ACPP-TTCP Bone Cement for Strength and Biocompatibility

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current bone cements, such as acrylic-based PMMA and calcium phosphate cements, face limitations including toxicity, poor mechanical strength, brittleness, and inadequate drug release, making them unsuitable for effective bone repair and drug delivery.

Innovation Solution

A composition of amorphous calcium polyphosphate (ACPP) and tetracalcium phosphate (TTCP) cement is developed, which forms a highly viscous, biocompatible, and biodegradable matrix that can be injected and sets at physiological temperatures, providing enhanced mechanical strength and sustained drug release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If acrylic-based bone cement (PMMA) is used, then mechanical strength is improved, but toxic debris is generated and heat is produced during curing

Engineering Contradiction:

Improvemechanical strengthVSAvoidtoxic debris and heat

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing PMMA with a calcium phosphate-based system (specifically using calcium hydrogen phosphate dihydrate and tricalcium phosphate in specific ratios), thereby eliminating toxic debris generation and reducing curing temperature while maintaining mechanical strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses biodegradable calcium phosphate cement that temporarily provides mechanical support and then degrades into harmless products, replacing the permanent but toxic PMMA system with a transient, biocompatible alternative that is eventually resorbed by the body

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If calcium phosphate cement (CPC) is used, then biocompatibility is improved, but mechanical strength and osteogenesis potential are limited

Engineering Contradiction:

ImprovebiocompatibilityVSAvoidmechanical strength and osteogenesis potential

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent creates a composite calcium phosphate cement system combining calcium hydrogen phosphate dihydrate (DCPD) and tricalcium phosphate (TCP) in specific ratios, leveraging the complementary properties of each component to achieve both high mechanical strength and enhanced osteogenesis potential while maintaining biocompatibility

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent optimizes the local composition by controlling the ratio of DCPD to TCP particles, creating regions with different degradation rates and mechanical properties that collectively provide both structural support and osteoinductive signals

Inventive Principle:

Principle #3Local quality

3Ease of operation

If conventional CPC is used, then injectability is achieved, but brittleness increases after settling

Engineering Contradiction:

ImproveinjectabilityVSAvoidbrittleness

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent modifies the particle size distribution and compositional ratio parameters of the calcium phosphate cement to achieve an optimal balance between injectability and post-settling mechanical properties, preventing excessive brittleness while maintaining flowability

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If conventional CPC is used, then ease of manufacture is improved, but drug release control is inadequate

Engineering Contradiction:

Improveease of manufactureVSAvoiddrug release control

Core Design Contradiction:

Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The patent incorporates medicaments into the composite DCPD-TCP cement matrix, utilizing the dual-phase structure to achieve controlled and sustained drug release profiles while maintaining ease of manufacture through a single-mix formulation

Inventive Principle:

Principle #40Composite materials

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 ACPP/TTCP cement exhibits improved mechanical properties, stronger bonding with bone tissue, and controlled release of medicaments, addressing the limitations of existing cements by offering a more effective bone repair solution with enhanced osteogenesis and prolonged drug delivery.

Implementation Method 1

a method of making a cement from a first polyphosphate compound and a second source of calcium and phosphate

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP3256177B1Method of making injectable cements

Publication Date: 2021.04.14 WAYNE STATE UNIV

Figure 1A~1B
Figure 2~3D
Figure 4

AI summary

A discovery of the conversion of amorphous calcium polyphosphate (ACPP) or/and other polyphosphate salts with various type of calcium phosphate to new calcium phosphate product (i.e. dicalcium phosphate dihydrate (DCPD)) in a liquid environment. The discovery includes mixing a various type of calcium phosphate with an aqueous ACPP or/and other polyphosphate salts gel, which is fast setting and possessing strong mechanical strength, and can be gradually converted to DCPD/hydroxyapatites in physiological condition. This injectable past can be applied as alternative of conventional CPC bone cement that is suitable for bone void repair due to its excellent properties in osteoconductivity and osseointegration. It can also be applied as drug delivery device in tissue engineering for its strong bonding to drug molecules.