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Steijvers E, Ghei A, Xia Z. Manufacturing artificial bone allografts: a perspective. BIOMATERIALS TRANSLATIONAL 2022; 3:65-80. [PMID: 35837344 PMCID: PMC9255790 DOI: 10.12336/biomatertransl.2022.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 11/16/2022]
Abstract
Bone grafts have traditionally come from four sources: the patients' own tissue (autograft), tissue from a living or cadaveric human donor (allograft), animal donors (xenograft) and synthetic artificial biomaterials (ceramics, cement, polymers, and metal). However, all of these have advantages and drawbacks. The most commercially successful bone grafts so far are allografts, which hold 57% of the current bone graft market; however, disease transmission and scarcity are still significant drawbacks limiting their use. Tissue-engineered grafts have great potential, in which human stem cells and synthetical biomaterials are combined to produce bone-like tissue in vitro, but this is yet to be approved for widespread clinical practice. It is hypothesised that artificial bone allografts can be mass-manufactured to replace conventional bone allografts through refined bone tissue engineering prior to decellularisation. This review article aims to review current literature on (1) conventional bone allograft preparation; (2) bone tissue engineering including the use of synthetic biomaterials as bone graft substitute scaffolds, combined with osteogenic stem cells in vitro; (3) potential artificial allograft manufacturing processes, including mass production of engineered bone tissue, osteogenic enhancement, decellularisation, sterilisation and safety assurance for regulatory approval. From these assessments, a practical route map for mass production of artificial allografts for clinical use is proposed.
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Tao M, Ao T, Mao X, Yan X, Javed R, Hou W, Wang Y, Sun C, Lin S, Yu T, Ao Q. Sterilization and disinfection methods for decellularized matrix materials: Review, consideration and proposal. Bioact Mater 2021; 6:2927-2945. [PMID: 33732964 PMCID: PMC7930362 DOI: 10.1016/j.bioactmat.2021.02.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/08/2021] [Accepted: 02/11/2021] [Indexed: 02/08/2023] Open
Abstract
Sterilization is the process of killing all microorganisms, while disinfection is the process of killing or removing all kinds of pathogenic microorganisms except bacterial spores. Biomaterials involved in cell experiments, animal experiments, and clinical applications need to be in the aseptic state, but their physical and chemical properties as well as biological activities can be affected by sterilization or disinfection. Decellularized matrix (dECM) is the low immunogenicity material obtained by removing cells from tissues, which retains many inherent components in tissues such as proteins and proteoglycans. But there are few studies concerning the effects of sterilization or disinfection on dECM, and the systematic introduction of sterilization or disinfection for dECM is even less. Therefore, this review systematically introduces and analyzes the mechanism, advantages, disadvantages, and applications of various sterilization and disinfection methods, discusses the factors influencing the selection of sterilization and disinfection methods, summarizes the sterilization and disinfection methods for various common dECM, and finally proposes a graphical route for selecting an appropriate sterilization or disinfection method for dECM and a technical route for validating the selected method, so as to provide the reference and basis for choosing more appropriate sterilization or disinfection methods of various dECM. Asepsis is the prerequisite for the experiment and application of biomaterials. Sterilization or disinfection affects physic-chemical properties of biomaterials. Mechanism, advantages and disadvantages of sterilization or disinfection methods. Factors influencing the selection of sterilization or disinfection methods. Selection of sterilization or disinfection methods for decellularized matrix.
