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Gökler DJ, Karácsony AF, Faragó D, Szebényi G, Kiss RM, Pap K. The effect of sterilization and storage on the viscoelastic properties of human tendon allografts - Continued: Storage for 0 to 4 months. J Biomech 2024; 162:111904. [PMID: 38134466 DOI: 10.1016/j.jbiomech.2023.111904] [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: 02/08/2023] [Revised: 12/09/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023]
Abstract
The role of donor-derived tendons, also known as allografts, in anterior cruciate ligament replacement surgeries is steadily increasing. Before surgery, temporary storage and, in most cases, sterilization are essential. It is, thus, crucial to determine how these procedures alter the grafts' biomechanical properties. The purpose of this research was to analyze the effect of different sterilization methods (native, frozen, frozen + 21 kGy gamma irradiation, frozen + 21 kGy electron beam irradiation) and storage durations (0 to 4 months) on the deformation and creep of two tendon types (tibialis anterior, peroneus longus). 80 tibialis anterior and 83 peroneus longus tendons from 51 human cadavers were included. The samples were removed, placed in a radio-cryoprotectant solution, then slowly cooled, sterilized and stored at -80 °C. All groups were subject to 60 s static creep test with 250 N load. Deformation during the loading phase, creep during static loading, and the ratio of these two were evaluated. Deformation at the end of the loading phase and creep consistently exhibited significantly smaller values in the tibialis anterior compared to the peroneus longus type, as well as in electron beam-sterilized grafts as opposed to gamma beam-sterilized ones. Prolonged storage periods (within 0 to 4 months) resulted in a notable increase in these values, particularly in deformation. Based on the experimental data, the tibialis anterior tendon type and sterilization by gamma beam irradiation are better choices for anterior cruciate ligament reconstruction than the peroneus longus and sterilization by electron beam. Increased storage time affects negatively the evaluated mechanical properties.
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Affiliation(s)
- Daniella Judit Gökler
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary
| | - Atilla Ferenc Karácsony
- Semmelweis University Budapest, Department of Traumatology, Hungary; Buda Hospital of the Hospitaller Order of Saint John of God, Department of Orthopedics, Hungary
| | - Dénes Faragó
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary
| | - Gábor Szebényi
- MTA-BME Lendület Lightweight Polymer Composites Research Group, Hungary; Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering, Hungary.
| | - Rita Mária Kiss
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary
| | - Károly Pap
- Semmelweis University Budapest, Department of Traumatology, Hungary; Uzsoki Hospital, Department of Orthopedics and Traumatology, Hungary
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Li H, Tan KG, Li Z, Wu X, Cai G, Zhu W, Huang T, Wang W, Crawford R, Mao X. Impaction Bone Grafting with Low Dose Irradiated Freeze-Dried Allograft Bone for Acetabular Reconstruction. Orthop Surg 2022; 14:2519-2526. [PMID: 36017764 PMCID: PMC9531074 DOI: 10.1111/os.13471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 07/10/2022] [Accepted: 07/25/2022] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE Reconstruction of acetabular defects has been extremely challenging in both primary and revision total hip arthroplasty (THA). Impaction bone grafting (IBG) can restore the acetabulum bone mass and anatomically reconstruct the acetabulum. Our study aimed to report the short and medium-term clinical and radiographic outcomes of IBG for acetabular reconstruction in the cemented THA in the Chinese population. METHODS This was a single-center retrospective review enrolling 57 patients between May 2013 and July 2019. The patients with acetabular defects were treated with IBG, using low dose irradiated freeze-dried allograft bone with or without autograft bone, in the cemented THA performed by one senior surgeon. Harris hip score (HHS), standard pelvis anterior-posterior radiograph and lateral hip radiograph were obtained before operation and at 1 week, 3 months, 12 months, and yearly. Graft osteointegration was evaluated by Oswestry's criteria, and complication was documented at the last follow-up. Independent sample ANOVA test and Pearson chi-square tests are used for statistical analysis. RESULTS There were 61 hips in 57 patients. The average follow-up time was 35.59 months (5-77 months). According to AAOS classification, a total of 18 hips were identified as segmental bone deficiency (type I), with 21 and 22 hips for cavitary bone deficiency (type II) and the combined bone deficiency (type III), respectively. The average HHS was improved from 44.49 (range: 32-58) preoperatively to 86.98 (range: 78-93) postoperatively. Graft osteointegration was satisfactory (Oswestry score ≥2) in all patients. No dislocation occurred in the 57 patients (61 hips) during follow-up. Although one cup migrated, no revision, re-revision, radiographic loosening, graft bone lysis, or postoperative complications were detected at the final follow-up. CONCLUSIONS IBG with low-dose irradiated freeze-dried allograft bone in acetabular bone defect reconstruction is a reliable technique for restoring acetabular bone defects in THA.
