Modification of Polymeric Scaffolds Made of PEG and Nanohydroxyapatite Embedded with Carbon Dots for Applications in Bone Tissue Regeneration

Composite scaffolds have been used to treat bone defects from severe trauma, pathologies, or congenital malformations. Polymers such as polyethylene glycol (PEG) and ceramics such as nanohydroxyapatite (nHA) have been used for scaffold fabrication due to their mechanical and biological properties, which favor osteoconduction as well as mimic physical and structural characteristics of natural bone. Nanomaterials, such as carbon dots, have been implemented for this application due to their biocompatible nature and ability to improve mechanical properties and enhance biological interactions. Hydroxyapatite nanoparticles embedded with carbon dots (nHA-CD) were obtained by a rapid continuous precipitation method. Carbon dots (CDs) were synthesized by the microwave-assisted method. Characterization performed by UV-Vis spectrophotometry, Scanning electron microscopy (SEM), and Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) confirmed the incorporation of CDs in nHA. A scaffold based on PEG and nHA embedded with carbon dots (PEG-nHA-CD) was synthesized using a direct mixing method. The scaffold presented a density of 0,48 g/cm3, similar to that of natural bone, indicating similar physical and structural characteristics. The cytotoxicity of the synthesized samples was evaluated by MTT and Trypan Blue assays. The results showed the potential of the PEG-nHA-CD scaffold fabricated for applications in tissue engineering aimed at future bone tissue applications.