John Autian

PROBLEMS IN THE USE OF POLYMERIC MATERIALS IN MEDICAL AND BIOMEDICAL APPLICATIONS

Perhaps one of the most dramatic achievements in the annals of modern surgery occurred within recent months when surgeons installed partial hearts in several patients. Even though these patients died in relatively short periods of time, the surgery demonstrated that the “implantable heart” is feasible and most likely will occur within the next five years. Other surgical successes with prosthetic devices for practically all parts of the body further confirm the strides taken by the medical professions in a relatively short period of time. Much of this achievement, however, may in a sense be traced to the synthetic materials that the polymer scientist and material scientist have created for the surgeon and his biomedical and bioengineering teams. Man-made materials for the medical and paramedical fields are of relative recent times, even though one source does point out that, as far back as 1890, celluloid was used in restorative surgery.l It is, however, in the past several decades and more particularly in the last decade that the health professions have investigated these polymeric materials for creation of various types of items and devices for the care, treatment, and protection of the ill, diseased, and injured population. In the early days of the use of man-made materials by the medical professions as well as the sister professions of dentistry, pharmacy, and nursing, it was the adventurous, tinkering-type of practitioner who designed and fabricated a new device to be used in his practice. It soon became clear, however, that the art and craft should give way to the science, and soon disciplines outside the conventional medical and paramedical professions were lured into the world of medicine. From this start developed the present interdisciplinary biomedical and bioengineering groups composed of scientists from practically all walks of life. As biomedical and bioengineering teams created new devices or improved older ones, a young new industry emerged catering to the needs of all the health professions by supplying an endless stream of items and devices fabricated from plastics. Even though no accurate figures are presently available, the market value of plastic medical supplies is most likely over a hundred million dollars a year, with some estimates running as high as two hundred million a year. This present conference is directed toward the subject of materials in biomedical engineering; and through these sessions, experts in their respective fields will discuss various facets of materials. I have been assigned the task of reviewing the problems in the use of plastics in medical practice. It is my intention in this presentation to discuss selective problems which I feel have not or perhaps will not be covered by the other speakers. No attempt will be made, if in fact this would be possible, to review each and every problem included in the literature or brought to my attention by my own research group or by other investigators in the field. Finally, I wish to end the discussion with comments concerning steps which might be taken to help prevent or circumvent some of these problems. * Currently Director, Materials Science Toxicology Laboratory, College of Dentistry and College of Pharmacy, University of Tennessee, Memphis, Tennessee.

Possible Toxic Effects from Inhalation of Dental Ingredients by Alteration of Drug Biologic Half-Life

A potential health problem that has received little attention in dentistry is the possibility that certain substances, when inhaled or absorbed, may cause indirect toxic reactions, which generally are subtle and not recognized easily at the time of occurrence. In particular, this may occur in small dental laboratories where hygienic standards and work conditions may not be the best. Workers in this type of environment may be exposed to various solvent vapors, as well as to other highly volatile chemicals. If some form of medication is being taken, particularly maintenance therapy, the inhaled agent could alter the activity of certain enzyme systems that in turn could have

Sorption of a Group of Dicarboxylic Acids by an Insoluble Polyamide

To develop a body of knowledge in regard to solute-polymer interactions, a study was initiated to investigate the sorption characteristics of a group of dicarboxylic acids when nylon-6,6 was used as the substrate. Results demonstrated the importance of the hydrophobic moiety in the group of acids.

Pyrolytic characterization of some plastics by a modified gas chromatography

Abstract An unconventional programmed pyrolysis was designed for the characterization of certain plastics, primarily those employed in medicine. The generally employed GC Packed Column was replaced by a stainless steel column containing glass wool, and a programmer was designed to elevate the temperature of the platinum pyrolysis filament in steps. Using a dual channel recorder, the signals from the flame ionization detector were recorded in one channel and the temperature of the filament in the other. The results obtained from the pyrolysis of a number of polyvinyl chlorides and polyacrylonitriles indicated that the method has the potential of providing characteristic “fingerprint-like” peak patterns for each polymer formulation.