Department of Life Sciences, University of Trieste, Trieste, Italy.
Biomacromolecules. 2012 Apr 9;13(4):1152-60. doi: 10.1021/bm300053d. Epub 2012 Mar 27.
The development of biomaterials endowed with bioactive features relies on a simultaneous insight into a proper terminal sterilization process. FDA recommendations on sterility of biomaterials are very strict: a sterility assurance level (SAL) of 10(-6) must be guaranteed for biomaterials to be used in human implants. In the present work, we have explored the potential of supercritical CO(2) (scCO(2)) in the presence of H(2)O(2) as a low-temperature sterilization process for thermoset materials and their bioactive surfaces. Different conditions allowing for terminal sterilization have been screened and a treatment time-amount of H(2)O(2) relationship proposed. The selected terminal sterilization conditions did not notably modify the mechanical properties of the thermoset nor of their fiber-reinforced composites. This was confirmed by μCT analyses performed prior to and after the treatment. On the contrary, terminal sterilization in the presence of H(2)O(2) induced a slight decrease in the surface hardness. The treatment of the thermoset material with scCO(2) led to a reduction in the residual unreacted monomers content, as determined by means of high performance liquid chromatography (HPLC) analyses. Finally, it was found that a thermoset coated with a polysaccharide layer containing silver nanoparticles maintained a very high antimicrobial efficacy even after the scCO(2)-based terminal sterilization.
生物材料的开发具有生物活性特征，这依赖于对适当的终端灭菌过程的同时洞察。FDA 对生物材料的无菌性的建议非常严格：生物材料要用于人体植入物，必须保证无菌保证水平（SAL）为 10(-6)。在目前的工作中，我们探索了超临界 CO(2)（scCO(2)）在 H(2)O(2)存在下作为热固性材料及其生物活性表面的低温灭菌过程的潜力。筛选了不同允许终端灭菌的条件，并提出了处理时间-双氧水用量关系。选择的终端灭菌条件不会显著改变热固性材料及其纤维增强复合材料的机械性能。这通过处理前后进行的 μCT 分析得到了证实。相反，在 H(2)O(2)存在下的终端灭菌会导致表面硬度略有下降。通过高效液相色谱（HPLC）分析，发现用 scCO(2)处理热固性材料会降低残留的未反应单体含量。最后，发现即使经过基于 scCO(2)的终端灭菌，涂有含有银纳米粒子的多糖层的热固性材料仍保持非常高的抗菌功效。
