Hydrogels based on @entity968 and @entity72662 or XXXX . III. In vivo biocompatibility and biostability.

@entity968 @entity72662 @entity72663 @entity16549 @entity13768 @entity35 @entity2636 @entity970 @entity616
To investigate the effects of polymer chemistry and topology (linear or graft copolymer) on in vivo biocompatibility and biostability based on cage implant system, various hydrogels, composed of short hydrophilic [ @entity968 ( @entity970 )] and @entity616 , were prepared by polycondensation reaction. @entity72662 ( @entity72663 ) or @entity13768 ( @entity16549 ) was chosen as a @entity616 because of their wide utilization as a biomaterial. By using the specimens retrieved from @entity35 killed after 1, 2, 3, 5, and 7 weeks' implantation, cellular and material responses were assessed. Most hydrogels showed a comparable value of macrophage density to @entity2636 (R), control polymer, whereas they did significantly lower foreign body giant cell (FBGC) density and coverage because of the presence of @entity970 . However, @entity970 block length and polymer topology did not affect macrophage adhesion and FBGC formation in our polymer composition. The hydrogel based on @entity16549 alone showed significantly lower macrophage density and FBGC density than @entity2636 (R), indicating that @entity16549 plays a role in inhibiting cellular adhesion. The results obtained from gel permeation chromatography curve and Fourier transform infrared spectra exhibited that all the polymers were susceptible to oxidative degradation in vivo. Although @entity2636 (R) revealed surface degradation by 5 weeks in vivo, hydrogels showed rapid degradation in the bulk within 2 weeks because of the penetration of oxidative chemicals released from phagocytic cells into @entity970 domain of phase-separated hydrogels. The more significant degradation was observed in the hydrogels with longer @entity970 block and PTMO as a @entity616 instead of @entity16549 . It was evident that the minor degradation could be achieved by grafting @entity970 and adopting @entity16549 as a @entity616 in the hydrogel.
