Cylinder-piston system for use in an injection syringe, comprising a. a cylinder, where at least one internal section of the internal surface of the cylinder is formed from a first polymeric material (C), b. a piston (1), comprising at least one sealing section on the outer surface (14) of the piston (1), which is formed from a second polymeric material (P), wherein c. the cylinder and the piston (1) are located or can be located in such a way that during a sliding movement of the piston (1) with respect to the cylinder, the internal section of the cylinder and the sealing section of the piston (1) slide between yes, wherein one of said polymeric materials, particularly the first polymeric material (C), comprises Polyethylene Terephthalate (PET) as the polar polymeric material, particularly is selected from Polyethylene Terephthalate, and the other polymeric material, particularly the second polymeric material (P), it comprises a thermoplastic elastomer (TPE) as a non-polar polymeric material, in particular it is selected from a thermoplastic elastomer (TPE), characterized in that the first polymeric material (C) comprises a super amorphous structure with a degree of crystallization of less than 3% .Sistema cilindro-pistón para su uso en una jeringa de inyección, que comprende a. un cilindro, en donde al menos una sección interna de la superficie interna del cilindro se forma a partir de un primer material polimérico (C), b. un pistón (1), que comprende al menos una sección de sellado en la superficie exterior (14) del pistón (1), que se forma a partir de un segundo material polimérico (P), en donde c. el cilindro y el pistón (1) están ubicados o se pueden ubicar de tal manera que durante un movimiento deslizante del pistón (1) con respecto al cilindro, la sección interna del cilindro y la sección de sellado del pistón (1) se deslizan entre sí, en donde uno de dichos materiales poliméricos, particularmente el primer material polimérico (C), comprende Polietilenteref
