Collagen Matrix with Hydroxyapatite for Sustained Growth Factor Release

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for delivering growth factors like bone morphogenic proteins using collagen sponges result in rapid release and migration, reducing their efficacy in promoting bone and cartilage growth, and requiring excessive dosages, which can lead to side effects and instability in the microenvironment.

Innovation Solution

A biodegradable collagen matrix is created by mixing an acidic collagen slurry with a water-soluble bioactive agent under conditions that allow self-assembly into macroscopic collagen fibers, with the bioactive agent being bound to the fibers, and optionally incorporating bone powder or calcium phosphate to enhance osteoinductivity and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If bone morphogenic proteins are added to collagen sponges, then the collagen sponge can deliver the bioactive agent, but the bone morphogenic proteins are released too quickly and migrate excessively, reducing their efficacy

Engineering Contradiction:
Improveretention time of bone morphogenic proteinsVSAvoidefficacy in promoting bone and cartilage growth
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent uses a composite material consisting of collagen sponges combined with hydroxyapatite particles. This composite structure allows the bone morphogenic proteins to bind to both the collagen matrix and the hydroxyapatite surface, creating multiple retention mechanisms that prevent rapid release and migration, thereby extending the duration of action while maintaining reliability of the bioactive agent's efficacy

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical and chemical parameters of the collagen sponge by incorporating hydroxyapatite particles, which alter the binding characteristics and release kinetics of the bone morphogenic proteins. This parameter change transforms the release profile from rapid to sustained, resolving the contradiction between retention time and efficacy

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If excessive amounts of growth factor are used to compensate for rapid release, then the microenvironment stability is maintained, but side effects are exaggerated and dosages become uneconomically large

Engineering Contradiction:
Improvestability of microenvironment for bone and cartilage growthVSAvoidside effects from excessive growth factor dosage
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

By changing the release parameters through the hydroxyapatite-collagen composite structure, the patent achieves stable microenvironment conditions with controlled, sustained release of bone morphogenic proteins. This eliminates the need for excessive dosages, thereby reducing side effects while maintaining microenvironment stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Hydroxyapatite acts as an intermediary material that mediates the release of bone morphogenic proteins from the collagen sponge. It provides a controlled interface that regulates the interaction between the bioactive agent and the surrounding tissue, ensuring stable microenvironment conditions without requiring excessive dosages

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If bone morphogenic proteins are physically incorporated in collagen sponges, then the collagen sponge can be used as a carrier, but the original bonding found in nature is not recreated, causing rapid release

Engineering Contradiction:
Improveease of incorporating bioactive agent into carrierVSAvoidretention time of bone morphogenic proteins
Core Design Contradiction:
Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The patent creates a composite material system where hydroxyapatite particles are incorporated into the collagen sponge matrix. This composite structure provides natural-like bonding sites for bone morphogenic proteins through the hydroxyapatite surface, recreating the original biological bonding while maintaining the ease of manufacturing associated with sponge-based carriers

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Hydroxyapatite serves as an intermediary that restores the natural bonding mechanism between bone morphogenic proteins and the carrier. The hydroxyapatite surface provides specific binding sites that mimic natural bone interfaces, allowing the proteins to bind in a manner similar to their natural state while still using the convenient sponge carrier format

Inventive Principle:
Principle #24Intermediary (Mediator)

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 collagen matrix effectively retains bioactive agents, providing sustained release and enhanced osteoinductive properties, improving bone and cartilage repair by maintaining the bioactive agents' efficacy and reducing side effects, while allowing for better integration and growth into host bone.

Implementation Method 1

raising the pH of the slurry to from about 5 to about a pH of 9; and/or adding bone powder, calcium phosphate, hydroxyapatite, DBM or a mixture thereof to the acidic collagen slurry in order to raise the pH from about 5 to about 9

Methodology Applied
Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 2

the bioactive agent is bound to the macroscopic collagen fibers

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentUS10111983B2Collagen matrix
Publication Date: 2018.10.30 WARSAW ORTHOPEDIC INC

AI summary

Methods for making a biodegradable collagen matrix having increased osteoinductivity and a biodegradable collagen matrix prepared by these methods are provided. In various embodiments, the methods include providing an acidic collagen slurry and mixing it with at least one water soluble and/or hydrophilic bioactive agent under conditions sufficient to cause the collagen slurry to self-assemble into macroscopic collagen fibers and cause the at least one bioactive agent to form a collagen matrix containing the bioactive agent. Conditions sufficient to cause the collagen slurry to self-assembly include raising the pH of the slurry to from about 5 to about a pH of 9 and/or adding bone powder, calcium phosphate, hydroxyapatite, DBM or a mixture thereof to the acidic collagen slurry in order to raise the pH from about 5 to about 9.