Ultrafiltration and concentration used for separating insulin-like growth factor-1 from Cervi Cornu Pantotrichum / 中草药

ABSTRACT

Objective: To establish the ultrafiltration process of concentrating insulin-like growth factor-1 (IGF-1) from Cervi Cornu Pantotrichum (CCP). Methods: The ultrafiltration technique was utilized to concentrate the IGF-1 with CCP freeze-dried powder as raw material. The polyethersulfone (PES) membrane and modified PES membrane were compared and studied. The effects of relative molecular weight cutoff (RMWCO), pressure, and pH value on IGF-1 ultrafiltration process were investigated. Furthermore, the cleaning methods were investigated, and the optimal conditions were obtained. Results: The optimal conditions were as follows The RMWCO of PES membrane was 4 000, the RMWCO of modified PES membrane was 5000, the pressure was 0.3 MPa, and the pH value was 12. The recovery rate of IGF-1 and protein reached 68.32% and 69.20%, respectively by the PES membrane, while the recovery rate of IGF-1 and protein reached 57.17% and 87.43% respectively by the modified PES membrane. Four different methods were employed to clean the membrane. The results showed that the membrane immersed in 0.4% NaOH-0.1% NaClO solution for 24 h was the appropriate cleaning method, by which the PES membrane permeation flux recovery rate could reach 98.65% and the modified PES membrane permeation flux recovery rate could reach 93.75%. Conclusion: The IGF-1 could be easily concentrated and separated using the ultrafilter condensing technique. The process is easy and stable, and the membrane is easy to be cleaned and has high recovery rate, which has the high potential of industrial production and application.