In the development of processes for plasmid concentration, viral vector and vaccine purification, the application of ultrafiltration technology is indispensable. Hollow fiber filters, with their simple structure, low shear stress, higher flux, suitable precision range, and smaller operational volume, exhibit strong scalability and are more suitable for the aforementioned applications. They can also serve as a robust complement and alternative to traditional TFF cassettes. In certain application cases, Cobetter's hollow fiber products have demonstrated stronger competitive advantages.

Hollow Fiber Model Recommendations in plasmid, viral and vaccine applications:
1. Plasmid/Viral Vector Concentration and Diafiltration: MWCO: 100 kDa, 300 kDa.
2. Multiple Virus Vaccine Concentration and Diafiltration: MWCO: 100 kDa, 300 kDa, 500 kDa, and 750 kDa.

Hollow Fiber Applications

Case 1: Application in Plasmid Concentration and Diafiltration

Cobetter-Minilab-30 hollow fiber filter (100kD-118cm², fiber I.D. 0.5mm) was used for concentration and diafiltration of clarified plasmid product (6kb), with a shear rate of 3000s^-1. Concentration step: Under the condition of TMP of 2.7psi, the stock solution was concentrated 3 times, with an average flux of 31.4 LMH; Diafiltration step: TMP is 2.3psi conditions, dialysis 7 times, the average flux is 34.8 LMH; after the filtration, using 0.5M NaOH wash the hollow fiber for 30mins, water flux recover to 89.29%.

Figure 1: Concentration step: Flux and TMP vs. Time

Figure 2: Diafiltration step: Flux and TMP vs. Time

By sampling and analyzing the permeation end, the permeation rate of the target plasmid was low, the superhelical structure of the upstream recovered plasmid remained intact, and the final product recovery rate was 103.01%. According to the data above, it is concluded that the hollow fiber filter can ensure the quality and product yield by controlling the lower shear rate and by controlling the shear rate and operating temperature as low as possible during the process of plasmid concentration.

Case 2: Application in Adeno-Associated Virus (AAV) Concentration and Diafiltration

Cobetter-Process-30 hollow fiber filter (100 kDa-2.45m², fiber ID 0.5mm) was used for the concentration and filtration of AAV2. The shear rate applied was 2000 s^-1. Concentration step: Under the condition of the TMP set at 4.85 psi, concentrate the virus solution 9.71 times with an average flux of 12.95 LMH. The final product recovery rate was above 90%.

Figure 3: Flux and TMP vs. Time

For shear-sensitive products like AAV, it is recommended to use hollow fiber membranes for ultrafiltration diafiltration, with shear rates controlled between 1000-3000 s^-1. For large-scale processing, a two-stage concentration may be conducted to meet titer requirements.

Case 3: Application in Viral Vaccine Concentration

Cobetter-Lab-3 hollow fiber membranes (500 kDa/750 kDa-236 cm², Fiber ID 0.5 mm) were used for the concentration and diafiltration of influenza virus. The shear rate applied was 6000 s^-1. Concentration step: Under the condition of the TMP set at 5-12 psi, concentrate the influenza virus 50 times with an average flux of 22 LMH. And diafiltration 10 times with an average flux of 24LMH.

Figure 4: 500K, 750K Hollow Fiber TMP and Flux vs. Time

Experimental results showed excellent impurity removal and virus recovery rates of over 70% after hollow fiber concentration and diafiltration.

Conclusion

Cobetter's hollow fiber filters have met expectations and actively respond to market demands. We welcome everyone to participate in evaluations. In the next release, we will continue to share more applications of Cobetter's hollow fiber products in other fields. Please stay tuned. For more technical inquiries and product needs, please feel free to contact support@cobetter.com.