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Affiliation(s)
- Hongxing Li
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | | | - Zhiling Li
- Center of Health Management, The Central Hospital of Shaoyang, Shaoyang, China
| | - Xiaoxin Wu
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Guangping Cai
- Department of endocrinology, The Xiangya Hospital, Central South University, Changsha, China
| | - Weihong Zhu
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Tianlong Huang
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Wanchun Wang
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ross Crawford
- Department of Orthopedic, Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Xinzhan Mao
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Changsha, China
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Farago D, Kozma B, Kiss RM. Categorize the existing clamps used for tensile test of human graft- a systematic review. BMC Musculoskelet Disord 2022; 23:707. [PMID: 35879684 PMCID: PMC9316330 DOI: 10.1186/s12891-022-05650-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The use of tendon allografts for orthopedic repair has gained wide acceptance in recent years, most notably in anterior cruciate tendon reconstruction. Multiple studies support the use of tendon allografts and the benefits of its use are well accepted and understood. One of the important criteria of the use of tendon allografts is statistically similar histological and biomechanical properties to autographs. The aim of this systematic literature review is to investigate and categorize existing clamps used in the determination of the biomechanical properties of tendons such as maximum load, maximum strength, modulus of elasticity, ultimate strain, and stiffness. A variety of clamps for use during the endurance test of tendons were categorized according to the temperature used during the measurement. The clamps are divided into three groups: room temperature, cooled and heated clamps. The second goal of our review is to overview of clamps on the following aspects: name of clamp, author and date, type of clamps, type of endurance test (static or dynamic), type preloading (dynamic or static), type of tendon and measured and calculated parameters, and summarize in Table 3, as a comprehensive catalogue. METHODS This systematic review was carried out in keeping with the PRISMA 2020 E&E and the PRISMA-S guidelines and checklists. A search was conducted for publications dating between 1991 and February 28th 2022 through three electronic databases (Web of Science, Scopus, and PubMed). We used Critical Appraisal Skills Program checklist to check the quality of included articles. RESULTS The database search and additional sources resulted in 1725 records. 1635 records eliminated during the screening for various reasons (case report, other languages, book chapter, unavailable text/conference abstract, unrelated topic). The number of articles used in the final synthesis was 90. A variety of clamps for use during the endurance test of tendons were identified and categorized according to the temperature used during the measurement. Based on this, the clamps are divided into three groups: room temperature, cooled or heated clamps. CONCLUSIONS On the basis of the systematic literature review, mechanical parameters determined by usage with cooled clamps proved to be more reliable than with those at room temperature and with heated clamps. The collected information from the articles included name of clamp, author and date, type of clamps, type of endurance test (static or dynamic), type preloading (dynamic or static), type of tendon and measured and calculated parameters given in Table 3. summarized. The main advantage of the cooled clamps is that there is no limit to the type and length of the tendon. This study provides an overview of clamps and does not represent the modernity of any method.
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Affiliation(s)
- Denes Farago
- Cooperation Research Center for Biomechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Budapest, Hungary.
