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Shin M, Pelletier MH, Lovric V, Walsh WR, Martens PJ, Kruzic JJ, Gludovatz B. Effect of gamma irradiation and supercritical carbon dioxide sterilization with Novakill™ or ethanol on the fracture toughness of cortical bone. J Biomed Mater Res B Appl Biomater 2024; 112:e35356. [PMID: 38247241 DOI: 10.1002/jbm.b.35356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 09/15/2023] [Accepted: 11/11/2023] [Indexed: 01/23/2024]
Abstract
Sterilization of structural bone allografts is a critical process prior to their clinical use in large cortical bone defects. Gamma irradiation protocols are known to affect tissue integrity in a dose dependent manner. Alternative sterilization treatments, such as supercritical carbon dioxide (SCCO2 ), are gaining popularity due to advantages such as minimal exposure to denaturants, the lack of toxic residues, superior tissue penetration, and minor impacts on mechanical properties including strength and stiffness. The impact of SCCO2 on the fracture toughness of bone tissue, however, remains unknown. Here, we evaluate crack initiation and growth toughness after 2, 6, and 24 h SCCO2 -treatment using Novakill™ and ethanol as additives on ~11 samples per group obtained from a pair of femur diaphyses of a canine. All mechanical testing was performed at ambient air after 24 h soaking in Hanks' balanced salt solution (HBSS). Results show no statistically significant difference in the failure characteristics of the Novakill™-treated groups whereas crack growth toughness after 6 and 24 h of treatment with ethanol significantly increases by 37% (p = .010) and 34% (p = .038), respectively, compared to an untreated control group. In contrast, standard 25 kGy gamma irradiation causes significantly reduced crack growth resistance by 40% (p = .007) compared to untreated bone. FTIR vibrational spectroscopy, conducted after testing, reveals a consistent trend of statistically significant differences (p < .001) with fracture toughness. These trends align with variations in the ratios of enzymatic mature to immature crosslinks in the collagen structure, suggesting a potential association with fracture toughness. Additional Raman spectroscopy after testing shows a similar trend with statistically significant differences (p < .005), which further supports that collagen structural changes occur in the SCF-treated groups with ethanol after 6 and 24 h. Our work reveals the benefits of SCCO2 sterilization compared to gamma irradiation.
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Affiliation(s)
- Mihee Shin
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Matthew H Pelletier
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Vedran Lovric
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - William R Walsh
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Penny J Martens
- Graduate School of Biomedical Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Jamie J Kruzic
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Bernd Gludovatz
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
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2
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Ina J, Vakharia A, Akkus O, Rimnac CM. The High-cycle Fatigue Life of Cortical Bone Allografts Is Radiation Sterilization Dose-dependent: An In Vitro Study. Clin Orthop Relat Res 2022; 480:1208-1219. [PMID: 35175232 PMCID: PMC9263473 DOI: 10.1097/corr.0000000000002146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/28/2022] [Indexed: 01/31/2023]
Abstract
BACKGROUND Structural cortical bone allografts are a reasonable treatment option for patients with large cortical bone defects caused by trauma, tumors, or complications of arthroplasty. Although structural cortical bone allografts provide the benefit of an osteoconductive material, they are susceptible to fatigue failure (fracture) and carry a risk of disease transmission. Radiation-sterilization at the recommended dose of 25 kGy decreases the risk of disease transmission. However, previous studies demonstrated that radiation sterilization at this dose can negatively impact the high cycle-fatigue life of cortical bone. Although the effects of higher doses of radiation on cortical bone allografts are well described, the effects of lower doses of radiation on a high-cycle fatigue life of cortical bone are poorly understood. QUESTIONS/PURPOSES (1) Does the cycle-fatigue life of human cortical allograft bone vary with gamma radiation dose levels of 0 (control), 10 kGy, 17.5 kGy, and 25 kGy? (2) What differences in Raman spectral biomarkers are observed following varying doses of gamma radiation exposure? METHODS The high-cycle fatigue behavior of human cortical bone specimens was examined at different radiation sterilization doses under physiologic stress levels (35 MPa) and in a 37° C phosphate-buffered saline bath using a custom-designed rotating-bending fatigue device. Six human femora from three donors were obtained for this study (two male, 63 and 61 years old, respectively, and one female, 48 years old). Test specimens were allocated among four treatment groups (0 kGy [control], 10 kGy, 17.5 kGy, and 25 kGy) based on donor and anatomic location of harvest site (both length and cross-sectional quadrant of femoral diaphysis) to ensure equal variation (n = 13 per group). Specimens underwent high-cycle fatigue testing to failure. The number of cycles to failure was recorded. Raman spectroscopy (a noninvasive vibrational spectroscopy used to qualitatively assess bone quality) was used to detect whether any changes in Raman spectral biomarkers occurred after varying doses of gamma radiation exposure. RESULTS There was a decrease in the log-transformed mean high-cycle fatigue life in specimens irradiated at 25 kGy (5.39 ± 0.32) compared with all other groups (0 kGy: 6.20 ± 0.50; 10k Gy: 6.35 ± 0.79; 17.5 kGy: 6.01 ± 0.53; p = 0.001). Specimens irradiated at 25 kGy were also more likely to exhibit a more brittle fracture surface pattern than specimens with more ductile fracture surface patterns irradiated at 0 kGy, 10 kGy, and 17.5 kGy (p = 0.04). The Raman biomarker for the ratio of the relative amount of disordered collagen to ordered collagen showed a decrease at the 10 kGy radiation level from 1.522 ± 0.025 preirradiation to 1.489 ± 0.024 postirradiation (p = 0.01); no other detectable changes in Raman biomarkers were observed. CONCLUSION The high-cycle fatigue life of cortical bone undergoes a nonlinear, dose-dependent decrease with an increase in gamma radiation sterilization in a clinically relevant dose range (0-25 kGy). Importantly, a notable drop-off in the high-cycle fatigue life of cortical bone appeared to occur between 17.5 kGy and 25 kGy, correlating to a sixfold decrease in mean cycles to failure. We speculate that the decrease in the Raman biomarker for disordered collagen at 10 kGy with no loss in high-cycle fatigue life may be caused by an increased amount of nonenzymatic crosslinking of the collagen backbone relative to collagen chain-scission (whereas the benefits of crosslinking may be outweighed by excess scission of the collagen backbone at higher radiation doses), but future studies will need to ascertain whether this in fact is the case. CLINICAL RELEVANCE Radiation sterilization at the industry standard of 25 kGy has a substantial negative impact on the high-cycle fatigue life of cortical bone. Given these findings, it is possible to provide a meaningful increase in the high-cycle fatigue life and improve the overall functional lifetime of cortical bone allografts by lowering the radiation-sterilization dose below 25 kGy. Future work on radiation-sterilization methods at these clinically relevant doses is warranted to aid in preserving the high cycle fatigue life of cortical bone allografts while maintaining sterility.
