Composite Bone Cement with Ammonium Ions for Adjustable Resorption
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Solution Overview
Problem
Conventional bone cements exhibit low bioresorption rates, high dissolution rates, and inadequate mechanical strength, limiting their effectiveness in orthopedic and dental applications, while also having prolonged setting times that hinder practical application.
Innovation Solution
A calcium phosphate-calcium sulfate composite bone cement formula with a specific powder and liquid component ratio, including tetracalcium phosphate, dicalcium phosphate, and calcium sulfate hemihydrate, and ammonium ions, which allows for adjustable bioresorption rates and enhanced mechanical strength, along with the incorporation of pore-forming agents for porosity and improved handling characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If calcium phosphate is used as bone cement, then mechanical strength and biocompatibility are improved, but bioresorption rate becomes too low
Solution Approach 1:
The patent applies composite materials by combining calcium phosphate (providing mechanical strength) with calcium sulfate (providing high bioresorption rate). The composite formula includes tetracalcium phosphate, dicalcium phosphate, and calcium sulfate hemihydrate in specific ratios, creating a material that exhibits both high strength and appropriate bioresorption characteristics for bone repair applications.
2Reliability
If calcium sulfate is used as bone cement, then bioresorption rate is improved, but mechanical strength becomes too low
Solution Approach 1:
The patent applies composite materials by combining calcium phosphate (providing mechanical strength) with calcium sulfate (providing high bioresorption rate). The composite formula includes tetracalcium phosphate, dicalcium phosphate, and calcium sulfate hemihydrate in specific ratios, creating a material that exhibits both high strength and appropriate bioresorption characteristics for bone repair applications.
3Reliability
If conventional bone cement paste is used, then biocompatibility is improved, but setting time becomes too prolonged
Solution Approach 1:
The patent applies parameter changes by optimizing the liquid-to-powder ratio to 0.20-0.50 cc/g and incorporating ammonium ions in the setting liquid. These parameter modifications accelerate the setting reaction while maintaining biocompatibility, reducing setting time from conventional prolonged durations to a practical range for surgical applications.
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 composite bone cement achieves a balance of bioresorbability, mechanical strength, and adjustable resorption rates, providing a suitable working and setting time, ensuring effective bone repair with minimal toxicity and improved handling properties.
Implementation Method 1
the compound of calcium sulfates also illustrate higher dissolution rates
Implementation Method 2
brushite forming bone cements comprising the powders beta-tricalcium phosphate (TCP), monocalcium phosphate monohydrate (MCP) and calcium sulphate hemihydrate (CSH)
Data Source
AI summary
The present invention provides a bone cement formula having a powder component and a setting liquid component, wherein the powder component includes a calcium sulfate source and a calcium phosphate source with a weight ratio of the calcium sulfate source less than 65%, based on the total weight of the calcium sulfate source and the calcium phosphate source, and the setting liquid component comprises ammonium ion (NH4+) in a concentration of about 0.5 M to 4 M, wherein the calcium phosphate source includes tetracalcium phosphate (TTCP) and dicalcium phosphate in a molar ratio of TTCP to dicalcium phosphate of about 0.5 to about 2.5, and the calcium sulfate source is calcium sulfate hemihydrate (CSH), calcium sulfate dehydrate (CSD), or anhydrous calcium sulfate.