A thermal perspective of the advancements in antibacterial polycaprolactone/graphene scaffolds

Abstract Excessive activation of osteoclasts during bone infections can result in destructive bone complications, including non-union and delayed fracture healing. Enterococcus faecalis and Streptococcus pyogenes are known pathogens associated with bone and joint infections, which can lead to severe complications and the deterioration of tissue. This study aimed to investigate the potential of mechano-bacteria intervention in combating these bacteria. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) tests were conducted on Polycaprolactone (PCL) and PCL/graphene (G) scaffolds containing different concentrations of graphene, namely 0.5, 1.5, and 2.5 wt%, to evaluate the thermal impact on the activity of E. faecalis and S. pyogenes. Furthermore, the Kirby Bauer Method was used to assess the antibacterial activity against both bacteria. The analysis of the average inhibition zone showed a correlation between the antibacterial effect and the concentration of G within the scaffolds. The highest inhibition zone was observed when 2.5 wt% G was used for both E. faecalis and S. pyogenes. The higher Tmax from Thermogravimetric Analysis showed PCL/G with 2.5 wt% G was due to the greater heat energy required to break down sp2 hybridized carbon atoms in a hexagonal framework. The TGA results indicate that higher graphene content (2.5 wt%) requires more energy for thermal decomposition compared to lower concentrations (0.5 wt% and 1.5 wt%) and PCL while the DSC results also showed that presence of G had a significant impact on Tg (glass transition temperature), Tc (crystallization temperature), and Tm (melting temperature), as the temperature increased with the addition of G. Based on the result of this study, it was concluded that G had potential for inhibiting bacteria growth.