Methods of orienting multifilament yarn and monofilaments of poly-4-hydroxybutyrate and copolymers thereof

摘要

Resorbable multifilament yarns and monofilament fibers including poly-4-hydroxybutyrate and copolymers thereof with high tenacity or high tensile strength have been developed. The yarns and fibers are produced by cold drawing the multifilament yarns and monofilament fibers before hot drawing the yarns and fibers under tension at temperatures above the melt temperature of the polymer or copolymer. These yarns and fibers have prolonged strength retention in vivo making them suitable for soft tissue repairs where high strength and strength retention is required. The multifilament yarns have tenacities higher than 8.1 grams per denier, and in vivo, retain at least 65% of their initial strength at 2 weeks. The monofilament fibers retain at least 50% of their initial strength at 4 weeks in vivo. The monofilament fibers have tensile strengths higher than 500 MPa. These yarns and fibers may be used to make various medical devices for various applications.

主权项

1. A multifilament yarn or monofilament fiber comprising a 4-hydroxybutyrate polymer or copolymer wherein the yarn has one or more properties selected from the group consisting of: a tenacity greater than 8.1 grams per denier but less than 12 grams per denier; an elongation to break of between 10% to 30%; and a denier per filament between 1.7 and 9.0, and wherein the monofilament fiber has one or more properties selected from the group consisting of: a tensile strength between 500 MPa and 1,500 MPa; a Young's Modulus of less than 2 GPa and an elongation to break of 15% to 120%,
wherein the multifilament yarn or monofilament fiber is produced by a method comprising (a) spinning a multifilament yarn or monofilament fiber comprising a 4-hydroxybutyrate polymer or copolymer, and (b) cold drawing the multifilament yarn or monofilament fiber, wherein the multifilament yarn or monofilament fiber is hot drawn after cold drawing at a temperature above the melt temperature of the polymer or copolymer, wherein the monofilament fiber is cold drawn with an orientation ratio of 3 to 4, and then hot drawn in one or more subsequent draws; or, wherein the multifilament yarn or monofilament fiber is produced by a method comprising: (a) producing the polymer with a recombinant E. coli cell culture, (b) extracting and purifying the polymer from the biomass, (c) spinning the multifilament yarn or monofilament fiber from the polymer, (d) cold drawing the multifilament yarn or monofilament fiber, (e) hot drawing the multifilament yarn or monofilament fiber after cold drawing at a temperature above the melt temperature of the polymer or copolymer, and (f) optionally relaxing and/or annealing the multifilament yarn or monofilament fiber, wherein the multifilament yarn or monofilament fiber is biocompatible.