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Affiliation(s)
- Meihan Tao
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Tianrang Ao
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xiaoyan Mao
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Xinzhu Yan
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Rabia Javed
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Weijian Hou
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Yang Wang
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Cong Sun
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Shuang Lin
- Department of Tissue Engineering, China Medical University, Shenyang, China
| | - Tianhao Yu
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Qiang Ao
- Department of Tissue Engineering, China Medical University, Shenyang, China.,Department of Developmental Cell Biology, Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China.,Institute of Regulatory Science for Medical Device, National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
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Formulation, Delivery and Stability of Bone Morphogenetic Proteins for Effective Bone Regeneration. Pharm Res 2017; 34:1152-1170. [PMID: 28342056 PMCID: PMC5418324 DOI: 10.1007/s11095-017-2147-x] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 03/17/2017] [Indexed: 12/22/2022]
Abstract
Bone morphogenetic proteins (BMPs) are responsible for bone formation during embryogenesis and bone regeneration and remodeling. The osteoinductive action of BMPs, especially BMP-2 and BMP-7, has led to their use in a range of insurmountable treatments where intervention is required for effective bone regeneration. Introduction of BMP products to the market, however, was not without reports of multiple complications and side effects. Aiming for optimization of the therapeutic efficacy and safety, efforts have been focused on improving the delivery of BMPs to lower the administered dose, localize the protein, and prolong its retention time at the site of action. A major challenge with these efforts is that the protein stability should be maintained. With this review we attempt to shed light on how the stability of BMPs can be affected in the formulation and delivery processes. We first provide a short overview of the current standing of the complications experienced with BMP products. We then discuss the different delivery parameters studied in association with BMPs, and their influence on the efficacy and safety of BMP treatments. In particular, the literature addressing the stability of BMPs and their possible interactions with components of the delivery system as well as their sensitivity to conditions of the formulation process is reviewed. In summary, recent developments in the fields of bioengineering and biopharmaceuticals suggest that a good understanding of the relationship between the formulation/delivery conditions and the stability of growth factors such as BMPs is a prerequisite for a safe and effective treatment.
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J A, Kuttappan S, Keyan KS, Nair MB. Evaluation of osteoinductive and endothelial differentiation potential of Platelet-Rich Plasma incorporated Gelatin-Nanohydroxyapatite Fibrous Matrix. J Biomed Mater Res B Appl Biomater 2016; 104:771-81. [DOI: 10.1002/jbm.b.33605] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/22/2015] [Accepted: 12/03/2015] [Indexed: 02/03/2023]
Affiliation(s)
- Anjana J
- Amrita Center for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences & Research Center, Amrita Vishwa Vidyapeetham University; Kochi 682041 Kerala India
| | - Shruthy Kuttappan
- Amrita Center for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences & Research Center, Amrita Vishwa Vidyapeetham University; Kochi 682041 Kerala India
| | - Kripa S. Keyan
- Amrita Center for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences & Research Center, Amrita Vishwa Vidyapeetham University; Kochi 682041 Kerala India
| | - Manitha B. Nair
- Amrita Center for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences & Research Center, Amrita Vishwa Vidyapeetham University; Kochi 682041 Kerala India
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Al Kayal T, Panetta D, Canciani B, Losi P, Tripodi M, Burchielli S, Ottoni P, Salvadori PA, Soldani G. Evaluation of the effect of a gamma irradiated DBM-pluronic F127 composite on bone regeneration in Wistar rat. PLoS One 2015; 10:e0125110. [PMID: 25897753 PMCID: PMC4405568 DOI: 10.1371/journal.pone.0125110] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/20/2015] [Indexed: 11/25/2022] Open
Abstract
Demineralized bone matrix (DBM) is widely used for bone regeneration. Since DBM is prepared in powder form its handling properties are not optimal and limit the clinical use of this material. Various synthetic and biological carriers have been used to enhance the DBM handling. In this study we evaluated the effect of gamma irradiation on the physical-chemical properties of Pluronic and on bone morphogenetic proteins (BMPs) amount in DBM samples. In vivo studies were carried out to investigate the effect on bone regeneration of a gamma irradiated DBM-Pluronic F127 (DBM-PF127) composite implanted in the femur of rats. Gamma irradiation effects (25 kGy) on physical-chemical properties of Pluronic F127 were investigated by rheological and infrared analysis. The BMP-2/BMP-7 amount after DBM irradiation was evaluated by ELISA. Bone regeneration capacity of DBM-PF127 containing 40% (w/w) of DBM was investigated in transcortical holes created in the femoral diaphysis of Wistar rat. Bone porosity, repaired bone volume and tissue organization were evaluated at 15, 30 and 90 days by Micro-CT and histological analysis. The results showed that gamma irradiation did not induce significant modification on physical-chemical properties of Pluronic, while a decrease in BMP-2/BMP-7 amount was evidenced in sterilized DBM. Micro-CT and histological evaluation at day 15 post-implantation revealed an interconnected trabeculae network in medullar cavity and cellular infiltration and vascularization of DBM-PF127 residue. In contrast a large rate of not connected trabeculae was observed in Pluronic filled and unfilled defects. At 30 and 90 days the DBM-PF127 samples shown comparable results in term of density and thickness of the new formed tissue respect to unfilled defect. In conclusion a gamma irradiated DBM-PF127 composite, although it may have undergone a significant decrease in the concentration of BMPs, was able to maintains bone regeneration capability.
