BONE SUBSTITUTE AND INDEPENDENT INJECTION SYSTEM

Abstract

The invention relates to the field of bioresorbable or non-bioresorbable bone substitutes to be implanted in humans in order to reconstitute the bone supply by replacing lost bone substance. More particularly, the invention concerns a device that is simple to manufacture and use and comprises a syringe provided with a single-use dose of a polymer which is fluid at the injection temperature while being solid and durable at body temperature.

Claims

1. Device comprising: a syringe prefilled with a single-use dose of a composition for bone filling, said composition comprising at least one resorbable or non-resorbable thermoplastic polymer material, said composition having a viscosity between 40 and 4000 Pa.Math.s at a temperature of about 50 C. and a Young's modulus between 0.5 and 4 GPa at about 37 C., said syringe enabling both the storage and administration of said composition, said syringe comprising a syringe body having an opening at each of its two ends, the distal first opening bearing sealing means for sealing it closed and/or means for the administration of said composition, the proximal second opening being sealed closed by sealing means slidable inside the syringe body, said syringe body, said sealing and/or administration means, and said slidable sealing means defining a volume within which said dose is contained; an external heating means structurally separate from the syringe and making it possible to heat it and melt or soften the dose of the composition for bone filling for the purposes of its administration.

2. Device according to claim 1, wherein the syringe body is made of metal.

3. Device according to claim 1, wherein the volume of the single-use dose of the composition stored in the syringe is between 1 and 50 ml.

4. Device according to claim 1, wherein the means for administration of the composition are joined to the end of the syringe body and comprise a cannula the diameter of which is between 8 gauge and 15 gauge.

5. Device according to claim 1, wherein the thermoplastic polymer material is a resorbable polymer and is selected from the group consisting of poly(lactic-co-glycolic acid), polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, poly(glycerol sebacate), poly(dioxanone), alone or in admixture.

6. Device according to claim 1, wherein the thermoplastic polymer material is a non-resorbable polymer and is selected from the group consisting of polymers and copolymers of acrylates and methacrylate, polyurethane, polyethylene, alone or in admixture.

7. Device according to claim 1, wherein the thermoplastic polymeric material is a polycaprolactone having a molecular weight between 30,000 and 60,000.

8. Device according to claim 1, wherein the composition further comprises an inorganic material.

9. Device according to claim 8, wherein the calcium phosphate biomaterial is a calcium phosphate bioceramic.

10. Device according to claim 9, wherein the bioceramic comprises or consists of one or more sintered calcium phosphate compounds selected from the group consisting of hydroxyapatite (HA), alpha- and beta-tricalcium phosphate (-TCP, -TCP), and biphasic calcium phosphate material (BCP), alone or in admixture.

11. Device according to claim 1, wherein the weight ratio of polymer/inorganic material of the composition is between 100/0 and 40/60.

12. Device according to claim 1, wherein the composition is in the form of a rod or pellets and comprises by weight 40 to 100% of a polycaprolactone polymer having a molecular weight between 30,000 and 60,000, 0 to 60% of a calcium phosphate biomaterial.

13. Device according to claim 1, wherein an insulating sheath completely or partially surrounding the syringe and the composition administration and/or sealing means is arranged on the syringe body.

14. Device according to claim 1, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

15. Device according to claim 2, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

16. Device according to claim 3, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

17. Device according to claim 4, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

18. Device according to claim 5, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

19. Device according to claim 6, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

20. Device according to claim 7, wherein the heating means comprises an oven suitable for regulating the temperature of said device, said oven in the form of a heating cylinder having a diameter substantially equal to but slightly greater than that of the syringe in order to allow insertion of the syringe into the body of the oven and having a length substantially equal to or slightly greater than the length overall of the device.

Description

EXAMPLE 1

Measurement of Rheological Properties

[0130] The used equipment consists of: [0131] MCR51 rheometer [0132] 3-EC-02 climate chamber (SLH 100Secasi) [0133] RheoPlus software

[0134] The tests for measuring the viscosity of the polycaprolactone polymer are carried out using an Anton Paar MCR51 rheometer/viscometer in dynamic shear mode (1 Hz). This apparatus makes it possible to record the evolution of the complex viscosity over time and at a constant temperature. In order to approximate the actual usage conditions of the heating injector, the polymer is melted at 90 C. in the apparatus and then a temperature setpointwas fixed (temperature at which the material will reach the bone site to be filled). The measurement acquisition is begun when the desired temperature (50 C.) of the support is stable.

EXAMPLE 2

[0135] Composition of PCL+strontium-containing calcium phosphate

[0136] PCL with molecular weight Mn=30,000 g/mol -TCP strontium

[0137] Ratio PCL/calcium phosphate agent

[0138] PCL/-TCP (Sr)=70/30

[0139] Particle size of calcium phosphate agent

[0140] B-TCP(Sr)=30 m

[0141] Injection device/syringe

[0142] Injection device according to the invention with a metal cartridge filled with a rod of PCL/TCP(Sr) connected to an 11 gauge cannula insertable into a 10 gauge trocar. The device was heated in a temperature-regulated heating chamber at 90 C. before its transfer for injection into the vertebra.