Glass-ceramic scaffolds for tissue engineering

This paper is a critical discussing key on previous results of the authors in the field of glass-ceramic scaffolds for tissue engineering. With the aim of developing biological substitutes that restore, maintain or improve tissue functionality, glass-ceramic scaffolds were produced starting from a glass system composition enriched with traces of specific elements. The presence of one or more specific ions can modulate the better environmental conditions to favour the growth of specific specialised cells, a necessary prerequisite to originate different kinds of tissues. The main predictable use is for bone reconstruction, but other possible uses are expectable for some specific tissues (cartilage, nerve, tendons, etc.). In order to obtain the best initial tissue integration, a decisive role is played by porosity of the glass scaffold. The glass structure can generally be resorbed, leaving its volume available for tissue nodules which grow and assemble together, producing an equal volume of tissue. In bone, the action is synergically increased thanks to the phenomena of bone conduction and bone induction of the proposed porous bioactive ceramics. On the other hand, glass-ceramic scaffolds have already been appreciated as a superior material for bone healing. Compared to similar hydroxyapatite structures, the glass-ceramic ones exhibit a greater starting mechanical resistance (useful for surgical manipulations) and differently from the hydroxyapatite ones, they are resorbed more easily in time. This is a good requisite for a material to be used in bone tissue engineering. The ceramic bioactive systems can be used both in bulk and as coatings.