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Gefel E, Moseke C, Schmitt AM, Dümmler N, Stahlhut P, Ewald A, Meyer-Lindenberg A, Vorndran E. Corrigendum to “Degradation of 3D-printed magnesium phosphate ceramics in vitro and a prognosis on their bone regeneration potential” [Bioact. Mater. 19 (2023) 376–391/22]. Bioact Mater 2023; 20:41. [DOI: 10.1016/j.bioactmat.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Schaufler C, Schmitt AM, Moseke C, Stahlhut P, Geroneit I, Brückner M, Meyer-Lindenberg A, Vorndran E. Physicochemical degradation of calcium magnesium phosphate (stanfieldite) based bone replacement materials and the effect on their cytocompatibility. Biomed Mater 2022; 18. [PMID: 36541469 DOI: 10.1088/1748-605x/aca735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022]
Abstract
Regenerative bone implants should be completely replaced by new bone within a period of time corresponding to the growth rate of native bone. To meet this requirement, suitable biomaterials must be biodegradable and promote osteogenesis. The combination of slowly degrading but osteoconductive calcium phosphates (CPs) with rapidly degrading and mechanically more resilient magnesium phosphates represents a promising material class for this purpose. In order to create the best possible conditions for optimal implant integration, microporous calcium magnesium phosphate (CMP) cements were processed using 3D powder printing. This technique enables the production of a defect-adapted implant with an optimal fit and a high degree of open porosity to promote bone ingrowth. Four different compositions of 3D printed CMP ceramics were investigated with regard to essential properties of bone implants, including chemical composition, porosity, microstructure, mechanical strength, and cytocompatibility. The ceramics consisted of farringtonite (Mg3(PO4)2) and stanfieldite (Ca4Mg5(PO4)6), with either struvite (NH4MgPO4·6H2O) or newberyite (MgHPO4·3H2O) and brushite (CaHPO4·2H2O) as additional phases. The CMP materials showed open porosities between 13 and 28% and compressive strengths between 11 and 17 MPa, which was significantly higher, as compared with clinically established CP. The cytocompatibility was evaluated with the human fetal osteoblast cell line hFOB 1.19 and was proven to be equal or to even exceed that of tricalcium phosphate. Furthermore, a release of 4-8 mg magnesium and phosphate ions per mg scaffold material could be determined for CMPs over a period of 21 d. In the case of struvite containing CMPs the chemical dissolution of the cement matrix was combined with a physical degradation, which resulted in a mass loss of up to 3.1 wt%. In addition to its beneficial physical and biological properties, the proven continuous chemical degradation and bioactivity in the form of CP precipitation indicate an enhanced bone regeneration potential of CMPs.
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Affiliation(s)
- Christian Schaufler
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
| | - Anna-Maria Schmitt
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
| | - Claus Moseke
- Institute for Biomedical Engineering (IBMT), University of Applied Sciences Mittelhessen (THM), Wiesenstraße 14, Gießen, Germany
| | - Philipp Stahlhut
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
| | - Isabel Geroneit
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
| | - Manuel Brückner
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
| | - Andrea Meyer-Lindenberg
- Clinic for Small Animal Surgery and Reproduction, Ludwig-Maximilians-Universität, Munich, Germany
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University Clinic Würzburg, Würzburg, Germany
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Kowalewicz K, Waselau AC, Feichtner F, Schmitt AM, Brückner M, Vorndran E, Meyer-Lindenberg A. Comparison of degradation behavior and osseointegration of 3D powder-printed calcium magnesium phosphate cement scaffolds with alkaline or acid post-treatment. Front Bioeng Biotechnol 2022; 10:998254. [PMID: 36246367 PMCID: PMC9554004 DOI: 10.3389/fbioe.2022.998254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Due to the positive effects of magnesium substitution on the mechanical properties and the degradation rate of the clinically well-established calcium phosphate cements (CPCs), calcium magnesium phosphate cements (CMPCs) are increasingly being researched as bone substitutes. A post-treatment alters the materials’ physical properties and chemical composition, reinforcing the structure and modifying the degradation rate. By alkaline post-treatment with diammonium hydrogen phosphate (DAHP, (NH4)2HPO4), the precipitation product struvite is formed, while post-treatment with an acidic phosphate solution [e.g., phosphoric acid (PA, H3PO4)] results in precipitation of newberyite and brushite. However, little research has yet been conducted on newberyite as a bone substitute and PA post-treatment of CMPCs has not been described in the accessible literature so far. Therefore, in the present study, the influence of an alkaline (DAHP) or acid (PA) post-treatment on the biocompatibility, degradation behavior, and osseointegration of cylindrical scaffolds (h = 5.1 mm, Ø = 4.2 mm) produced from the ceramic cement powder Ca0.75Mg2.25(PO4)2 by the advantageous manufacturing technique of three-dimensional (3D) powder printing was investigated in vivo. Scaffolds of the material groups Mg225d (DAHP post-treatment) and Mg225p (PA post-treatment) were implanted into the cancellous part of the lateral femoral condyles in rabbits. They were evaluated up to 24 weeks by regular clinical, X-ray, micro-computed tomographic (µCT), and histological examinations as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis and compared with tricalcium phosphate (TCP). All materials showed excellent biocompatibility and rapid osseointegration. While TCP degraded only slightly, the CMPCs showed almost complete degradation. Mg225d demonstrated significantly faster loss of form and demarcability from surrounding bone, scaffold volume reduction, and significantly greater degradation on the side towards the bone marrow than to the cortex than Mg225p. Simultaneously, numerous bone trabeculae have grown into the implantation site. While these were mostly located on the side towards the cortex in Mg225d, they were more evenly distributed in Mg225p and showed almost the same structural characteristics as physiological bone after 24 weeks in Mg225p. Based on these results, the acid post-treated 3D powder-printed Mg225p is a promising degradable bone substitute that should be further investigated.
