Production and characterization of biomanufactured scaffolds for bone regeneration

Abstract

Periodontitis is considered one of the most aggressive chronic inflammatory oral diseases, affecting the integrity of the soft and hard tissues surrounding the tooth, which, in severe cases of destruction, can result in tooth loss. Originally, the principles of guided tissue/bone regeneration (GBR) were followed to restore the architecture and functionality of the periodontal system. In essence, a biocompatible polymer-based occlusive membrane is used as a barrier to prevent epithelial and connective tissue migration to the regenerating site. In this way, slow migration of progenitor cells located in the remaining periodontal ligament are able to recolonize the root area and differentiate into new periodontal tissues, alveolar bone and new conjunctiva insertion.The use of synthetic or tissue-derived (collagen) membranes with or without calcium phosphate-based bone graft materials has been the treatment used. The barrier membrane provides stability to the bone graft, prevents soft tissue invasion into the defect, prevents the migration of competing non-osteogenic cells such as fibroblasts, and accumulates growth factors. Ideally, these membranes need to exhibit biocompatibility and an adequate degradation profile that not only matches the formation of new tissue, but more importantly, allows sufficient tissue maturation prior to membrane degradation. In addition, these membranes need to present some characteristics such as: (i) present sufficient initial mechanical resistance to allow handling and implantation, (ii) withstand the various mechanical stresses suffered during surgery, maintaining their integrity, (iii) withstand the process of bone tissue regeneration and repair by resisting cellular tensile forces and wound contraction forces during tissue healing in vivo. In addition, it is necessary that these membranes carefully balance the biomechanical properties with the kinetics of degradation, that is, they degrade originating non-toxic products, finally being absorbed by the body at the same time as the tissue is regenerated.Although different products for RTG/ROG available on the market are known, they have serious deficiencies in terms of mechanical strength and biodegradation rates. Indeed, the barrier function of the membrane is compromised and it loses its ability to prevent the migration of gingival epithelium cells. In this context, the development of a membrane with a better combination of mechanical, degradation and biological characteristics is still necessary for RTG/ROG. Thus, this research project aims to develop and characterize membranes to be used in RTG/ROG strategies. In this sense, it is proposed the production of a semi-resorbable multifunctional system consisting of two layers produced by different methods and biocomposites with different properties, being an outer layer (EC), produced by electrospinning and an inner layer (IC) produced by 3D bioprinting. The association of these techniques may enable the development of a membrane with different properties on each side (bifunctional). (AU)