Infections associated with osseointegrated amputation prostheses are a chronic source of pain and suffering. To address the problems of infection in these devices, a new collaboration has been formed between two research teams. The team at Thomas Jefferson University has pioneered the use of tethering technology and has successfully covalently bonded antibiotics to Ti implants for the eradication of peri-prosthetic infection. The research team at University College London has designed a biomimetic intraosseous transcutaneous amputation prosthesis (ITAP) that has been shown to be highly effective clinically. The PIs propose to combine these two technologies to generate a permanent lower limb prosthesis anchor in which infection is controlled and soft tissue bonding optimized. The goal of Specific Aim 1 is to fabricate a Ti alloy surface based on the topography of the ITAP and modified with antibiotics effective against both gram-positive (vancomycin, VAN) and gram-negative (doxycycline, dox) organisms. The objective of the studies described in Specific Aim 2 is to create a robust soft tissue-ITAP interface through bonding of ECM proteins to the implant surface. These modified surfaces will optimize the barrier function of skin to improve implant stability and resist infection.
In Specific Aim 3 both antibiotics and ECM molecules will be tethered to the ITAP to optimize soft tissue attachment and resistance to infection. As a result of these studies, modified ITAP implants will be evaluated in vivo in Specific Aim 4. Immunogenicity, biocompatibility, and resistance to subcutaneous infection will be tested in a rodent pouch model, while production of an optimized soft tissue interface and efficacy will be tested in a transcutaneous caprine model. The PIs expect that this new generation of infection-free ITAPs will ultimately result in the amelioration of the pain, suffering, and disability associated with lower limb amputation. Public Health Relevance: Osseointegrated prostheses hold out the highest probability of return to function for lower limb amputees, but are plagued by high infection rates largely due to poor skin integration and soft tissue breakdown at the implant interface. The PIs propose to integrate the work of anti-infective technologies to create an antibiotic- and extracellular matrix-bearing permanent prosthesis anchor that prevents infection and actively stabilizes the implant-soft tissue interface. A successful device would increase quality of life, and be especially beneficial for young active patients who have lost limbs and digits due to trauma, disease, or developmental abnormalities.

Public Health Relevance

Osseointegrated prostheses hold out the highest probability of return to function for lower limb amputees, but are plagued by high infection rates largely due to poor skin integration and soft tissue breakdown at the implant interface. We propose to integrate the work of anti-infective technologies to create an antibiotic- and extracellular matrix-bearing permanent prosthesis anchor that prevents infection and actively stabilizes the implant-soft tissue interface. A successful device would increase quality of life, and be especially beneficial for young active patients who have lost limbs and digits due to trauma, disease, or developmental abnormalities.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD061053-04
Application #
8307484
Study Section
Special Emphasis Panel (ZHD1-RRG-K (12))
Program Officer
Quatrano, Louis A
Project Start
2009-08-10
Project End
2014-07-31
Budget Start
2012-08-01
Budget End
2014-07-31
Support Year
4
Fiscal Year
2012
Total Cost
$316,854
Indirect Cost
$71,651
Name
Thomas Jefferson University
Department
Orthopedics
Type
Schools of Medicine
DUNS #
053284659
City
Philadelphia
State
PA
Country
United States
Zip Code
19107
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