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Affiliation(s)
- Tamer Al Kayal
- Institute of Clinical Physiology- CNR, Pisa, Italy
- * E-mail:
| | | | - Barbara Canciani
- University & IRCCS AOU San Martino—IST, National Institute for Cancer Research, DIMES, Genova, Italy
| | - Paola Losi
- Institute of Clinical Physiology- CNR, Pisa, Italy
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Hu Z, Peel SA, Lindholm TC, Sàndor GK, Clokie CML, Su Y. Osteoinductivity of partially purified bovine, ostrich and emu bone morphogenetic proteins in vitro. J Biomed Mater Res A 2011; 98:473-7. [DOI: 10.1002/jbm.a.33119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 02/26/2011] [Accepted: 03/17/2011] [Indexed: 11/07/2022]
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Tölli H, Kujala S, Levonen K, Jämsä T, Jalovaara P. Bioglass as a carrier for reindeer bone protein extract in the healing of rat femur defect. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:1677-1684. [PMID: 20162331 DOI: 10.1007/s10856-010-4017-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Accepted: 01/28/2010] [Indexed: 05/28/2023]
Abstract
Bioactive glasses have been developed as scaffolds for bone tissue engineering but combination with reindeer bone protein extract has not been evaluated. We investigated the effects of bone protein extract implants (5-40 mg dosages) with bioglass (BG) carrier on the healing of rat femur defects. Bioglass implants and untreated defects served as controls. All doses of extract increased bone formation compared with the control groups, and bone union was enhanced with doses of 10 mg or more. In comparison with untreated defect, mean cross-sectional bone area at the defect site was greater when implants with BG + 15 mg of extract or bioglass alone were used, bone density at the defect site was higher in all bioglass groups with and without bone extract, and the BG + 15 mg extract dosage marginally increased bone torsional stiffness in mechanical testing. Bioglass performed well as a carrier candidate for reindeer bone protein extract.
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Affiliation(s)
- Hanna Tölli
- Department of Orthopaedic and Trauma Surgery, University of Oulu, FIN-90014, Oulu, Finland.
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Wiegand C, Abel M, Ruth P, Wilhelms T, Schulze D, Norgauer J, Hipler UC. Effect of the sterilization method on the performance of collagen type I on chronic wound parametersin vitro. J Biomed Mater Res B Appl Biomater 2009; 90:710-9. [DOI: 10.1002/jbm.b.31338] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Han B, Yang Z, Nimni M. Effects of gamma irradiation on osteoinduction associated with demineralized bone matrix. J Orthop Res 2008; 26:75-82. [PMID: 17724732 DOI: 10.1002/jor.20478] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gamma irradiation is frequently used to sterilize implanted devices but has limitations when used on biologically active materials and composites. In this study, we have evaluated the changes of biological activity of demineralized bone matrix (DBM) in the dry state and in the presence of aqueous and non-aqueous carriers while exposed to various levels of ionizing radiation. The activity of DBM in the dry state remains relatively stable with only a small loss of activity. Composites of DBM with a carrier such as lecithin, to which no water has been added, lose activity at approximately the same rate as DBM in the anhydrous form. In composites that contain water, the loss of activity occurs even at much lower levels of radiation exposure. Gamma irradiation does not change cell attachment to the DBM matrix but has an influence on both stem cell and osteoprecursor cell proliferation rates. Because of the limitations imposed by radiation, it seems most practical to handle DBM aseptically throughout the procedures of compositing pastes, putties, or suspensions, and only if necessary exposing the inert excipients to radiation sterilization prior to mixing.
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Affiliation(s)
- Bo Han
- Tissue Engineering Laboratory, Department of Surgery, Keck School of Medicine, University of Southern California, 1840 N. Soto Street, EDM-191, Los Angeles, California 90032, USA.
