Soltmann U.,GMBU E.V. |
Nies B.,InnoTERE GmbH |
Bottcher H.,GMBU E.V.
Advanced Engineering Materials | Year: 2011
Living bacteria (Rhodococcus ruber) and yeast (Saccharomyces cerevisiae) cells can be embedded within magnesium phosphate cement (MPC). The cements are prepared by the admixture of microorganisms to a water-based slurry system of Mg3(PO4)2 powder and ammonium phosphate solution whereas the setting of the slurry occurs within few minutes. To test the biocatalytic activity of the embedded microorganisms the phenol degradation by R. ruber and the glucose conversion by S. cerevisiae are described. Embedded cells survived within the cements and remain active. However, the glucose or phenol consumption rate was clearly reduced after immobilization within the compact macroporous concrete matrix. By using leachable pore forming additives or by admixture of cellulose fibers the macroporous structure of the MPC can be improved. The bioactive composite material exhibits good mechanical and chemical stability. It can be used as new stable biocatalysts, e.g., for applications in bioremediation and biotechnology. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Luo Y.,TU Dresden |
Lode A.,TU Dresden |
Sonntag F.,Fraunhofer Institute for Material and Beam Technology |
Nies B.,InnoTERE GmbH |
Gelinsky M.,TU Dresden
Journal of Materials Chemistry B | Year: 2013
Herein, we present a new type of biphasic organic-inorganic scaffold, which can be fabricated by multi-channel 3D plotting under mild conditions based on a highly concentrated alginate paste and a ready-to-use calcium phosphate cement (CPC) for bone and osteochondral tissue engineering. The structures of scaffolds were characterised by light and scanning electron microscopy (SEM). Results indicated that the concentrated alginate and CPC pastes had comparable plotting consistency, and therefore could be combined in one (biphasic) scaffold by applying predesigned plotting parameters. After crosslinking of alginate and setting of CPC, the biphasic scaffold obtained mechanical and structural stability. Mechanical test data revealed that biphasic CPC-alginate scaffolds had significantly increased compressive strength and modulus compared to pure alginate as well as mixed calcium phosphate (CaP)-alginate scaffolds in a wet state and improved strength and toughness compared to pure CPC scaffolds in both dry and wet conditions. Culture of human mesenchymal stem cells (hMSCs) on these scaffolds over 3 weeks demonstrated the good cytocompatibility of the selected materials. Because of the mild preparation conditions, bovine serum albumin (BSA) as a model protein was loaded in alginate and CPC pastes prior to plotting with high loading efficiency. Release studies in vitro showed that BSA released much faster from alginate strands than from CPC strands, which might allow amount-controlled protein release from biphasic CPC-alginate scaffolds. Furthermore, an upgraded bipartite osteochondral scaffold consisting of an alginate part for chondral and a biphasic CPC-alginate part for bony repair was fabricated based on this technique. This scaffold showed a strong organic-inorganic interface binding due to interlocking and crosslinking of the alginate strands. This journal is © 2013 The Royal Society of Chemistry.
Heinemann S.,TU Dresden |
Rossler S.,InnoTERE GmbH |
Lemm M.,InnoTERE GmbH |
Ruhnow M.,TU Dresden |
Nies B.,InnoTERE GmbH
Acta Biomaterialia | Year: 2013
Calcium phosphate cements (CPCs) are highly valuable materials for filling bone defects and bone augmentation by minimal invasive application via percutaneous injection. In the present study some key features were significantly improved by developing a novel injectable ready-to-use calcium phosphate cement based on water-immiscible carrier liquids. A combination of two surfactants was identified to facilitate the targeted discontinuous exchange of the liquid for water after contact with aqueous solutions, enabling the setting reaction to take place at distinct ratios of cement components to water. This prolonged the shelf life of the pre-mixed paste and enhanced reproducibility during application and setting reactions. The developed paste technology is applicable for different CPC formulations. Evaluations were performed for the formulation of an α-TCP-based CPC as a representative example for the preparation of injectable pastes with a powder-to-carrier liquid ratio of up to 85:15. We demonstrate that the resulting material retains the desirable properties of conventional CPC counterparts for fast setting, mechanical strength and biocompatibility, shows improved cohesion and will most probably show a similar degree of resorbability due to identical mineral structure of the set products. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Vorndran E.,University of Würzburg |
Geffers M.,University of Würzburg |
Ewald A.,University of Würzburg |
Lemm M.,InnoTERE GmbH |
And 2 more authors.
