Capturing the Full Power of Biomaterials for Military Medicine: Report of a Workshop (2004)

Workshop participants observed that all of the technologies discussed the workshop had one thing in common, which was that new materials and processes will be needed to transition ideas into products.

It is of particular importance when working with materials that will be used in the human body to understand the variety and range of new materials evaluation protocols.¹ While all of these protocols may not be critical to the final application, workshop participants advocated the consideration of each item before materials development proceeds. Important characteristics listed by the participants include the following:

• The ability to easily form the product to fit a variety of shapes, ideally in situ;

• Erosion resistance;

• Environmental durability in a variety of conditions;

• Well-characterized bioactivity;

• Appropriate mechanical properties;

• Potential for use in multiple applications;

• Cost-effectiveness; and

• The ability to deliver the material in a sterile and bioactive state out of the package and directly into the application.

Workshop participants also described the usefulness of establishing minimum or optimum design characteristics for materials in a number of product applications. Other useful guidance mentioned was for rapid screening techniques for new materials.

A time line for the development of new materials and drug formulations is presented in Table 3.1. Each stage consists of tasks and requirements that must be satisfied as product development proceeds.² The time needed to get a product to the battlefield will depend on where it is on this time line, ranging from the early concept stage to commercial availability. Certain assumptions also must be made as progress along time lines is estimated. These assumptions, along with regulatory, military, industrial, and academic requirements, have a great impact on time to reach the battlefield. Because of their experience with extensive regulatory and testing requirements, workshop attendees believed that few new products could be available to the warfighter in less than 2 to 4 years. Many of these new products will depend on the identification and maturation of enabling materials technologies.

A number of new materials technologies offer the potential for rapid application to identified military needs; these include the following:

• Biomaterials incorporating controlled-release antibiotics; these are especially useful when an antibiotic can be tailored to the clinical indication.

• Ways to ensure shelf life for biomaterials and combination products

• Improved understanding of the three-dimensional interactions of cells on materials

• Improved understanding of the immune response to biomaterials

• Techniques for rapid prototyping, micropatterning, and manufacturing of devices

Workshop attendees also offered a short list of near-term applications in which impact may be relatively easy to achieve. These included combining existing technologies, for example, new coatings on existing materials. Another short-term opportunity is to leverage existing approved technologies, as in drug-eluting stents.

While the technologies themselves set an interesting array of challenges for researchers, a number of nontechnical issues must also be considered. There was overwhelming agreement among workshop participants that primary among these is the need to predetermine a regulatory approval path. Some very useful lessons can be taken from the Accelerated Insertion of Materials (AIM) program, funded by the Defense Advanced Research Projects Agency. This program is intended to create and validate new approaches for materials development that will accelerate the insertion of materials into production hardware. The program works to establish approaches to use the required technical content and fidelity of identified military needs to drive the optimized development and use of models and experiments.

In the AIM program, efforts center on understanding how to use materials models effectively, how to link them across various length and time scales, and how to couple them with an optimized series of experiments to yield the appropriate information for the designer. When dealing with new materials for

medical applications however, different guidelines prevail. For example, the regulatory process does not recognize the results of accelerated testing, a protocol that forms the basis for a large fraction of materials modeling. One near-term process improvement offered by attendees included standardizing procedures to enable a clear path to prove the efficacy of new materials.

The need for an easy path to make new materials available to product developers was also noted. Although this may seem trivial, workshop attendees pointed out that some new materials were not available for research because of a new interpretation of intellectual property laws. Improved communication is needed among materials developers and device designers to gain the most from all.

Finally, it was noted at the workshop that the regulatory governance of medical devices does not control their use outside the United States. Because the bulk of military combat takes place overseas, some discussion ensued as to whether the military needed to follow these approval protocols at all. Regardless of the letter of the law, the U.S. military has chosen to abide by U.S. guidelines, including operating with the informed consent of the soldier. However, the demands of battlefield care can provide the opportunity to gain valuable clinical trial information in the field. Many workshop attendees felt that a recognized path for using field trials to prove efficacy would be very useful.

Throughout the meeting, workshop participants discussed the outcomes of their efforts to develop and implement new materials for military medicine. Success in the implementation of these suggested goals was linked in the breakout sessions to a number of benefits for the nation's defense, as follows:

• Preserving fighting strength—improving soldier health and well-being could result from improved battlefield diagnostics and care that would keep soldiers at their best and could also allow wounded soldiers in the field to complete their mission. It would result as well from successful tissue engineering technologies that could heal more serious wounds quickly and allow a soldier to return to duty.

• Improving the benefit of medical spending—new materials and processing technologies can reduce the cost of medical care and therefore stretch the funding available and provide better care.

• Transferring cutting-edge technologies developed for the military to civilian medical practice—in many ways, military needs are the most demanding. Success in transitioning technology to field use can push new technologies into other applications. This will require the involvement of new partners, including civilian practitioners and the reimbursement industry.

• Strengthening the biomedical technology industry—by creating and nurturing a critical mass of innovative researchers and product developers, the growth and impacts of biomaterials technology could multiply accordingly.

• Improving troop morale and public perception—confidence that medical technology can save lives in the field and can repair the damage from severe battlefield wounds is important to many soldiers as well as to their families and the general public.

The following performance metrics were suggested by workshop participants the accelerate the availability of biomaterials and related products developed for military applications:

• In the near term, make field clinical trials for new battlefield products routine.

• In the mid-term, establish a transition path to move existing new biomaterials into military applications.

• In the long term, decrease the time required to develop new biomaterials by 50 percent by using emerging techniques.

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