Feature Article

Innovative Technologies for the Biofunctionalisation and Terminal Sterilisation of Medical Devices


Posted in Sterilization Equipment by Brian Buntz on February 1, 2011

New enabling technologies are driving growth in the biological products market.


 

Therapeutic proteins are becoming more and more important in the development of novel medical devices. Biofunctionalised stents with antibodies coupled to the surface are one example of this new class of device. Compared with bare metal and drug-eluting stents, which often cause inflammatory reactions and uncontrolled tissue growth, stents functionalised with antibodies collect endothelial cells that circulate in the blood stream, thus promoting natural endothelialisation within 72 hours. This significantly reduces the rate of inflammation and restenosis. Other examples of combination products where devices and biologics intersect include wound dressings and orthopaedic implants functionalised with growth factors. The novel devices stimulate wound healing processes and the attachment of new bone material, respectively.
 
Stabilizing and Protecting Solutions technologies have been successfully tested on a range of functional molecules from 8 to 900 kDa. In this example, they were exposed to a 25-kGy dose of beta radiation).

Therapeutic proteins are sensitive to physical stress, which poses a significant challenge during production and sterilisation procedures. Preserving and protecting a proper three-dimensional structure is essential for maintaining the physiological activity of proteins. Many proteins are prone to chemical and physical degradation as well as destabilisation in response to temperature, radiation and hydrolosis during production and sterilisation processes. Liquid protein formulations in biopharmaceutical applications are typically sterilised by filtration, but this is not feasible when the proteins are attached to a surface. Thermal-based methods also are inapplicable, since proteins tend to be heat sensitive. Gamma or beta radiation is frequently used to sterilise food and medical devices, but it had been impossible to maintain the proteins’ functionality following the standard radiation doses applied during sterilisation. Thus, shelf life and sterilisation are key bottlenecks in the design strategies and commercial success of new biologics-and-device combination products.

 
Stabilizing and Protecting Solution
Leukocare AG, a privately owned German biotech company based in Martinsried near Munich, has developed technologies that enable the stabilisation of proteins during production, sterilisation by irradiation and storage. The Stabilizing and Protecting Solutions (SPS) technologies are biocompatible and easy to implement. They do not require major adjustments in the production process, are customisable and can be adapted to customer requirements and the demands of a given application. In addition to functionalising medical devices, SPS technologies can be applied to biopharmaceuticals, vaccines and diagnostic products.
 
The SPS stabilisation mechanism can be compared with a glaze on top of a fruit tart. Imagine a strawberry tart without the glaze—the strawberries would turn brown after a few hours. The glaze preserves look and taste. Similarly, SPS technology forms a thin protective amorphous coat around the proteins during the drying stage. It increases proteins’ stability during storage and protects the three-dimensional structure during gamma, E-beam or EtO sterilisation.
 
Stabilizing and Protecting Solutions technologies developed by Leukocare stabilises the three-dimensional structure of proteins under dehydrated conditions and protects them from chemical and physical stress during terminal radiation- or gas-based sterilisation.

The protective SPS layer is easily removed when it comes in contact with water or body fluids prior to application of the product, and the original functionality of the proteins that are coupled to the surface is restored. Leukocare’s SPS technologies also offer an important advantage for the formulation of delayed-release applications: highly concentrated proteins tend to aggregate, which causes loss of function and an undesired immune response. SPS technology helps to reduce the aggregation of proteins.

 
Proof of Concept
Leukocare’s SPS technologies were successfully tested within several projects. One example is an in vivo diagnostic catheter that is functionalised with antibodies. The antibodies fish for certain circulating cell types in the patient’s blood stream. Enrichment of the target cells on the surface can be used for cancer or prenatal diagnostics. The use of SPS technologies significantly increased the stability of the coupled antibodies during sterilisation and storage.
 
Similar results have been achieved with molecules including small peptides, oligonucleotides, enzymes, growth factors and even IgM antibodies.

 

Julian Hergenröther
is responsible for Business Development at Leukocare AG, Am Klopferspitz 19, D-82152 Martinsried/Munich, Germany
tel. +49 8978 016 650
e-mail: info@leukocare.com
www.leukocare.de
 
* A related post on this technology titled "Medtech World News: Of Fruit Pies and Biofunctionalised Coatings" is available on medtechinsider.


Find more content on:
No votes yet


Login or register to post comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

The functionalisation they

The functionalisation they have is really great. I guess that is the key right there. - Marla Ahlgrimm