Polymer patterns and scaffolds for biomedical applications and tissue engineering

Abstract

Polymers have gained a remarkable place in the biomedical field as materials for fabrication of various devices and tissue engineering applications. The versatility of their chemical composition and mechanical properties, the large pool of processing methodologies and the tailored biodegradability at physiological conditions have made them the obvious material choice for many biomedical applications. Undoubtedly, all those bulk properties are determinant for the long performance and the proper function of a biomaterial. However, the initial acceptance or rejection of an implantable device is dictated by the crosstalk of the material surface with the bioentities present in the physiological environment. Any medical intervention, including an introduction of a biodevice/biomaterial in the human body, induces changes in this environment. Controlled and predictable cellular response to these changes is highly desirable for tissue engineering and regenerative medicine. However, the regulation of cellular behaviour as response to environmental changes reminds to be one of the main obstacles in the biomedical materials design and it is associated with pathological states 1, 2, including blood clotting and wound healing defects as well as malignant tumour formation. Living cells are extremely complex entities presenting remarkable, inherent capacity to sense, integrate, and respond to environmental cues 3, 4. Their native environment is a three-dimensional scaffold comprising an insoluble aggregate of several highly organised, multifunctional large proteins and glycosaminoglycans (GAGs), collectively known as extracellular matrix (ECM) 5, 6. ECM provides a mechanical support for cells (most mammalian cells are anchorage dependent, i.e. they must adhere to a surface in order to survive) but also profoundly influences the fundamental cellular functions (e.g. migration, proliferation, differentiation, and apoptosis) of cells in contact with. By interacting directly with ECM, cells gather information about the chemical and physical nature of the environment, integrate and interpret it, and then generate an appropriate physiological response 4, 7. Keeping in mind this extreme intelligence and sensitivity of cells, it seems convenient that their behaviour can be directed through precisely designed environment.