Silicon Substituted Oxyapatite Bone Biomaterial
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Solution Overview
Problem
Current synthetic bone biomaterials face challenges in effectively promoting bone growth and integration, often leading to foreign body reactions and compromised physical performance, making them unsuitable for orthopedic and dental applications.
Innovation Solution
Development of silicon substituted oxyapatite (Si-OAp) with the formula Ca5(PO4)3-x(SiO4)xO(1-x)/2, where 0<x<1.0, which is synthesized by mixing a calcium phosphate colloidal suspension with fumed silica and sintering at high temperatures under vacuum, allowing silicon substitution without collapsing the apatite structure, enabling its use in various orthopedic and dental applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon is substituted into hydroxyapatite to improve biocompatibility and bone growth promotion, then the material's ability to promote bone tissue synthesis is improved, but the apatite structure may collapse to form silicocarnotite at high silicon concentrations
Solution Approach 1:
The patent applies parameter changes by precisely controlling the silicon substitution level (x value in the formula Ca5(PO4)3-x(SiO4)xO(1-x)/2) to remain below 1.0, and by controlling the sintering atmosphere (vacuum or inert gas) and temperature (900-1200°C) to prevent structure collapse while achieving desired biocompatibility and bone growth promotion properties
Solution Approach 2:
The patent creates a composite material system by substituting silicon into the hydroxyapatite lattice to form silicon-substituted oxyapatite, combining the benefits of calcium phosphate's biocompatibility with silicon's osteogenic properties while maintaining structural stability through controlled substitution levels
2Productivity
If conventional sintering methods are used to synthesize silicon-substituted hydroxyapatite, then the material can be produced, but calcium oxide and tricalcium phosphate impurities are formed compromising material purity
Solution Approach 1:
The patent employs vacuum sintering or sintering in inert gas atmosphere (nitrogen or argon) to prevent unwanted chemical reactions during the sintering process, thereby eliminating the formation of calcium oxide and tricalcium phosphate impurities while maintaining high material purity and production efficiency
Solution Approach 2:
The patent changes the sintering atmosphere parameter from conventional air to vacuum or inert gas, and optimizes the sintering temperature range (900-1200°C) to achieve complete reaction without forming impurity phases, thus simultaneously improving productivity and manufacturing precision
3Reliability
If high silicon concentration is used to enhance bone integration, then bone growth promotion is improved, but the material may undergo phase transformation to silicocarnotite losing apatite structure benefits
Solution Approach 1:
The patent precisely controls the silicon concentration parameter (x < 1.0 in the formula) to optimize bone integration capability while staying below the threshold that triggers phase transformation to silicocarnotite, thereby maintaining the beneficial apatite structure and its versatility for various orthopedic applications
Solution Approach 2:
The patent uses controlled silicon substitution as an intermediary mechanism to transfer the osteogenic benefits of silicon to the hydroxyapatite structure without allowing excessive silicon accumulation that would cause harmful phase transformation, thus mediating between bone integration requirements and structural stability
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
Si-OAp promotes biocompatibility and bone tissue synthesis, providing a substrate for mineralized matrix formation, effectively addressing the limitations of existing biomaterials by enhancing bone growth and integration while maintaining structural integrity.
Implementation Method 1
silicon substitutes for phosphorous and the OH− is progressively removed from the lattice to charge compensate for the silicon substitution
Implementation Method 2
mixing a calcium phosphate colloidal suspension with a finely dispersed, fumed silica while maintaining a ratio of Ca/(P+Si) at about 1.67 in said mixture; and sintering for about 1 hour at a temperature of about 1000° C. to about 1200° C. under vacuum
Data Source
AI summary
The invention is a silicon substituted oxyapatite compound (Si-OAp) for use as a synthetic bone biomaterial either used alone or in biomaterial compositions. The silicon substituted oxyapatite compound has the formula Ca5(PO4)3-x(SiO4)xO(1-x)/2, where 0<x<1.0.