Colonic Microbiota Responsive Polymer for Targeted Drug Delivery
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Solution Overview
Problem
Existing colon-target delivery systems face challenges due to low specificity of colon response, early leakage in the stomach or small intestine, and limited efficiency of colon-specific release, primarily due to the instability of polymer materials in gastrointestinal acid-base environments and non-specific enzyme responses.
Innovation Solution
A colonic microbiota responsive polymer is developed, utilizing cellobiose or lactose as response monomers that specifically degrade in the presence of β-glucosidase and β-galactosidase, ensuring stability in gastrointestinal acid-base environments and targeted release in the colon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If commonly used colon microbiota responsive polymer materials (sodium alginate, chitosan, guar gum) are used, then the delivery system can respond to colon microbiotas, but the response specificity is low due to degradation under acid and alkaline environment stimulation and non-specific enzyme responses
Solution Approach 1:
The polymer is segmented into specific functional units: β-glucosidase responsive units (cellobiose, p-nitrophenyl-β-D-glucoside) and β-galactosidase responsive units (lactose, p-nitrophenyl-β-D-galactoside) linked to a stable backbone (carboxymethyl cellulose). This segmentation allows the polymer to maintain stability in acid-base environments while providing specific enzymatic response in the colon.
Solution Approach 2:
The invention creates a composite polymer structure combining a stable acid-base resistant backbone (carboxymethyl cellulose) with specific enzymatic response units (cellobiose, lactose, p-nitrophenyl glucoside/galactoside). This composite structure achieves both environmental stability and colon-specific responsiveness, resolving the contradiction between reliability and harmful early leakage.
2Reliability
If polymer materials are designed to respond to colon microbiotas, then targeted release can be achieved, but the materials face instability in gastrointestinal acid-base environment causing premature degradation and release
Solution Approach 1:
The polymer architecture is segmented into two functional components: a stable backbone (carboxymethyl cellulose) that resists acid-base degradation, and responsive side units (β-glucosidase/β-galactosidase responsive units) that remain intact until colon arrival. This segmentation maintains compositional stability in the upper GI tract while enabling targeted release in the colon.
Solution Approach 2:
The stable carboxymethyl cellulose backbone acts as an intermediary protective structure that shields the enzymatic response units from acid-base degradation in the stomach and small intestine. This intermediary backbone allows the polymer to traverse the upper GI tract intact and only undergo degradation when encountering specific colon enzymes, thus resolving the stability versus responsiveness contradiction.
3Reliability
If existing microbiota responsive polymers are used, then some enzyme response can be achieved, but the response lacks disease tissue specificity compared to pH or redox response materials
Solution Approach 1:
The polymer incorporates specific local quality features through the selection of β-glucosidase and β-galactosidase responsive units, which are highly abundant in colonic microbiota but absent or low in other GI tract regions. This local quality approach provides superior colon-specificity compared to general pH or redox responsive materials, while maintaining adaptability through the modular polymer structure that can accommodate different responsive units.
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 polymer achieves specific and controlled release of diagnostic or therapeutic agents in the colon, preventing early leakage in the upper digestive tract and enhancing the efficiency and specificity of colon-target delivery.
Implementation Method 1
the response monomer is a cellobiose with a β-(1,4)-glucoside bond or/and a lactose with a β-galactoside bond; the linking monomer is a monomer that reacts with the hydroxyl group of the response monomer to form an ester or ether
Implementation Method 2
β-glucosidase and β-galactosidase are the microbiotas with the highest abundance and colon specificity in colon environment
Data Source
AI summary
The invention provides a colonic microbiota responsive polymer characterized in that it is prepared by the polymerization of a response monomer and a linking monomer, wherein the response monomer is a cellobiose with a β-(1,4)-glucoside bond or/and a lactose with a β-galactoside bond; the linking monomer is a monomer that reacts with the hydroxyl group of the response monomer to form an ester or ether directly or by a crosslinking agent. The invention also provides a method for preparation of a colonic microbiota responsive polymer, a degradable film based on the polymer and a preparation method thereof. By means of the characteristics that β-(1,4)-glucoside bond provided by cellobiose or/and β-galactoside bond provided by lactose monomer unit in the polymer can specifically respond to the high abundance of microbiotas (β-glucosidase or/and β-galactosidase) in the colon to specifically degrade in the colon, a colon-targeted delivery system for diagnosis and treatment of colon diseases is constructed.