Low-Swelling Sealing Hydrogel for Dura Mater and Drug Loading

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current hydrogel sealants for spinal and cerebral dura mater have high swelling ratios, causing tissue irritation and are not suitable for drug loading, and they lack effective antibacterial properties.

Innovation Solution

A sealing hydrogel composed of a multiarm polyethylene glycol derivative and a polyarm copolyester with an oligopeptide, optimized for low swelling and drug loading, using specific molecular weights and ratios of components, along with a bacteriostatic agent and color developer, to reduce swelling and enhance sealing strength and drug release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional PEG-based hydrogel sealants are used for spinal and cerebral dura mater sealing, then the hydrogel provides basic sealing function, but the swelling ratio becomes too large causing tissue irritation and making drug loading impossible

Engineering Contradiction:

Improveswelling ratioVSAvoidtissue irritation

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent uses a composite hydrogel system combining PEG derivative (compound A) with copolyester of glycidyl isopropyl ether and ethyl glycidyl ether (compound B). This composite material approach allows the hydrogel to achieve low swelling ratio while maintaining sealing function and enabling drug loading, thereby resolving the contradiction between swelling control and tissue irritation prevention.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If conventional hydrogel sealants with large swelling ratio are used, then the hydrogel can be applied for sealing, but the sealing performance deteriorates after drug loading

Engineering Contradiction:

Improvedrug loading capacityVSAvoidsealing performance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the physical and chemical parameters of the hydrogel by optimizing the molecular weight of PEG (1250-8000) and the composition ratio of compounds A and B. These parameter changes result in a hydrogel with controlled swelling ratio that maintains reliable sealing performance even after drug loading, thus resolving the contradiction between drug loading capacity and sealing performance.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If low-swelling PEG hydrogel is used to reduce swelling ratio, then the swelling is controlled, but strong acidity and alkalinity cause adverse irritation to tissues

Engineering Contradiction:

Improveswelling ratioVSAvoidchemical irritation

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful strong acidity/alkalinity characteristic of low-swelling PEG hydrogel into a beneficial property by combining it with copolyester compound B. This combination neutralizes the adverse chemical irritation while preserving the low swelling ratio, thus resolving the contradiction between swelling control and chemical irritation prevention.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Quantity of substance

If conventional hydrogel sealants are used for spinal surgery, then the sealing function is provided, but the risk of nerve compression increases due to swelling

Engineering Contradiction:

Improveswelling ratioVSAvoidsurgical safety

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent optimizes the molecular weight parameters of PEG (1250-8000) and the arm number (n1: 2-8, n2: 4-8) to achieve minimal swelling ratio. This parameter optimization ensures surgical safety by preventing nerve compression while maintaining effective sealing function in spinal and cerebral dura mater applications.

Inventive Principle:

Principle #35Parameter changes

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 hydrogel achieves low swelling, minimal tissue irritation, effective drug loading and release, and antibacterial properties, suitable for spinal and cerebral dura mater sealing with reduced metabolic impact and improved clinical safety.

Implementation Method 1

the sealant mainly comprises hydrophilic raw material, nucleophilic raw material... wherein the hydrophilic raw material mainly refers to the derivatives of polyethylene glycol and the nucleophilic raw material mainly refers to polyamino acid

Methodology Applied

Scientific EffectAmide bond formation: Chemical Bonding

Data Source

PatentEP4186537B1Sealing hydrogel, preparation method therefor and application thereof

Publication Date: 2025.08.20 NKD PHARMA CO LTD

AI summary

A sealing hydrogel, a preparation method therefor and an application thereof, relating to the technical field of polymer materials. Raw materials for preparing the sealing hydrogel comprise a first component and a second component. The first component comprises a compound A and a compound B. The compound A is a multiarm polyethylene glycol derivative, and the compound B is polyarm copolyester of glycidyl isopropyl ether and ethyl glycidyl ether. The second component comprises oligopeptide or a derivative thereof. By means of the selection of a high molecular weight compound in gel components and the coordination of the first component and the second component, the swelling ratio of the hydrogel can be effectively reduced.