Wojciech Święszkowski, Tadeusz Chudoba, Sylwia Kuśnieruk, Aleksandra Kędzierska, Bartosz Woźniak, Julia Rogowska Tylman, Dariusz Smoleń, Elżbieta Pietrzykowska, Witold Łojkowski, Jacek Wojnarowicz, Aharon Gedanken, Janis Locs, Vita Zalite, Mara Pilmane, Ilze Salma
Publication of US11260148B2 on 2022-03-01, Priorrity to PL 412238A, 2016-05-05
The method of making an implant consists on coating of a supporting structure with synthetic hydroxyapatite by immersing the supporting structure in a suspension and triggering of a cavitation in a portion of the suspension being in contact with the supporting structure . The suspension is formed by a liquid external phase, advantageously water, and internal phase, i.e. particles of synthetic hydroxyapatite having an average particle size not exceeding 100 nm and containing structural water in an amount from 2 to 6% by weight. The implant is coated with the above described hydroxyapatite subjected to cavitation and a thickness of 50 nm to 1000 nm, advantageously 50 nm to 300 nm.
The invention regards a method of producing bone implants having a character of supporting structure at least partially coated with a synthetic hydroxyapatite and bone implants for use in orthopaedic surgery, trauma surgery (traumatology), regenerative implantology, which facilitate or accelerate the regeneration of bone tissue.
In medicine, particularly in orthopaedics, dentistry and traumatology, and in the treatment of bone defects caused by the removal of the tumour, implants, also known as scaffolds for bone tissue regeneration, are used in order to induce or accelerate regeneration of the bone tissues by the organism; tissue that was lost as a result of trauma, surgery of cancer removal, orthopaedic surgery, dental surgery, tooth extraction, other causes or improvement of aesthetics. For the production of such implants various kinds of synthetic biomaterials (metals, ceramics, synthetics—polymers, composites) as well as natural materials are used. They must meet a number of criteria, including no toxicity to the body, proper filling of the missing bone volume and appropriate mechanical properties. In particular, a very valuable feature of such materials is their bioresorption.
Presently, there are many treatment methods for small defects in bones, but still no solution for large tissue loss (so-called critical loss) is known. To fill the cavity and facilitate active bone regeneration an scaffold should be created (implant), both filling the space of bone loss and transferring mechanical stresses, enabling the bone tissue to gradually fill the empty space. The most preferable solution is to have an implant undergoing resorption over time, thus enabling the entire space to be filled with new bone tissue. Another criterion is ensuring the flow of nutrients and cells in the bloodstream trough the scaffolds material. Also some modifications to the implant surfaces are used to accelerate the regeneration of substantial loss of the tissue.
In the effectiveness of the bone implant use the surface layers of an implant containing calcium phosphates play an important role. The natural bone in up to 70% (depending on the type of bone tissue) consists of an inorganic matter, largely composed of hydroxyapatite deposited in a form of crystals. Hydroxyapatite Ca10(PO4)6(OH)2 is one of the major minerals in the human body. It is responsible for the hardness and strength of bones and teeth. In the human body hydroxyapatite occurs in a form of crystals with lamellar structure, 2 nm thick, 25 nm wide, and 50 nm long. [M. Sadat-Shojai, M.-T. Khorasani, E. Dinpanah-Khoshdargi, A. Jamshidi “Synthesis methods for nanosized hydroxyapatite with diverse structures”, Acta Biomaterialia, Vol. 9, 2013, pp. 7591-7621]. Hydroxyapatite is a material widely used in orthopaedics, maxillofacial and implant surgeries, inter alia, for the production of layers of implants aimed at bone regeneration…(partial quotation of patent description Backgrount Art)