Description
The need for spare parts for the human body has never been greater than at present. More people than ever are living longer, but the human body, shaped by millions of years of evolution, isn’t keeping up. Spare parts must be available to replace organs and tissues that are worn out from operating beyond their expiration dates, as well as those damaged by injury, disease, or developmental mishaps.
The biomaterials field has come a long way from its empirical beginnings, with researchers taking whatever materials were available and attempting to integrate them into the human body, sometimes with disastrous results. Now, the body’s response to foreign materials is better understood than ever before. Furthermore, the past 15 years have seen great strides in tissue engineering. Spare parts consisting of living tissues are poised for significant clinical application. Tissue engineering, especially of tissues derived from the patient’s own cells, offers total acceptance by and integration with the patient’s body, unlike nonliving materials or living tissues from other humans or species.
The active ingredient in a medicine is only part of the arsenal against disease. The drug must somehow get to the right place at the right time. That’s where drug delivery comes in. Drug delivery companies work to devise new dosage forms for medications. The main challenge is to create the technologies for the easier and most convenient systematic delivery systems. For proteins and other macromolecules, however, the oral route is by far the hardest to accomplish.
From a practical perspective, medical applications of polymers fall into three broad categories: (1) extracorporeal uses (catheters, tubing, and fluid lines; dialysis membranes/artificial kidney; ocular devices; wound dressings and artificial skin), (2) permanently implanted devices (sensory devices; cardiovascular devices; orthopedic devices; dental devices), and (3) temporary implants (degradable sutures; implantable drug delivery systems; polymeric scaffolds for cell or tissue transplants; temporary vascular grafts and arterial stents; temporary small bone fixation devices).
Today, biomaterial research has developed into a major interdisciplinary effort involving chemists, biologists, engineers, and physicians. Biomaterials research has provided the clinician with a large number of new materials and new medical devices. As the biomaterials device industry continues to grow, degradable polymers will increase at the expense of traditional biomaterials such as metals and conventional, biostable polymers.
This volume consists of two parts: Part I: Polymers as Biomaterials and Part II: Medical and Pharmaceutical Applications of Polymers.
The fundamental questions of polymer synthesis, the types of polymers used for medical purposes, and modification of polymers to increase their biocompatibility, are presented in the first part. The applications of the two major groups of biomaterial —natural biomaterials (polysaccharides, cellulose, chitosan, proteins, etc.) and synthetic biomaterials (polyesters, silicones, elastomers, etc.)—are also reviewed. Part II deals with concrete utilization of polymeric biomaterials in the domains of tissue engineering, ophthalmic delivery, vascular prostheses (grafts), dental and maxillofacial surgery, blood contacting, skin graft polymers, sensors in biomedical applications, medical adhesives, medical textiles, and topical hemostat biomaterials.
The uses of polymers in the pharmaceutical domain fall into two areas: drug polymers and drug carrier polymers for controlled release. Part II provides the groundwork for understanding the fundamentals of drug delivery including conventional, nonconventional, and modulated systems; structure–property relations of selected supports and their role in drug delivery; delivery of drugs to sites such as the gastrointestinal tract, lung, skin, tumors, and blood vessels; and marketing considerations in new drug delivery systems.
This book is truly international, with authors from Austria, Canada, Finland, France, Germany, India, Israel, Italy, Japan, the Netherlands, Portugal, Slovenia, Spain, Switzerland, Thailand, the United Kingdom, and the United States. I am grateful to all the contributors.
Severian Dumitriu