TABLE 2.

Different types of polymeric valves.

Polymer	Properties	Disadvantage(s)	Performance	References
PU	Good viscoelasticity	Rapid hydrolysis	Calcium deposition and biodegradation hinders its performance	Simmons et al., 2004
PEU	Resistance to hydrolysis	Susceptibility to oxidation		Christenson et al., 2004
PCU	Resistance to oxidation and hydrolysis	Susceptibility to calcification		Tang et al., 2001
PTFE	Good hemodynamics	Possible occurrence of thromboembolism, low resistance and high calcification and stiffening	Major complications	Nistal et al., 1990
Silicone	Good flexibility and biocompatibility	Low durability, distorted and thickened leaflets, tearing, thrombosis formation	Structural failure and impaired hemodynamic performance	Kiraly et al., 1982
PVA	Proper mechanical features	Not appropriate for dip-casting	Low elasticity	Jiang et al., 2004
PS-PIB-PS	High resistance to hydrolysis and oxidation	Platelet activation and thrombogenicity	Proper bio-stability	Gallocher et al., 2006
PDMS–PHMO PU	Proper mechanical properties; proper resistance to calcification and oxidation	Difficult processing	Proper bio-stability	Dabagh et al., 2005
POSS–PCU Nanocomposite	Proper resistance to oxidation, hydrolysis and calcification; high biocompatibility; anti-thrombogenicity		High bio-stability	Kannan et al., 2005

PU, Polyurethane; PEU, polyether urethane; PCU, polycarbonate-urethane; PTEE, polytetrafluoroethylene; PVA, polyvinyl alcohol; PS-PIB-PS, poly (styrene–b–isobutylene–b–styrene); PDMS–PHMO PU, poly (dimethylsiloxane)/poly (hexamethylene oxide)-based polyurethane; POSS–PCU, polyhedral oligomeric silsesquioxane poly (carbonate-urea) urethane.