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Pekkarinen T, Jämsä T, Määttä M, Hietala O, Jalovaara P. Reindeer BMP extract in the healing of critical-size bone defects in the radius of the rabbit. Acta Orthop 2006; 77:952-9. [PMID: 17260207 DOI: 10.1080/17453670610013286] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Native BMP extracts from reindeer effectively induce ectopic new bone formation in vivo, but their bone healing properties have not yet been evaluated. We investigated the effect of reindeer BMP extracts on the healing of long bone defects. METHODS The implants tested contained 5 mg or 10 mg of unsterilized BMP extract from reindeer and 10 mg of gamma-sterilized BMP extract administered with collagen carrier (Lyostypt, B. Braun, Germany). 70 micro g of rhBMP-2 with collagen carrier (InductOs; Wyeth Europa) served as positive control, and collagen implants (Lyostypt) and untreated defects served as negative controls. New Zealand White rabbits with 1.5 cm of critical-size radius bone defects were used, with 8 weeks of follow-up. RESULTS Radiographic analysis showed bone formation (BF) to be higher in all groups containing BMPs than in the untreated controls. BF was also higher in the rhBMP-2 group, and marginally higher in the group treated with 10 mg of unsterilized reindeer BMP extract (p = 0.06) as compared to the collagen controls. Bone union (BU) was better in the unsterilized BMP extract groups and rhBMP-2 group than in the untreated controls. BU was also better in the implants with 10 mg of unsterilized reindeer BMP extract and rhBMP-2 than in the collagen-treated implants. The mean area of new bone at the site of the defect proved to be higher in all implants containing BMP than in the untreated defects. It was also higher in the groups with 10 mg of unsterilized reindeer BMP extract and rhBMP-2 than in the collagen-treated controls. Mechanical tests showed torsional stiffness of the bones to be higher in the group with 10 mg of unsterilized BMP extract than in the collagen group. The mean cross-sectional bone area measured by pQCT densitometry was higher in the rhBMP-2 group than in the collagen group. The mean bone density at the defect area was higher in the group with 10 mg of unsterilized BMP than in the rhBMP-2 group. INTERPRETATION We conclude that both reindeer BMP extract and rhBMP-2 induced improved healing of the rabbit radius bone defects at the doses used. Gamma sterilization of reindeer BMP extract reduced osteoinductivity slightly, but not significantly.
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Affiliation(s)
- Tarmo Pekkarinen
- Bone Transplantation Research Group, Department of Orthopaedic and Trauma Surgery, University of Oulu, Oulu, Finland.
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Ulmanen MS, Pekkarinen T, Hietala OA, Birr EA, Jalovaara P. Osteoinductivity of partially purified native ostrich (Struthio camelus) bone morphogenetic protein: Comparison with mammalian species. Life Sci 2005; 77:2425-37. [PMID: 16005022 DOI: 10.1016/j.lfs.2005.01.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Accepted: 01/13/2005] [Indexed: 11/15/2022]
Abstract
Bone morphogenetic proteins (BMPs) are members of the TGF-beta superfamily. They are capable of inducing ectopic bone formation. Until now, the main interest has been focused on mammalian osteoinductive BMPs, and there are no reports of native BMP extracts of birds. In this study, we isolated and characterized native BMPs of ostrich (Struthio camelus) and compared them with identically isolated native bovine (cow) and reindeer BMPs with regard to BMP pattern and osteoinductive capacity. The ostrich BMP pattern differed markedly from that of cow and reindeer BMP in non-reduced SDS-PAGE, reduced SDS-PAGE and Western blot. The differences in isoelectric focusing analysis were smaller. However, the ostrich BMP extract had a peak at pH 5.1, clearly differing from the BMPs of cow and reindeer. The osteoinductive capacity and density of ectopic bone, induced by BMP extracts in a mouse thigh muscle pouch, were determined radiographically. The ostrich BMP extract displayed significantly lower osteoinductive capacity and density of induced bone than the bovine and reindeer BMP extracts. In conclusion, our results indicate that the BMP pattern of birds differs considerably from that of mammals, and that the osteoinductive capacity of BMPs and the density of induced bone are lower in birds than in mammals. They also suggest that the bone metabolism of birds is adapted to make light bones suitable for flying.
