Engineering the Performance of Biomaterials through Understanding and Optimisation of Their Viscoelastic Properties

Biomaterials are materials that are employed to replace or enhance a bodily function and, as such, are commonly used in modern medicine. The performance of these systems is directly related to their viscoelastic properties. This paper provides an overview of the importance of such properties and how they may be manipulated to achieve optimal performance. INTRODUCTION In recent years medicine has benefited from the use of polymeric-based biomaterials, e.g. as medical devices/artificial organs, implantable drug delivery systems and biosensors. The importance of biomaterials in clinical medicine cannot be ignored and indeed, it has been reported that “ultimately, almost every human in technologically advanced societies will host a biomaterial”. Unfortunately, the design of many clinical biomaterials is inadequate and limitations associated with their use have been reported[1]. The design of medical devices/bioactive implants/drug delivery systems is performed according to key product requirements. For example, in the design of medical devices, the ability to undergo stresses in situ and maintain structural integrity is vital to their performance. Similarly the mechanical/rheological properties of coatings for medical devices directly affect key properties including, lubricity, encrustation and drug release[2]. The rheological properties of drug delivery systems (particularly those designed as implants) are key to their subsequent clinical (and indeed non-clinical) performance. Examples of properties that are directly consequences of the rheological properties include ease of spreading to and retention at the site of application, removal from the container, drug release kinetics and the resistance to removal from the site of application following dilution with body fluids. Therefore, when designing such systems, consideration of these properties is essential to the development of biomaterials that exhibit optimal in vitro and in vivo performance EXAMPLES OF THE IMPORTANCE OF RHEOLOGICAL PROPERTIES TO BIOMATERIAL PERFORMANCE This paper will use a series of examples to highlight the importance of rheological properties on biomaterial performance. Bioadhesive drug delivery systems designed for the treatment of local disorders Periodontal disease is an inflammatory disease of the oral cavity that affects the supporting structures of the teeth and which Engineering the Performance of Biomaterials through Understanding and Optimisation of Their Viscoelastic Properties