Creation of Porous Fibers that Adsorb Pathogenic Substances of Intractable Diseases

Toray Industries, Inc. (Headquarters: Chuo-ku, Tokyo; President: Mitsuo Ohya; hereinafter "Toray") has developed a technology (hereinafter "this technology") that allows arbitrary control of the pore diameter of polymethyl methacrylate (PMMA) porous fibers within a wide range from several nanometers to approximately 1,000 nm. This led to the creation of porous fibers capable of selectively adsorbing pathogenic substances of intractable diseases. This technology contributes to proposing new blood purification therapy options that can replace or synergistically enhance conventional treatments for intractable diseases such as autoimmune diseases, cardiovascular metabolic diseases, neurodegenerative diseases, and cancer.

With the aging population and diversification of lifestyles, the number of patients with intractable diseases such as autoimmune diseases, cardiovascular metabolic diseases, neurodegenerative diseases, and cancer is increasing year by year. In many cases, conventional treatments like drug therapy and surgery for these diseases do not yield sufficient effects, or they pose challenges such as side effects and recurrence risks. Amidst this, there is a growing demand for technologies capable of efficiently removing high-molecular-weight pathogenic substances in the blood, typified by autoantibodies, lipoproteins, and exosomes.

PMMA is a material with excellent biocompatibility and moderate protein adsorption properties, and Toray is the only company in the industry to commercialize PMMA porous fibers. Specifically, they are manufactured and sold as artificial kidneys and adsorption-type blood purifiers, with a track record of approximately 50 years in blood purification therapy applications.

Toray utilized a combination of advanced analytical techniques, such as small-angle X-ray scattering, and digital technologies, such as phase separation simulations, to analyze the nano-level phase separation behavior during the spinning process of PMMA porous fibers in real time. This led to the development of a pore diameter control technology capable of regulating pore sizes up to approximately 1,000 nm, which is more than 50 times larger than conventional methods. Generally, increasing pore diameter can lead to a sparse fiber structure and reduced strength; however, this technology achieves both large pore diameters and high strength. The application of this technology makes it possible to selectively adsorb and remove high-molecular-weight pathogenic substances that could not previously be captured within the pores.

Moving forward, Toray aims for early practical application by advancing the design of pore diameters suitable for each disease and developing mass production technology for the treatment of intractable diseases such as autoimmune diseases, cardiovascular metabolic diseases, neurodegenerative diseases, and cancer. Furthermore, this technology can also be expanded beyond medical devices; for example, its application in biopharmaceutical manufacturing is also being promoted.