Influence of the porous morphology on the in vitro degradation and mechanical properties of poly(L-lactide) disks

Poly(L-lactide) (PLLA) materials having an interconnected porosity are proposed as an alternative to nonporous biornaterials. Such materials allow for the potential of modulating the degradation behavior and the mechanical properties. In this article, the preparation of porous PLLA disks or cylinders with 50 and 65% void volume is presented. It is demonstrated that both a symmetric and asymmetric porosity can be generated within the disk itself. In addition, open- and closed-cell structures can also be prepared. The accelerated hi vitro degradation on symmetric open-cell porous PLLA disks and on the nonporous control indicate a similar behavior in terms of melting temperature and inherent viscosity of the remaining pieces of the specimens, but the crystallinity and the mass of the remaining fragments are much smaller for the porous specimens. The mechanical properties under compression are determined for open and closed-cell porous cylinders, porous tubes, and for the nonporous PLLA. The results highlight the excellent mechanical integrity of the prepared porous structures and demonstrate that such materials could have potential for use as biomedical implants. (c) 2006 Wiley Periodicals, Inc.