Oxygen permeability of biodegradable copolycaprolactones

Polycaprolactone is one of the biodegradable polymers with good drug permeability. In the present paper, polycaprolactone and three kinds of copolycaprolactone-polycaprolactone-poly(ethylene oxide)-polycaprolactone triblock copolymer (PCE), polycaprolactone/polycaprolactone-poly(ethylene oxide)/polylactide tricomponents random block copolymer (PCEL) and polycaprolactone/ poly(ethylene terephthalate) random block copolymer (PETCL)-were synthesized. The biodegradation behavior of these polymers were shown by degradation tests in vitro, ex vivo and in vivo. The oxygen permeabilities of these polymers were in the range of 10^-10 ∼ 10^-9 cm³ (STP) cm/cm² sec cm Hg. Copolymers PCE and PCEL displayed O₂ and N₂ permeability coefficients (PO₂/PN₂) ratios of about 9. The effects of composition and crystallinity of the copolymers on biodegradability and the oxygen permeability of the polymer were discussed.