University of Texas-Pan American Dr. Javier Macossay-Torres (Edinburg, TX) discovered that certain synthetic polymers can be formed into nanofibers and assembled into specific structures that may possess mechanical properties similar to natural ligaments and tendons. These polymers may be formed into nanofibers with particular secondary structural features that mimic structural features of natural ligaments and tendons, allowing for production of novel artificial ligaments and tendons.
According to U.S. Patent Application 20090306775, the prosthetic ligament or tendon is comprised of: a sterile, biocompatible multifilament ligament- or tendon-mimicking (LTM) nanofibers with a secondary structure. The multifilament exhibits one or more properties selected from the group consisting of: (a) a Young modulus of about 0.1-3000 MPa; (b) a tensile strength value of about 10-100 MPa; (c) a cross-sectional area of about 1-150 mm.sup.2; (d) a stiffness of about 50-1000 N/mm; and(e) an ultimate tensile load of about 1000-6000 N.
Macossay-Torres' invention generally involves the production of ligament- or tendon-mimicking nanofibers ("LTM nanofibers") that may be used as artificial (prosthetic) ligaments or tendons. The production and use of LTM nanofibers may be manufactured from carbon nanoparticles, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene, graphene oxide, and/or other graphene derivatives. The LTM nanofibers may be designed to exhibit secondary structural features that offer improved biocompatibility and mechanical characteristics over nanofibers and other materials that lack such secondary structure features.
A non-limiting example of a class of LTM nanofibers is polyurethanes (that is, a polyurethane nanofiber). Non-limiting examples of polyurethanes include Lycra®, Hydrothane®, Elasthane® and Biospan®. Other examples of classes of polymer nanofibers include poly(ether urethanes), poly(ester urethanes), poly(carbonate urethanes), silicone containing poly(ether urethanes), silicone containing poly(ester urethanes), silicone containing poly (carbonate urethanes), polyureas (and derivatives), and blends thereof.
Ligaments and tendons are bands or sheets of fibrous connective tissue that provide support and stability to the musculoskeletal system. Ligaments extend between adjacent bone structures and serve a primary function of providing appropriate stability to the bone structures to maintain them in an aligned, spaced relation, particularly when subjected to loads in tension or upon torsional movement. Tendons, also capable of withstanding tension, are tough bands of fibrous connective tissue that usually connect muscle to bone
Figures 12a, 12b and 12c show artificial ligaments (300) made by Dr. Macossay-Torres compared with a dime (304) in size as well as their ability to flex and straighten.
A non-limiting example of a class of LTM nanofibers is polyurethanes (that is, a polyurethane nanofiber). Non-limiting examples of polyurethanes include Lycra®, Hydrothane®, Elasthane® and Biospan®. Other examples of classes of polymer nanofibers include poly(ether urethanes), poly(ester urethanes), poly(carbonate urethanes), silicone containing poly(ether urethanes), silicone containing poly(ester urethanes), silicone containing poly (carbonate urethanes), polyureas (and derivatives), and blends thereof.
Ligaments and tendons are bands or sheets of fibrous connective tissue that provide support and stability to the musculoskeletal system. Ligaments extend between adjacent bone structures and serve a primary function of providing appropriate stability to the bone structures to maintain them in an aligned, spaced relation, particularly when subjected to loads in tension or upon torsional movement. Tendons, also capable of withstanding tension, are tough bands of fibrous connective tissue that usually connect muscle to bone
Figures 12a, 12b and 12c show artificial ligaments (300) made by Dr. Macossay-Torres compared with a dime (304) in size as well as their ability to flex and straighten.
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