Implantable medical device with thermoplastic composite body and method for forming thermoplastic composite body
Inventors
Snell, Douglas • Ball, Robert • Roeder, Ryan K.
Assignees
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Publication Number
US-11607476-B2
Publication Date
2023-03-21
Expiration Date
Abstract
An implantable medical device is disclosed comprising a thermoplastic composite body having anterior, first lateral, second lateral, posterior, superior, and inferior surfaces, and at least one dense portion and at least one porous portion which are integrally formed. The at least one dense portion is formed of a first thermoplastic polymer matrix that is essentially non-porous, and which is continuous through a thickness dimension from the superior surface to the inferior surface. The at least one porous portion is formed of a porous thermoplastic polymer scaffold having a second thermoplastic polymer matrix which is continuous through the thickness dimension. A method for forming the thermoplastic composite body is disclosed comprising disposing a first powder mixture in a first portion of a mold, disposing a second powder mixture in a second portion of the mold, simultaneously molding the first powder mixture and the second powder mixture, and leaching porogen.
Core Innovation
The invention relates to an implantable medical device comprising a thermoplastic composite body with an anterior surface, first and second lateral surfaces, a posterior surface, a superior surface, and an inferior surface. The thermoplastic composite body includes at least one dense portion formed of a first thermoplastic polymer matrix that is essentially non-porous and continuous through a thickness dimension from the superior surface to the inferior surface, and at least one porous portion formed of a porous thermoplastic polymer scaffold formed of a second thermoplastic polymer matrix, continuous through the thickness dimension from the superior surface to the inferior surface.
The dense portion and the porous portion are integrally formed so that the thermoplastic composite body is a single continuous article free of adhesive and mechanical joints between the at least one dense portion and the at least one porous portion. The thermoplastic composite body includes a superior-inferior axial stiffness relative to compression of less than 40 kN/mm.
A method is also described for forming the thermoplastic composite body by disposing a first powder mixture in a first portion of a mold and a second powder mixture in a second portion of the mold, followed by compacting each mixture to densify at respective pressures. The method includes simultaneously molding the first powder mixture and the second powder mixture at a molding temperature above room temperature and at a final molding pressure to form at least one dense portion from the first powder mixture and at least one proto-porous portion from the second powder mixture.
The method then leaches the porogen material from the proto-porous portion, forming at least one porous portion having a porous thermoplastic polymer scaffold continuous from the proto-porous portion and integrally forming the dense and porous portions as a single continuous article free of adhesive and mechanical joints, with the thermoplastic composite body including the superior-inferior axial stiffness relative to compression of less than 40 kN/mm.
Claims Coverage
The document provides two independent device claims and one independent method claim. Across the independent claims, the inventive concepts focus on integrally forming a single continuous thermoplastic composite article with essentially non-porous dense regions and porous thermoplastic polymer scaffold regions continuous through thickness, together with a quantitative superior-inferior axial stiffness relative to compression requirement and, in the method, a powder-molding plus porogen-leaching formation sequence.
Integrally formed dense-and-porous thermoplastic composite scaffold
An implantable medical device with a thermoplastic composite body that includes at least one dense portion formed of a first thermoplastic polymer matrix that is essentially non-porous and continuous through a thickness dimension from the superior surface to the inferior surface, and at least one porous portion formed of a porous thermoplastic polymer scaffold formed of a second thermoplastic polymer matrix and continuous through the thickness dimension from the superior surface to the inferior surface.
Single continuous article free of adhesive and mechanical joints
The at least one dense portion and the at least one porous portion are integrally formed such that the thermoplastic composite body is a single continuous article free of adhesive and mechanical joints between the at least one dense portion and the at least one porous portion.
Superior-inferior axial stiffness relative to compression less than 40 kN/mm
The thermoplastic composite body includes a superior-inferior axial stiffness relative to compression of less than 40 kN/mm.
Central through cavity with porous outer wall and dense core geometry
An implantable medical device where a thermoplastic composite body includes at least one central through cavity extending from the superior surface to the inferior surface and disposed inward from the anterior surface, first lateral surface, second lateral surface, and posterior surface, where the at least one porous portion includes at least one porous outer wall disposed along the anterior surface, first lateral surface, and second lateral surface, and includes at least one porous central portion defining an outer boundary of the at least one central through cavity, and where the at least one dense portion includes at least one dense core disposed between the at least one porous central portion and the at least one porous outer wall and extending to the posterior surface to form a dense posterior edge.
Reinforcement material dispersed throughout dense and porous portions
An implantable medical device where at least one reinforcement material is dispersed throughout the at least one dense portion and the at least one porous portion.
Simultaneous molding of separate powder mixtures and porogen leaching to form continuous scaffold
A method for forming a thermoplastic composite body by disposing a first powder mixture in a first portion of a mold and a second powder mixture in a second portion of a mold, compacting each mixture to densify at respective pressures, simultaneously molding the first and second powder mixtures at a molding temperature above room temperature and at a final molding pressure to form at least one dense portion and at least one proto-porous portion, and leaching the porogen material from the proto-porous portion to form at least one porous portion having a porous thermoplastic polymer scaffold continuous from the proto-porous portion.
Integrally formed single continuous article during simultaneous molding and leaching
The simultaneous molding and the leaching integrally form the at least one dense portion and the at least one porous portion as a single continuous article free of adhesive and mechanical joints between the at least one dense portion and the at least one porous portion.
Overall, the independent claims collectively cover an implantable thermoplastic composite body with dense essentially non-porous and porous scaffold portions continuous through thickness and integrally formed as a single continuous joint-free article, and they require a superior-inferior axial stiffness relative to compression of less than 40 kN/mm; one independent claim further specifies a central through cavity with porous outer wall/porous central portion and a dense core forming a dense posterior edge, and the method claim covers simultaneous molding of separate powder mixtures followed by porogen leaching to integrally form the dense and porous portions.
Stated Advantages
Provides a single continuous article free of adhesive and mechanical joints between the dense portion and the porous portion.
Achieves a superior-inferior axial stiffness relative to compression of less than 40 kN/mm.
Documented Applications
No documented applications found
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