Preparation of Nano-Sized Particles of Collagen II by an Electrostatic Field System

This study described a novel method for preparing nano-sized particles of collagen II by using a high voltage electrostatic field system. The preliminary results showed that the collagen II particles exhibited good sphericity and the particles diameters increased after longer electric field treatment. They were in the range of 208 plusmn 27, 277 plusmn 26 and 467 plusmn 35 nm in diameter at the treatment of 3 kV/cm for 1, 3, and 5 hours respectively at 25degC (collagen concentration was 0.2 mg/ml). Moreover, the particles size increased to 1621 plusmn 49 nm in diameter when the concentration of collagen II was increased from 0.2 mg/ml to 0.5 mg/ml. However, the collagen II was hard to form a nano-particle shape under 30degC at 0.2 mg/ml and 0.5 mg/ml concentration of collagen II. When the temperature increased to 37degC, the collagen II was unable to produce particle, instead, fibrous structures were formed under this temperature setting. This result probably contributed by a entropy driven process which termed fibrillogenesis, a larger force to yield the collagen molecules to self-assemble and then formed collagen fibrils. Incidentally, smoother outer surface of nano-particle was observed after 5-hour treatment (collagen concentration was 0.2mg/ml at 25degC). The most important finding was that, no collagen II nano-particles were produced without the treatment of electrostatic field, no matter at either collagen concentration or temperature settings.