Charged Collagen Matrices with Variable Cross-Linking for Release Control
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Solution Overview
Problem
Existing collagen matrices for drug delivery and tissue regeneration lack optimal control over the binding and release of therapeutic agents, leading to excessive or off-target release, and require improved modularity in degradability.
Innovation Solution
A cross-linking method using water-soluble cross-linkers to impart charge and vary cross-linking density in collagen matrices, allowing for controlled release and degradation profiles, achieved by using dextran aldehyde, DEAE-dextran aldehyde, and CM-dextran aldehyde cross-linkers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional collagen matrices are used for drug delivery, then the therapeutic agents can be carried and released in physiological environment, but the binding of therapeutic agents to collagen matrices is not optimal leading to excessive or off-target release
Solution Approach 1:
The patent applies parameter changes by introducing charged cross-linkers (cationic or anionic) to modify the charge density of collagen matrices. This changes the electrostatic interaction parameters between the matrix and therapeutic agents, enabling optimal binding and controlled release. The charge density is adjusted as a key parameter to achieve reliable therapeutic agent delivery without excessive or off-target release.
2Reliability
If collagen matrices are used for tissue regeneration, then they provide structural support and promote healing, but the degradability of the collagen devices cannot be effectively modulated
Solution Approach 1:
The patent uses parameter changes by varying the cross-linking density through different concentrations of charged cross-linkers. This modifies the degradation rate parameter of the collagen matrix while maintaining its structural support function. Higher cross-linking density slows degradation, providing longer-lasting structural support, while lower density allows faster degradation for temporary support applications.
Solution Approach 2:
The patent creates composite materials by combining collagen with charged cross-linkers (dextran aldehyde, DEAE-dextran aldehyde, or CM-dextran aldehyde). This composite structure provides both the structural support properties of collagen and the tunable degradability through the cross-linking network, enabling adaptability in degradation rates while maintaining reliable tissue regeneration support.
3Strength
If uniform cross-linking is applied throughout collagen matrix, then structural integrity is maintained, but variable resorption time and localized control over therapeutic release cannot be achieved
Solution Approach 1:
The patent applies local quality by enabling spatially variable cross-linking density within the collagen matrix. Different regions can have different concentrations of charged cross-linkers, creating zones with different degradation rates and therapeutic release profiles. This allows localized control over resorption time while maintaining overall structural integrity through the interconnected cross-linked network.
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 method enables precise control over the release and sequestration of therapeutic agents, directing cell growth and enhancing tissue regeneration by varying charge and degradation profiles, with applications in wound healing and drug delivery.
Implementation Method 1
The cross linkers are water soluble solids that can be dissolved into collagen suspension prior to lyophilization. This allows for varying cross-linking density within a continuous lyophilized collagen foam.
Implementation Method 2
The cross linkers can also carry a negative or positive charge which can vary charge density of cross-linked collagen foam. The charge may sequester proteins and drugs in a specific manner along the surface of a collagen device.
Implementation Method 3
A sheet of collagen matrix may be produced from a process comprising the steps of preparing a dispersion of collagen, lyophilizing the collagen dispersion to dryness
Data Source
AI summary
Collagen matrices of varying charge and cross-linking density are disclosed, and methods for preparing such collagen matrices. The cross-linking methods for collagen impart charge and allow for variable cross-linking density within the collagen device. Such variable cross-linking density imparts variable collagen resorption time, and the variable charge allows sequestering and then releasing therapeutics in a controlled manner. The techniques may be used to impact in vitro mineralization via the charged collagen platform by its interaction with rhBMP-2. The techniques can be used to create a positively charged collagen skin substitute that resists infection and supports wound closure.