Cell Surface Conjugation Using Sortase Recognition Motifs for Stable Delivery
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Solution Overview
Problem
Existing drug delivery systems using red blood cells face challenges such as poor stability, unwanted toxicity, and immune responses, and require genetic engineering of hematopoietic stem or progenitor cells, limiting their application.
Innovation Solution
A method to modify cells, such as red blood cells, by linking agents to membrane proteins via a sortase recognition motif using a bifunctional crosslinker, allowing for efficient and stable delivery of therapeutic agents without genetic engineering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If direct encapsulation or noncovalent attachment methods are used to modify RBCs for drug delivery, then the modification process is simple, but the stability and in vivo survival time of the modified cells deteriorate
Solution Approach 1:
The patent introduces a sortase recognition motif as an intermediary element that enables specific covalent bonding between the drug payload and RBC membrane proteins. The motif acts as a molecular mediator that facilitates stable attachment while maintaining biological functionality, resolving the contradiction between simple modification and stable in vivo survival.
Solution Approach 2:
The patent changes the chemical bonding parameter from noncovalent to covalent attachment through sortase-mediated ligation. This parameter change transforms the weak, reversible interactions into strong, stable covalent bonds, significantly improving in vivo survival time while keeping the modification process relatively simple.
2Reliability
If genetic engineering of hematopoietic stem or progenitor cells is performed to express membrane proteins, then stable drug delivery is achieved, but the complexity and time required for cell production increases significantly
Solution Approach 1:
The patent applies preliminary action by pre-modifying the drug payload with a sortase recognition motif before RBC modification. This allows the payload to be prepared in advance with the necessary recognition element, eliminating the need for complex genetic engineering of RBCs and simplifying the overall production process while maintaining stable drug delivery.
Solution Approach 2:
The patent inverts the traditional approach by instead of engineering cells to express recognition motifs, the payload is engineered with the motif and then attached to native RBC membrane proteins. This inversion simplifies the process by using naturally occurring RBCs without genetic modification, reducing complexity while achieving stable drug delivery.
3Reliability
If wild type sortase A is used for covalent attachment of payloads to RBCs, then stable linkage is achieved, but the process requires complex multi-step procedures including HSPC engineering and differentiation
Solution Approach 1:
The patent extracts the essential function of sortase-mediated ligation from the complex HSPC engineering process. By separating the recognition motif attachment from cell engineering, the patent achieves stable payload linkage using a simplified procedure that directly modifies RBCs without requiring stem cell manipulation and differentiation.
4Adaptability or versatility
If encapsulation methods are used to load drugs into RBCs, then drug delivery capability is improved, but cell membrane integrity is disrupted and in vivo survival rates decrease
Solution Approach 1:
The patent uses a sortase recognition motif as an intermediary that enables drug attachment to the cell surface without disrupting membrane integrity. This mediator approach allows effective drug delivery capability while preserving RBC membrane structure and function, improving in vivo survival rates compared to encapsulation methods.
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
The modified cells maintain their biological properties and stability, with agents remaining in circulation for up to 28 days, enabling effective delivery of drugs and probes for treating various diseases.
Implementation Method 1
Bacterial sortases are transpeptidases capable of modifying proteins in a covalent and site-specific manner
Implementation Method 2
the first bifunctional crosslinker crosslinks said side chain amino group and at least one exposed sulfhydryl of the at least one membrane protein
Data Source
AI summary
Provided is a cell having an agent linked thereto, wherein the agent is linked to at least one membrane protein of the cell via a linker comprising a N-terminal glycine through sortase recognition motif. Also provided is a method for obtaining the modified cell, as well as the use of the modified cells for delivering agents such as drugs and probes.