There is an increasing interest on new sterilization techniques for biological materials, for instance, due to the extension of collagen scaffold usage for reconstructing various tissues such as cartilages. Preservation of the collagen scaffold structures is important with respect to its biocompatibility and stability. The latter is prerequisite for an enhanced reconstruction of injured tissues. Thus, some standard sterilization methods using heat or steam are unfavourable, because they cause instability of the collagen scaffold as a result of thermal denaturation, thermal annealing and/or moisture treatment. Moisturizing the scaffold degrades the 3D structure due to swelling of the collagen matrix and further decreases the thermal stability.
The established sterilization methods utilize gamma rays , X-rays, or electron-beam, which need an ambitious technical equipment. Thus, they are inflexible and expensive. Moreover, they have a destructive effect on the molecular structure of collagen. Methods utilizing ethylene oxide as reagent are disadvantageous too, due to its toxicity and the effort to detoxify the sterilized material . Surprisingly, there are just few reports on studies utilizing gas-plasma sterilization techniques for biomaterials. Thus, we present a new sterilization method for collagen utilizing hydrogen peroxide as reactive reagent. This method bypasses the drawbacks of other sterilization methods, and it represents a simple and efficient sterilization technique. The properties of the collagen scaffolds and its structural modification were investigated with regard to the variation of hydrogen peroxide concentrations, the duration of exposure to hydrogen peroxide and plasma treatment. The figure shows that H2O2-Plasma does not lead to marked degradation, while gamma-rays markedly affect the collagen structure. Furthermore, we investigated the change in the mechanical properties by AFM. The results show no changes. Therefore, the modified low temperature sterilization method based on H2O2 gas plasma is a promising method for thermal sensitive biomaterials.