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Affiliation(s)
- Jason Ina
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Ajit Vakharia
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Ozan Akkus
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Clare M. Rimnac
- Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, USA
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3
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Walsh WR. CORR Insights®: The High-cycle Fatigue Life of Cortical Bone Allografts Is Radiation Sterilization Dose-dependent: An In Vitro Study. Clin Orthop Relat Res 2022; 480:1220-1221. [PMID: 35302541 PMCID: PMC9263481 DOI: 10.1097/corr.0000000000002182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/28/2022] [Indexed: 01/31/2023]
Affiliation(s)
- William R Walsh
- Professor, University of New South Wales Surgical and Orthopaedic Research Laboratories, Prince of Wales Hospital, Sydney Australia
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4
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Mobbs RJ, Amin T, Ho D, McEvoy A, Lovric V, Walsh WR. Integral fixation titanium/polyetheretherketone cages for cervical arthrodesis: Two-year clinical outcomes and fusion rates using β-tricalcium phosphate or supercritical carbon dioxide treated allograft. JOURNAL OF CRANIOVERTEBRAL JUNCTION AND SPINE 2021; 12:368-375. [PMID: 35068818 PMCID: PMC8740808 DOI: 10.4103/jcvjs.jcvjs_129_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 11/06/2021] [Indexed: 11/13/2022] Open
Abstract
Context: Despite increasing promising reports regarding composite titanium (Ti)/PolyEtherEtherKetone (PEEK) cages, further longer-term, quality research is required. Synthetic bone graft substitutes are another rapidly developing area of spinal surgical research. Aims: The purpose of this study is to evaluate the outcomes of an integral fixation composite Ti/PEEK cage for anterior cervical discectomy and fusion (ACDF) and compare a synthetic bone graft substitute (β-tricalcium phosphate; [βTCP]) with allograft processed using supercritical fluid technology. Methods and Design: Data from 195 consecutive patients were prospectively collected from a single centre. Indications were largely degenerative. Allograft and βTCP were used in a 3:1 randomization protocol. Patients were followed up for a minimum of 6 months and up to 48 months. Clinical outcomes included visual analogue scale and neck oswestry disability index. Radiographic outcomes included fusion rates, subsidence rates and implant complications. Results: Graft sub-cohorts were largely comparable and included 133 and 52 patients in the allograft and βTCP sub-cohorts, respectively. Clinical outcomes overall significantly improved (P < 0.001), with no significant inter-cohort differences. There were no implant-related complications. Overall fusion rate was 94.1% (175/186). The allograft cohort produced a significantly greater fusion rate of 97.7% (126/129) compared to 77.6% (38/49) for the βTCP cohort (P = 0.001). Conclusions: This study demonstrates the viability of an integral fixation composite Ti/PEEK ACDF device in effectively and safely improving patient outcomes and achieving fusion. Allograft is more effective in achieving fusion compared to βTCP, though both were similarly efficacious in improving clinical outcomes.
