The National Institutes of Health (NIH) and the National Institute of Biomedical Imaging and Bioengineering, define “biomaterial” as any natural or synthetic substance that may be used in medical science to improve or replace damaged tissue or a biological function. These materials may come from almost anything from anywhere. They may come from organs or cells in the body, or made from collagen, gelatin, glass, plastic metal, or ceramic. They may be formed into teeth, knee or hip joints, contact lenses, arterial stents, heart valves, or something as simple as dissolvable wound dressings or sutures.
Biomaterials are also used in the development of vaccines and immunotherapy. New developments in immunotherapy, allow for the targeting of cancer cells, reduction of allergies, and reduced organ rejection.
In an article in the journal Trends in Immunology, Dr. Jonathan S. Bromberg (professor of surgery and microbiology and immunology), and Christopher M. Jewell, Ph.D., (associate professor in the Fischell Department of Bioengineering), at the University of Maryland relate that one of the secrets to advanced vaccines and immunotherapy is in advancing the use of biomaterials to potentiate faster and more complete eradication of diseases. Many of the emerging biomaterials science allow for improved functioning at the microscopic level such as micro and nano-particles. Using lipids and polymers these tiny particles can be formulated to be injected by micro-needles (almost painless) and delivered to immune cells,
Profs. Jewell and Bromberg point out that while biomaterials are well known in many areas of medicine today, such as heart valves and implants, they are relatively new in the field of immunotherapy and vaccines. Their advantage is faster and more targeted delivery while protecting from stomach acid and/or enzymatic degradation, thereby improving the immune system response.
When it comes to vaccines for infectious diseases there are two elements: the infectious organism itself and the “adjuvant” which actually activates or stimulates the immune system. Currently aluminum is the most common adjuvant, however many scientists would like to see a less harmful substance used as aluminum is a heavy metal and can cause neurological damage. Certain new biomaterials may serve as the next-generation adjuvants; not only for delivery, but to actually improve immune system response by themselves, because they can be modified for each individual task by their chemistry, size or shape says Prof. Jewell. One study with mice involved improved immune response using delivery of an HIV vaccine using nano-particles and lipids.
Another new innovation is the use of (painless) Microneedles and patches to penetrate the skin and deliver vaccines. This technology is also being used in the cosmetic industry for delivery of rejuvenating substances and stem cells for facials and skin rejuvenation in lieu of chemical, laser, or dermabrasion for less pain, irritation and faster recovery.
In a new trial a dissolvable microneedle patch was used to deliver a flu virus vaccine. The results were similar to use of standard needle delivery whether applied by doctor, nurse, or at home by the patient.
Drs. Bromberg and Jewell feel that this technology could change the way vaccines are delivered and improve accessibility of other formulations especially in areas where medical professionals and health care delivery is scarce.
Biomaterials can help in cancer therapy as well by improving the targeting of vaccines to a specific tumor or cell type. They can be designed with a molecule that’s specific to a cancer cell, allowing the biomaterial to lock onto a cancer cell bearing the same molecule (lock and key). It can then deliver the chemotherapy to kill only specific cancer cells; thereby greatly reducing the side-effects of the chemo therapy.