Acta Biomaterialia | Year: 2013
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. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
InnoTERE GmbH | Date: 2013-04-11
The invention relates to an implant and a set for producing an implant and their uses. Furthermore, the invention describes a method of making an implant as per the invention. An implant for producing bone implants with improved mechanical characteristics, especially with adjustable mechanical characteristics, is provided via the invention. The implant as per the invention made up of a fiber composite material contains
InnoTERE GmbH | Date: 2012-10-19
The invention relates to a preparation for manufacturing an implant, preferably a bone implant, a process for said manufacture and mouldings obtainable therefrom. The preparation comprises the following components: a) mineral cement powder comprising at least one calcium-ion-containing and/or at least one magnesium-ion-containing inorganic compound as a reactive component; b) at least one organic carrier liquid; c) at least two surfactants selected from at least two of the groups of anionic, cationic, amphoteric and nonionic surfactants; d) less than 1% w/w water based on the total mass of the composition, wherein the weight ratio of the total solids present in the formulation solids to the sum of the weight of the organic carrier liquid and the at least two surfactants is more than if the cement powder contains calcium-ion-containing and no magnesium-ion-containing compounds as the reactive component, or is more than 6 if the cement powder contains magnesium-ion-containing or magnesium-ion- and calcium-ion-containing compounds as the reactive component.
InnoTERE GmbH | Date: 2011-06-15
The invention relates to a bone implant which comprises a magnesium-containing metallic material having a reduced corrosion rate and inorganic bone cement, and to methods and a kit for producing the bone implant. With a method according to the invention, it is possible to obtain a bone implant which comprises inorganic bone cement and a magnesium-containing metallic material with a corrosion-inhibiting coating which contains magnesium-ammonium phosphates. In the method according to the invention, a magnesium-containing metallic material, of which the surface has a magnesium oxide layer and/or a magnesium salt layer, is combined with inorganic bone cement in order to generate a solid composite material that comprises the inorganic bone cement and the magnesium-containing metallic material. The inorganic bone cement contains inorganic powder constituents, which set in the presence of water to form a solid, and water-soluble phosphate-ion-containing salts, preferably water-soluble phosphate-ion-containing and ammonium-ion-containing salts. According to the invention, the magnesium-containing metallic material is brought into contact with water before and/or during the combination with the inorganic bone cement in the presence pt of water-soluble ammonium-ion-containing and phosphate-ion-containing salts. Moreover, the inorganic bone cement is set by being brought into contact with water.
InnoTERE GmbH | Date: 2010-03-31
A bioactive PMMA (polymethylmethacrylate) bone cement contains a powder component and a reactive monomer liquid, wherein the powder component and the reactive monomer liquid when mixed with one another react with one another and form a polymer-based solid material. The powder component contains particulate polymer powder of polymethylmethacrylates; a radical starter; and anionic copolymer nanoparticles. The anionic copolymer nanoparticles are distributed in nano-particulate form within the particulate powder component or coated as a film on particles of the particulate polymer powder.
InnoTERE GmbH | Date: 2010-09-03
The invention relates to methods for producing a partial or complete bioactive coating of an iron and/or zinc based metal implant material with calcium phosphates, a bioactively coated iron and/or zinc based metal implant, which is partially or completely coated with calcium phosphates, and bone implants containing an implant material according to the invention. In order to produce the coating according to the invention, iron and/or zinc based metal implant materials are brought in contact with acidic aqueous solutions, which have a pH value of 6.0 or less and contain calcium phosphates, whereby a calcium phosphate layer is deposited on the surface of the implant materials. The iron and/or zinc based metal implant materials, which are used in methods according to the invention, are materials consisting of base iron alloys or pure iron or materials that contain other substances, which are coated with pure iron, with a base iron alloy and/or with zinc.
InnoTERE GmbH | Date: 2014-10-23
The invention relates to dimensionally stable molded bone replacement elements made of mineral bone cement with residual hydraulic activity that contain at least one share of hardened mineral bone cement and at least one share of unconverted or unhardened reactive mineral bone cement, wherein the share of hardened mineral bone cement is 5% to 90% by weight. The dimensionally stable molded bone replacement elements have at least 5% of the maximum value of the strength of a completely hardened bone cement comprised of the same mineral components and with the same structural characteristics and reach compressive strengths in the range of 2 to 200 MPa. They are substantially free of water and can be converted under biological conditions.