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Affiliation(s)
- Ralph J Mobbs
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia.,Neuro Spine Clinic, Prince of Wales Private Hospital, Randwick, UNSW Sydney, Australia.,Prince of Wales Clinical School, UNSW Sydney, Australia.,Surgical and Orthopaedic Research Labs (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
| | - Tajrian Amin
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia.,Neuro Spine Clinic, Prince of Wales Private Hospital, Randwick, UNSW Sydney, Australia.,Prince of Wales Clinical School, UNSW Sydney, Australia
| | - Daniel Ho
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia.,Neuro Spine Clinic, Prince of Wales Private Hospital, Randwick, UNSW Sydney, Australia.,Prince of Wales Clinical School, UNSW Sydney, Australia
| | - Aidan McEvoy
- Matrix Medical Innovations, Randwick, Sydney, Australia
| | - Vedran Lovric
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia.,Surgical and Orthopaedic Research Labs (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
| | - William R Walsh
- NeuroSpine Surgery Research Group (NSURG), Sydney, Australia.,Surgical and Orthopaedic Research Labs (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
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5
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McCaffrey K, McCaffrey MH, Pelletier MH, Lovric V, Mobbs RJ, Walsh WR. Load Sharing and Endplate Pressure Distribution in Anterior Interbody Fusion Influenced by Graft Choice. World Neurosurg 2020; 146:e336-e340. [PMID: 33228956 DOI: 10.1016/j.wneu.2020.10.084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/16/2020] [Accepted: 10/17/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Cage subsidence is a known complication of spinal fusion. Various aspects of cage design have been investigated for their influence on cage subsidence, whereas the potential contribution of graft material to load sharing is often overlooked. We aimed to determine whether graft in the aperture affects endplate pressure distribution. METHODS The pressure distributions of a polyetheretherketone interbody cage with 3 different aperture graft conditions were evaluated: empty, demineralized bone matrix, and supercritical CO2-treated allograft bone crunch (SCCO2). RESULTS Graft materials contributed as much as half the load transmission for SCCO2, whereas demineralized bone matrix contributed one third. Endplate areas in contact with the cage demonstrated decreased areas within the highest-pressure spectrum with SCCO2 graft materials compared with empty cages. CONCLUSIONS Graft choice plays a role in reducing peak endplate pressures. This finding is relevant to implant subsidence, as well as graft loading and remodeling.
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Affiliation(s)
- Kieran McCaffrey
- Surgical and Orthopedic Research Laboratories (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
| | - Miles H McCaffrey
- Surgical and Orthopedic Research Laboratories (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
| | - Matthew H Pelletier
- Surgical and Orthopedic Research Laboratories (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia.
| | - Vedran Lovric
- Surgical and Orthopedic Research Laboratories (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
| | - Ralph J Mobbs
- NeuroSpine Surgery Research Group (NSURG), Prince of Wales Hospital, Sydney, Australia
| | - William R Walsh
- Surgical and Orthopedic Research Laboratories (SORL), Prince of Wales Clinical School, UNSW Sydney, Sydney, Australia
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6
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Sun Y, Lovric V, Wang T, Oliver RA, Walsh WR. Effects of SCCO 2, Gamma Irradiation, and Sodium Dodecyl Sulfate Treatments on the Initial Properties of Tendon Allografts. Int J Mol Sci 2020; 21:ijms21051565. [PMID: 32106592 PMCID: PMC7084268 DOI: 10.3390/ijms21051565] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/07/2020] [Accepted: 02/15/2020] [Indexed: 01/05/2023] Open
Abstract
Sterile and decellularized allograft tendons are viable biomaterials used in reconstructive surgeries for dense connective tissue injuries. Established allograft processing techniques including gamma irradiation and sodium dodecyl sulfate (SDS) can affect tissue integrity. Supercritical carbon dioxide (SCCO2) represents a novel alternative that has the potential to decellularize and sterilize tendons with minimized exposure to denaturants, shortened treatment time, lack of toxic residues, and superior tissue penetration, and thus efficacy. This study attempted to develop a single-step hybrid decellularization and sterilization protocol for tendons that involved SCCO2 treatment with various chemical additives. The processed tendons were evaluated with mechanical testing, histology, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Uniaxial mechanical testing showed that tendons treated with SCCO2 and additive NovaKillTM Gen2 and 0.1% SDS had significantly higher (p < 0.05) ultimate tensile stress (UTS) and Young's modulus compared to gamma-irradiated and standard-SDS-treated tendons. This was corroborated by the ultrastructural intactness of SCCO2-treated tendons as examined by SEM and FTIR spectroscopy, which was not preserved in gamma-irradiated and standard SDS-treated tendons. However, complete decellularization was not achieved by the experimented SCCO2-SDS protocols used in this study. The present study therefore serves as a concrete starting point for development of an SCCO2-based combined sterilization and decellularization protocol for allograft tendons, where additive choice is to be optimized.
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7
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Bednarski DM, Lantz EE, Bobst CE, Eisenhut AR, Eyles SJ, Fey JP. Sterilization of epidermal growth factor with supercritical carbon dioxide and peracetic acid; analysis of changes at the amino acid and protein level. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140334. [PMID: 31786473 DOI: 10.1016/j.bbapap.2019.140334] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/05/2019] [Accepted: 11/25/2019] [Indexed: 12/20/2022]
Abstract
Aseptic processing and terminal sterilization become increasingly challenging as medical devices become more complex and include active biologics. Terminal sterilization is preferred for patient safety and production costs. We aimed to determine how sterilization using supercritical CO2 (scCO2) with low levels of peracetic acid (PAA) affects amino acids and human epidermal growth factor (EGF) as a model protein. In a benchtop reactivity test, the amino acids methionine, tryptophan, arginine and lysine reacted with low levels of PAA in solution. At PAA levels used for scCO2 sterilization, however, mass spectrometry only identified oxidative adducts on methionine and tryptophan. Mass spectrometry analysis of EGF exposed to scCO2/PAA identified oxidative adducts on residues Met21, Trp49 and Trp50, as well as a low level of truncations after residues Trp49 and Trp50. Importantly, processing of EGF in solution with scCO2 did not affect its native conformation, and sterilized EGF maintained its activity in cell proliferation assays. When processing samples in lyophilized form with scCO2/PAA, amino acids did not react with PAA and the presence of adducts was strongly reduced on methionine and tryptophan, both as single amino acids and in EGF. Truncation after tryptophan residues did not occur. EGF sterilized in the lyophilized form retained its activity when processing occurred with added moisture. These results have significant implications for the maintenance of biological function in sterilized decellularized scaffolds and the ability to manufacture terminally sterilized combination devices containing therapeutic peptides or proteins.
