Papers by Keyword: Injectable Bone Substitute

Abstract: This study aims to determine the effect of pitch variations on pedicle screws for spinal osteoporosis applications. Five variations of pedicle screw pitch (1.75; 2.00; 2.25; 2.50; 2.75 mm) were printed with filaments made of Polylactide Acid (PLA) using a 3D-printing with the Fused Deposition Modelling (FDM) technique. The materials mixed to make the Injectable Bone Substitute (IBS) paste injected into the pedicle screw were Hydroxyapatite (HA), gelatin, hydroxypropyl methylcellulose (HMPC), and alendronate. The pull-out test results showed that the pedicle screw with a pitch of 2.75 mm had the highest value, namely 24.568 ± 0.431 N for screws without IBS paste and 44.814 ± 0.939 N for screws with IBS paste. The results showed that the pedicle screw with the larger pitch had better pull-out and torsional test values, but the larger pitch made the characterization of the bending test decreased. Thus, it can be stated that a pedicle screw with a large pitch is suitable for spinal osteoporosis applications.

Abstract: Spinal tuberculosis is one of the infectious diseases which according to the World Health Organization (WHO), is a major cause of health problems and one of the top 10 causes of death worldwide. The aim of this study was to fabricate a 3D printing scaffold with the design of truncated hexahedron, then combined with Injectable Bone Substitute (IBS) paste as a method for drug delivery in the case of spinal tuberculosis. Injectable Bone Substitute (IBS) paste was synthesized by combining some materials including hydroxyapatite, gelatin, hydroxypropyl methylcellulose (HPMC), and streptomycin. The scaffold was characterized with IBS paste through the digital microscope and the mechanical test to determine the mechanical strength of the scaffold. The results of the 3D printing scaffold showed that the scaffold has interconnectivity between pores. After being injected with IBS, it was seen that the entire surface of the scaffold pores was covered by IBS paste evenly. Scanning Electron Microscope (SEM) tests showed that the surface of the scaffold has been covered by IBS paste, and proves that the pores are still formed. Energy Dispersive X-Ray (EDX) test results showed that the IBS paste containing a hydroxyapatite component consisting of Ca, P, and O elements. Mechanical tests showed that the scaffold for all pore sizes had a compressive strength of 1.49-3.97 MPa before IBS injection and increased to 3.45-4.77 MPa after IBS injection. Then the bending test showed that the scaffold had a bending strength of 16.76-36.09 MPa and increased to around 21.57-40.36 MPa after being injected with IBS. The drug release test showed that the 3D printing scaffold could release streptomycin by 4.944%-6.547%, which has met the percentage of drug release that is able to kill tuberculosis bacteria. It can be concluded that 3D printing scaffold combined with IBS paste can be applied as a drug carrier as well as a method of healing spinal tuberculosis.

Abstract: Mechanical properties are important characteristics of scaffolds as biomaterials implant in tissue engineering. This study focused on the analysis of the tensile strength of the 3D printing scaffold with a geometric design of the truncated hexahedron unit with pore size variation and combinFive variations of pore size of the scaffold (600, 800, 1,000, 1,200, and 1,400 µm) were fabricated from Polylactide acid (PLA) filament using the Fused Deposition Modelling (FDM) method through an ordinary commercial 3D printer. The IBS paste was synthesized from hydroxyapatite (HA), gelatin, hydroxypropyl methylcellulose (HPMC), and streptomycin. The characterization performed in this study were the pore size test with a digital microscope, tensile strength, elongation test, porosity, and contact angle. The 3D printed scaffold formed micropores after injected with IBS paste from a range of 130-230 µm. The tensile test results showed that the tensile strength of the 3D printing scaffold increased after being injected with IBS paste. In addition, the elongation test also shows a positive trend with increasing values of elongation after injection of IBS paste. The contact angle test results indicated that the scaffold was hydrophilic. From those characterizations, it could be concluded that 3D printing scaffold meet the criteria of scaffold for bone tissue engineering and drug carrier for tuberculosis.

