Publication Date: 2012-Jan-17
The IP.com Prior Art Database
Page 01 of 3
This invention relates to a polymeric material and particularly, although not exclusively, relates to a material comprising a polymeric material and a filler, for example a fugitive or resorbable material, wherein the filler may be removable in order to define a porous structure defined by the polymeric material. In preferred embodiments, the material defines an osseoconductive polymeric material and/or is suitable for medical use such as for making medical implants or parts thereof. Preferred embodiments relate to materials comprising polyaryletherketones, for example polyetheretherketone (PEEK).
It is well known to make porous medical implants and there are numerous prior art proposals. For example, WO2007/051307 discloses porous medical implants made from polyetheretherketone and salt (e.g. sodium chloride) in a process wherein the ingredients are placed in a mould cavity, compressed and heated to melt the polyetheretherketone but not the salt and form a moulded part. After subsequent cooling to solidify the mixture, the moulded material is placed in a water bath at 100ºC to dissolve the salt from the moulded part and define a porous moulded part.
In porous materials for medical implants, it is desirable to define a substantially fully interconnected network of voids, firstly to facilitate complete removal of a fugitive materials used in the preparation of the porous material and, secondly, to define a highly osseoconductive material.
In accordance with the present disclosure substantially spherical filler particles (e.g. of a salt such as sodium chloride) may be mixed with particles of a polymeric material (e.g. of polyetheretherketone (PEEK)). The mixture may then be compression moulded (or consolidated using an alternative technique). Optionally, the filler particles (which suitably define a fugitive filler) may be removed by dissolution to leave a porous structure made of the polymeric material (e.g. PEEK).
The porous structure may be advantageous for reasons discussed in Biomaterials 25 (2004) 4955-4962.
The spherical filler (e.g. of sodium chloride) may be made as described in Journal of Alloys and Compounds 499 (2010) 43-47 or as described in Biomaterials 25 (2004) 4955- 4962.
The spherical filler may be used as made or heat exposed to burn out to make the filler (e.g. NaCl) more porous and/or more readily dissolvable.
Page 02 of 3
The polymeric material is preferably PEEK as described. Alternatively, it could be another polyaryletherketone, polyarylethersulphone or a copolymer comprising two or more aryletherketone and/or arylethersulphone repeat units. Said polymeric material may be selected from PEEK, PEK, PEKEKK and PEKK.
Said polymeric material may have a D50 of 100µm to 1000µm, suitably 200µm to 800µm, preferably 300µm to 700µm, especially 400µm to 600µm.
Said polymeric material suitably has a melt viscosity (MV) of at least 0.06 kNsm-2, 10
preferably has a MV of...