1
|
Getsy PM, Coffee GA, May WJ, Baby SM, Bates JN, Lewis SJ. The Reducing Agent Dithiothreitol Modulates the Ventilatory Responses That Occur in Freely Moving Rats during and following a Hypoxic-Hypercapnic Challenge. Antioxidants (Basel) 2024; 13:498. [PMID: 38671945 PMCID: PMC11047747 DOI: 10.3390/antiox13040498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
The present study examined the hypothesis that changes in the oxidation-reduction state of thiol residues in functional proteins play a major role in the expression of the ventilatory responses in conscious rats that occur during a hypoxic-hypercapnic (HH) gas challenge and upon return to room air. A HH gas challenge in vehicle-treated rats elicited robust and sustained increases in minute volume (via increases in frequency of breathing and tidal volume), peak inspiratory and expiratory flows, and inspiratory and expiratory drives while minimally affecting the non-eupneic breathing index (NEBI). The HH-induced increases in these parameters, except for frequency of breathing, were substantially diminished in rats pre-treated with the potent and lipophilic disulfide-reducing agent, L,D-dithiothreitol (100 µmol/kg, IV). The ventilatory responses that occurred upon return to room air were also substantially different in dithiothreitol-treated rats. In contrast, pre-treatment with a substantially higher dose (500 µmol/kg, IV) of the lipophilic congener of the monosulfide, N-acetyl-L-cysteine methyl ester (L-NACme), only minimally affected the expression of the above-mentioned ventilatory responses that occurred during the HH gas challenge or upon return to room air. The effectiveness of dithiothreitol suggests that the oxidation of thiol residues occurs during exposure to a HH gas challenge and that this process plays an essential role in allowing for the expression of the post-HH excitatory phase in breathing. However, this interpretation is contradicted by the lack of effects of L-NACme. This apparent conundrum may be explained by the disulfide structure affording unique functional properties to dithiothreitol in comparison to monosulfides. More specifically, the disulfide structure may give dithiothreitol the ability to alter the conformational state of functional proteins while transferring electrons. It is also possible that dithiothreitol is simply a more efficient reducing agent following systemic injection, although one interpretation of the data is that the effects of dithiothreitol are not due to its reducing ability.
Collapse
Affiliation(s)
- Paulina M. Getsy
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA; (P.M.G.); (G.A.C.)
| | - Gregory A. Coffee
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA; (P.M.G.); (G.A.C.)
| | - Walter J. May
- Department of Pediatrics, University of Virginia, Charlottesville, VA 22903, USA;
| | - Santhosh M. Baby
- Galleon Pharmaceuticals, Inc., 213 Witmer Road, Horsham, PA 19044, USA;
| | - James N. Bates
- Department of Anesthesiology, University of Iowa Hospitals and Clinics, Iowa, IA 52242, USA;
| | - Stephen J. Lewis
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106, USA; (P.M.G.); (G.A.C.)
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA
- Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH 44106, USA
| |
Collapse
|
2
|
XRD and ATR-FTIR techniques for integrity assessment of gamma radiation sterilized cortical bone pretreated by antioxidants. Cell Tissue Bank 2020; 22:305-321. [PMID: 33165827 DOI: 10.1007/s10561-020-09879-4] [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: 08/16/2020] [Accepted: 10/30/2020] [Indexed: 01/22/2023]
Abstract
Terminal sterilization of bone allograft by gamma radiation is required to reduce the risk of infection. Free radical scavengers could be utilized to minimize the deteriorating effects of gamma radiation on bone allograft mechanical properties. The objective of this research is to assess the changes in structural and chemical composition induced by hydroxytyrosol (HT) and alpha lipoic acid (ALA) free radical scavengers in gamma sterilized cortical bone. Bovine femurs specimens were soaked in different concentrations of HT and ALA for 7 and 3 days respectively before irradiation with 35 KGy gamma radiation. The attenuated total reflection-Fourier transform infrared spectroscopy and the X-ray diffraction techniques were utilized to analyze the changes in chemical composition induced by irradiation in the presence of free radical scavengers. A significant increase in the proportion of amide I and amide II to phosphate was noticed in the irradiated group, while in the pretreated groups with ALA and HT this effect was minimized. In addition, gamma radiation reduced the mature to immature cross links while ALA and HT alleviated this reduction. No significant changes were noticed in the mineral crystallinity or crystal size. Bone chemical structure has been changed due to gamma irradiation and these changes are mainly relevant to amide I, amide II proportions and collagen crosslinks. The deteriorating effects of gamma sterilization dose (35 kGy) on chemical structure of bone allograft can be alleviated by using (HT) and (ALA) free radical scavengers before irradiation.