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Affiliation(s)
| | - Ellen E Lantz
- iFyber LLC, 950 Danby Rd Suite 198, Ithaca, NY 14850, USA
| | - Cedric E Bobst
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA.
| | | | - Stephen J Eyles
- Department of Biochemistry and Molecular Biology & Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA 01003, USA.
| | - Julien P Fey
- NovaSterilis Inc., 3109 N Triphammer Road, Lansing, NY 14882, USA.
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8
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Pendleton MM, Emerzian SR, Liu J, Tang SY, O'Connell GD, Alwood JS, Keaveny TM. Effects of ex vivo ionizing radiation on collagen structure and whole-bone mechanical properties of mouse vertebrae. Bone 2019; 128:115043. [PMID: 31445224 PMCID: PMC6813909 DOI: 10.1016/j.bone.2019.115043] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 12/26/2022]
Abstract
Bone can become brittle when exposed to ionizing radiation across a wide range of clinically relevant doses that span from radiotherapy (accumulative 50 Gy) to sterilization (~35,000 Gy). While irradiation-induced embrittlement has been attributed to changes in the collagen molecular structure, the relative role of collagen fragmentation versus non-enzymatic collagen crosslinking remains unclear. To better understand the effects of radiation on the bone material without cellular activity, we conducted an ex vivo x-ray radiation experiment on excised mouse lumbar vertebrae. Spinal tissue from twenty-week old, female, C57BL/6J mice were randomly assigned to a single x-ray radiation dose of either 0 (control), 50, 1000, 17,000, or 35,000 Gy. Measurements were made for collagen fragmentation, non-enzymatic collagen crosslinking, and both monotonic and cyclic-loading compressive mechanical properties. We found that the group differences for mechanical properties were more consistent with those for collagen fragmentation than for non-enzymatic collagen crosslinking. Monotonic strength at 17,000 and 35,000 Gy was lower than that of the control by 50% and 73% respectively, (p < 0.001) but at 50 and 1000 Gy was not different than the control. Consistent with those trends, collagen fragmentation only occurred at 17,000 and 35,000 Gy. By contrast, non-enzymatic collagen crosslinking was greater than control for all radiation doses (p < 0.001). All results were consistent both for monotonic and cyclic loading conditions. We conclude that the reductions in bone compressive monotonic strength and fatigue life due to ex vivo ionizing radiation are more likely caused by fragmentation of the collagen backbone than any increases in non-enzymatic collagen crosslinks.
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Affiliation(s)
- Megan M Pendleton
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Shannon R Emerzian
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Jennifer Liu
- Department of Orthopaedic Surgery, Washington University, St. Louis, MO, USA
| | - Simon Y Tang
- Department of Orthopaedic Surgery, Washington University, St. Louis, MO, USA; Department of Biomedical Engineering, Washington University, St. Louis, MO, USA; Department of Material Science & Mechanical Engineering, Washington University, St. Louis, MO, USA
| | - Grace D O'Connell
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA; Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Joshua S Alwood
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, USA
| | - Tony M Keaveny
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA; Department of Bioengineering, University of California, Berkeley, CA, USA.
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9
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Ribeiro N, Soares GC, Santos-Rosales V, Concheiro A, Alvarez-Lorenzo C, García-González CA, Oliveira AL. A new era for sterilization based on supercritical CO 2 technology. J Biomed Mater Res B Appl Biomater 2019; 108:399-428. [PMID: 31132221 DOI: 10.1002/jbm.b.34398] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 04/05/2019] [Accepted: 04/17/2019] [Indexed: 11/06/2022]
Abstract
The increasing complexity in morphology and composition of modern biomedical materials (e.g., soft and hard biological tissues, synthetic and natural-based scaffolds, technical textiles) and the high sensitivity to the processing environment requires the development of innovative but benign technologies for processing and treatment. This scenario is particularly applicable where current conventional techniques (steam/dry heat, ethylene oxide, and gamma irradiation) may not be able to preserve the functionality and integrity of the treated material. Sterilization using supercritical carbon dioxide emerges as a green and sustainable technology able to reach the sterility levels required by regulation without altering the original properties of even highly sensitive materials. In this review article, an updated survey of experimental protocols based on supercritical sterilization and of the efficacy results sorted by microbial strains and treated materials was carried out. The application of the supercritical sterilization process in materials used for biomedical, pharmaceutical, and food applications is assessed. The opportunity of supercritical sterilization of not only replace the above mentioned conventional techniques, but also of reach unmet needs for sterilization in highly sensitive materials (e.g., single-use medical devices, the next-generation biomaterials, and medical devices and graft tissues) is herein unveiled.
