Preparation of nano-sized particles from collagen II by a high-voltage electrostatic field system

The pilot study describes a novel method for preparing nano-sized particles from collagen II using a high-voltage electrostatic field system. Observations from transmission electron microscopy showed that, in one of the cases, the nano-sized collagen II particles exhibited good sphericity, and the particles were in the range of 23.3±1.7 nm in diameter at the experimental setting of 3 kV cm^-1, for a 3 h treatment period and at 25°C (with a collagen concentration of 0.2 mg ml^-1). When the treatment temperature increased to 30°C, the collagen II began to lose the tendency to form individually separated spherically shaped nano-particles. Moreover, a fibrous structure of collagen II was formed instead of a nano-particle shape at the temperature of 37°C. This result is probably contributed to by an entropy-driven process that is termed fibrillogenesis, a larger force causing the collagen molecules to self-assemble and then form collagen fibrils. It is interesting to note that this is practically the first attempt to produce nano-particles directly from collagen II solution under the treatment of a high-voltage electrostatic field, together with a set of working parameters for the collagen concentration and low-temperature setting.