Collapse
|
3
|
El-Hansi NS, Sallam AM, Talaat MS, Said HH, Khalaf MA, Desouky OS. Biomechanical properties enhancement of gamma radiation-sterilized cortical bone using antioxidants. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2020; 59:571-581. [PMID: 32444954 DOI: 10.1007/s00411-020-00848-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
Gamma radiation sterilization is the method used by the majority of tissue banks to reduce disease transmission from infected donors to recipients through bone allografts. However, many studies have reported that gamma radiation impairs the structural and mechanical properties of bone via formation of free radicals, the effect of which could be reduced using free radical scavengers. The aim of this study is to examine the radioprotective role of hydroxytyrosol (HT) and alpha lipoic acid (ALA) on the mechanical properties of gamma-sterilized cortical bone of bovine femur, using three-point bending and microhardness tests. Specimens of bovine femurs were soaked in ALA and HT for 3 and 7 days, respectively, before being exposed to 35-kGy gamma radiation. In unirradiated samples, both HT and ALA pre-treatment improved the cortical bone bending plastic properties (maximum bending stress, maximum bending strain, and toughness) without affecting microhardness. Irradiation resulted in a drastic reduction of the plastic properties and an increased microhardness. ALA treatment before irradiation alleviated the aforementioned reductions in maximum bending stress, maximum bending strain, and toughness. In addition, under ALA treatment, the microhardness was not increased after irradiation. For HT treatment, similar effects were found. In conclusion, the results indicate that HT and ALA can be used before irradiation to enhance the mechanical properties of gamma-sterilized bone allografts.
Collapse
Affiliation(s)
- Naglaa S El-Hansi
- Biophysics Lab, Radiation Physics Department, (NCRRT), Atomic Energy Authority (AEA), Nasr City, Cairo, Egypt
| | - Abdelsattar M Sallam
- Biophysics Branch, Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Mona S Talaat
- Biophysics Branch, Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Hoda H Said
- Biophysics Lab, Radiation Physics Department, (NCRRT), Atomic Energy Authority (AEA), Nasr City, Cairo, Egypt.
| | - Mahmoud A Khalaf
- Microbiology Department (NCRRT), Atomic Energy Authority (AEA), Nasr City, Cairo, Egypt
| | - Omar S Desouky
- Biophysics Lab, Radiation Physics Department, (NCRRT), Atomic Energy Authority (AEA), Nasr City, Cairo, Egypt
| |
Collapse
|
4
|
Suhardi JV, Morgan DFA, Muratoglu OK, Oral E. Radioprotection and cross-linking of allograft bone in the presence of vitamin E. J Biomed Mater Res B Appl Biomater 2020; 108:2354-2367. [PMID: 31975566 DOI: 10.1002/jbm.b.34569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/11/2019] [Accepted: 01/06/2020] [Indexed: 11/08/2022]
Abstract
Bone allografts are the preferred method for bone augmentation in over 500,000 orthopedic surgical procedures in the US. Sterilization by ionizing radiation is the most effective method of minimizing the bioburden of bone allografts; however, radiation causes chain scission of collagen, resulting in the reduction of the allografts' mechanical strength. In this study, we doped bone allografts with vitamin E as radioprotectant using a novel two-step process to protect the collagen architecture against radiation damage and to preserve the mechanical strength of the construct. In addition, combining the radioprotectant with a cross-linking agent further minimized collagen degradation and further preserved the mechanical strength of the allografts. Both vitamin E and combined vitamin E/genipin-treated allograft were less cytotoxic to both osteoblasts and osteoclasts when compared to irradiated-only allografts. Host bone-allograft unionization was faster in a rat calvaria defect model with vitamin E-treated and combined vitamin E and genipin-treated allograft when compare to irradiated-only allografts. This method can enable the efficient and uniform radioprotective treatment of bone allograft of desired shapes for sterilization with improved mechanical strength and biointegration.
