With the rapid development of biomedical technology, Collagen—a natural biopolymer, has become a critical material in the biomedical industry. This article explores the molecular structure, physical and chemical properties, and applications of collagen. It also highlights strategies for removing viral threats during the collagen purification process using Cobetter products.

1. Natural Collagen

Collagen is a helical protein composed of three intertwined polypeptide chains. This structure not only provides skin with elasticity and luster, but also serves as an important component in maintaining the structure and function of various organs in human body. 

Owe to its stable physical and chemical properties and excellent biocompatibility, collagen is widely used in the production of artificial skin and vascular stents in biomedical applications. Additionally, its low immunogenicity and biodegradability make it an ideal carrier for drug delivery systems.

2. Recombinant Collagen (rCol)

With the development of genetic engineering technology, recombinant collagen (rCol) has become the preferred method of collagen production. Collagen genes are typically introduced into host cells by constructing expression vectors, followed by using the cellular expression system to produce large quantities of recombinant collagen. This approach not only enables large-scale industrial production but also reduces immunogenicity.

The purification process is critical during production. To obtain high-purity collagen with minimal virus risk, a series of purification steps are involved to separate collagen from the culture medium, these steps include filtration, chromatography, and dialysis, etc.

3. Virus Filtration Strategy

Ensuring safety is crucial for collagen products used in medical applications. During the manufacturing process, effectively removing potential viral contamination is essential to ensuring the safety of collagen products.

Here are some common virus removal strategies:

1. Virus Inactivation

Inactivate viruses by heat treatment, ultraviolet irradiation, chemical reagent treatment, etc. These methods are simple and easy, but they may have a certain impact on the activity of collagen.

2. Chromatography

Virus separation is achieved based on the differences in adsorption and elution properties between viruses and collagen on the chromatography medium. This method has high requirements for equipment and operation but can achieve a higher virus removal LRV.

3. Nanofiltration

Use nano-scale filters to remove virus particles. This method has minimal impact on collagen activity and provides sufficient and robust viral clearance.

The choice of virus removal strategy depends on the specific application and purification requirements of the collagen product. For collagen products that need to maintain high activity, nanofiltration or chromatography is preferred. For products with low activity demands, virus inactivation methods can be used.

4. Collagen Virus Filtration Case Studies

Using injectable human recombinant collagen as an example, CHO cells are generally used as the expression system. The virus removal filtration is performed after multiple purification steps.

Case Study 1: A recombinant Collagen Fragment

Filter Combination: PNY + VF Plus X
Protein information: MW <200 KD, 0.1~0.5g/L

Constant pressure: 30 psi

Outcome: The filtration process achieves a volumetric throughput of approximately 350L/m2 in 75 minutes, with flux decline controlled within 50%. The protein recovery rate also meets customer requirements.

Case 2: Human Recombinant Collagen

Filter Combination: PNY + RC H
Protein information: MW 300KD, 0.5g/L
Constant pressure: 30 psi

Outcome: The filtration process achieves a volumetric throughput of approximately 200L/m2 in 225 minutes, with flux decline controlled within 60%. The protein recovery rate also meets customer requirements.

Summary:

Based on Cobetter’s extensive experience with virus filtration cases. 

• For collagen with low concentration and molecular weight under 200 KD, the PNY series nylon pre-filters combined with PES virus removal filter Viruclear VF Plus X are recommended.
• For collagen with molecular weight more than 200KD and high concentration, the RC membrane virus removal filter Viruclear RC H are recommended.

Collagen, as a significant biomaterial, holds vast potential for applications in the medical field. By integrating advanced production technologies and stringent purification processes, we can ensure the purity and viral safety of collagen products. Cobetter's currently developed and marketed series of virus removal products are available for your selection during the research, development, and production processes of collagen products.