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Budapest, Hungary.
| | - Blanka Kozma
- Department of Biomedical Engineering, SUNY University at Buffalo, Buffalo, USA
| | - Rita Maria Kiss
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Budapest, Hungary
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Gökler DJ, Faragó D, Szebényi G, Kiss RM, Pap K. The effect of sterilization and storage on the viscoelastic properties of human tendon allografts. J Biomech 2021; 127:110697. [PMID: 34419827 DOI: 10.1016/j.jbiomech.2021.110697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 11/17/2022]
Abstract
Allografts have become increasingly preferred for anterior cruciate ligament replacement purposes. The risk of infections necessitates thorough sterilization procedures, and the allografts usually need to be stored prior to surgery. Classical mechanical tests have been performed with various types of tendons, however, tibialis anterior and peroneus longus tend to suffer the least biomechanical changes after irradiation. Only few results are available of the strain and creep behaviour of tendons, even though this information is necessary to provide suitable allografts. The aim of the present study is to analyze the effect of different tendon types (T-tibialis anterior, P-peroneus longus), sterilization methods (G-gamma irradiation of 21 kGy, E-electron beam irradiation of 21 kGy) and storage times (5 and 6 months) on the creep behavior, which is characterized by the strain at the end of the loading phase and creep deformation after static loading. Static creep tests were performed with 250 N load during 60 s. Deformation at the end of the loading phase of both tendons was significantly smaller after 5 months long storage than that after 6 months long storage. TE5 showed significantly less creep than group TE6, and TE6 significantly greater than PE6. The creep of TE5 was significantly lower than that of TG5. Based on the data, the peroneus longus sterilized by electron beam and stored deep frozen for 5 months is a better choice for anterior cruciate ligament reconstruction than tibialis anterior sterilized by gamma irradiation stored for 6 months.
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Affiliation(s)
- Daniella Judit Gökler
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary
| | - Dénes Faragó
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary; Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Biomechanical Research Centre, Hungary
| | - Gábor Szebényi
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Biomechanical Research Centre, Hungary; Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Polymer Engineering, Hungary
| | - Rita Mária Kiss
- Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Department of Mechatronics, Optics, and Mechanical Engineering Informatics, Hungary; Budapest University of Technology and Economics, Faculty of Mechanical Engineering, Biomechanical Research Centre, Hungary.
| | - Károly Pap
- Semmelweis University Budapest, Department of Traumatology, Hungary; Uzsoki Hospital, Department of Orthopedics and Traumatology, Hungary
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Different sterilization and disinfection methods used for human tendons - a systematic review using mechanical properties to evaluate tendon allografts. BMC Musculoskelet Disord 2021; 22:404. [PMID: 33941147 PMCID: PMC8091719 DOI: 10.1186/s12891-021-04296-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/23/2021] [Indexed: 11/25/2022] Open
Abstract
Background It is important to know the biomechanical properties of an allograft. This is because when looking to do a transplant of a tendon, the tendon must have very similar biomechanical properties to the original tendon. To use tendon allografts, it is critical to properly sterilize the tendon before implantation. In past decades, several sterilization procedures have been used. This study aimed to systematically evaluate the existing literature to compare the values of failure load/ultimate strength and Young’s modulus of elasticity of different sterilization methods on commonly used tendon allografts. Five major scientific literature databases (Web of Science, Science Direct, Scopus, PLOS ONE, Hindawi) and additional sources were used. Results Studies used had to show a particular sterilization method. Studies were identified to meet the following inclusion criteria: is a controlled laboratory study, gamma irradiation (dose reported), and other sterilization methods. Search for publications dated between 1991 and March 31st, 2020. The database search and additional sources resulted in 284 records. Two hundred thirty records eliminated during the screening for various reasons. The number of articles used in the final synthesis was 54. Conclusions Identified sterilization methods (gamma irradiation, ethylene oxid, supercritical carbon dioxide (SCCO2), BioCleanse, Electron Beam) are offered as a catalog of potential methods. As a result of the broadness of the present research, it provides an overview of sterilization methods and their effect on the mechanical properties (failure load and Young’s modulus of elasticity) of tendons. It does not stand for the state-of-the-art of any single process. Based on a systematic literature review, we recommend freezing and gamma irradiation or electron beam at 14.8–28.5 kGy. These methods are effective at keeping or improving the mechanical properties, while fully sterilizing the inside and the outside of the tendon. Other sterilization method (ethylene oxide, supercritical carbon dioxide (SCCO2), BioCleanse) deteriorated the mechanical properties. These methods are not recommended. Supplementary Information The online version contains supplementary material available at 10.1186/s12891-021-04296-4.
