Cationic Lipid Delivery of Anionic CRISPR Chimeras for Deafness
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Solution Overview
Problem
Current protein delivery methods face challenges such as low efficiency, rapid degradation, and limited in vivo efficacy due to the inability of proteins to spontaneously enter mammalian cells, and existing technologies for nucleic acid delivery do not effectively address the need for efficient protein delivery, especially for intracellular targets.
Innovation Solution
A cationic lipid formulation encapsulating a chimeric molecule comprising a CRISPR/Cas molecule or Cas9 nuclease fused or complexed with a guide RNA and a negatively charged fluorescent protein, which targets the Pmca2 genetic locus, is used for efficient delivery into mammalian cells, including the inner ear, to treat deafness and associated disorders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If proteins are delivered using conventional methods (DNA/mRNA transfection), then intracellular targets can be addressed, but the risk of genomic insertion, immune response, and loss of post-translational modifications occurs
Solution Approach 1:
The patent uses cationic lipids as intermediary carriers to deliver anionic proteins across cell membranes. The lipids form complexes with the negatively charged proteins, enabling their uptake by cells through endocytosis while avoiding the need for genetic material delivery, thus eliminating genomic insertion risks while delivering functional proteins.
Solution Approach 2:
The patent changes the charge parameter of proteins by fusing them with anionic domains (such as poly glutamic acid or fluorescent proteins with net negative charge). This parameter change enables the proteins to interact with cationic lipid carriers, facilitating cellular uptake while maintaining the protein's functional integrity and post-translational modifications.
2Productivity
If proteins are delivered using cationic peptide fusion methods, then cellular uptake is enhanced, but protease degradation and neutralization by serum proteins increases
Solution Approach 1:
The patent employs cationic lipids as protective intermediaries that shield anionic proteins from protease degradation and neutralization by serum proteins during circulation. The lipid-protein complexes remain stable in bloodstream, delivering the protein intact to target cells where the protein becomes functional.
Solution Approach 2:
The patent creates composite delivery systems combining cationic lipids with anionic proteins to form stable complexes. This composite structure provides both protection during circulation and efficient cellular uptake, resolving the contradiction between stability and productivity.
3Ease of operation
If endocytic protein delivery strategies are used, then cellular entry is achieved, but endosomal escape efficiency remains low and lysosomal degradation occurs
Solution Approach 1:
The patent inverts the conventional approach by using anionic proteins with cationic lipid carriers instead of cationic proteins with anionic carriers. This inversion, combined with the specific properties of the lipid-protein complexes, enhances endosomal escape efficiency through mechanisms such as membrane disruption or pH-dependent release, thereby improving cytoplasmic delivery reliability.
4Productivity
If DNA delivery methods are used, then intracellular gene expression is achieved, but permanent genomic recombination and disruption of endogenous genes occurs
Solution Approach 1:
The patent extracts the protein delivery function from genetic material delivery. Instead of delivering DNA or mRNA that requires nuclear transport and risks genomic integration, the patent directly delivers the functional protein product through cationic lipid-anionic protein complexes, eliminating all risks associated with genomic insertion while maintaining the ability to achieve intracellular therapeutic effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables efficient and specific delivery of proteins and peptides into cells, overcoming the limitations of existing methods by utilizing cationic lipids to facilitate endosomal escape and protect against degradation, thereby effectively targeting and modifying genetic loci associated with deafness.
Implementation Method 1
A cationic lipid formulation encapsulating a chimeric molecule comprising a CRISPR/Cas molecule or Cas9 nuclease fused or complexed with a guide RNA and a negatively charged fluorescent protein
Data Source
Figure 1A~1B
Figure 2A~2F
Figure 3A~3B
AI summary
A chimeric molecule of one or more proteins or peptides fused, complexed or linked to one or more anionic molecules. Efficient in vitro and in vivo delivery is attained by encapsulating these molecules in cationic lipids or cationic liposomes. Methods of treatment include the intracellular delivery of these molecules to a specific therapeutic target.