In situ pore formation in a polymer matrix by differential polymer degradation

A new approach for the in situ formation of porosity in a matrix based on differential polymer degradation has been studied. This approach exploits the differences in polymer properties such as molecular weight, hydrophilicity (hydrophobicity), and degradation to induce preferential degradation of one phase in a biphasic polymer system. Biphasic polymer systems polymers derived from alpha-hydroxy acids and poly(anhydrides), which vary in their erosion characteristics (surface vs. bulk) and hydrophobicities were studied. In addition to examining the generality of the approach, potential advantages of such systems in the context of tissue engineering and drug delivery are briefly discussed.