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Yang X, Feng J, Wang F, Hu Y. Irradiation sterilization used for allogenetic tendon: a literature review of current concept. Cell Tissue Bank 2019; 20:129-139. [PMID: 31054008 DOI: 10.1007/s10561-019-09756-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 02/13/2019] [Indexed: 01/27/2023]
Abstract
Tendon injury is a very common type of sports trauma, and its incidence has increased over the past decades. Surgical reconstruction with tendon allograft has been increasingly used to restore the motor function and stability of the injured site. However, the risk of disease transmission caused by allogeneic tendon transplantation has been a major problem for tissue bank researchers and clinicians. In order to eliminate the risk of disease transmission, a process of terminal sterilization is necessary. Ionizing irradiation, including gamma irradiation and electron beam irradiation is the most commonly used method for the terminal sterilization, which has been widely proved to be able to effectively inactivate the contained pathogens. Nevertheless, some accompanying damage to the mechanical and histological properties of collagen fibers in tendons will be caused. Therefore, more and more studies have begun to pay attention to the protective effect of radiation protection agents, including the radical scavengers and cross-linking agents, in the irradiation sterilization of allogeneic tendons.
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Affiliation(s)
- Xionggang Yang
- Graduate School, Tianjin Medical University, Tianjin, 300070, China
| | - Jiangtao Feng
- Graduate School, Tianjin Medical University, Tianjin, 300070, China
| | - Feng Wang
- Graduate School, Tianjin Medical University, Tianjin, 300070, China
| | - Yongcheng Hu
- Department of Orthopedic Oncology, Tianjin Hospital, Tianjin, 300211, China.
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Czarnecki JS, Lafdi K, Tsonis PA. The future of carbon-based scaffolds in foot and ankle surgery. Clin Podiatr Med Surg 2015; 32:73-91. [PMID: 25440419 DOI: 10.1016/j.cpm.2014.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Carbon may represent an alternative material suitable for future development as a soft-tissue substitute that potentially optimizes the biological and mechanical properties required for a graft product used in surgery. In addition, other modes of characterization such as 3-dimensional computational modeling may offer an insight into material performance in a biological environment. Further investigation is required to characterize and model the relationships between biological, mechanical, and design properties of this material to maximize its potential as a biomechanical scaffold and vehicle for delivering biologics that promote tissue repair and regeneration.
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Affiliation(s)
- Jarema S Czarnecki
- Department of Mechanical Engineering, University of Dayton, 300 College Park, Dayton, OH 45469, USA.
| | - Khalid Lafdi
- Chemical and Materials Engineering, University of Dayton, 300 College Park, Dayton, OH 45469-0240, USA
| | - Panagiotis A Tsonis
- Biology, Center for Tissue Regeneration and Engineering (TREND), University of Dayton, 300 College Park, Dayton, OH 45469, USA
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Elenes EY, Hunter SA. Soft-tissue allografts terminally sterilized with an electron beam are biomechanically equivalent to aseptic, nonsterilized tendons. J Bone Joint Surg Am 2014; 96:1321-6. [PMID: 25143491 DOI: 10.2106/jbjs.l.00841] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Allograft safety is contingent on effective sterilization. However, current sterilization methods have been associated with decreased biomechanical strength and higher failure rates of soft-tissue allografts. In this study, electron beam (e-beam) sterilization was explored as an alternative sterilization method to preserve biomechanical integrity. We hypothesized that e-beam sterilization would not significantly alter the biomechanical properties of tendon allograft compared with aseptic, nonsterilized controls and gamma-irradiated grafts. METHODS Separate sets of forty fresh-frozen tibialis tendon allografts (four from each of ten donors) and forty bisected bone-patellar tendon-bone (BTB) allografts (four from each of ten donors) were randomly assigned to four study groups. One group received a 17.1 to 21.0-kGy gamma radiation dose; two other groups were sterilized with an e-beam at either a high (17.1 to 21.0-kGy) or low (9.2 to 12.2-kGy) dose. A fourth group served as nonsterilized controls. Each graft was cyclically loaded to 200 N of tension for 2000 cycles at a frequency of 2 Hz, allowed to relax for five minutes, and then tested in tension until failure at a 100%/sec strain rate. One-way analysis of variance testing was used to identify significant differences. RESULTS Tibialis tendons sterilized with both e-beam treatments and with gamma irradiation exhibited values for cyclic tendon elongation, maximum load, maximum displacement, stiffness, maximum stress, maximum strain, and