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Affiliation(s)
- Mari S Ulmanen
- Bone Transplantation Research Group, Department of Orthopaedic Surgery, University of Oulu, PL 5000, 90014 Oulu, Finland
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Pekkarinen T, Hietalal O, Jämsä T, Jalovaara P. Gamma irradiation and ethylene oxide in the sterilization of native reindeer bone morphogenetic protein extract. Scand J Surg 2005; 94:67-70. [PMID: 15865121 DOI: 10.1177/145749690509400116] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS For human use, it is necessary to sterilize bone morphogenetic proteins (BMPs), in order to reduce the risk of infections and associated complications. We compared the effects of ethylene oxide and gamma irradiation in the sterilization of native reindeer BMP extract with regard to bone induction in the Balb/C mouse thigh muscle pouch model. MATERIALS AND METHODS BMP extract, sterilized with ethylene oxide gas (Steri-Vac 4XL, temperature 29 degrees C, exposure time 4 h, ethylene oxide concentration 860 mg/l), or gamma irradiation at doses of 3.15 MRad was administered in implants containing 5 or 10 mg of BMP extract with collagen carrier. Non-sterilized collagen implants served as controls. New bone formation was evaluated based on the incorporation of Ca45 and radiographically three weeks after implantation. RESULTS The collagen was not able to induce new bone visible in radiographs. The mean Ca45 incorporation in the gamma sterilized group containing 5 mg of BMP extract was 30% (p = 0.04) and that containing 10 mg of BMP extract was 60% (p = 0.02) higher than seen in the corresponding ethylene oxide sterilized groups. The mean new bone areas were 45% higher in the gamma sterilized groups than in the corresponding ethylene oxide sterilized groups, but the differences were not significant. The mean optical density of new bone in the gamma sterilized group containing 5 mg of BMP extract was 75% (p = 0.00) and in that containing 10 mg of BMP extract was 70% (p = 0.00) higher than seen in the corresponding ethylene oxide sterilized groups. CONCLUSION Native reindeer BMP extract is more sensitive to the effects of ethylene oxide gas sterilization than gamma irradiation. These results suggest that gamma irradiation is recommendable for the sterilization of BMP extracts.
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Affiliation(s)
- T Pekkarinen
- Bone Transplantation Research Group, Department of Orthopaedic and Trauma Surgery, University of Oulu, P.O. Box 5000, FIN - 90014 Oulu, Finland.
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Pekkarinen T, Hietala O, Jämsä T, Jalovaara P. Effect of gamma irradiation on the osteoinductivity of morphogenetic protein extract from reindeer bone. Acta Orthop 2005; 76:231-6. [PMID: 16097549 DOI: 10.1080/00016470510030625] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Bone morphogenetic proteins (BMPs), which are capable of stimulating the production of new bone, must be sterilized before preclinical and clinical use to reduce the risk of infections and associated complications. In this study, we investigated the effects of gamma sterilization on the osteoinductivity of native reindeer BMP extract in the Balb/C mouse thigh muscle pouch model. METHODS 5 mg of native reindeer BMP extract and 5 mg of bovine serum albumin were administered separately either in gelatine capsules or mixed with gelatine as injections. The dose of gamma irradiation was 4.1 Mrad. Unsterile capsules and injections served as controls. New bone formation was evaluated based on the incorporation of Ca45 and also radiographically 3 weeks after implantation. RESULTS Albumin-containing implants and injections did not induce new bone formation, as monitored in radiographs. Gamma sterilization did not reduce the osteoinductivity of native BMP extract in capsules, but a significant decrease in osteoinductivity--measured as area (50%) and Ca45 incorporation of new bone (27%)--was seen after injection. Gamma sterilization had no effect on the optical density of new bone induced by native BMP extract administered in capsules or by injection. INTERPRETATION We conclude that, as gamma irradiation did not reduce the osteoinductivity of reindeer BMP extract in gelatine capsules, this method appears to be suitable for sterilization of BMPs to be given in capsule form. Native reindeer BMP extract was more sensitive to irradiation in soluble collagen (gelatine) than BMP in gelatine capsules. This finding must be given serious consideration regarding treatment of patients, but the remaining activity may be sufficient for the induction of bone formation in preclinical and clinical situations.
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Affiliation(s)
- Tarmo Pekkarinen
- Bone Transplantation Research Group, Department of Orthopaedic and Trauma Surgery, University of Oulu, Oulu, Finland.
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