Delayed-Setting Calcium Phosphate Paste for Orthopedic Implants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing calcium phosphate implants and delivery vehicles face limitations such as limited conformability, inadequate structural integrity, and difficulty in shaping to fit individual skeletal defects, along with challenges in long-term storage due to premature hardening of calcium phosphate pastes.
Innovation Solution
Development of delayed-setting calcium phosphate pastes using non-aqueous liquids with less than 5% water, which form a hardened material when exposed to a moist environment, allowing for improved conformability and storage stability, and can be formulated with biologically active agents for orthopedic applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If calcium phosphate paste is stored for long-term, then storage stability is improved, but the paste hardens over time making manipulation difficult
Solution Approach 1:
A non-aqueous liquid serves as an intermediary medium between the calcium phosphate powder and water. This liquid contains a water-trapping agent that sequesters water molecules, preventing them from catalyzing the hardening reaction. The non-aqueous liquid acts as a protective barrier that allows long-term storage while delaying the setting process until implantation.
Solution Approach 2:
The invention changes the chemical environment parameters by using a non-aqueous liquid with specific water content (less than 5% w/w) instead of conventional aqueous liquids. This parameter change fundamentally alters the reaction kinetics, transforming the paste from one that hardens rapidly to one that remains stable for extended periods while maintaining workability.
2Strength
If conventional ceramics are used for structural support, then structural integrity is improved, but conformability to skeletal defects deteriorates
Solution Approach 1:
The calcium phosphate paste transitions from a static, rigid ceramic form to a dynamic, moldable paste state. The paste maintains structural integrity during storage but becomes adaptable and conformable when applied to skeletal defects, allowing it to be shaped to fit individual patient requirements before hardening in place.
Solution Approach 2:
The invention utilizes parameter changes in the physical state and chemical composition to achieve both structural integrity and conformability. The non-aqueous liquid formulation maintains the material in a stable, transportable state while allowing it to be molded and shaped, then triggers controlled hardening to achieve final structural support.
3Strength
If sintered hydroxyapatite blocks are used, then structural support is improved, but ease of shaping deteriorates
Solution Approach 1:
The calcium phosphate material is prepared in a pre-molded paste form that can be shaped and contoured to fit specific skeletal defects before implantation. This preliminary shaping action is possible because the non-aqueous liquid formulation maintains workability and moldability while providing sufficient structural support during handling and application.
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 delayed-setting pastes provide a biocompatible, bioresorbable, and bioactive material that can be easily shaped and stored, offering enhanced structural integrity and controlled release of therapeutic agents, improving orthopedic treatments by promoting bone growth and structural support.
Implementation Method 1
the paste forms a hardened calcium phosphate material when placed in a moist environment
Implementation Method 2
The delayed-setting paste includes poorly crystalline apatitic calcium phosphate solids with calcium-to-phosphate (Ca/P) ratios comparable to naturally occurring bone minerals
Data Source
AI summary
The invention features delayed-setting calcium phosphate pastes which are useful for the preparation of delivery vehicles for biologically active agents, useful for the treatment of orthopedic conditions and can be stored for long periods without prematurely setting.