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Affiliation(s)
- Katharina Kowalewicz
- Clinic for Small Animal Surgery and Reproduction, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Anja-Christina Waselau
- Clinic for Small Animal Surgery and Reproduction, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Franziska Feichtner
- Clinic for Small Animal Surgery and Reproduction, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Anna-Maria Schmitt
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany
| | - Manuel Brückner
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany
| | - Andrea Meyer-Lindenberg
- Clinic for Small Animal Surgery and Reproduction, Ludwig-Maximilians-University of Munich, Munich, Germany
- *Correspondence: Andrea Meyer-Lindenberg,
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Golafshan N, Willemsen K, Kadumudi FB, Vorndran E, Dolatshahi‐Pirouz A, Weinans H, Wal BCH, Malda J, Castilho M. 3D-Printed Regenerative Magnesium Phosphate Implant Ensures Stability and Restoration of Hip Dysplasia. Adv Healthc Mater 2021; 10:e2101051. [PMID: 34561956 DOI: 10.1002/adhm.202101051] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/06/2021] [Indexed: 11/10/2022]
Abstract
Osteoarthritis of the hip is a painful and debilitating condition commonly occurring in humans and dogs. One of the main causes that leads to hip osteoarthritis is hip dysplasia. Although the current surgical methods to correct dysplasia work satisfactorily in many circumstances, these are associated with serious complications, tissue resorption, and degeneration. In this study, a one-step fabrication of a regenerative hip implant with a patient-specific design and load-bearing properties is reported. The regenerative hip implant is fabricated based on patient imaging files and by an extrusion assisted 3D printing process using a flexible, bone-inducing biomaterial. The novel implant can be fixed with metallic screws to host bone and can be loaded up to physiological loads without signs of critical permanent deformation or failure. Moreover, after exposing the hip implant to accelerated in vitro degradation, it is confirmed that it is still able to support physiological loads even after losing ≈40% of its initial mass. In addition, the osteopromotive properties of the novel hip implant is demonstrated as shown by an increased expression of osteonectin and osteocalcin by cultured human mesenchymal stem cells after 21 days. Overall, the proposed hip implant provides an innovative regenerative and mechanically stable solution for hip dysplasia treatment.
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Affiliation(s)
- Nasim Golafshan
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
- Regenerative Medicine Utrecht Utrecht University Utrecht 3584 CT The Netherlands
| | - Koen Willemsen
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
| | - Firoz Babu Kadumudi
- Department of Health Technology Technical University of Denmark Lyngby 2800 Denmark
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry University of Würzburg Würzburg 97070 Germany
| | | | - Harrie Weinans
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
- Department of Biomechanical Engineering TU Delft Delft 2628 CD The Netherlands
| | - Bart C. H. Wal
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
| | - Jos Malda
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
- Regenerative Medicine Utrecht Utrecht University Utrecht 3584 CT The Netherlands
- Department of Clinical Sciences Faculty of Veterinary Medicine Utrecht University Utrecht 3584 CL The Netherlands
| | - Miguel Castilho
- Department of Orthopaedics University Medical Center Utrecht Utrecht 3584 CX The Netherlands
- Regenerative Medicine Utrecht Utrecht University Utrecht 3584 CT The Netherlands
- Orthopaedic Biomechanics Department of Biomedical Engineering Eindhoven University of Technology Eindhoven 5612 AZ The Netherlands
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Golafshan N, Vorndran E, Zaharievski S, Brommer H, Kadumudi FB, Dolatshahi-Pirouz A, Gbureck U, van Weeren R, Castilho M, Malda J. Tough magnesium phosphate-based 3D-printed implants induce bone regeneration in an equine defect model. Biomaterials 2020; 261:120302. [PMID: 32932172 PMCID: PMC7116184 DOI: 10.1016/j.biomaterials.2020.120302] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/16/2020] [Accepted: 08/04/2020] [Indexed: 12/25/2022]
Abstract