Abstract: Calcium phosphate bioceramic granules associated with hydrosoluble polymers formed putties currently more used in clinical applications as they are easy to handle (injectability, moldability). In this study, 2 kinds of materials were tested in rabbit bone defects. The first one is InOss (Biomatlante), a microporous biphasic CaP granules (BCP, HA/TCP mixture) with polysaccharidic hydrogel; and the second one is Actifuse ABX (Baxter/Apatech), pure hydroxyapatite granules containing silicate (HA-Si) with blocks copolymer hydrogel (poloxamer), . The aim of this study was to compare osteogenic properties of two kinds of CaP putties containing HA-Si versus BCP and the kinetic of resorption of their hydrogel. Data have demonstrated that both hydrogels increase the handling properties. Bone regeneration was observed in the two types of sample, however at 3 weeks, Actifuse ABX hydrogel was not totally absorbed, while InOss hydrogel was no longer observed. The second difference observed was osteoconduction. Newly formed bone over the time period studied was moreover in close contact with BCP granules than with HA-Si granules. Larger granules resorption on time was observed for BCP compared to HA-Si. Resorption of Actifuse ABX remains limited and explains the faster kinetic of absorption for InOss. This study demonstrates biocompatibility, absorbability and bone ingrowth at the expense of the two types of putty injectable/moldable bioceramic used for bone regeneration.

Abstract: This paper reports on the research into multiphase bone substitutes carried out by laboratories from the ‘Pays de la Loire’ region in France. This collaborative research was funded by both the French Government and the Regional Council in the period 2000-2007. Calcium phosphate bioceramics, polymers and combinations have been developed as bone substitutes for various maxillofacial and orthopaedic applications. These bone substitutes should support and regenerate bone tissue and resorb after implantation. In the bone tissue engineering area, they have been combined with autologous bone marrow cells or bioactive factors. The bone substitutes were tested in various animal models mimicking clinical situations or under pathological conditions (osteoporosis). In order to complete our research, the multiphase materials were also evaluated in clinical trials.

Abstract: An injectable bone substitute (IBS) made of a suspension of calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. Compared with current filling materials, which are toxic to periapical tissues, calcium phosphate materials, due to their biocompatibility and bioactive properties, may be viewed as possible alternatives. The aim of this study was first to determine if an injectable bone substitute could be used to obtain further healing of apical tissue by the neoformation of a mineralized barrier. In the next step, the paper will focus on rheological measurements as a tool for physical characterisation and on the improvement of the injection technique. Rheology concerns the flow and deformation of the suspension and, in particular, its behaviour in the transient area between solids and fluids. The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. Other experiments with other animal models closer to a Human model have to be performed before human trials.

Abstract: An injectable bone substitute (IBS) made of a suspension of Calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. The aim of this study was to verify the ability of calcium phosphate ceramic suspension to fill the apical zone of teeth ex vivo (n=40) and in vivo in a sheep model (n=8). The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. In vivo, the presence of blood pressure due to the pulpectomy is a negative parameter to allow a good filling. The scanning electron microscopy revealed mineral formation at the apex level with mineral tissue conduction between the BCP granules but only one tooth showed a good apical filling with a good sealing. The sealing of the apex seems to depend of the amount of BCP granules. Other experiments with other animal models closer to a Human model have to be performed before human trials.

Abstract: For the first time, an injectable bone substitute (IBS) made of a suspension of Calcium phosphate ceramic was used in a clinical trial in human after extraction of non conservable tooth (36 or 46). 11 patients did agree for implantation of their sockets with the biomaterial. It was an explorative study and the results showed no pain due to the biomaterial implantation, no infection, no inflammation and perfect biocompatibility. The safety and the bioactivity of this concept of biomaterial were confirmed in human implantation after several animals’ pre-clinical studies.

Abstract: Injectable bone substitutes (IBS) based on calcium phosphate (CaP) and/or calcium sulphate (CaS) are used as fillers in bone defects to stimulate bone integration and allow mechanical loading. Two types of IBS, IBS-1 is CaP+20%CaS and IBS-2 is CaS+40% hydroxyapatite, were investigated. The materials were injected into holes in the femur and tibia in rabbits. After 10 weeks the femora were subjected to indentation testing and tibiae were prepared for histology evaluation. IBS-1 lead to an higher indentation load compared to control, that is no material inserted, while IBS-2 showed no significant difference between material and control. Histology showed that with IBS-1, the bone penetrated into and integrated with the material in the defect. With IBS-2, new bone grew into the outer 0.5-1.0 mm. The materials could be used for different indications, such as to support fracture healing or in contained cavities.