Note: This is the first article of a three-part series covering medical plastics (1) trends, (2) material/process advances and (3) applications.

The medical device industry is making important contributions to advances in healthcare. The sector is characterized by a high level of innovation and intense competition.

One of the interesting aspects of research and development within the medical devices field is the coupling of diverse biomedical and engineering disciplines. The medical devices industry involves the input of companies within the plastics and other advanced materials fields as well as microelectronics, software, telecommunications and biopharmaceutical, as outlined by the Advanced Medical Technology Association (AdvaMed).

The global medical device industry market is large, complex and fragmented. Estimates of the value of the global market depend on the interpretation of the term "medical device" as it can be applied to a wide range of products.

It has been suggested that the global market is comprised of about 8,500 types of medical devices, ranging from simple bandages and spectacles, through life-maintaining implantable devices, equipment to screen and diagnose disease and health conditions, to the most sophisticated diagnostic imaging and minimally-invasive surgery equipment.

Although estimates of the global market value (generally estimated to be in the $150 billion-plus range) differ, it is agreed that the largest market is that of the United States, followed by Europe and then Japan.

International markets for the medical device industry.

Innovative medical technologies offer an important solution for nations that face growing healthcare needs and constraints on resources, including the demands of aging populations. Advanced medical technology cannot only save and improve patients' lives, but also lower healthcare costs, improve the efficiency of the healthcare delivery system and improve productivity by allowing people to return to work sooner.

To deliver this value to patients, the medical technology industry invests heavily in research and development (R&D), and the U.S. industry is a global leader in medical technology R&D. The level of R&D spending in the medical device and diagnostics industry (as a percentage of its sales) more than doubled during the 1990s.

In absolute terms, R&D spending has increased 20 percent on a cumulative annual basis since 1990. This level of spending is on par with spending by the pharmaceutical industry and more than three times the overall U.S. average.

The medical technology industry is fueled by intense competition and the innovative energy of small companies. These firms drive rapid innovation cycles among products, which in many cases lead to new product iterations every 18 months. For example, let's take a look at innovative commercialized medical plastics application trends in the area of bioengineered tissue adhesives, sealants and fasteners.

Incisive Surgical Inc.'s patented Insorb 20 subcuticular skin stapler is a sterile, single-patient-use device that deploys up to 20 absorbable staples, sufficient to close a 17-centimeter incision. The Insorb 20 represents a new skin closure modality designed to combine the cosmetic result of an absorbable suture with the rapid closure times associated with metal skin staplers.

The absorbable staple offers increased patient comfort over metal staples while eliminating the need for metal staple removal post-operatively. The product also provides lower risk of infection and may shorten operative time, compared to other wound-closure methods.

The staple is composed of a copolymer of polylactic acid and polyglycolic acid, which is absorbed by the body over a period of a few months. The disposable stapler is made of sterilizable acetal.

3M Tegaderm foam adhesive dressing.

Continuing, 3M has innovated with a highly absorbent, breathable wound dressing that is constructed from a conformable polyurethane foam pad, and an additional absorbent nonwoven layer from National Wovens, with a border of transparent adhesive film impermeable to liquids, bacteria and viruses.

The polyurethane foam pad prevents exudate pooling and migration onto surrounding tissue while the film barrier helps prevent external contamination and exudate strike-through, and evaporates moisture vapor out of the dressing. The 3M foam adhesive dressing is used for treating moderate to highly exuding dermal wounds such as pressure ulcers, neuropathic ulcers, abrasions and first- and second-degree burns.

Heavily draining wounds often result in skin maceration, frequent dressing changes and patient discomfort. The 3M foam adhesive dressing provides total fluid management by a combination of fast wicking, high absorbency and breathability and uses an innovative "moist" skin adhesive technology. The unique spoke-shaped delivery system allows fast, easy application for wounds over body contours.

Finally, ProPen XL, manufactured by Closure Medical Corp., is an applicator system for Johnson & Johnson Ethicon's Dermabond topical skin adhesive, 2-octyl cyanoacrylate. The polyethylene disposable, sterile, single-use delivery system is designed for precise application of the topical skin adhesive, which can replace sutures and staples in surgical procedures.

A key design goal of the ProPen XL was to make the device intuitive to the user while maintaining a high level of product performance. Rapid prototyping methods were used to quickly modify and adapt early design concepts that were then taken directly to clinicians for evaluation.

Extensive preference studies, surgeon panels and one-on-one interviews with physicians, in addition to direct observation of surgical procedures, were used to ensure that user needs were addressed from the earliest stages of product development.

The glue in the ProPen XL applicator is packaged in a glass vial. A twist of the applicator breaks the glass vial and depressing the integrated plunger dispenses the glue through a felt applicator, similar to a pen. Simplistic as this may seem, the designers spent considerable time getting to this level of ease of use.

The topical adhesive can be applied with the same intuitiveness as drawing on a tablet. No mixing is required and cleanup is a matter of disposing of the applicator. While the adhesive product itself is not new, ProPen XL significantly improves its ease of use.