One of the important challenges in bone tissue engineering is the development of biodegradable bone substitutes with appropriate mechanical and biological properties for the treatment of larger defects and those with complex shapes. Recently, magnesium phosphate (MgP) doped with biologically active ions like strontium (Sr2+) have shown to significantly enhance bone formation when compared with the standard calcium phosphate-based ceramics. However, such materials can hardly be shaped into large and complex geometries and more importantly lack the adequate mechanical properties for the treatment of load-bearing bone defects. In this study, we have fabricated bone implants through extrusion assisted three-dimensional (3D) printing of MgP ceramics modified with Sr2+ ions (MgPSr) and a medical-grade polycaprolactone (PCL) polymer phase. MgPSr with 30 wt% PCL (MgPSr-PCL30) allowed the printability of relevant size structures (>780 mm3) at room temperature with an interconnected macroporosity of approximately 40%. The printing resulted in implants with a compressive strength of 4.3 MPa, which were able to support up to 50 cycles of loading without plastic deformation. Notably, MgPSr-PCL30 scaffolds were able to promote in vitro bone formation in medium without the supplementation with osteo-inducing components. In addition, long-term in vivo performance of the 3D printed scaffolds was investigated in an equine tuber coxae model over 6 months. The micro-CT and histological analysis showed that implantation of MgPSr-PCL30 induced bone regeneration, while no bone formation was observed in the empty defects. Overall, the novel polymer-modified MgP ceramic material and extrusion-based 3D printing process presented here greatly improved the shape ability and load-bearing properties of MgP-based ceramics with simultaneous induction of new bone formation.
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Affiliation(s)
- Nasim Golafshan
- Department of Orthopedics, University Medical Center Utrecht, GA, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Utrecht, the Netherlands
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University of Wurzburg, Germany
| | - Stefan Zaharievski
- Department of Orthopedics, University Medical Center Utrecht, GA, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Utrecht, the Netherlands
| | - Harold Brommer
- Department of Equine Sciences, Faculty of Veterinary Sciences, Utrecht University, the Netherlands
| | - Firoz Babu Kadumudi
- Technical University of Denmark, Department of Health Technology, 2800 Kgs, Lyngby, Denmark
| | - Alireza Dolatshahi-Pirouz
- Technical University of Denmark, Department of Health Technology, Center for Intestinal Absorption and Transport of Biopharmaceuticals, 2800 Kgs, Lyngby, Denmark; Department of Regenerative Biomaterials, Radboud University Medical Center, Philips van Leydenlaan 25, Nijmegen, 6525 EX, the Netherlands
| | - Uwe Gbureck
- Department for Functional Materials in Medicine and Dentistry, University of Wurzburg, Germany
| | - René van Weeren
- Department of Equine Sciences, Faculty of Veterinary Sciences, Utrecht University, the Netherlands
| | - Miguel Castilho
- Department of Orthopedics, University Medical Center Utrecht, GA, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Utrecht, the Netherlands; Orthopedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
| | - Jos Malda
- Department of Orthopedics, University Medical Center Utrecht, GA, Utrecht, the Netherlands; Regenerative Medicine Utrecht, Utrecht, the Netherlands; Department of Equine Sciences, Faculty of Veterinary Sciences, Utrecht University, the Netherlands
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Meininger S, Moseke C, Spatz K, März E, Blum C, Ewald A, Vorndran E. Effect of strontium substitution on the material properties and osteogenic potential of 3D powder printed magnesium phosphate scaffolds. Mater Sci Eng C Mater Biol Appl 2019; 98:1145-1158. [PMID: 30812998 DOI: 10.1016/j.msec.2019.01.053] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 12/27/2022]
Abstract
3D powder printing is a versatile method for the fabrication of individual bone implants and was used for the processing of in vivo degradable ceramic scaffolds based on ammonium magnesium phosphate hexahydrate (struvite). In this study, synergetic effects could be achieved by the substitution of magnesium phosphate cements with strontium carbonate. This substitution resulted in 8.2 wt%, 16.4 wt%, and 24.6 wt% Sr2+ doped scaffolds, with a 1.9-3.1 times increased radiopacity compared to pure struvite. The maximal compressive strength of (16.1 ± 1.1) MPa found for strontium substituted magnesium phosphate was in the range of cancelleous bone, which makes these 3D printed structures suitable for medical application in low-load-bearing bone areas. In an ion release study over a course of 18 days, the release of strontium, magnesium, calcium, and phosphate ions from scaffolds was analyzed by means of inductively coupled plasma mass spectrometry. Independent of the scaffold composition the Mg2+ concentrations (83-499 mg/l) continuously increased in the cell media. The Sr2+ release varied between 4.3 μg/day and 15.1 μg/day per g scaffold, corresponding to a Sr2+ concentration in media between 1.14 mg/l and 7.24 mg/l. Moreover, decreasing calcium and phosphate concentrations indicated the precipitation of an amorphous calcium phosphate phase. The superior osteogenic properties of strontium substituted magnesium phosphate, e.g. the increase of osteoblast activity and cell number and the simultaneous suppression of osteoclast differentiation could be verified in vitro by means of WST-assay, TRAP-staining, and SEM imaging.
