TiN Microgrooved PCL Nanofiber Coating for Joint Prosthesis
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Solution Overview
Problem
Current metal implants face challenges with poor osseointegration due to inadequate adhesion of polycaprolecton (PCL) electrospun nanofibers (ENF) with implant surfaces, leading to implant loosening and failure, especially in total joint arthroplasty surgeries, as existing methods struggle with fiber detachment and toxicity issues.
Innovation Solution
The method involves creating microgrooves on titanium implants using machine sawing and titanium nitride (TiN) ion deposition, followed by coating with PCL ENF and collagen, enhanced with magnesium oxide nanoparticles and fibronectin, to improve mechanical stability and osseointegration by increasing the surface area contact and bioactivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PCL electrospun nanofibers are applied as a coating around the implant, then bone growth is improved, but adhesion with implant surface is poor leading to fiber detachment
Solution Approach 1:
The patent introduces an intermediary layer consisting of microgrooves and TiN deposition on the implant surface to mediate between the PCL nanofibers and the metal implant. The microgrooves provide mechanical interlocking while TiN creates a bioactive surface that enhances fiber adhesion, solving the detachment problem while maintaining bone growth promotion
Solution Approach 2:
The patent creates a composite coating structure combining PCL electrospun nanofibers with TiN deposited microgrooves on the implant surface. This composite approach integrates the bone growth properties of PCL with the adhesion-enhancing properties of TiN, achieving both improved bone growth and strong fiber-implant bonding
2Reliability
If PCL ENF matrix is used as coating material, then bone growth is promoted, but adhesion with implant surface is insufficient at physiological load bearing conditions
Solution Approach 1:
The patent applies preliminary surface modification actions by creating microgrooves and depositing TiN on the implant surface before applying the PCL nanofiber coating. This preliminary preparation ensures that the coating has optimal adhesion properties from the outset, enabling it to withstand physiological loads while promoting bone growth
Solution Approach 2:
The patent applies local quality enhancement by concentrating TiN deposition and microgroove formation at the implant surface where adhesion is critical, while the PCL nanofibers provide localized bone growth promotion. This spatial differentiation of functions optimizes both mechanical stability and biological activity
3Ease of manufacture
If existing coating methods are used, then implant surface is modified, but fiber detachment and toxicity issues occur
Solution Approach 1:
The patent uses TiN deposition as an intermediary layer that facilitates coating retention. The TiN layer acts as a bridge between the metal implant and PCL nanofibers, preventing direct contact that causes detachment while maintaining ease of coating application through standard electrospinning processes
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
This approach significantly enhances the mechanical stability and osseointegration of titanium implants by promoting better bone growth and reducing the risk of implant loosening, as demonstrated by increased shear strength and bone tissue growth in experimental results.
Implementation Method 1
Polycaprolecton (PCL) Electrospun Nanofibers (ENF) have numerous biomedical applications. Co-pending application Ser. No. 14/734,147 and U.S. Pat. No. 9,359,694 by the present Applicant disclose a method and apparatus for controlled deposition of branched ENF on biomedical implants and material.
Implementation Method 2
The method involves creating microgrooves on titanium implants using machine sawing and titanium nitride (TiN) ion deposition
Implementation Method 3
coating with PCL ENF and collagen, enhanced with magnesium oxide nanoparticles and fibronectin, to improve mechanical stability and osseointegration by increasing the surface area contact and bioactivity
Implementation Method 4
coating with PCL ENF and collagen, enhanced with magnesium oxide nanoparticles and fibronectin, to improve mechanical stability and osseointegration
Data Source
AI summary
The present invention provides a process to functionalize nanofiber membrane (NFM) on a total joint replacement (TJR) implant surface to support bone ingrowth and reduce macrophage-associated inflammation, the process comprising amending the implant surface by laser cutting microgrooves greater than 100 μm in depth to protect functional PCL NFM from applied loading, induce a higher amount of osteoblast cell function, increase implant-bone contact area, and serve as a reservoir for the local delivery of biomolecules to increase osseointegration of the implant; depositing aligned fibers on the implant surface, the fibers aligned in the direction of the microgrooves and collected in layers until a thickness less than 30 μm is reached and preferably in the range of 1 μm to 10 μm. Biofunctionalized NFM are used to indirectly attach biomolecules on said implant surface, or extracellular matrix proteins with biomolecules are immobilized and deposited on the PCL NFM coated implant.