Fig. 1

FT-IR results of syntheses, including P (PLGA), P-P (PLGA-PCL), and P-P-Cur (PLGA-PCL-Cur). According to the graph of PLGA, wide characteristic peaks at around 3150–3650 cm⁻¹ are responsible for the –OH groups, and the intense characteristic peaks at around 1650 cm⁻¹ and 1709 cm⁻¹ are recorded owing to the stretching vibration of C=O groups of PLGA monomers. For the P-P sample, the peaks at around 3500 cm⁻¹ and 1727 cm⁻¹ are assigned due to hydroxyl and ester (carbonyl) groups, respectively. Moreover, the absorption peaks of aliphatic groups are recorded at around 2920 cm⁻¹ (O–CH₃) to 2866 cm⁻¹ (O–CH₂) in P-P nanobeads. Regarding the P-P-Cur sample, the broad peaks at around 3441 cm⁻¹ and 2945 cm⁻¹ are attained owing to the stretching vibration of phenolic O–H and aromatic C–H stretch vibrations, respectively. The absorption peaks at around 1633 cm⁻¹ and 1606 cm⁻¹ are attributed to C=O stretching and aromatic ring stretching of Cur in the compartment of nanobeads