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Affiliation(s)
- Susanne Meininger
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany
| | - Claus Moseke
- Institute for Biomedical Engineering (IBMT), University of Applied Sciences Mittelhessen (THM), Gießen, Germany
| | - Kerstin Spatz
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany
| | - Emilie März
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany
| | - Carina Blum
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany
| | - Andrea Ewald
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Germany.
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Holzmeister I, Schamel M, Groll J, Gbureck U, Vorndran E. Artificial inorganic biohybrids: The functional combination of microorganisms and cells with inorganic materials. Acta Biomater 2018; 74:17-35. [PMID: 29698705 DOI: 10.1016/j.actbio.2018.04.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/12/2018] [Accepted: 04/22/2018] [Indexed: 02/07/2023]
Abstract
Biohybrids can be defined as the functional combination of proteins, viable cells or microorganisms with non-biological materials. This article reviews recent findings on the encapsulation of microorganisms and eukaryotic cells in inorganic matrices such as silica gels or cements. The entrapment of biological entities into a support material is of great benefit for processing since the encapsulation matrix protects sensitive cells from shear forces, unfavourable pH changes, or cytotoxic solvents, avoids culture-washout, and simplifies the separation of formed products. After reflecting general aspects of such an immobilization as well as the chemistry of the inorganic matrices, we focused on manufacturing aspects and the application of such biohybrids in biotechnology, medicine as well as in environmental science and for civil engineering purpose. STATEMENT OF SIGNIFICANCE The encapsulation of living cells and microorganisms became an intensively studied and rapidly expanding research field with manifold applications in medicine, bio- and environmental technology, or civil engineering. Here, the use of silica or cements as encapsulation matrices have the advantage of a higher chemical and mechanical resistance towards harsh environmental conditions during processing compared to their polymeric counterparts. In this perspective, the article gives an overview about the inorganic material systems used for cell encapsulation, followed by reviewing the most important applications. The future may lay in a combination of the currently achieved biohybrid systems with additive manufacturing techniques. In a longer perspective, this would enable the direct printing of cell loaded bioreactor components.
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Castilho M, Rodrigues J, Vorndran E, Gbureck U, Quental C, Folgado J, Fernandes PR. Computational design and fabrication of a novel bioresorbable cage for tibial tuberosity advancement application. J Mech Behav Biomed Mater 2017; 65:344-355. [DOI: 10.1016/j.jmbbm.2016.08.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/11/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
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Vorndran E, Lindberg P. In situ-immobilization of two model cyanobacterial strains in ceramic structures: A new biohybrid material for photobioreactor applications. J Biotechnol 2016; 223:1-5. [PMID: 26902690 DOI: 10.1016/j.jbiotec.2016.02.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/02/2016] [Accepted: 02/16/2016] [Indexed: 11/30/2022]
Abstract
Two cyanobacterial strains, Synechocystis sp. PCC 6803 and Nostoc punctiforme ATCC 29133 were immobilized within magnesium phosphate based cements, showing a viability and activity for at least 4 weeks. These biohybrids are considered as an alternative photobioreactor material for bioremediation or an improved yield of biotechnologically relevant molecules.
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Affiliation(s)
- Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University Clinic, Würzburg, Germany.
| | - Pia Lindberg
- Department of Chemistry-Ångström, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
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Castilho M, Rodrigues J, Pires I, Gouveia B, Pereira M, Moseke C, Groll J, Ewald A, Vorndran E. Fabrication of individual alginate-TCP scaffolds for bone tissue engineering by means of powder printing. Biofabrication 2015; 7:015004. [PMID: 25562119 DOI: 10.1088/1758-5090/7/1/015004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The development of polymer-calcium phosphate composite scaffolds with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the functional performance of brittle ceramic scaffolds by developing a promising biopolymer-ceramic network. For this purpose, two strategies, namely, direct printing of a powder composition consisting of a 60:40 mixture of α/β-tricalcium phosphate (TCP) powder and alginate powder or vacuum infiltration of printed TCP scaffolds with an alginate solution, were tracked. Results of structural characterization revealed that the scaffolds printed with 2.5 wt% alginate-modified TCP powders presented a uniformly distributed and interfusing alginate TCP network. Mechanical results indicated a significant increase in strength, energy to failure and reliability of powder-modified scaffolds with an alginate content in the educts of 2.5 wt% when compared to pure TCP, as well as to TCP scaffolds containing 5 wt% or 7.5 wt% in the educts, in both dry and wet states. Culture of human osteoblast cells on these scaffolds also demonstrated a great improvement of cell proliferation and cell viability. While in the case of powder-mixed alginate TCP scaffolds, isolated alginate gels were formed between the calcium phosphate crystals, the vacuum-infiltration strategy resulted in the covering of the surface and internal pores of the TCP scaffold with a thin alginate film. Furthermore, the prediction of the scaffolds' critical fracture conditions under more complex stress states by the applied Mohr fracture criterion confirmed the potential of the powder-modified scaffolds with 2.5 wt% alginate in the educts as structural biomaterial for bone tissue engineering.
