while preserving delivery efficiency through controlled cellular uptake.
3Reliability
If non-viral DNA vectors are used, then safety is improved, but persistent expression worsens
Solution Approach 1:
The patent adopts circular DNA topology instead of linear plasmid structure. This circular configuration prevents linear DNA degradation, promotes stable maintenance within the cell nucleus, and enables persistent expression over time without requiring integration into the host genome, thus maintaining safety while improving duration of action.
4Productivity
If CpG sequences are included in DNA vectors, then gene expression is improved, but immunogenicity worsens
Solution Approach 1:
The patent systematically removes CpG sequences from the DNA vector construction. Alternative strategies include using synonymous codons that avoid CpG dinucleotides, removing promoter regions rich in CpG, or using circular DNA topologies that reduce CpG content. This eliminates immunogenicity while preserving gene expression through alternative regulatory elements.
Data Source
AI summary
The present disclosure relates to circular, non-viral DNA vectors, compositions including one or more of the disclosed vectors, and methods for delivering and/or expressing one or more therapeutic genes (e.g., proteins) in mammals, e.g., human patients. In some embodiments, the present disclosure is directed to circular, non-viral DNA vectors, such as circular non-viral DNA vectors including at least two inverted repeat sequences, where the at least two inverted repeat sequences are separated by a non-repeated nucleotide sequence which is not part of the at least two inverted repeat sequences. In some embodiments, the disclosed circular, non-viral DNA vectors do not include a “DD element.” In some embodiments, the disclosed circular, non-viral DNA vectors do not include a “DD element,” but include at least a portion of a bacterial origin of replication.