EPR Diagnostics of D,L-Polylactide Porous Matrices Formed in Supercritical CO 2

The regularities of formation of D,L-polylactide porous matrices in supercritical CO 2 environment with simultaneous impregnation with paramagnetic biologically active 4-hydroxy-2,2,6,6-tetramethylpiperidine- 1-oxyl (TEMPOL) was studied using spin probe electron paramagnetic resonance (EPR) and optical microscopy. The dependence of the average and local concentration of a dopant on impregnation conditions was assessed. The resulting matrices meet important requirements for porous materials for tissue engineering. Considering that impregnation of a polymer with a paramagnetic compound makes it possible to study the uniform distribution of a dopant in a sample at macroscopic and microscopic levels and to study a structure of a polymer matrix, EPR spectroscopy is a promising method for studying porous polymeric materials formed under supercritical conditions.