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Affiliation(s)
- Miguel Castilho
- LAETA, IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal. Altakitin SA, Loures, Portugal
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Castilho M, Dias M, Vorndran E, Gbureck U, Fernandes P, Pires I, Gouveia B, Armés H, Pires E, Rodrigues J. Application of a 3D printed customized implant for canine cruciate ligament treatment by tibial tuberosity advancement. Biofabrication 2014; 6:025005. [DOI: 10.1088/1758-5082/6/2/025005] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Castilho M, Moseke C, Ewald A, Gbureck U, Groll J, Pires I, Teßmar J, Vorndran E. Direct 3D powder printing of biphasic calcium phosphate scaffolds for substitution of complex bone defects. Biofabrication 2014; 6:015006. [PMID: 24429776 DOI: 10.1088/1758-5082/6/1/015006] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The 3D printing technique based on cement powders is an excellent method for the fabrication of individual and complex bone substitutes even in the case of large defects. The outstanding bone remodeling capacity of biphasic calcium phosphates (BCPs) containing hydroxyapatite (HA) as well as tricalcium phosphate (TCP) in varying ratios makes the adaption of powder systems resulting in BCP materials to this fabrication technique a desirable aim. This study presents the synthesis and characterization of a novel powder system for the 3D printing process, intended for the production of complexly shaped BCP scaffolds by a hydraulic setting reaction of calcium carbonate and TCP with phosphoric acid. The HA/TCP ratio in the specimens could be tailored by the calcium/phosphate ratio of the starting powder. The scaffolds could be fabricated with a dimensional accuracy of >96.5% and a minimal macro pore size of 300 µm. Independent of the phase composition the printed specimens showed a microporosity of approximately 68%, while the compressive strength strongly depended on the chemical composition and increased with rising TCP content in the scaffolds to a maximum of 1.81 MPa. Post-treatment of the scaffolds with a polylactic-co-glycolic acid-solution enhanced the mechanical properties by a factor of 8. In vitro studies showed that all BCP scaffolds were cytocompatible and enhanced the cell viability as well as the cell proliferation, as compared with pure TCP. Cell proliferation is even better on BCP when compared to HA and cell viability is in a similar range on these materials.
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Affiliation(s)
- Miguel Castilho
- Institute of Mechanical Engineering/IST, Technical University of Lisbon, Portugal
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Vorndran E, Geffers M, Ewald A, Lemm M, Nies B, Gbureck U. Ready-to-use injectable calcium phosphate bone cement paste as drug carrier. Acta Biomater 2013; 9:9558-67. [PMID: 23954526 DOI: 10.1016/j.actbio.2013.08.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 07/31/2013] [Accepted: 08/06/2013] [Indexed: 01/31/2023]
Abstract
Current developments in calcium phosphate cement (CPC) technology concern the use of ready-to-use injectable cement pastes by dispersing the cement powder in a water-miscible solvent, such that, after injection into the physiological environment, setting of cements occurs by diffusion of water into the cement paste. It has also been demonstrated recently that the combination of a water-immiscible carrier liquid combined with suitable surfactants facilitates a discontinuous liquid exchange in CPC, enabling the cement setting reaction to take place. This paper reports on the use of these novel cement paste formulations as a controlled release system of antibiotics (gentamicin, vancomycin). Cement pastes were applied either as a one-component material, in which the solid drugs were physically dispersed, or as a two-component system, where the drugs were dissolved in an aqueous phase that was homogeneously mixed with the cement paste using a static mixing device during injection. Drug release profiles of both antibiotics from pre-mixed one- and two-component cements were characterized by an initial burst release of ∼7-28%, followed by a typical square root of time release kinetic for vancomycin. Gentamicin release rates also decreased during the first days of the release study, but after ∼1 week, the release rates were more or less constant over a period of several weeks. This anomalous release kinetic was attributed to participation of the sulfate counter ion in the cement setting reaction altering the drug solubility. The drug-loaded cement pastes showed high antimicrobial potency against Staphylococcus aureus in an agar diffusion test regime, while other cement properties such as mechanical performance or phase composition after setting were only marginally affected.