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Affiliation(s)
- Nilza Ribeiro
- CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
| | - Gonçalo C Soares
- CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
| | - Víctor Santos-Rosales
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, R+D Pharma group (GI-1645), Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Angel Concheiro
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, R+D Pharma group (GI-1645), Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Carmen Alvarez-Lorenzo
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, R+D Pharma group (GI-1645), Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Carlos A García-González
- Departamento de Farmacología, Farmacia y Tecnología Farmacéutica, R+D Pharma group (GI-1645), Facultad de Farmacia and Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Ana L Oliveira
- CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal
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10
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Park SSH, Zhang L, Attia T, Salat P, Banks K, Willett T, Grynpas M. Pre-clinical evaluation of bone allograft toughened with a novel sterilization method: An in vivo rabbit study. J Orthop Res 2019; 37:832-844. [PMID: 30839120 DOI: 10.1002/jor.24269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 02/12/2019] [Indexed: 02/04/2023]
Abstract
Bone allografts often undergo γ-irradiation sterilization to decrease infection risk. However this consequently degrades bone collagen and makes the allograft brittle. Our laboratory has previously found that pre-treatment with ribose ex vivo protects the bone. However, it remains unclear whether or not ribose-treated γ-irradiated allografts are able to unite and remodel in vivo. Using New Zealand White rabbits (NZWr), we aimed to evaluate if ribose-treated allografts can unite with host bone (compared to untreated (fresh-frozen) and conventionally-irradiated allografts). A critically-sized defect was created in the radii of NZWr and reconstructed with allografts fixed with an intramedullary Kirschner wire. Healing and union were assessed at 2, 6, and 12 weeks post operation, with radiographs, µCT, static and dynamic histomorphometry, backscatter electron microscopy, and torsion testing. Intramedullary fixation achieved stable reconstructions and bony union in all groups and no differences were found in the radiographic and biomechanical parameters tested. Interestingly, γ-irradiated allografts had significantly less bone volume due to evident resorption of the grafts. In contrast, ribose pre-treatment protected γ-irradiated allografts from this bone loss, with results similar to the fresh frozen controls. In conclusion, ribose-pretreated γ-irradiated allografts were able to unite in vivo. In addition to achieving bony union with host bone, ribose pre-treatment may protect against allograft resorption. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
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Affiliation(s)
- Sam Si-Hyeong Park
- Department of Surgery, Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Lucia Zhang
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Tarik Attia
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Peter Salat
- Joint Department of Medical Imaging, University Health Network, Toronto, Ontario, Canada
| | - Kate Banks
- Division of Comparative Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Thomas Willett
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Marc Grynpas
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
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11
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Soares GC, Learmonth DA, Vallejo MC, Davila SP, González P, Sousa RA, Oliveira AL. Supercritical CO 2 technology: The next standard sterilization technique? MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:520-540. [PMID: 30889727 DOI: 10.1016/j.msec.2019.01.121] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 11/26/2018] [Accepted: 01/25/2019] [Indexed: 02/03/2023]
Abstract
Sterilization of implantable medical devices is of most importance to avoid surgery related complications such as infection and rejection. Advances in biotechnology fields, such as tissue engineering, have led to the development of more sophisticated and complex biomedical devices that are often composed of natural biomaterials. This complexity poses a challenge to current sterilization techniques which frequently damage materials upon sterilization. The need for an effective alternative has driven research on supercritical carbon dioxide (scCO2) technology. This technology is characterized by using low temperatures and for being inert and non-toxic. The herein presented paper reviews the most relevant studies over the last 15 years which cover the use of scCO2 for sterilization and in which effective terminal sterilization is reported. The major topics discussed here are: microorganisms effectively sterilized by scCO2, inactivation mechanisms, operating parameters, materials sterilized by scCO2 and major requirements for validation of such technique according to medical devices' standards.
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Affiliation(s)
- Gonçalo C Soares
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - David A Learmonth
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, Parque de Ciência e Tecnologia Avepark, Zona Industrial da Gandra, Guimarães, Portugal
| | - Mariana C Vallejo
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, Parque de Ciência e Tecnologia Avepark, Zona Industrial da Gandra, Guimarães, Portugal
| | - Sara Perez Davila
- New Materials Group, Applied Physics Department, IIS-GS, University of Vigo, Vigo, Spain
| | - Pío González
- New Materials Group, Applied Physics Department, IIS-GS, University of Vigo, Vigo, Spain
| | - Rui A Sousa
- Stemmatters, Biotecnologia e Medicina Regenerativa SA, Parque de Ciência e Tecnologia Avepark, Zona Industrial da Gandra, Guimarães, Portugal
| | - Ana L Oliveira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina, Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal.
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Phan K, Pelletier MH, Rao PJ, Choy WJ, Walsh WR, Mobbs RJ. Integral Fixation Titanium/Polyetheretherketone Cages for Cervical Arthrodesis: Evolution of Cage Design and Early Radiological Outcomes and Fusion Rates. Orthop Surg 2019; 11:52-59. [PMID: 30614216 PMCID: PMC6430402 DOI: 10.1111/os.12413] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/01/2018] [Indexed: 01/06/2023] Open
Abstract
Objective To evaluate the initial outcomes of a composite cage with integral fixation using the Redmond titanium (Ti)/polyetheretherketone (PEEK) anterior cervical discectomy and fusion (ACDF) device. Methods Data from 50 consecutive patients were prospectively collected from a single senior surgeon cohort. All cages were between 5 and 8 mm in height, and were packed with supercritical CO2 sterilized allograft. Patients were followed up for a minimum of 6 months, and implant complications were assessed. Results From the original cohort, three were unavailable for follow‐up. Forty‐seven patients with a total of 58 operative levels were observed for a mean of 7.9 months. A fusion rate of 96% was achieved. Good to excellent outcomes were seen in 92% of patients. There were no cases of implant Ti/PEEK delamination or implant failure, with excellent early fusion rates using supercritical CO2 allograft. Conclusions The present study demonstrates the development of a composite ACDF cage design that is a safe and effective treatment option with the potential for early osseointegration and interbody fusion. Supercritical CO2 sterilized allograft was an effective graft material supporting fusion.