Collapse
Affiliation(s)
- Jeremy V Suhardi
- Harris Orthopedic Laboratory, Massachusetts General Hospital, Boston, Massachusetts.,Department of Medical Engineering and Medical Physics, Massachusetts Institute of Technology, Boston, Massachusetts.,Department of Orthopaedic Surgery, Harvard Medical School, Boston, Massachusetts
| | | | - Orhun K Muratoglu
- Harris Orthopedic Laboratory, Massachusetts General Hospital, Boston, Massachusetts.,Department of Orthopaedic Surgery, Harvard Medical School, Boston, Massachusetts
| | - Ebru Oral
- Harris Orthopedic Laboratory, Massachusetts General Hospital, Boston, Massachusetts.,Department of Orthopaedic Surgery, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Attia T, Tupy J, Asker D, Hatton B, Grynpas M, Willett T. The effect of ribose pre-treatment of cortical bone on γ-irradiation sterilization effectiveness. Cell Tissue Bank 2017; 18:555-560. [PMID: 29032461 DOI: 10.1007/s10561-017-9662-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/05/2017] [Indexed: 11/30/2022]
Abstract
Reconstruction of large skeletal defects is a significant and challenging issue. Tissue banks often use γ-irradiation (15-35 kGy) to sterilize bone allografts, which, however, drastically impairs the post-yield mechanical properties. In previous studies, we reported the development of a method that protects human bone collagen connectivity through ribose crosslinking while still undergoing γ-irradiation. Given these promising results, the next step was to determine if the presence of ribose within the bone tissue would interfere with the effectiveness of the γ-irradiation sterilization against bacteria. This study had two stages. The aim of the first stage was to assess the protective effect of ribose in solution using a Bacillus pumilus spore strip model. The aim of the second stage was to assess the protective effect of ribose (R) on spores within a human cortical bone model in comparison to conventionally irradiated bone (I). Treatment of B. pumilus spore strips with ribose in solution led to temperature-dependent effects on spore viability versus spore strips treated with PBS alone. Ribose solution at 60 °C led to a notable two logs decrease in spore count relative to PBS at 60 °C. In the human bone model, the number of spores in the I and R groups were greatly decreased in comparison to the non-irradiated N group. No spore colonies were detected in the R group (n = 4) whereas two of the four plates of group I formed colonies. This study provides evidence that the method of pre-treating bone with ribose crosslinking prior to irradiation sterilization, while improving irradiation sterilized bone allograft quality, also may improve the effectiveness of the sterilization process.
Collapse
Affiliation(s)
- Tarik Attia
- Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Jindra Tupy
- Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada
| | - Dalal Asker
- Materials Science and Engineering, University of Toronto, Toronto, ON, Canada.,Alexandria University, Alexandria, Egypt
| | - Benjamin Hatton
- Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Marc Grynpas
- Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Thomas Willett
- Biomedical Engineering Program, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON, Canada.
| |
Collapse
|
7
|
Mohr J, Germain M, Winters M, Fraser S, Duong A, Garibaldi A, Simunovic N, Alsop D, Dao D, Bessemer R, Ayeni OR. Disinfection of human musculoskeletal allografts in tissue banking: a systematic review. Cell Tissue Bank 2016; 17:573-584. [PMID: 27665294 PMCID: PMC5116033 DOI: 10.1007/s10561-016-9584-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 09/09/2016] [Indexed: 01/12/2023]
Abstract
Musculoskeletal allografts are typically disinfected using antibiotics, irradiation or chemical methods but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of microorganism kill; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. A systematic review of three databases found 68 laboratory and clinical studies that analyzed the microbial bioburden or contamination rates of musculoskeletal allografts. The use of peracetic acid–ethanol or ionizing radiation was found to be most effective for disinfection of tissues. The use of irradiation is the most frequently published method for the terminal sterilization of musculoskeletal allografts; it is widely used and its efficacy is well documented in the literature. However, effective disinfection results were still observed using the BioCleanse™ Tissue Sterilization process, pulsatile lavage with antibiotics, ethylene oxide, and chlorhexidine. The variety of effective methods to reduce contamination rate or bioburden, in conjunction with limited high quality evidence provides little support for the recommendation of a single bioburden reduction method.