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Mehrban N, Bowen J, Vorndran E, Gbureck U, Grover LM. Structural changes to resorbable calcium phosphate bioceramic aged in vitro. Colloids Surf B Biointerfaces 2013; 111:469-78. [DOI: 10.1016/j.colsurfb.2013.06.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/27/2013] [Accepted: 06/11/2013] [Indexed: 11/30/2022]
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15
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Castilho M, Dias M, Gbureck U, Groll J, Fernandes P, Pires I, Gouveia B, Rodrigues J, Vorndran E. Fabrication of computationally designed scaffolds by low temperature 3D printing. Biofabrication 2013; 5:035012. [PMID: 23887064 DOI: 10.1088/1758-5082/5/3/035012] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The development of artificial bone substitutes that mimic the properties of bone and simultaneously promote the desired tissue regeneration is a current issue in bone tissue engineering research. An approach to create scaffolds with such characteristics is based on the combination of novel design and additive manufacturing processes. The objective of this work is to characterize the microstructural and the mechanical properties of scaffolds developed by coupling both topology optimization and a low temperature 3D printing process. The scaffold design was obtained using a topology optimization approach to maximize the permeability with constraints on the mechanical properties. This procedure was studied to be suitable for the fabrication of a cage prototype for tibial tuberosity advancement application, which is one of the most recent and promising techniques to treat cruciate ligament rupture in dogs. The microstructural and mechanical properties of the scaffolds manufactured by reacting α/β-tricalcium phosphate with diluted phosphoric acid were then assessed experimentally and the scaffolds strength reliability was determined. The results demonstrate that the low temperature 3D printing process is a reliable option to create synthetic scaffolds with tailored properties, and when coupled with topology optimization design it can be a powerful tool for the fabrication of patient-specific bone implants.
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Affiliation(s)
- Miguel Castilho
- Institute of Mechanical Engineering/IST, Technical University of Lisbon, Portugal.
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16
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Zorn K, Mitró D, Vorndran E, Gbureck U, Müller FA. Hydrothermal synthesis of calcium-deficient hydroxyapatite whiskers and their thermal transformation to polycrystalline β-tricalcium phosphate short fibers. Bioinspired, Biomimetic and Nanobiomaterials 2013. [DOI: 10.1680/bbn.12.00019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Resorbable calcium phosphate fibers are of particular interest to reinforce biodegradable bone substitutes for load-bearing applications. The aim of the present study was to prepare calcium-deficient hydroxyapatite (dHAp) whiskers with a molar Ca/P ratio of 1·5 by a hydrothermal synthesis and to transform them to β-tricalcium phosphate (β-TCP) by a subsequent thermal treatment. For the hydrothermal synthesis, calcium tripolyphosphate was used and different amounts of 2-propanol were added to adjust the pH. Average whisker lengths of 160 µm were obtained at a 2-propanol content of 27 volume-percent. However, 33% dicalcium phosphate anhydrate (DCPA) were present as a secondary phase. The amount of DCPA could be reduced by increasing the amount of 2-propanol. Whisker samples consisting of 88% dHAp and 12% DCPA were selected to investigate microstructural changes and phase transformations during thermal treatment. Polycrystalline single phase -TCP short fibers were obtained after a thermal treatment at 1125°C.
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Affiliation(s)
- Katharina Zorn
- Institute of Materials Science and Technology (IMT), Friedrich-Schiller-University of Jena, Jena, Germany
| | - Daniel Mitró
- Institute of Materials Science and Technology (IMT), Friedrich-Schiller-University of Jena, Jena, Germany
| | - Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany
| | - Uwe Gbureck
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany
| | - Frank A. Müller
- Institute of Materials Science and Technology (IMT), Friedrich-Schiller-University of Jena, Jena, Germany
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17
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Christel T, Kuhlmann M, Vorndran E, Groll J, Gbureck U. Dual setting α-tricalcium phosphate cements. J Mater Sci Mater Med 2013; 24:573-581. [PMID: 23239262 DOI: 10.1007/s10856-012-4828-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 11/30/2012] [Indexed: 06/01/2023]
Abstract
An extension of the application of calcium phosphate cements (CPC) to load-bearing defects, e.g. in vertebroplasty, would require less brittle cements with an increased fracture toughness. Here we report the modification of CPC made of alpha-tricalcium phosphate (α-TCP) with 2-hydroxyethylmethacrylate (HEMA), which is polymerised during setting to obtain a mechanically stable polymer-ceramic composite with interpenetrating organic and inorganic networks. The cement liquid was modified by the addition of 30-70 % HEMA and ammoniumpersulfate/tetramethylethylendiamine as initiator. Modification of α-TCP cement paste with HEMA decreased the setting time from 14 min to 3-8 min depending on the initiator concentration. The 4-point bending strength was increased from 9 MPa to more than 14 MPa when using 50 % HEMA, while the bending modulus decreased from 18 GPa to approx. 4 GPa. The addition of ≥50 % HEMA reduced the brittle fracture behaviour of the cements and resulted in an increase of the work of fracture by more than an order of magnitude. X-ray diffraction analyses revealed that the degree of transformation of α-TCP to calcium deficient hydroxyapatite was lower for polymer modified cements (82 % for polymer free cement and 55 % for 70 % HEMA) after 24 h setting, while the polymerisation of HEMA in the cement liquid was quantitative according to FT-IR spectroscopy. This work demonstrated the feasibility of producing fracture resistant dual-setting calcium phosphate cements by adding water soluble polymerisable monomers to the liquid cement phase, which may be suitable for an application in load-bearing bone defects.
