Helen Newman, PhD, CTBS (Certified Tissue Bank Specialists) is CEO and founder of Veterinary Transplant Services Inc. (Kent, WA). Since 1989, she has been involved in tissue banking at the American Red Cross Tissue Services and the Northwest Tissue Center where she served as technical supervisor and associate director, and was responsible for donor recruitment, procurement, processing, and cryopreservation of all types of allografts. In a Q&A with OrthoTec, Newman discusses the allograft industry and the challenges that orthopaedic manufacturers face
OrthoTec: Talk a bit about your experience with allograft tissue and the changes in working with the technology over the years.
Helen Newman: I’ve been involved with tissue banking for more than 20 years and pretty much all aspects of it from procuring or harvesting tissue through processing, preserving, and testing tissues in a really wide variety of tissue, such as skin, cartilage, bone, tendons, blood vessels, heart valves, and stem cells. Tissue banks get themselves involved with a lot of different kinds of tissue, and a lot of people don’t realize that. When you paint the picture about organ and tissue banking, people understand the heart, lung, liver, and kidney transplants, but they may not be thinking about eye surgery that could benefit from having amnions or tendons replaced.
The changes in working with this technology over the years have been in a lot of those areas—for example, in donor screening we know what types of question to ask, and how to better test them for transmissible diseases. Tissue banking has come an enormous way in understanding harvesting or procurement techniques to minimize contamination of the graft and understanding what happens if something gets contaminated and how it might have an adverse impact.
Tissue banks have also come an enormous way in understanding process control and packaging requirements to ensure that there aren’t changes to the tissue. A lot of people think long-term, and if they’re going to use it in a few months. But a lot of people don’t realize how quickly freeze-dried bone, for example, will rehydrate. The whole point of running it through the freeze dryer is to reduce the moisture content, but the minute you take bone out of a freeze dryer it starts absorbing moisture from the atmosphere. If your packaging doesn’t prevent moisture vapor from slowly leaking through it, you can slowly change (or even rapidly change) the moisture content of the product. That can make a difference in how it functions either in formulating it with other additives or if you’re doing comparative studies with it over time. There is a lot better understanding in screening, harvesting, and what [factors] can cause inflammation or [other] problems.
OrthoTec: Are you seeing exciting applications emerging in allografts?
Newman: The more exciting thing is for tissue bankers and people who understand the details of tissue that process control leads to more consistent products. Some of the challenges that tissue banks have faced in the past are that older methods of processing or tissue recovery didn’t control for these things, so there would be a lot more variability from lot-to-lot. I think the exciting thing is to be able to enhance the quality of the product.
|Visit Veterinary Transplant Services Inc. in booth #405 at OrthoTec 2012.
OrthoTec: What are the main challenges that orthopaedic manufacturers face when working with allograft tissue?
Newman: The challenge that we see, and I think it’s a small part of what orthopedic manufacturers face, is that they are developing a product that is used in orthopaedic surgeries and a part of their product either interacts with allograft tissue, contains allograft tissue, or may be mixed with it. They are challenged to test their new product ideas, whether it’s a new spackle carrier vehicle to deliver growth factors or a new spinal implant that has a component that is allograft. The researchers (the manufacturers who are developing the new product) are familiar with bone, but it’s difficult for people who aren’t in tissue banking to realize all the steps involved between tissue harvesting and creating the demineralized bone powder that they ultimately want to implant.
[There are] subtle details that aren’t written up in materials and methods. Those can be significant factors that can lead to inflammation if people don’t follow routine tissue banking practices. Our challenge is to have manufacturers and researchers understand that they shouldn’t make their own bone graft when there is a whole industry out there that works to ensure that these products are [processed] properly and consistently and meet certain specifications. Tissue banking is a behinds-the-scenes industry, people aren’t aware of [it].
OrthoTec: What are the top five issues that manufacturers must address when working with allograft tissue?
- I’m hopeful that manufacturers come to realize that tissue harvesting, procuring, processing, preserving, and packaging can make a difference in the success or failure of a graft material. Having it professionally and consistently produced lot after lot is very important if they’re going to embark on an expensive study that involves animal implants, etc. You need to ensure that your materials are as high quality as possible.
- There are standards. The American Association of Tissue Banks has standards documents that tissue banks need to follow provide tissues for transplant. Some of these standards purely require time to complete. For example, when you recover tissue for transplant from a donor, you should do microbiology cultures of the grafts and incubate them for 14 days. [The process] requires time, and in our experience, we’ve found a lot of people don’t realize this procurement and culture time. I think people don’t understand the lead time that it takes if you want your preclinical trial material to mimic the human stuff as closely as possible.
- Scaling down from the animal model sizes.
- Researchers should keep in mind that there are tissue bank standards for endotoxin and sterilization techniques.
- [Companies should have in mind whether] test bone is analogously processed to the bone that will be in the human clinical reapplied product.
OrthoTec: What is the potential of this technology?
Newman: One of the areas that is developing is using tissues as biologic carriers for proteins that enhance healing. That applies in a lot of different techniques, not just orthopaedics. Having tissues, because they’re biologic materials, become the ideal biologic carrier is something that companies are moving toward. That means that they’ll need to have these biologic materials in their prototyping, product developing, and clinical trials.
Maria Fontanazza is managing editor at UBM Canon. Follow her on Twitter @MariaFontanazza.
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