Collapse
Affiliation(s)
- J Mohr
- Canadian Blood Services, 270 John Savage Ave., Dartmouth, NS, B3B 0H7, Canada
| | - M Germain
- Héma-Québec, 1070 Sciences-de-la-Vie Avenue, Quebec, QC, G1V 5C3, Canada
| | - M Winters
- Nelson Laboratories, 6280 South Redwood Road, Salt Lake City, UT, 84123-6600, USA
| | - S Fraser
- Canadian Blood Services, 270 John Savage Ave., Dartmouth, NS, B3B 0H7, Canada
| | - A Duong
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - A Garibaldi
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - N Simunovic
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - D Alsop
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - D Dao
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - R Bessemer
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada
| | - O R Ayeni
- Department of Surgery, McMaster University, 293 Wellington St. N, Suite 110, Hamilton, ON, L8L 8E7, Canada. .,McMaster University Medical Centre, 1200 Main St W, Room 4E15, Hamilton, ON, L8N 3Z5, Canada.
| | | |
Collapse
|
8
|
Allaveisi F, Mirzaei M. Effects of high-dose gamma irradiation on tensile properties of human cortical bone: Comparison of different radioprotective treatment methods. J Mech Behav Biomed Mater 2016; 61:475-483. [DOI: 10.1016/j.jmbbm.2016.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/24/2016] [Accepted: 04/08/2016] [Indexed: 12/15/2022]
|
9
|
Woodside M, Willett TL. Elastic-plastic fracture toughness and rising JR-curve behavior of cortical bone is partially protected from irradiation-sterilization-induced degradation by ribose protectant. J Mech Behav Biomed Mater 2016; 64:53-64. [PMID: 27479894 DOI: 10.1016/j.jmbbm.2016.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/24/2016] [Accepted: 07/03/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE This study tested the hypothesis that pre-treating cortical bone with ribose would protect the rising fracture resistance curve behavior and crack initiation fracture toughness of both bovine and human cortical bone from the degrading effects of γ-irradiation sterilization. MATERIALS AND METHODS A ribose pre-treatment (1.8 M for bovine, and 1.2 M for human, in PBS at 60 °C for 24 h) was applied to single-edge notched bending fracture specimens prior to sterilization with a 33 kGy dose of γ-irradiation. Fracture resistance curves were generated with a single specimen method using an optical crack length measurement technique. The effect of the treatment on overall fracture resistance behavior, crack initiation fracture toughness, and tearing modulus was compared with non-irradiated and conventionally irradiation sterilized controls. Hydrothermal isometric tension testing was used to examine collagen network connectivity and thermal stability to explore relationships between collagen network quality and fracture resistance. RESULTS The ribose pre-treatment successfully protected the crack growth initiation fracture toughness of bovine and human bone by 32% and 63%, respectively. The rising JR-curve behavior was also partially protected. Furthermore, collagen connectivity and thermal stability followed similar patterns to those displayed by fracture toughness. CONCLUSIONS This paper demonstrates that the fracture toughness of irradiation-sterilized bone tissue can be partially protected with a ribose pre-treatment. This new approach shows potential for the production and clinical application of sterilized allografts with improved mechanical performance and durability.
Collapse
Affiliation(s)
- Mitchell Woodside
- Materials Science and Engineering, University of Toronto, Toronto, ON, Canada; Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld-Tanenbaum Research Institute, Toronto, ON, Canada
| | - Thomas L Willett
- Materials Science and Engineering, University of Toronto, Toronto, ON, Canada; Musculoskeletal Research Laboratory, Mount Sinai Hospital - Lunenfeld-Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, ON, Canada; Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, ON, Canada.