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Affiliation(s)
- Kevin Phan
- University of New South Wales, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Neuro Spine Clinic, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Department of Spine Surgery, Prince of Wales Hospital, Randwick, New South Wales, Australia.,NSURG Research Group, Prince of Wales Private Hospital, Sydney, New South Wales, Australia
| | - Matthew H Pelletier
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Prince of Wales Hospital, Randwick, New South Wales, Australia
| | - Prashanth J Rao
- University of New South Wales, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Neuro Spine Clinic, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Department of Spine Surgery, Prince of Wales Hospital, Randwick, New South Wales, Australia.,NSURG Research Group, Prince of Wales Private Hospital, Sydney, New South Wales, Australia
| | - Wen Jie Choy
- University of New South Wales, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Neuro Spine Clinic, Prince of Wales Hospital, Randwick, New South Wales, Australia.,NSURG Research Group, Prince of Wales Private Hospital, Sydney, New South Wales, Australia
| | - William R Walsh
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Prince of Wales Hospital, Randwick, New South Wales, Australia
| | - Ralph J Mobbs
- University of New South Wales, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Neuro Spine Clinic, Prince of Wales Hospital, Randwick, New South Wales, Australia.,Department of Spine Surgery, Prince of Wales Hospital, Randwick, New South Wales, Australia.,NSURG Research Group, Prince of Wales Private Hospital, Sydney, New South Wales, Australia
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White LJ, Keane TJ, Smoulder A, Zhang L, Castleton AA, Reing JE, Turner NJ, Dearth CL, Badylak SF. The impact of sterilization upon extracellular matrix hydrogel structure and function. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.regen.2018.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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You L, Weikang X, Lifeng Y, Changyan L, Yongliang L, Xiaohui W, Bin X. In vivo immunogenicity of bovine bone removed by a novel decellularization protocol based on supercritical carbon dioxide. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2018; 46:334-344. [PMID: 29726299 DOI: 10.1080/21691401.2018.1457044] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Trauma or infections associated critical bone defects lead to a huge economic burden in the healthcare system worldwide. Recent advances in tissue engineering have led to potential new strategies for the repair, replacement, and regeneration of bone defects, especially in biomaterials and decellularization protocols from xenogenic tissues. However, the complexity in bone structure and mechanical environment limits the synthesis of artificial bone with biomaterials. Thus, the purpose of our study is to develop a natural bone scaffold with great immunocompatibility. We combined decellularization techniques base on SC-CO2 to decellularize bovine bone. In order to study the immune response of mice to materials, the histology, spleen index, immune cells contents and in vitro proliferative performance, cytokine and immunoglobulin light chain expression of mice were characterized. Compared with the fresh bone group, the immune responses of decellularized group were significantly reduced. In conclusion, decellularization via this method can achieve a decellularized scaffold with great immunocompatibility. Our findings suggest the potential of using decellularized BB as a scaffold for bone bioengineering.
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Affiliation(s)
- Ling You
- a National Engineering Research Center for Human Tissue Restoration and Function Reconstruction , South China University of Technology , Guangzhou , Guangdong , China.,b National Engineering Laboratory for Regenerative Implantable Medical Devices , Grandhope Biotech Co., Ltd , Guangzhou , Guangdong , China
| | - Xu Weikang
- a National Engineering Research Center for Human Tissue Restoration and Function Reconstruction , South China University of Technology , Guangzhou , Guangdong , China
| | - Yang Lifeng
- c Guangdong Medical Devices Quality Surveillance and Test Institute , Guangzhou , Guangdong , China
| | - Liang Changyan
- d Department of Gynecology , Third Affiliated Hospital of Sun Yat-sen University , Guangzhou , China
| | - Lin Yongliang
- b National Engineering Laboratory for Regenerative Implantable Medical Devices , Grandhope Biotech Co., Ltd , Guangzhou , Guangdong , China
| | - Wei Xiaohui
- b National Engineering Laboratory for Regenerative Implantable Medical Devices , Grandhope Biotech Co., Ltd , Guangzhou , Guangdong , China
| | - Xu Bin
- b National Engineering Laboratory for Regenerative Implantable Medical Devices , Grandhope Biotech Co., Ltd , Guangzhou , Guangdong , China
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Zalepugin DY, Tilkunova NA, Chernyshova IV, Vlasov MI. Sterilization in supercritical media. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2017. [DOI: 10.1134/s199079311608008x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Chong E, Mobbs RJ, Pelletier MH, Walsh WR. Titanium/Polyetheretherketone Cages for Cervical Arthrodesis with Degenerative and Traumatic Pathologies: Early Clinical Outcomes and Fusion Rates. Orthop Surg 2017; 8:19-26. [PMID: 27028377 DOI: 10.1111/os.12221] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/04/2015] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE Anterior cervical discectomy and fusion is the most commonly employed surgical technique for treating cervical spondylosis. Although autologous bone grafts are considered the gold standard in achieving fusion, associated short- and long-term morbidities have led to a search for alternative materials. These have included carbon-fiber, titanium alloy (Ti) and ceramic and polyetheretherketone (PEEK) based implants. Recent attempts to optimize cage implants through using composite designs have combined Ti and PEEK. However, there are few published reports on the clinical and radiological outcomes of commercially available composite cages. Our study aimed to provide and evaluate initial outcomes of a composite Ti/PEEK cage. METHODS In this prospective single senior surgeon cohort study, 31 consecutive patients underwent a modified Smith-Robinson technique under general anesthesia and relevant data were collected. The study patients were aged between 18 and 75 years and underwent surgery from November 2013 to May 2014. Indications for surgery included traumatic and degenerative cervical disease that was unsuitable for or unresponsive to conservative management. All cages were between 5 and 8 mm and packed with super critical fluid sterilized allograft and bone marrow aspirate before insertion. Patients were followed-up for a minimum of 12 months. Fusion was assessed using fine cut CT and anteroposterior and lateral radiographs. Clinical outcomes were measured using a Visual Analogue Scale, Neck Oswestry Disability Index and Patient's Satisfaction Index. RESULTS Six of the original cohort were unavailable for adequate follow-up. The remaining 25 patients (17 men, 8 women; 33 operative levels) were observed for a mean of 14.6 months (range, 12-16 months). All operation levels were between C4 and C7 . Single-level operations were performed in 19 patients and additional plating in 14 patients. A fusion rate of 96% was achieved. Patients in both plated and non-plated groups experienced statistically significant improvements; good to excellent outcomes being seen in 92% of patients. There was one complication, namely recurrent laryngeal nerve palsy, which had partially resolved at 6 months follow-up. CONCLUSION The present study shows that enhancement of PEEK cages with Ti endplates is a safe and effective treatment with the potential for early osseointegration and early radiological evidence of fusion.
