In this article, mesoporous 58S and 58S bioactive glasses (BGs) were surface modified by dodecyl alcohol through esterification reaction and PDLLA/modified BGs composite films were prepared. The purpose of this study was to investigate the properties of the modified BGs particles and the PDLLA/modified BGs composite films before and after hydrolytic treatment. The modified BGs powders and composite films were treated in boiling water for 20 min to remove the dodecyl chains. After hydrolytic treatment, the modified BGs powders showed increased hydrophilicity and the FTIR analysis revealed that most dodecyl chains were removed. Furthermore, the hydrophilicity of the PDLLA/modified BGs composite films was also greatly improved. The tensile strength of the composite films after hydrolysis decreased slightly, but was still much higher than that of pure PDLLA film. In addition, bone marrow mesenchymal stem cells from dogs on the composite films after hydrolytic treatment showed the highest proliferation rate. The results suggest that hydrolytic treatment is an effective and practicable method to remove alcohol chains from surface-modified BGs and polymers/modified BG composites, which may be used for preparation of bioactive scaffolds for tissue engineering applications.