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Biomodulation of an implant for enhanced bone-implant anchorage

Raina, Deepak Bushan LU ; Larsson, David LU ; Sezgin, Erdem Aras LU ; Isaksson, Hanna LU orcid ; Tägil, Magnus LU and Lidgren, Lars LU (2019) In Acta Biomaterialia 96. p.619-630
Abstract

Aseptic loosening of implants is the major cause for revision surgery. By modulating the bone-implant interface, early bone-implant anchorage could be improved. Implant surface manipulation by the addition of osteopromotive molecules locally and systemically to promote implant integration has been described with limited success. This study describes a novel approach by making the implant capable of biologically modulating its surroundings. It was hypothesized that the early implant fixation would improve by filling the interior of the implant with a carrier providing spatio-temporal release of bone active drugs with known osteogenic effect. The implant consisted of a threaded polyether ether ketone (PEEK) hollow chamber with holes at... (More)

Aseptic loosening of implants is the major cause for revision surgery. By modulating the bone-implant interface, early bone-implant anchorage could be improved. Implant surface manipulation by the addition of osteopromotive molecules locally and systemically to promote implant integration has been described with limited success. This study describes a novel approach by making the implant capable of biologically modulating its surroundings. It was hypothesized that the early implant fixation would improve by filling the interior of the implant with a carrier providing spatio-temporal release of bone active drugs with known osteogenic effect. The implant consisted of a threaded polyether ether ketone (PEEK) hollow chamber with holes at the bottom. The implant was filled with a calcium sulphate (CaS)/hydroxyapatite (HA) carrier, delivering two bone active molecules; zoledronic acid (ZA) and bone morphogenic protein-2 (BMP-2). At first, a rat abdominal muscle pouch model indicated a sustained in-vivo release of both 125I-rhBMP-2 (57%) and 14C-ZA (22%) from the CaS/HA carrier over a period of 4-weeks. The biomodulated implant was then inserted in the proximal tibia in rats with the following experimental groups: G1) Empty implant, G2) Implant + CaS/HA, G3) Implant + CaS/HA + ZA and G4) Implant + CaS/HA + ZA + rhBMP-2. Significantly higher bone volume (BV) was seen around the implant in groups G3 (3.3 ± 0.7 mm3) and G4 (3.1 ± 0.7 mm3) compared to the control (1.3 ± 0.4 mm3) using micro-computed tomography and qualitative histology. Group G3, also exhibited significantly higher pull-out force and absorbed energy when compared to the control group G1. These findings indicate that a low dose of ZA alone, released in a controlled manner from within a fenestrated implant is enough to improve implant anchorage without the need of adding rhBMP-2. This simple method of using a fenestrated implant containing a ceramic carrier releasing bone active molecules improved bone anchorage and could clinically reduce prosthetic failure. Statement of Significance: Aseptic loosening remains as a major cause for implant revisions and early reaction of surrounding bone to the prosthesis is important for longevity. A novel approach to enhance early bone-implant anchorage is presented. The implant is filled with a carrier providing controlled release of bone active molecules. In an animal model, a calcium sulphate (CaS)/hydroxyapatite (HA) carrier was used to provide a spatio-temporal release of bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA). Significantly better bone-implant integration was achieved using ZA alone, thereby eliminating the need for adding BMP-2. The developed method of implant biomodulation holds potential to prevent implant loosening and is an alternative to prosthetic coatings or systemic drug treatment. Importantly, all constituents are approved for clinical use.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
BMP-2, Ceramic carrier, Fracture fixation, Implant anchorage, Zoledronic acid
in
Acta Biomaterialia
volume
96
pages
619 - 630
publisher
Elsevier
external identifiers
  • pmid:31301423
  • scopus:85068967836
ISSN
1742-7061
DOI
10.1016/j.actbio.2019.07.009
language
English
LU publication?
yes
id
24d122cc-813f-40be-ad87-3c1eb468698a
date added to LUP
2019-07-24 12:18:07
date last changed
2024-06-27 02:25:51
@article{24d122cc-813f-40be-ad87-3c1eb468698a,
  abstract     = {{<p>Aseptic loosening of implants is the major cause for revision surgery. By modulating the bone-implant interface, early bone-implant anchorage could be improved. Implant surface manipulation by the addition of osteopromotive molecules locally and systemically to promote implant integration has been described with limited success. This study describes a novel approach by making the implant capable of biologically modulating its surroundings. It was hypothesized that the early implant fixation would improve by filling the interior of the implant with a carrier providing spatio-temporal release of bone active drugs with known osteogenic effect. The implant consisted of a threaded polyether ether ketone (PEEK) hollow chamber with holes at the bottom. The implant was filled with a calcium sulphate (CaS)/hydroxyapatite (HA) carrier, delivering two bone active molecules; zoledronic acid (ZA) and bone morphogenic protein-2 (BMP-2). At first, a rat abdominal muscle pouch model indicated a sustained in-vivo release of both <sup>125</sup>I-rhBMP-2 (57%) and <sup>14</sup>C-ZA (22%) from the CaS/HA carrier over a period of 4-weeks. The biomodulated implant was then inserted in the proximal tibia in rats with the following experimental groups: G1) Empty implant, G2) Implant + CaS/HA, G3) Implant + CaS/HA + ZA and G4) Implant + CaS/HA + ZA + rhBMP-2. Significantly higher bone volume (BV) was seen around the implant in groups G3 (3.3 ± 0.7 mm<sup>3</sup>) and G4 (3.1 ± 0.7 mm<sup>3</sup>) compared to the control (1.3 ± 0.4 mm<sup>3</sup>) using micro-computed tomography and qualitative histology. Group G3, also exhibited significantly higher pull-out force and absorbed energy when compared to the control group G1. These findings indicate that a low dose of ZA alone, released in a controlled manner from within a fenestrated implant is enough to improve implant anchorage without the need of adding rhBMP-2. This simple method of using a fenestrated implant containing a ceramic carrier releasing bone active molecules improved bone anchorage and could clinically reduce prosthetic failure. Statement of Significance: Aseptic loosening remains as a major cause for implant revisions and early reaction of surrounding bone to the prosthesis is important for longevity. A novel approach to enhance early bone-implant anchorage is presented. The implant is filled with a carrier providing controlled release of bone active molecules. In an animal model, a calcium sulphate (CaS)/hydroxyapatite (HA) carrier was used to provide a spatio-temporal release of bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA). Significantly better bone-implant integration was achieved using ZA alone, thereby eliminating the need for adding BMP-2. The developed method of implant biomodulation holds potential to prevent implant loosening and is an alternative to prosthetic coatings or systemic drug treatment. Importantly, all constituents are approved for clinical use.</p>}},
  author       = {{Raina, Deepak Bushan and Larsson, David and Sezgin, Erdem Aras and Isaksson, Hanna and Tägil, Magnus and Lidgren, Lars}},
  issn         = {{1742-7061}},
  keywords     = {{BMP-2; Ceramic carrier; Fracture fixation; Implant anchorage; Zoledronic acid}},
  language     = {{eng}},
  month        = {{07}},
  pages        = {{619--630}},
  publisher    = {{Elsevier}},
  series       = {{Acta Biomaterialia}},
  title        = {{Biomodulation of an implant for enhanced bone-implant anchorage}},
  url          = {{http://dx.doi.org/10.1016/j.actbio.2019.07.009}},
  doi          = {{10.1016/j.actbio.2019.07.009}},
  volume       = {{96}},
  year         = {{2019}},
}