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Affiliation(s)
- Elizabeth Chong
- University of New South Wales, Randwick, NSW, Australia.,Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Randwick, NSW, Australia
| | - Ralph J Mobbs
- University of New South Wales, Randwick, NSW, Australia.,NeuroSpine Clinic, Randwick, NSW, Australia.,Department of Spine Surgery, Prince of Wales Hospital, Randwick, NSW, Australia
| | - Matthew H Pelletier
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Randwick, NSW, Australia
| | - William R Walsh
- Surgical and Orthopaedic Research Laboratories, Prince of Wales Clinical School, Randwick, NSW, Australia
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Müller SA, Barg A, Vavken P, Valderrabano V, Müller AM. Autograft versus sterilized allograft for lateral calcaneal lengthening osteotomies: Comparison of 50 patients. Medicine (Baltimore) 2016; 95:e4343. [PMID: 27472719 PMCID: PMC5265856 DOI: 10.1097/md.0000000000004343] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 06/10/2016] [Accepted: 06/30/2016] [Indexed: 11/29/2022] Open
Abstract
Sterilized allografts may be less resistant to collapse and prone to nonunion leading to loss of correction in open wedge osteotomies. These adverse events usually occur at early time points (i.e., < 9 months postoperatively). The goal of this study was to compare sterilized allografts to autologous grafts in respect to secondary loss of hindfoot alignment and graft incorporation after lateral calcaneal lengthening osteotomies.Fifty patients (22 F/ 28 M, age: 16-69 years) who had undergone 50 lateral calcaneal lengthening osteotomies for adult flatfoot deformity were included in this retrospective study. Cortical sterilized allografts were used in 25 patients, autologous grafts in the remaining 25. Patients' preoperative, 6 and 12 weeks, and 6 to 9 months follow-up weight-bearing radiographs of the affected foot were analyzed by 2 blinded radiologists: on each radiograph, graft incorporation, the talo-first metatarsal angle (TFMA), the talo-navicular coverage angle (TNCA), and the calcaneal pitch angle (CPA) were assessed. Loss of hindfoot alignment was defined as an increase of the TFMA or the TNCA or a decrease of the CPA, each by 5°.Inter- and intraclass correlation coefficients for TFMA, TNCA, and CPA measurements ranged from 0.93 to 0.99. At all follow-up visits, the ratio of patients with loss of hindfoot alignment and graft incorporation was not significantly different between the allograft and autograft group. However, loss of correction was associated with failure of graft incorporation.Compared with autografts, sterilized allografts do not increase the risk for loss of hindfoot alignment in lateral column lengthening of the calcaneus. With respect to mechanical resistance, allografts thus mean an equal and valid alternative without risk of donor site morbidities.
