Asymmetrically Branched Degradable PEG Derivative Limits Cell Vacuolation
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Solution Overview
Problem
Existing high-molecular-weight branched polyethylene glycol derivatives cause vacuolation in cells and lack effective degradation mechanisms, limiting their use in modifying bio-related substances.
Innovation Solution
A branched degradable polyethylene glycol derivative with an oligopeptide structure that is stable in blood and degrades intracellularly, featuring specific enzymatic degradation sites to prevent vacuole formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If high-molecular-weight polyethylene glycol (molecular weight 40,000 or more) is used to modify bio-related substances, then the blood half-life is significantly extended, but vacuoles are generated in cells of tissues
Solution Approach 1:
The invention changes the molecular weight parameter of polyethylene glycol from high-molecular-weight (40,000 or more) to low-molecular-weight (20,000 or less), specifically using 6,000 or less. This parameter change resolves the contradiction by maintaining the blood half-life extension effect while eliminating vacuole formation in cells, as confirmed by the experimental data showing no vacuoles at molecular weight 20,000 and below
Solution Approach 2:
The invention uses low-molecular-weight polyethylene glycol that can be rapidly excreted from the body through kidneys and lungs. This short-living approach allows the polyethylene glycol to perform its blood half-life extension function temporarily without accumulating to toxic levels that cause vacuole formation, enabling safe repeated administration
2Object-affected harmful factors
If the molecular weight of polyethylene glycol is reduced to suppress vacuoles, then vacuole formation is prevented, but the blood half-life cannot be improved sufficiently
Solution Approach 1:
The invention optimizes the molecular weight parameter to a specific range (6,000 or less, preferably 2,000 or less) where the polyethylene glycol maintains sufficient blood half-life extension capability while completely preventing vacuole formation. This precise parameter optimization resolves the contradiction by identifying the optimal molecular weight window that balances both requirements
Solution Approach 2:
The invention creates a composite structure by combining low-molecular-weight polyethylene glycol with bio-related substances through chemical modification. This composite approach allows the polyethylene glycol to provide its protective and half-life extending functions while its low molecular weight ensures rapid excretion and prevents vacuole formation, achieving both goals simultaneously
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 derivative maintains blood stability and half-life comparable to conventional polyethylene glycol derivatives while preventing vacuole formation in cells, facilitating industrial production with reduced impurities.
Implementation Method 1
a branched degradable polyethylene glycol derivative... that is degraded in the cells... featuring specific enzymatic degradation sites
Data Source
AI summary
A branched degradable polyethylene glycol derivative with a high molecular weight that does not cause vacuolation of cells is provided. A branched degradable polyethylene glycol derivative represented by the following formula (1), containing, in a molecule, an oligopeptide that is degraded in the cells:wherein k1 and k2 are each independently 1-12, j1 and j2 are each independently 45-950, R is a hydrogen atom, a substituted or unsubstituted alkyl group having 1-12 carbon atoms, a substituted aryl group, an aralkyl group or a heteroalkyl group, Z is an oligopeptide that is degraded by enzyme in the cells, X is a functional group capable of reacting with a bio-related substance, and L1 and L2 are each independently a single bond or a divalent spacer.