High strength and tenacity degradable strontium calcium superphosphate composite bone cement and its preparation method

Abstract

The invention discloses a high tensile degradable strontium phosphate calcium composite bone cement for repairing or intensifying fixation of human body holding bone defect and preparation method thereof. The solid material of bone cement is mixed powder of Ca4(PO4)2O ceramic with high crystallinity, SrHPO4, CaHPO4, curing liquid is thin phosphoric acid water solution, additive plasticizing unit is biocompatibility degradable macomolecule fiber with high tensile strength, selecting from lactic acid - hydroxyacetic acid copolymer fibre, polylatic acid fiber or polyglycolic acid fiber or other absorbable surgical suture, the enhancing unit is Ca4(PO4)2O residual ceramic particles after curing reaction. The preparation method coalesces kinds of techniques of ceramic particles in-situ reinforcing, initial plasticizing and later stage degradation of degradable fiber, Sr modification to get a novel high tensile degradable strontium phosphate calcium composite bone cement in like physiologic environment. The material has good biocompatibility, bioactivity, bone conductivity and degradation property.

Description

technical field [0001] The invention belongs to the field of biomedical materials, and relates to a high-strength and tough degradable strontium-calcium calcium phosphate composite bone cement suitable for repairing or strengthening fixation of bone defects in bearing parts of the human body and a preparation method thereof. The preparation method combines highly crystalline tetracalcium phosphate ceramics In-situ reinforcement of particles, initial toughening of degradable polymer fibers, post-degradation pore formation, strontium ion modification and other technical advantages. Background technique [0002] Among artificial synthetic materials, calcium phosphate bone cement has unique advantages: on the one hand, the cured product is hydroxyapatite, which is consistent with the inorganic mineral composition of human bone, and has good biocompatibility, bioactivity and osteoconductivity; On the other hand, as a biocement, it has the advantages of self-curing, injectability,...

AI Technical Summary

Problems solved by technology

However, the existing calcium phosphate bone cement products mainly have two deficiencies: first, the strength is generally low (the compressive strength is generally 30-55MPa), and it cannot be used in the bone defect of the bearing part (the transverse resistance of the long bone of the human body). The compressive strength is 106-133 MPa) repair; second, the in vivo degradability is poor, it is difficult to match the fast growth rate of new bone tissue, and the undegraded cement residue may become a potential source of infection in the body; third, the brittleness is large , prone to fatigue failure when serving in vivo

However, these fibers and whiskers cannot be degraded after the bone cement is implanted in the body, making it difficult to achieve permanent repair

Using biodegradable Ployglactin910 fibers to replace these non-degradable fibers improved the fracture work of composite cement at the initial stage of curing, but its compressive strength decreased (XuHHK, Janet B. Quinn. Calcium phosphate cement containing resilient fibers for short-term reinforcement and macroporosity. Biomaterials, 2002, 23: 193-202)

Domestic scholars have increased the strength of bone cement to 76.1MPa by adding seed crystals and selecting a solidifying solution, and have developed a bone cement product with independent intellectual property rights, but the strength level of this cement is lower than the corresponding level of human long bones, which still cannot meet The application requirements for the repair of bone defects in bearing parts, and the brittleness and degradation performance of the initial material implanted in the body have not been fundamentally resolved (Shao Huifang, Liu Changsheng, etc. Morphology control of hydroxyapatite seed crystals and its effect on calcium phosphate bone cement In situ reinforcement research. Journal of Inorganic Materials, 2001; 16(5): 933-938)

In addition, in terms of improving degradability, in 1995, Constanz et al. reported in the international authoritative journal Science that carbonated hydroxyapatite bone cement had a superior degradation rate than conventional bone cement, and achieved good clinical repair effects, but unfortunately Unfortunately, its compressive strength is less than 50Mpa (Constanz BR, Ison JC, Fulmer MT et al. Skeletal repair by in situationation of the mineral phase of bone. Science, 1995; 257: 1796-1799.)

So far, the preparation technology and performance of this kind of ceramic in-situ reinforced fiber-toughened degradable strontium calcium phosphate bioactive composite bone cement have not been reported.