## 3 Results and Discussion
### Ft-Ir  
The successful encapsulation of the drugs into the MOFs and composite materials was further examined by comparing their IR-spectra (Figure 4). The spectra for the pristine MOF-5 were consistent with literature, [30] with its absorption band centred at a region of 2932 cm\({}^{-1}\) because of the C-H aromatic bond stretching vibration. Two other strong bands were evident at 1656 cm\({}^{-1}\) and 1595 cm\({}^{-1}\), which is attributed to C=O and C-C stretching vibration due to the presence of the skeletal vibration of the aromatic ring found in the linker 1,4-benzene dicarboxylic acid. Another band is observed at 1378 cm\({}^{-1}\) due to the C-H stretching vibration, while minor bands found between 822 cm\({}^{-1}\) and 1153 cm\({}^{-1}\) are also assigned to the O-C=O symmetric and asymmetric stretching vibrations; also, the C-O stretching vibration found in the unreacted 1,4 benzene dicarboxylic acid contributes to these minor bands as well. The remaining absorption bands between 660 cm\({}^{-1}\) and 822 cm\({}^{-1}\) occur because of the stretching vibrations of the aromatic ring [46]. Figure 3: SEM images of (**a**) PCL-ceph@MOF-5; the scale bar is 50 \(\upmu\)m. (**b**) PCL-met@MOF-5; the scale bar is 1 mm. (**c**) PLGA-ceph@MOF-5; (**d**) PLGA-met@MOF-5. Figure 2: SEM images of (**a**) pristine MOF-5, (**b**) met@MOF-5 and (**c**) ceph@MOF-5 are shown. The scale bar is 200 \(\upmu\)m.  
In the case of Met, the stretching of the CH\({}_{3}\) functional group was shown at 2954 cm\({}^{-1}\) and 2897 cm\({}^{-1}\)[47]. The spectra of the met@MOF-5 showed characteristic peaks of the Met at 1600 cm\({}^{-1}\) and at 1523 cm\({}^{-1}\), where additional peaks were observed because of the C=C and C=N stretching, whilst the N=O asymmetry accounted for the peaks at 1479 cm\({}^{-1}\). Extra peaks found from 1275 cm\({}^{-1}\) to 1096 cm\({}^{-1}\), at 1070 cm\({}^{-1}\) and 711 cm\({}^{-1}\), occurred due to C-O stretching, C-N stretching and C-H bending. This shows that the drug had been successfully loaded, while the absorption band found at 2935 cm\({}^{-1}\) is present due to the stretching of the O-H bond. The spectra of ceph@MOF-5 also showed that the characteristic peaks of the Ceph drug at 3275 cm\({}^{-1}\) due to the N-H bond present, from 1680 cm\({}^{-1}\) to 1760 cm\({}^{-1}\), was because of the C=O, whilst additional peaks from 2550 cm\({}^{-1}\) to 2620 cm\({}^{-1}\) were due to the S-H. The C-N bond accounted for the peaks from 1020 cm\({}^{-1}\) to 1220 cm\({}^{-1}\), and those found from 1000 cm\({}^{-1}\) to 1300 cm\({}^{-1}\) were because of the C-O bond. This indicates the presence of the Ceph drug molecules, and this is in agreement with the XRD patterns  
Figure 4: FT-IR spectra for Met, met@MOF-5 and pristine MOF-5 compared (**a**) with the characteristic peak of Met found between 1232 cm\({}^{-1}\) and 1404 cm\({}^{-1}\) of the met@MOF-5 spectra. IR spectra of Ceph, ceph@MOF-5 and pristine MOF-5 (**b**), with the characteristic peak of Ceph present at 1504 cm\({}^{-1}\), confirming the presence of the drugs in their respective samples. and SEM images shown above, which all suggest the successful incorporation of the drug molecules into the pores of the loaded MOF-5. The FT-IR analysis conducted on the polymer composites showed the characteristic peaks of the loaded drug molecules, as depicted in Figure 5. It was observed that comparing the IR spectra of PLGA-ceph@MOF-5 with the spectra of the pristine PLGA, the peak found at 1571 cm\({}^{-1}\) was intensified after the loading. Another major characteristic peak found at 1376 cm\({}^{-1}\) was observed to have intensified after loading due to the symmetric stretched vibration of COO and the bending vibration of the hydrogen bond amongst the NH groups of the Ceph molecule, and this suggests the presence of the Ceph drug molecules due to the incorporation of the loaded MOF-5 into the PLGA-ceph@MOF-5. This same peak was found in both ceph@MOF-5 and PCL-ceph@MOF-5, as shown above.