**2. Experimental**

### **2.1 Materials**

Calcium nitrate tetrahydrate (CNT; Ca(NO3)2.4H2O), tetraethyl orthosilicate (TEOS; Si(OC4H9)4, 98%), triethyl phosphate (TEP; P(OEt)3, 99%) were purchased from Acros Organic, sodium nitrate (NaNO3), nitric acid (HNO3) were purchased from Merck, Germany, the surfactant Pluronic P123 (EO20-PO70-EO20, average Mn ~ 5800) were produced from Sigma-Aldrich, Germany. Gentamicin was obtained from Fuan Pharmaceutical group Yantai Co., LTD. Polymethylmethacrylate (PMMA) colloidal crystals with 300 nm size were prepared by our previous worked [29].

### **2.2 Preparation of bioactive glass ceramics**

Two different 3DOM-MBGCs; 45S5 and S53P4 were synthesized *via* sol–gel method follow by published work [30]. The synthesis process went through hydrolysis and polycondensation of TEOS, TEP, CNT and NaNO3 (**Figure 1**) with the appropriate mol ratio mentioned in **Table 1**. HNO3 was used to catalyze the hydrolysis process and non-ionic block copolymer P123 was chosen as structure-directing agent. The solution was vigorously stirred (700 rpm) at room temperature to obtain a clear sol (hydrolysis reaction) and further stirred to reach the gel point (condensation reaction). To obtain 3DOM structure, a monolithic piece of the PMMA colloidal crystal templates were completely immersed in the sol and excess solution was removed. The products were aged in sealed vials at 45°C for 24 h to allow the polycondensation reaction followed by a drying process at 45°C for 24 h to eliminate excess solvents and by products. Finally, the samples were stabilized at 600°C in air for 4 h with a fixed heating rate of 2°C/min. The morphology of the bioactive glasses was analyzed in detail by scanning electron microscopy (SEM). Their element compositions were characterized by energy dispersive spectroscopy (EDS) attached to the SEM with Silicon crystal detectors. Fourier Transform Infrared Spectroscopy (FTIR) was carried out in the transmission mode with mid-infrared range 400–4000 cm−1 at a resolution of 4 cm−1 by using the KBr pellet method. The N2 adsorption–desorption measurements carried out by Brunauer–Emmett–Teller (BET) for surface area analysis and Barrett–Joyner–Halenda (BJH) for pore size and volume analysis.

### **Figure 1.**

*Synthesis of 3DOM-MBGCs via sol–gel method.*


### **Table 1.**

*Chemicals used in synthesis of 45S5 and S53P4 3DOM-MBGCs.*