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Willett TL, Burton B, Woodside M, Wang Z, Gaspar A, Attia T. γ-Irradiation sterilized bone strengthened and toughened by ribose pre-treatment. J Mech Behav Biomed Mater 2015; 44:147-55. [PMID: 25637825 DOI: 10.1016/j.jmbbm.2015.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/22/2014] [Accepted: 01/03/2015] [Indexed: 01/22/2023]
Abstract
OBJECTIVE This study tested the hypothesis that a ribose-based pre-treatment would protect the strength, ductility and toughness of γ-irradiation sterilized cortical bone. METHODS Experiment 1: The effects of ribose pre-treatment (1.8M in PBS at 60°C for 24h) prior to 33 kGy of irradiation on strength, ductility and toughness (beams in three-point bending) and fracture toughness (J-integral at instability in single edge notched (bending)) were tested against matched non-irradiated and irradiated controls from bovine tibiae. Experiment 2: Three-point bending tests were conducted using beams from human femora (males, 59-67 years). Bone collagen thermal stability and network connectivity were examined using hydrothermal isometric tension testing. RESULTS Ribose pre-treatment protected the strength, ductility and toughness of irradiation sterilized bovine and human specimens to differing degrees. Their ultimate strength was not detectably different from non-irradiated control levels; toughness in bovine and human specimens was protected by 57 and 76%, respectively. Untreated human bone was less affected by irradiation and ribose pre-treatment was more effective in human bone than bovine bone. CONCLUSIONS This paper presents the first proof-of-principle that irradiation-sterilized bone with improved mechanical properties can be produced through the application of a ribose pre-irradiation treatment, which provides a more stable and connected collagen network than found in conventionally irradiated controls.
Collapse
Affiliation(s)
- Thomas L Willett
- Musculoskeletal Research Laboratory, Mount Sinai Hospital-Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada; Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, ON, Canada; Department of Surgery, University of Toronto, Toronto, ON, Canada.
| | - Brianne Burton
- Musculoskeletal Research Laboratory, Mount Sinai Hospital-Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Mitchell Woodside
- Musculoskeletal Research Laboratory, Mount Sinai Hospital-Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada; Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Zhirui Wang
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON, Canada
| | - Anne Gaspar
- Musculoskeletal Research Laboratory, Mount Sinai Hospital-Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Tarik Attia
- Musculoskeletal Research Laboratory, Mount Sinai Hospital-Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
12
|
Giedraitis A, Arnoczky SP, Bedi A. Allografts in soft tissue reconstructive procedures: important considerations. Sports Health 2014; 6:256-64. [PMID: 24790696 PMCID: PMC4000469 DOI: 10.1177/1941738113503442] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
CONTEXT Allografts offer several important advantages over autografts in musculoskeletal reconstructive procedures, such as anterior cruciate ligament reconstruction. Despite growing widespread use of allograft tissue, serious concerns regarding safety and functionality remain. We discuss the latest knowledge of the potential benefits and risks of allograft use and offer a critical review of allograft tissue regulation, management, and sterilization to enable the surgeon to better inform athletes considering reconstructive surgery options. EVIDENCE ACQUISITION A review of sources published in the past 10 years is the primary basis of this research. STUDY DESIGN Observational analysis (cohort study). LEVEL OF EVIDENCE Level 3. RESULTS Comparable outcome data for autografts and allografts do not support universal standards for anterior cruciate ligament reconstruction, and physician recommendation and bias appear to significantly influence patient preference and satisfaction. Sterilization by gamma and electron-beam irradiation diminishes the biomechanical integrity of allograft tissue, but radioprotective agents such as collagen cross-linking and free radical scavengers appear to have potential in mitigating the deleterious effects of irradiation and preserving tissue strength and stability. CONCLUSION Allografts offer greater graft availability and reduced morbidity in orthopaedic reconstructive procedures, but greater expansion of their use by surgeons is challenged by the need to maintain tissue sterility and biomechanical functionality. Advances in the radioprotection of irradiated tissue may lessen concerns regarding allograft safety and structural stability.