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Affiliation(s)
- T Christel
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, 97070, Würzburg, Germany
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18
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Moseke C, Bayer C, Vorndran E, Barralet JE, Groll J, Gbureck U. Low temperature fabrication of spherical brushite granules by cement paste emulsion. J Mater Sci Mater Med 2012; 23:2631-2637. [PMID: 22903599 DOI: 10.1007/s10856-012-4740-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
Secondary protonated calcium phosphates such as brushite (CaHPO(4)·2H(2)O) or monetite (CaHPO(4)) have a higher resorption potential in bone defects than sintered ceramics, e.g. tricalcium phosphate or hydroxyapatite. However, processing of these phosphates to monolithic blocks or granules is not possible by sintering due to thermal decomposition of protonated phosphates at higher temperatures. In this study a low temperature technique for the preparation of spherical brushite granules in a cement setting reaction is presented. These granules were synthesized by dispersing a calcium phosphate cement paste composed of β-tricalcium phosphate and monocalcium phosphate together with a surfactant to an oil/water emulsion. The reaction products were characterized regarding their size distribution, morphology, and phase composition. Clinically relevant granule sizes ranging from 200 μm to 1 mm were obtained, whereas generally smaller granules were received with higher oil viscosity, increasing temperature or higher powder to liquid ratios of the cement paste. The hardened granules were microporous with a specific surface area of 0.7 m(2)/g and consisted of plate-like brushite (>95 % according to XRD) crystals of 0.5-7 μm size. Furthermore it was shown that the granules may be also used for drug delivery applications. This was demonstrated by adsorption of vancomycin from an aqueous solution, where a load of 1.45-1.88 mg drug per g granules and an almost complete release within 2 h was obtained.
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Affiliation(s)
- Claus Moseke
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Würzburg, Germany.
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19
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Schnieders J, Gbureck U, Vorndran E, Schossig M, Kissel T. Erratum: The effect of porosity on drug release kinetics from vancomycin microsphere/calcium phosphate cement composites. J Biomed Mater Res B Appl Biomater 2012. [DOI: 10.1002/jbm.b.32682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Schnieders J, Gbureck U, Vorndran E, Schossig M, Kissel T. The effect of porosity on drug release kinetics from vancomycin microsphere/calcium phosphate cement composites. J Biomed Mater Res B Appl Biomater 2011; 99:391-8. [DOI: 10.1002/jbm.b.31910] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 04/21/2011] [Accepted: 05/16/2011] [Indexed: 11/05/2022]
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21
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Vorndran E, Ewald A, Müller FA, Zorn K, Kufner A, Gbureck U. Formation and properties of magnesium-ammonium-phosphate hexahydrate biocements in the Ca-Mg-PO4 system. J Mater Sci Mater Med 2011; 22:429-436. [PMID: 21221732 DOI: 10.1007/s10856-010-4220-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 12/16/2010] [Indexed: 05/30/2023]
Abstract
Calcium substituted trimagnesium phosphate with the general formula Ca(x)Mg((3-x))(PO(4))(2) (0 < x < 1.5) was synthesized by calcination of powder mixtures with the appropriate stoichiometry and reacted with 3.5 M diammonium hydrogenphosphate solution to form a cementitious matrix of magnesium ammonium phosphate hexahydrate (struvite). The degree of ionic substitution was shown to influence physical cement properties; clinically suitable cement formulations with setting times in the range 5-15 min and compressive strengths of >50 MPa were obtained for x ≤ 0.75 together with a grinding time ≥ 1 h and a powder to liquid ratio ≥ 2.5 g/ml. The cement cytocompatibility was investigated by culturing human osteoblast cell line MG63 on cement surfaces demonstrating pronounced cell growth during 13 days cultivation.
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Affiliation(s)
- Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, D-97070, Würzburg, Germany
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22
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Klammert U, Gbureck U, Vorndran E, Rödiger J, Meyer-Marcotty P, Kübler AC. 3D powder printed calcium phosphate implants for reconstruction of cranial and maxillofacial defects. J Craniomaxillofac Surg 2010; 38:565-70. [DOI: 10.1016/j.jcms.2010.01.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 11/24/2009] [Accepted: 01/26/2010] [Indexed: 10/19/2022] Open
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23
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Klammert U, Vorndran E, Reuther T, Müller FA, Zorn K, Gbureck U. Low temperature fabrication of magnesium phosphate cement scaffolds by 3D powder printing. J Mater Sci Mater Med 2010; 21:2947-2953. [PMID: 20740307 DOI: 10.1007/s10856-010-4148-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Accepted: 08/06/2010] [Indexed: 05/29/2023]
Abstract
Synthetic bone replacement materials are of great interest because they offer certain advantages compared with organic bone grafts. Biodegradability and preoperative manufacturing of patient specific implants are further desirable features in various clinical situations. Both can be realised by 3D powder printing. In this study, we introduce powder-printed magnesium ammonium phosphate (struvite) structures, accompanied by a neutral setting reaction by printing farringtonite (Mg(3)(PO(4))(2)) powder with ammonium phosphate solution as binder. Suitable powders were obtained after sintering at 1100°C for 5 h following 20-40 min dry grinding in a ball mill. Depending on the post-treatment of the samples, compressive strengths were found to be in the range 2-7 MPa. Cytocompatibility was demonstrated in vitro using the human osteoblastic cell line MG63.