elastic modulus that were not significantly different from those of nonsterilized controls. BTB allografts sterilized with the high e-beam dose and with gamma irradiation were not significantly different in cyclic tendon elongation, maximum load, maximum displacement, stiffness, maximum stress, maximum strain, and elastic modulus from nonsterilized controls. BTB allografts sterilized with the e-beam at the lower dose were significantly less stiff than nonsterilized controls (p = 0.014) but did not differ from controls in any other properties. The difference in stiffness likely resulted from variations in tendon size rather than the treatments, as the elastic moduli of the groups were similar. CONCLUSIONS The biomechanical properties of tibialis and BTB allografts sterilized with use of an e-beam at a dose range of 17.1 to 21.0 kGy were not different from those of aseptic, nonsterilized controls or gamma-irradiated allografts. CLINICAL RELEVANCE E-beam sterilization can be a viable method to produce safe and biomechanically uncompromised soft-tissue allografts.
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Affiliation(s)
- Egleide Y Elenes
- School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, 317 ICTAS, Stanger Street (0298), Blacksburg, VA 24061. E-mail address:
| | - Shawn A Hunter
- Department of Research and Development, Community Tissue Services, 2900 College Drive, Kettering, OH 45420. E-mail address:
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Almeida OMD, Jorgetti W, Oksman D, Jorgetti C, Rocha DL, Gemperli R. Comparative study and histomorphometric analysis of bone allografts lyophilized and sterilized by autoclaving, gamma irradiation and ethylene oxide in rats. Acta Cir Bras 2013; 28:66-71. [PMID: 23338116 DOI: 10.1590/s0102-86502013000100011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/19/2012] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To compare three sterilization methods (autoclave, gamma irradiation and ethylene oxide) over non demineralized lyophilized bone allografts. METHODS Bone allografts were implanted on paravertebral muscles of 21 rats. After 30 days animals were sacrificed and grafts underwent comparative analysis regarding histomorphometric and macroscopic parameters. RESULTS Allografts that underwent the three sterilization methods presents similar weight gain, cortical thickness similar to control group, and less fibrosis than the control group. Grafts that underwent sterilization in autoclave presented less presence of multinucleated giant cells, although not statistically significant. There was also no statistically significant difference regarding mineralization on the three groups. CONCLUSION The three sterilization methods cause similar effects on bone allografts regarding macroscopic and histomorphometric parameters.
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Czarnecki JS, Lafdi K, Joseph RM, Tsonis PA. Hybrid carbon-based scaffolds for applications in soft tissue reconstruction. Tissue Eng Part A 2012; 18:946-56. [PMID: 22092333 DOI: 10.1089/ten.tea.2011.0533] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Current biomedical scaffolds utilized in surgery to repair soft tissues commonly fail to meet the optimal combination of biomechanical and tissue regenerative properties. Carbon is a scaffold alternative that potentially optimizes the balance between mechanical strength, durability, and function as a cell and biologics delivery vehicle that is necessary to restore tissue function while promoting tissue repair. The goals of this study were to investigate the feasibility of fabricating hybrid fibrous carbon scaffolds modified with biopolymer, polycaprolactone and to analyze their mechanical properties and ability to support cell growth and proliferation. Environmental scanning electron microscopy, micro-computed tomography, and cell adhesion and cell proliferation studies were utilized to test scaffold suitability as a cell delivery vehicle. Mechanical properties were tested to examine load failure and elastic modulus. Results were compared to an acellular dermal matrix scaffold control (GraftJacket(®) [GJ] Matrix), selected for its common use in surgery for the repair of soft tissues. Results indicated that carbon scaffolds exhibited similar mechanical maximums and capacity to support fibroblast adhesion and proliferation in comparison with GJ. Fibroblast adhesion and proliferation was collinear with carbon fiber orientation in regions of sparsely distributed fibers and occurred in clusters in regions of higher fiber density and low porosity. Overall, fibroblast adhesion and proliferation was greatest in lower porosity carbon scaffolds with highly aligned fibers. Stepwise multivariate regression showed that the variability in maximum load of carbon scaffolds and controls were dependent on unique and separate sets of parameters. These finding suggested that there were significant differences in the functional implications of scaffold design and material properties between carbon and dermis derived scaffolds that affect scaffold utility as a tissue replacement construct.