Collapse
Affiliation(s)
- Andrius Giedraitis
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Steven P Arnoczky
- Laboratory for Comparative Orthopaedic Research, Michigan State University, East Lansing, Michigan
| | - Asheesh Bedi
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
| |
Collapse
|
13
|
Radioprotective effect of N-acetyl-L-cysteine free radical scavenger on compressive mechanical properties of the gamma sterilized cortical bone of bovine femur. Cell Tissue Bank 2014; 16:97-108. [PMID: 24737302 DOI: 10.1007/s10561-014-9446-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/01/2014] [Indexed: 12/30/2022]
Abstract
Gamma sterilization of bone allografts is used as a gold standard method to provide safety against disease transmission. However, it is well documented that high dose levels of ionizing radiation can degrade bone mechanical properties. This effect, which is attributed to the formation of free radicals through radiolysis of the water content of collagen, can lead to post-implantation difficulties such as pre-failure and/or secondary fractures of bone allografts. Recently, treatment of irradiated allografts with free radical scavengers is used to protect them against radiation-induced damages. This study aimed to investigate the radioprotective role of N-acetyl-L-cysteine (NAC) during the gamma sterilization of the cortical bone of bovine femurs using the compressive test. Totally, 195 cubic specimens with a dimension of 5 × 5 × 3 cubic mm were divided into 13 groups including a control and 12 experimental groups exposed to 18, 36, and 70 kGy at three different NAC concentrations (1.25, 12.5, and 25 mM for 18 kGy; 5, 50, and 100 mM for 36 kGy; 10, 100, and 200 mM for 70 kGy). The mechanical behavior of the sterilized specimens was studied using the uniaxial compressive test. The results indicated a concentration-dependent radioprotection effect of NAC on the plastic properties of the cortical bones. The concentration dependency of NAC was in turn related to radiation dose levels. In conclusion, treatment of bone specimens with a characteristic concentration of NAC during exposure to specific radiation dose levels can provide an efficient radioprotection window for preserving the mechanical stability of gamma sterilized allografts.
Collapse
|
14
|
Delgado LM, Pandit A, Zeugolis DI. Influence of sterilisation methods on collagen-based devices stability and properties. Expert Rev Med Devices 2014; 11:305-14. [PMID: 24654928 DOI: 10.1586/17434440.2014.900436] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sterilisation is essential for any implantable medical device in order to prevent infection in patients. The selection of the most appropriate sterilisation method depends on the nature and the physical state of the material to be sterilised; the influence of the sterilisation method on the properties of the device; and the type of the potential contaminant. In this context, herein we review the influence of ethylene oxide, γ-irradiation, e-beam irradiation, gas plasma, peracetic acid and ethanol on structural, biomechanical, biochemical and biological properties of collagen-based devices. Data to-date demonstrate that chemical approaches are associated with cytotoxicity, whilst physical methods are associated with degradation, subject to the device physical characteristics. Thus, the sterilisation method of choice is device dependent.
Collapse
Affiliation(s)
- Luis M Delgado
- Network of Excellence for Functional Biomaterials (NFB), National University of Ireland Galway (NUI Galway), Galway, Ireland
| | | | | |
Collapse
|
15
|
Abstract
Secondary sterilization of musculoskeletal allografts may use chemicals, radiation, or combinations of these. No sterilization techniques have been definitively proven to be more effective than others, and their biomechanical and biological effects on allograft tissue remain largely unknown. The current risk of an allograft infection appears to be much less than the risk of infection surrounding the surgical procedure itself. With appropriate donor screening, improved donor testing—including nucleic acid testing (NAT), and adherence to AATB standards—the risk of disease transmission or infections can be eliminated or substantially decreased.
Collapse
Affiliation(s)
- Frederick M Azar
- University of Tennessee-Campbell Clinic Department of Orthopaedic Surgery, 1211 Union Avenue, Suite 520, Memphis, TN 38104, USA.
| |
Collapse
|