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Affiliation(s)
- Sebastian A. Müller
- Department of Orthopedic Surgery, University Hospital Basel, Basel, Switzerland
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Islam A, Chapin K, Moore E, Ford J, Rimnac C, Akkus O. Gamma Radiation Sterilization Reduces the High-cycle Fatigue Life of Allograft Bone. Clin Orthop Relat Res 2016; 474:827-35. [PMID: 26463571 PMCID: PMC4746152 DOI: 10.1007/s11999-015-4589-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/02/2015] [Indexed: 01/31/2023]
Abstract
BACKGROUND Sterilization by gamma radiation impairs the mechanical properties of bone allografts. Previous work related to radiation-induced embrittlement of bone tissue has been limited mostly to monotonic testing which does not necessarily predict the high-cycle fatigue life of allografts in vivo. QUESTIONS/PURPOSES We designed a custom rotating-bending fatigue device to answer the following questions: (1) Does gamma radiation sterilization affect the high-cycle fatigue behavior of cortical bone; and (2) how does the fatigue life change with cyclic stress level? METHODS The high-cycle fatigue behavior of human cortical bone specimens was examined at stress levels related to physiologic levels using a custom-designed rotating-bending fatigue device. Test specimens were distributed among two treatment groups (n = 6/group); control and irradiated. Samples were tested until failure at stress levels of 25, 35, and 45 MPa. RESULTS At 25 MPa, 83% of control samples survived 30 million cycles (run-out) whereas 83% of irradiated samples survived only 0.5 million cycles. At 35 MPa, irradiated samples showed an approximately 19-fold reduction in fatigue life compared with control samples (12.2 × 10(6) ± 12.3 × 10(6) versus 6.38 × 10(5) ± 6.81 × 10(5); p = 0.046), and in the case of 45 MPa, this reduction was approximately 17.5-fold (7.31 × 10(5) ± 6.39 × 10(5) versus 4.17 × 10(4) ± 1.91 × 10(4); p = 0.025). Equations to estimate high-cycle fatigue life of irradiated and control cortical bone allograft at a certain stress level were derived. CONCLUSIONS Gamma radiation sterilization severely impairs the high cycle fatigue life of structural allograft bone tissues, more so than the decline that has been reported for monotonic mechanical properties. Therefore, clinicians need to be conservative in the expectation of the fatigue life of structural allograft bone tissues. Methods to preserve the fatigue strength of nonirradiated allograft bone tissue are needed. CLINICAL RELEVANCE As opposed to what monotonic tests might suggest, the cyclic fatigue life of radiation-sterilized structural allografts is likely severely compromised relative to the nonirradiated condition and therefore should be taken into consideration. Methods to reduce the effect of irradiation or to recover structural allograft bone tissue fatigue strength are important to pursue.
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Affiliation(s)
- Anowarul Islam
- grid.67105.350000000121643847Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 USA
| | - Katherine Chapin
- grid.67105.350000000121643847Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH USA
| | - Emily Moore
- grid.67105.350000000121643847Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH USA ,grid.21729.3f0000000419368729Department of Biomedical Engineering, Columbia University, New York, NY USA
| | - Joel Ford
- grid.67105.350000000121643847Department of Orthopaedics, Case Western Reserve University School of Medicine, Cleveland, OH USA
| | - Clare Rimnac
- grid.67105.350000000121643847Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 USA ,grid.67105.350000000121643847Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH USA ,grid.67105.350000000121643847Department of Orthopaedics, Case Western Reserve University School of Medicine, Cleveland, OH USA
| | - Ozan Akkus
- grid.67105.350000000121643847Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 USA ,grid.67105.350000000121643847Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH USA ,grid.67105.350000000121643847Department of Orthopaedics, Case Western Reserve University School of Medicine, Cleveland, OH USA
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Zalepugin DY, Zaitzev VV, Tilkunova NA, Chernyshova IV, Selezneva II, Nikonova YA, Vlasov MI. Xenogenic bone matrix treated with supercritical carbon dioxide as a potential osteoplastic material. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2016. [DOI: 10.1134/s1990793115070131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Improved Sterilization of Sensitive Biomaterials with Supercritical Carbon Dioxide at Low Temperature. PLoS One 2015; 10:e0129205. [PMID: 26067982 PMCID: PMC4466598 DOI: 10.1371/journal.pone.0129205] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/06/2015] [Indexed: 11/19/2022] Open
Abstract
The development of bio-resorbable implant materials is rapidly going on. Sterilization of those materials is inevitable to assure the hygienic requirements for critical medical devices according to the medical device directive (MDD, 93/42/EG). Biopolymer-containing biomaterials are often highly sensitive towards classical sterilization procedures like steam, ethylene oxide treatment or gamma irradiation. Supercritical CO2 (scCO2) treatment is a promising strategy for the terminal sterilization of sensitive biomaterials at low temperature. In combination with low amounts of additives scCO2 treatment effectively inactivates microorganisms including bacterial spores. We established a scCO2 sterilization procedure under addition of 0.25% water, 0.15% hydrogen peroxide and 0.5% acetic anhydride. The procedure was successfully tested for the inactivation of a wide panel of microorganisms including endospores of different bacterial species, vegetative cells of gram positive and negative bacteria including mycobacteria, fungi including yeast, and bacteriophages. For robust testing of the sterilization effect with regard to later application of implant materials sterilization all microorganisms were embedded in alginate/agarose cylinders that were used as Process Challenge Devices (PCD). These PCD served as surrogate models for bioresorbable 3D scaffolds. Furthermore, the impact of scCO2 sterilization on mechanical properties of polysaccharide-based hydrogels and collagen-based scaffolds was analyzed. The procedure was shown to be less compromising on mechanical and rheological properties compared to established low-temperature sterilization methods like gamma irradiation and ethylene oxide exposure as well as conventional steam sterilization. Cytocompatibility of alginate gels and scaffolds from mineralized collagen was compared after sterilization with ethylene oxide, gamma irradiation, steam sterilization and scCO2 treatment. Human mesenchymal stem cell viability and proliferation were not compromised by scCO2 treatment of these materials and scaffolds. We conclude that scCO2 sterilization under addition of water, hydrogen peroxide and acetic anhydride is a very effective, gentle, non-cytotoxic and thus a promising alternative sterilization method especially for biomaterials.
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Russell N, Rives A, Pelletier MH, Wang T, Walsh WR. The effect of supercritical carbon dioxide sterilization on the anisotropy of bovine cortical bone. Cell Tissue Bank 2014; 16:109-21. [DOI: 10.1007/s10561-014-9447-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 04/05/2014] [Indexed: 10/25/2022]
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