Approximately 80% of biomaterials used today have been around an awful long time, according to Ekaterina Tkatchouk, PhD, Principal Chemist, Edwards Lifesciences (Irvine, CA). In one sense, that’s reassuring, since a long history of in vivo use provides us with plentiful evidence as to the safety and efficacy of the materials. But over-reliance on tried and true formulas also hampers innovation, which often begins at the material level. Tkatchouk has a real passion for this topic—“As a chemist and materials scientist, I will always defend the magic of chemistry and development of smart materials,” she told PlasticsToday. In this interview, Tkatchouk, who has more than 10 years’ experience developing biomaterials for implantable medical devices, shares some thoughts on the state of biomaterials development. She is scheduled to address challenges in design with biomaterials at next month’s co-located Medical Design & Manufacturing (MD&M) and PLASTEC West trade show and conference.
As everybody knows, developing a biomaterial entails many challenges, says Tkatchouk, from scale up and validation to USP Class VI or ISO 10993 testing. But, for the sake of argument, let’s assume that we have a new polymer that meets all of the compliance requirements and has mechanical properties that are a perfect fit with a given medical device. “You would think it would be easy and straightforward to use this material in a medical device, but that is not happening,” says Tkatchouk. Part of the reason is institutional.
“Many divisions within a company need to approve a change in materials: Purchasing, engineering, R&D, regulatory, clinical and even legal,” explains Tkatchouk. Those filters are necessary, she acknowledges, but they make the process so long and resource heavy that as soon as there is the slightest hiccup, the project is abandoned.
To illustrate, Tkatchouk sketched out the typical materials approval process at a big medical device company.
|Ekaterina Tkatchouk, PhD, Principal Chemist, Edwards Lifesciences.|
“It begins with supplier approvals by the supply chain division. The engineering team works in parallel on developing processing methods. The legal team will assess if the polymer is being used by any other company and the clinical team will assess its in vivo performance. Sometimes the teams will opt for full biology, microbiology and chemical testing. You might remind everyone that the resin has already been through USP Class VI and ISO 10993, so why are we repeating biological and chemical tests? Well, we have to because once the resin is processed into the actual component, no one can claim that the properties of the material or its performance will be unaltered,” says Tkatchouk. And we’re not done yet, she adds.
“The manufacturing team has to be involved to ensure the component will be easy to handle during the manufacturing process and will withstand various processes such as sterilization and packaging. We will also have to validate each test method that we will be using to test the component, and retrain our assembly team.
“As you can see, this is already a huge amount of work that involves a lot of people and money. Let’s say that all of the groups agree we have a material with a better clinical and mechanical performance [than a legacy material], has a great price and that all manufacturing processes are in place and have been validated. Do you think we’re done? Well, we’re not.”