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Affiliation(s)
- Jarema S Czarnecki
- Carbon Research Laboratory, University of Dayton Research Institute, Dayton, Ohio 45469, USA.
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Fractionation of high-dose electron beam irradiation of BPTB grafts provides significantly improved viscoelastic and structural properties compared to standard gamma irradiation. Knee Surg Sports Traumatol Arthrosc 2011; 19:1955-61. [PMID: 21541710 DOI: 10.1007/s00167-011-1518-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 04/12/2011] [Indexed: 12/14/2022]
Abstract
PURPOSE Irradiation >30 kGy is required to achieve sterility against bacterial and viral pathogens in ACL allograft sterilization. However, doses >20 kGy substantially reduce the structural properties of soft-tissue grafts. Fractionation of irradiation doses is a standard procedure in oncology to reduce tissue damage but has not been applied in tissue graft sterilization. METHODS Forty-four human 10-mm wide bone-patellar-tendon-bone grafts were randomized into four groups of sterilization with (1) 34 kGy of ebeam (2) 34 kGy gamma (3) 34 kGy fractionated ebeam, and (4) non sterilized controls. Graft´s biomechanical properties were evaluated at time zero. Biomechanical properties were analyzed during cyclic and load-to-failure testing. RESULTS Fractionation of ebeam irradiation resulted in significantly higher failure loads (1,327 ± 305) than with one-time ebeam irradiation (1,024 ± 204; P = 0.008). Compared to gamma irradiation, significantly lower strain (2.9 ± 1.5 vs. 4.6 ± 2.0; P = 0.008) and smaller cyclic elongation response (0.3 ± 0.2 vs. 0.6 ± 0.4; P = 0.05), as well as higher failure loads (1,327 ± 305 vs. 827 ± 209; P = 0.001), were found. Compared to non-irradiated BPTB grafts, no significant differences were found for any of the biomechanical parameters. Non-irradiated controls had significantly lower cyclic elongation response and higher failure loads than ebeam and gamma irradiation. CONCLUSIONS In this study, it was found that fractionation of high-dose electron beam irradiation facilitated a significant improvement of viscoelastic and structural properties of BPTB grafts compared to ebeam and gamma irradiation alone, while maintaining levels of non-irradiated controls. Therefore, this technique might pose an important alternative to common methods for sterilization of soft-tissue allografts.
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12
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Nguyen H, Morgan DAF, Forwood MR. Validation of 11 kGy as a radiation sterilization dose for frozen bone allografts. J Arthroplasty 2011; 26:303-8. [PMID: 20570097 DOI: 10.1016/j.arth.2010.03.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 03/26/2010] [Indexed: 02/01/2023] Open
Abstract
A radiation sterilization dose (RSD) of 25 kGy is deleterious to bone allografts. This study aimed to establish a lower RSD for bone allografts using method 1 of International Standard Organisation 11137.2:2006. This provides a database to select an RSD corresponding to an allograft's bioburden, given that the bioburden's gamma resistance is equal to or less than the standard. This can be verified by irradiating 100 allografts at a dose selected to provide a sterility assurance level of 10(-2). The bioburden of our allografts was 0, which prescribed a verification dose of 1.3 kGy. After irradiating 100 allografts, sterility tests returned no positive cultures. We therefore validated an RSD of 11 kGy for allografts with that bioburden. According to the standard, this RSD provides a sterility assurance level of 10(-6) for bone allografts.
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Affiliation(s)
- Huynh Nguyen
- School of Medical Science, Griffith University, Gold Coast, Queensland, Australia
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