Sterilizing Injectable Collagen via Freezing and Radiation
Solution Overview
Problem
Current methods for sterilizing injectable collagen materials are ineffective in reducing biological contaminants without damaging the material, particularly due to radiation-induced alterations in protein structure and difficulty in achieving a sterility assurance level of 10−6.
Innovation Solution
The method involves freezing the collagen material below 0°C and irradiating it with a controlled dose of radiation between 5 kGy and 8 kGy to sterilize it without significantly affecting its properties, using cryoprotectants like mannitol or hyaluronic acid for protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiation sterilization is applied to injectable collagen materials, then sterility assurance level is improved, but the collagen material structure is damaged
Solution Approach 1:
The collagen material is frozen before radiation sterilization to protect its structure. This preliminary action of freezing creates a protective state that prevents radiation-induced damage while allowing the sterilization process to proceed effectively, achieving both sterility and structural preservation
Solution Approach 2:
The physical state of the collagen material is changed from liquid to frozen state before radiation exposure. This parameter change (temperature state) fundamentally alters how the material responds to radiation, enabling sterilization without the structural damage that would occur in the liquid state
2Reliability
If conventional sterilization methods are used, then biological contaminants are reduced, but the chemical, physical or physiological properties of the collagen are altered
Solution Approach 1:
Changing the temperature parameter to frozen state before radiation exposure fundamentally alters the material's response to sterilization. This parameter change enables effective contaminant reduction while preserving the collagen's chemical, physical, and physiological properties that would otherwise be altered by conventional sterilization methods
3Reliability
If filtration sterilization is used to achieve sterility assurance level of 10−6, then sterility is improved, but the process complexity increases
Solution Approach 1:
The invention utilizes the phase transition of freezing the collagen material as a protective measure during radiation sterilization. This phase transition approach achieves the high sterility assurance level of 10−6 through a relatively simple two-step process (freeze then irradiate) compared to complex multi-stage filtration systems
Solution Approach 2:
The invention replaces complex mechanical filtration systems with a combination of freezing and radiation. This substitution achieves equivalent or superior sterility assurance while simplifying the overall process, eliminating the need for complex filtration equipment and multiple processing stages
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces biological contaminants to a sterility assurance level of 10−6 while preserving the collagen material's properties, as demonstrated by SDS-PAGE and DSC analysis, with minimal degradation (<15%) and maintaining the material's fluidity and functionality.
Implementation Method 1
freezing the filler or material at a temperature below its freezing temperature, which is generally below 0° C.
Implementation Method 2
irradiating the filler or material with a suitable dose of radiation at an effective rate for a time effective to sterilize the filler or material
Data Source
AI summary
Methods of sterilizing dermal fillers and injectable collagen material have been developed which reduce the level of active biological contaminants or pathogens without adversely affecting the material, i.e., wherein the dermal fillers and injectable collagen material retain their same properties before and after its terminal sterilization. In one embodiment the method for sterilizing the dermal filler or injectable collagen material that is sensitive to radiation contains the steps of protecting the filler or material from radiation, and irradiating the filler or material with a suitable dose of radiation for a time and at a rate effective to sterilize the filler or injectable material. In a preferred embodiment the method for sterilizing the dermal filler or injectable collagen material that is sensitive to radiation includes the steps of a) freezing the filler or material at a temperature below its freezing temperature, which is generally below 0° C. and b) irradiating the filler or material with a suitable dose of radiation at an effective rate for a time effective to sterilize the filler or material. The exposure of the radiation differs depending upon the density of the filler or material, but is preferably between 5 kGy and 12 kGy and more preferably between 6 kGy and 8 kGy. These doses result in a sterility assurance level (SAL) of 10−6 SAL for the filler or material.