Cement-forming compositions, monetite cements, implants and methods for correcting bone defects
Inventors
Åberg, Jonas • Engstrand, Thomas • Engqvist, Håkan
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-9913931-B2
Publication Date
2018-03-13
Expiration Date
Abstract
A calcium phosphate monetite cement-forming composition comprises a monetite-forming calcium-based precursor powder and from 3 to 30 wt %, based on the weight of the precursor powder, of dicalcium pyrophosphate powder. Monetite cements formed form such compositions may be used in implants for correcting bone defects. Methods for bone defect repair employ implants formed from such monetite cements and slow implant resorption and/or improve in vivo bone induction in a patient.
Core Innovation
The disclosed invention relates to calcium phosphate monetite cement-forming compositions in which a monetite-forming precursor powder includes monocalcium phosphate and β-tricalcium phosphate (β-TCP) together with 3–30 wt% β-dicalcium pyrophosphate. The material is configured to form a hardened monetite cement having a high monetite content, with monetite present at least 70 wt%.
The invention addresses monetite implant resorption and bone induction by incorporating β-dicalcium pyrophosphate into a monetite cement system. The described compositions are intended to slow implant resorption and/or improve in vivo bone induction compared with monetite-only formulations.
In vivo and in vitro behavior is described as dependent on the inclusion of β-dicalcium pyrophosphate. Example 1 reports very little resorption and new bone formation over time for a formulation containing dicalcium pyrophosphate/β-dicalcium pyrophosphate, while contrasting substantially complete resorption for a monetite-only formulation.
Claims Coverage
The partial set includes two independent claims. Independent claim 1 focuses on a hardened monetite cement composition defined by monetite and β-dicalcium pyrophosphate wt% amounts, while independent claim 21 focuses on a monetite-forming precursor powder composition defined by monocalcium phosphate, β-TCP, and β-dicalcium pyrophosphate amounts and their weight ratio constraint.
Hardened monetite cement with defined monetite and β-dicalcium pyrophosphate content
A hardened monetite cement comprising at least 70 wt% of monetite and from 3 to 30 wt% of β-dicalcium pyrophosphate.
Monetite-forming precursor powder with constrained monocalcium phosphate/β-TCP ratio and β-dicalcium pyrophosphate amount
A monetite-forming precursor powder comprising monocalcium phosphate, β-tricalcium phosphate (β-TCP), and from 3 to 30 wt% β-dicalcium pyrophosphate, wherein the weight ratio of monocalcium phosphate and β-TCP is in a range of 40:60 to 60:40.
Overall claim coverage is centered on monetite-based hardened cements and monetite-forming precursor powders where β-dicalcium pyrophosphate is present at 3–30 wt%. The claims also include a constrained monocalcium phosphate to β-TCP weight ratio range for the precursor powder.
Stated Advantages
Slow implant resorption, with very little resorption and new bone formation over time reported in vivo for the formulation containing dicalcium pyrophosphate/β-dicalcium pyrophosphate.
Improved bone induction outcomes are described via new bone formation over time in in vivo cranial defect trials for the β-dicalcium pyrophosphate-containing formulation.
Documented Applications
Bone repair implant use, including mosaic ceramic tiles on a titanium wire/mesh and hardened granules, for correction of cranial defects.
In vivo cranial defect trials with CT imaging and (18)F fluoride PET reporting new bone formation over time and differing resorption outcomes between formulations.
Interested in licensing this patent?