RICERCA ITALIANA     

Polymer Processing for Biomedical Applications By Innovative and Sustenaible Technologies

Università degli Studi di Trieste

Abstract

The production processes of polymers and the synthesis of new polymers with different properties is a prerequisite for the utilization of these materials as biomaterials.
GMP practices are required for the production processes in the case of biomaterials. Special attention is paid to the elimination of any contaminant. The peculiar characteristics of supercritical fluids and, particularly, of supercritical carbon dioxide allows the replacement of organic solvents in the industrial applications producing new materials not obtainable using the traditional techniques and without solvent residual in the final product. The materials thet will be used in the present research project are monomers for the production of polymers that successively will be modified with the introduction of drugs or other compounds with angiogenic activity. For the same scope commercially available polymers (but approved for biomedical use) will be used. The following techniques will be used: the dispersion polymerization with supercritical carbon dioxide, the precipitation with supercritical antisolvent, the atomization assisted by the supercritical fluid, the impregnation of polymer matrices and the production of foams or polymeric membranes.
The research units will be involved both on process engineering and new products development. The design and construction of bench-scale plants will be carried out, and the effect of process parameters on the properties of the materials will be >>>

Principal Investigator

Ireneo KIKIC Università degli Studi di TRIESTE

Research Objectives

The chemical engineering research activity is moving, in the last years towards sectors that are common to others scientific areas: materials science, pharmaceutical science and technology, biology, medicine. It is a need to study phenomena different from those typical of the chemical industry but that can be solved with the same methodologies. For example, the study of diffusional processes inside a catalyst pellet or of the diffusion of a liquid in a liquid-liquid extraction unit are not different from the study of the release process of a drug inside the human body. The new problem is perhaps more difficult due to the boundary conditions.
Starting from this need the goal of the present research project is the application of new advanced technologies that are developed in the chemical engineering environment, to the solution of problems in the biomedical area. The scope is the production of drug release systems, of polymers for biomedical use through a new chemical synthesis process, of micro and macro polymeric systems for the tissue engineering. The production processes will be characterized by a very low environmental impact.
The technology proposed is based on the use of supercritical fluids.
The research units involved in the project present a good expertise for the different processes based on the use of supercritical fluids. This is demonstrated by the scientific production of the different components and from the fact that the Coordinator of >>>

First Results

The first attempt of the programme is the collection of physical and chemical properties of the materials to be processed. Bibliographic data and experimental analysis will be used.
Particularly, the main result of this first period is an in deep knowledge of the thermodynamic behavior of the mixture solvent/Supercritical fluid/solid at high pressure. Indeed, the knowledge of the phase behavior is fundamental for the phenomenological description of the processes.
In this step some experimental apparatus will be also, eventually modified. The Experimental tests on the selected compounds will be performed on lab-scale apparatus. Drugs, polymers and composite drug/polymer material will be generated. These materials will be characterized through the proper analytical techniques. The first result is the understanding of the phenomenology of the processes and the effect of the process parameters on the product properties. The main expected result is the production of one of more than one composite drug/polymer to be proposed and patented as drug delivery system. Finally, it will be proposed a scheme of applications of the process that allow to choice what material or class of material can be properly obtained with SCF-based processes.The scope of this last step is the development of the processes on the pilot scale, the study of the scaling, and the optimization of the processes (for example of the heat exchange, mixing..).

Timescale

24 months

National and international background

No longer is the treatment of diabets, osteoporosis, asthma, cardiac problems, cancer and other diseases based only on conventional pharmaceutical formulations. Biology and the medicine are beginning to reduce the problems of disease to problems of molecular science, and are creating new opportunities for treating and curing disease. Such advances are coupled closely with advances in biomaterials and are leading to a variety of approaches for relieving suffering and prolonging life. Biomaterials are generally substances other than food or drug contained in therapeutic or diagnostic systems that are in contact with tissue or biological fluids.. They are used in many biomedical and pharmaceutical preparations; they play a central role in extracorporeal devices, from contact lenses to kidney dialysers, and are essential components of implants, from vascular grafts to cardiac pacemakers. There are many current biomaterial applications, found in about 8000 different kinds of medical devices, 2500 separate diagnostic products, and 40000 different pharmaceutical preparations [1].
Although biomaterials already contribute greatly to the improvement of health, the need exists for better polymer, ceramic, and metal systems. In particular improved methods of characterizing and producing polymers for: drug release systems, tissue applications and biomedical devices are needed.
Many biomaterials in clinical use were not originally designed as such and for this reason they >>>