The research activities concerning the materials for biomedical applications are oriented not only to the preparation and development of innovative materials with advanced fuctional properties, but also to the modification of a wide range of traditional materials, such as polymers, metals, ceramics and plastics by chemical grafting with polymers, at the aim of improving resistance and durability, but mostly at the aim of imparting new properties and/or functionalities to the final product, such as wettability, biocompatibility, hydrophilicity, selective sensitivity to biomolecules. Some examples are surface modification of inorganic materials with dextran to impart hemocompatibility, surface modifications of metals to obtain products suitable for sensing applications and many modifications of polymers to obtain materials for controlled release and transport of active ingredients.
Specific research activities concern shape memory polymers for smart biomedical devices, sensors for medical devices, the development of polymeric systems for the production, by micro-injection molding, of capsule devices for oral drug administration and the design/prototyping of products for biomedical applications.
Fabrication and characterization of shape memory polymers for smart biomedical devices
The peculiarities of the shape memory behavior of polymeric materials, i.e. their ability to implement significant changes in shape in response to an external stimulus, has been the subject of study of the Materials Science and Technology group for several years. The group has gained experience in characterizing the response of these materials and identifying guidelines for optimizing their response.
For pre-industrial research purposes, the group, assisted by other research groups of the Department of Mechanical and Industrial Engineering, has also been involved in a feasibility study for the characterization of stents made of polymeric material; this research has focused both on the development of materials and artifacts that meet the application needs of the stent, and on the realization of instrumentation dedicated to the characterization of systems with complex shape variations.
Characterization of polymer substrate sensors for the realization of biomedical devices
As part of a collaboration with colleagues from the Department of Information Engineering, the Materials Science and Technology group is developing an activity of mechanical characterization of stress/strain sensors on polymer substrate, with potential applications in the fields of motor rehabilitation (gloves for upper limb rehabilitation; intraoral devices for tongue rehabilitation).
The use of these sensors requires a precise characterization of the correlations between electrical signal (voltage or resistance variation) and mechanical response (strain and force). This characterization is mainly aimed at describing the response of the sensor for complex histories (unloading cycles; prolonged maintenance of loads/deformations; etc.) in which it may be difficult to separate the variations in the mechanical behavior of the substrate material, due to its viscoelastic nature, from the electrical drifts of the sensing element. The results will allow to describe the response of the sensors and/or to guide their performance optimization.
Development of polymeric systems for the realization, by micro-injection moulding, of capsular containers for oral drug administration
This research, carried out by the Materials Science and Technology Group in collaboration with the University of Milan (Department of Pharmaceutical Sciences) and the Polytechnic University of Milan (Department of Chemistry, Materials and Chemical Engineering "G. Natta") aims at the development of new thermoplastic polymeric systems suitable for the obtainment by micro-injection molding of capsular containers for oral administration of drugs, with specific release performances.
Particular attention is given to the study of the process characteristics that govern the transformability of the above-mentioned polymeric systems, which in fact consist of a basic polymer of pharmaceutical grade (e.g. ethylcellulose) in which fillers and/or active pharmaceutical ingredients are dispersed.
Design of manufactured articles for the biomedical sector
Specific design procedures have been developed in order to obtain high-performance products, free from defects and with reduced tolerances for the realization of manufactured articles in polymeric material (polymers/rubbers).