Degradation Rate Of Bioresorbable Materials

Bioresorbable materials are extensively used for a wide range of biomedical applications from drug delivery to fracture fixation, and may remain in the body for weeks, months or even years. Accurately predicting and evaluating the degradation rate of these materials is critical to their performance and the controlled release of bioactive agents. Degradation rate of bioresorbable materials provides a comprehensive review of the most important techniques in safely predicting and evaluating the degradation rate of polymer, ceramic and composite based biomaterials.Part one provides an introductory review of bioresorbable materials and the biological environment of the body. Chapters in Part two address degradation mechanisms of commonly used materials such as polymers and ceramics. This is followed by chapters on bioresorption test methods and modelling techniques in Part three. Part four discusses factors influencing bioresorbability such as sterilisation, porosity and host response. The final section reviews current clinical applications of bioresorbable materials.With its distinguished editor and multidisciplinary team of international contributors, Degradation rate of bioresorbable materials: prediction and evaluation provides a unique and valuable reference for biomaterials scientists, engineers and students as well as the medical community. - Comprehensively reviews the most pertinent techniques in safely predicting and evaluating the degradation rate of bioresorbable materials - Addresses degradation mechanisms of commonly used materials - Discusses factors influencing bioresorbability such as sterilisation and host response

The use of bioresorbable polymers in stents, fixation devices and tissue engineering is revolutionising medicine. Both industry and academic researchers are interested in using computer modelling to replace some experiments which are costly and time consuming. This book provides readers with a comprehensive review of modelling polymers and polymeric medical devices as an alternative to practical experiments. Chapters in part one provide readers with an overview of the fundamentals of biodegradation. Part two looks at a wide range of degradation theories for bioresorbable polymers and devices. The final set of chapters look at advances in modelling biodegradation of bioresorbable polymers. This book is an essential guide to those concerned with replacing tests and experiments with modelling. - Provides a comprehensive mathematical framework for computer modelling of polymers and polymeric medical devices that can significantly reduce the number of experiments needed - Reviews the fundamental methods of modelling degradation, and applies these to particular materials including amorphous bioresorbable polyesters, semicrystalline biodegradable polyesters, and composite materials made of biodegradable polyesters and triclcium phosphates

This book presents a generalised computational model for the degradation of resorbable composites, using analytic expressions to represent the interwoven phenomena present during degradation. It then combines this modelling framework with a comprehensive database of quantitative degradation data mined from existing literature and from novel experiments, to provide new insights into the interrelated factors controlling degradation. Resorbable composites made of biodegradable polyesters and calcium-based ceramics have significant therapeutic potential as tissue engineering scaffolds, as temporary implants and as drug-loaded matrices for controlled release. However, their degradation is complex and the rate of resorption depends on multiple connected factors such as the shape and size of the device, polymer chemistry and molecular weight, particle phase, size, volume fraction, distribution and pH-dependent dissolution properties. Understanding and ultimately predicting the degradation of resorbable composites is of central importance if we are to fully unlock the promise of these materials.

Bioresorbable or biodegradable polymers are commonly used in various biomedical applications. The application of bioresorbable polymers in the biomedical sector has been widely exploited by immobilising suturing thread with an analgesic or antibacterial drugs, and the development of bioresorbable vascular scaffolds, wound-healing and intravenous drug-delivery devices. Furthermore, biodegradable polymers have been investigated as a replacement for metallic orthopaedic devices due to their precise control of material composition and microstructure. These polymers are eliminated from the body via dissolution, assimilation and excretion through metabolic pathways. The hydrolysing process breaks down the polymer into smaller units and its degradation products are excreted by means of the citric acid cycle or by direct renal excretion with no residual side effects.Processing of bioresorbable implants can be achieved via conventional polymer processing methods such as extrusion, injection and compressing moulding, solvent spinning or casting. However, special consideration must be given when processing these materials because heat can cause a reduction in molecular weight due to the hydrolysing of bonds. In addition, overheating can depolymerise the polymer and, as a result, monomers can have a plasticising effect on the polymer. Recently, alternative approaches utilising rapid prototyping and micro-/nanofabrication processes have been employed.This book addresses these issues and highlights recent advances in the biomedical field that have being enabled by the use of biodegradable polymers. This book is designed as a reference guide for academic researchers utilising biodegradable polymers in a range of areas from tissue engineering to controlled release of active pharmaceuticals, through to industry-based processors of biodegradable polymers.

Conventional materials technology has yielded clear improvements in regenerative medicine. Ideally, however, a replacement material should mimic the living tissue mechanically, chemically, biologically and functionally. The use of tissue-engineered products based on novel biodegradable polymeric systems will lead to dramatic improvements in health

Bioresorbable Polymers for Biomedical Applications: From Fundamentals to Translational Medicine provides readers with an overview of bioresorbable polymeric materials in the biomedical field. A useful resource for materials scientists in industry and academia, offering information on the fundamentals and considerations, synthesis and processing, and the clinical and R and D applications of bioresorbable polymers for biomedical applications. - Focuses on biomedical applications of bioresorbable polymers - Features a comprehensive range of topics including fundamentals, synthesis, processing, and applications - Provides balanced coverage of the field with contributions from academia and industry - Includes clinical and R and D applications of bioresorbable polymers for biomedical applications

Science and Principles of Biodegradable and Bioresorbable Medical Polymers: Materials and Properties provides a practical guide to the use of biodegradable and bioresorbable polymers for study, research, and applications within medicine. Fundamentals of the basic principles and science behind the use of biodegradable polymers in advanced research and in medical and pharmaceutical applications are presented, as are important new concepts and principles covering materials, properties, and computer modeling, providing the reader with useful tools that will aid their own research, product design, and development. Supported by practical application examples, the scope and contents of the book provide researchers with an important reference and knowledge-based educational and training aid on the basics and fundamentals of these important medical polymers. - Provides a practical guide to the fundamentals, synthesis, and processing of bioresorbable polymers in medicine - Contains comprehensive coverage of material properties, including unique insights into modeling degradation - Written by an eclectic mix of international authors with experience in academia and industry

Intensive studies are being carried out to use devices made of bioresorbable polymers inside the human body to provide various temporary functions. Typical examples include scaffolds for tissue engineering, fixation screws for broken bones and drug-loaded matrices for controlled-release. The development is entirely based on trial and error. The degradation rate strongly depends on the shape and size of the devices, making it difficult to transfer experience from one device to another. The degradation time ranges from weeks to years; animal and ultimately human trials have to be carried out, making the trial and error approach time-consuming and expensive. The entire field would benefit enormously from mathematical models capable of predicting the degradation and property change of the devices. This PhD project will develop such models as following: a) A multi-scale model for degradation of bioresorbable polyesters was developed. Events that occur at the molecular scale are modelled at the molecular scale using the kinetic Monte Carlo schemes while events that occur at the device scale are modelled using macroscopic diffusion model. b) A phenomenological model for simultaneous crystallisation and biodegradation of biodegradable polymers was developed. This model completed the degradation theory developed by Wang et al. at University of Leicester. c) The model in (b) was improved and applied to the analysis of accelerated degradation data. Temperature effects were taking into account by using Arrhenius relations. d) A model for the biodegradation of composite materials made of polyesters and calcium phosphates was developed. A calcium phosphate effectiveness map is established to show the conditions under which incorporating calcium phosphates into polyesters is effective, saturated or ineffective. f) A phase field model was developed for drug release from a swelling Hydroxypropyl methylcellulose matrix. This model can be readily extended to full three dimensional problems.