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Affiliation(s)
- Uwe Klammert
- Department of Cranio-Maxillo-Facial Surgery, University of Würzburg, Pleicherwall 2, 97070 Würzburg, Germany.
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24
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Vorndran E, Spohn N, Nies B, Rössler S, Storch S, Gbureck U. Mechanical properties and drug release behavior of bioactivated PMMA cements. J Biomater Appl 2010; 26:581-94. [PMID: 20819922 DOI: 10.1177/0885328210376996] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Septic loosening of cemented implants represents an unresolved long-term problem of total hip endoprostheses. Common treatments of infected prostheses involve the use of temporary antibiotic-loaded PMMA spacer-implants or antibiotic-loaded cements. The latter are either provided by a manufacturer or are obtained by simply mixing specific antibiotic powders according to a microbial sensitivity test with PMMA cement. This study is aimed to investigate the antibiotic release behavior and mechanical properties of novel modified PMMA cements, which were bioactivated by chemical modification of commercial cements with either 0.5% hydroxyethylmethacrylate-phosphate (HEMA-P) or 0.5% hydroxyethylmethacrylate-phosphate + calcium chloride and sodium carbonate as buffer. Tobramycin release experiments from the cements were performed statically by immersion of the drug-loaded samples in PBS buffer following liquid change after different periods of time or during cyclic mechanical loading of the cement samples. Cement modification did not significantly alter the mechanical properties of the cements, but affected the release rate from the matrix. While the unmodified cement released approximately 0.33 mg/cm(2) tobramycin after 48 h independent of the testing regime, modification with both HEMA-P and salt buffer increased the antibiotic release to 37-50 mg/cm(2) when tested under cyclical mechanical loading.
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Affiliation(s)
- Elke Vorndran
- Department for Functional Materials in Medicine and Dentistry University of Würzburg, Würzburg Germany.
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25
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Barralet J, Gbureck U, Habibovic P, Vorndran E, Gerard C, Doillon CJ. Angiogenesis in Calcium Phosphate Scaffolds by Inorganic Copper Ion Release. Tissue Eng Part A 2009; 15:1601-9. [DOI: 10.1089/ten.tea.2007.0370] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Jake Barralet
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Uwe Gbureck
- Abteilung für Funktionswerkstoffe der Medizin und der Zahnheilkunde, ZMK-Klinik, Universität Würzburg, Würzburg, Germany
| | - Pamela Habibovic
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada
| | - Elke Vorndran
- Abteilung für Funktionswerkstoffe der Medizin und der Zahnheilkunde, ZMK-Klinik, Universität Würzburg, Würzburg, Germany
| | - Catherine Gerard
- Department of Surgery, Universite Laval, and Oncology and Molecular Endocrinology Research Centre, CHUL Research Centre, Quebec City, Quebec, Canada
| | - Charles J. Doillon
- Department of Surgery, Universite Laval, and Oncology and Molecular Endocrinology Research Centre, CHUL Research Centre, Quebec City, Quebec, Canada
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26
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Gbureck U, Vorndran E, Barralet JE. Modeling vancomycin release kinetics from microporous calcium phosphate ceramics comparing static and dynamic immersion conditions. Acta Biomater 2008; 4:1480-6. [PMID: 18485844 DOI: 10.1016/j.actbio.2008.02.027] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 02/14/2008] [Accepted: 02/19/2008] [Indexed: 11/30/2022]
Abstract
The release kinetics of vancomycin from calcium phosphate dihydrate (brushite) matrices and polymer/brushite composites were compared using different fluid replacement regimes, a regular replacement (static conditions) and a continuous flow technique (dynamic conditions). The use of a constantly refreshed flowing resulted in a faster drug release due to a constantly high diffusion gradient between drug loaded matrix and the eluting medium. Drug release was modeled using the Weibull, Peppas and Higuchi equations. The results showed that drug liberation was diffusion controlled for the ceramics matrices, whereas ceramics/polymer composites led to a mixed diffusion and degradation controlled release mechanism. The continuous flow technique was for these materials responsible for a faster release due to an accelerated polymer degradation rate compared with the regular fluid replacement technique.
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Affiliation(s)
- Uwe Gbureck
- Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, D-97070 Würzburg, Germany.
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