## 2 Results
### Cinnamaldehyde Entrapment Efficiency and In Vitro Release Studies  
The total amount of CIN loaded in 1 mg MPs (loading) was 120 \(\upmu\)g (so, 8.4 mg of CIN in 70 mg of loaded MPs obtained). Since 40% \(v/w\) of CIN was used in the preparation, the entrapment efficiency is 21%.  
CIN release profiles were evaluated in vitro as a function of time (at 1, 4 and 24 h) in three different conditions (in ethanol, in Sensititre(tm) YeastOne Broth and in Sensititre(tm) YeastOne Broth in presence of _Candida_ spp.). The temperature used during the test (37 \({}^{\circ}\)C) was chosen to resemble ideal microbial growth conditions.  
As shown in Table 2 and Figure 3, in ethanol, CIN-MPs presented the highest initial burst release, reaching almost 67% of the CIN's amount originally present in the sample and about 100% was released after 24 h. In Sensititre(tm) YeastOne Broth after 24 h, CIN-MPs released 26,30% of the CIN. The difference in CIN release profiles in ethanol and in Sensititre(tm) YeastOne Broth is statistically significant (\(p\) value < 0.0001).  
Finally, as shown in Table 3 CIN release was almost total in presence of _C. albicans_ or _C. glabrata_ on a growth area of 1.90 cm\({}^{2}\), in 24 h, for all three concentrations analyzed. The difference in release percentage between 600 \(\upmu\)g/mL and 300 \(\upmu\)g/mL showed slightly significant differences (\(p\) value = 0.0031) while there was no significant differences be-tween 300 \(\upmu\)g/mL and 150 \(\upmu\)g/mL. In wells with growth area equal to 0.31 cm\({}^{2}\), the release decreased as the concentration increased. This phenomenon was due to the aggregation of the MPs in a restricted area and the reduced surface of the same in contact with the ground that promoted the release. Moreover, the release in the presence of _Candida_ increased as the  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Timepoints**} & \multicolumn{2}{c}{**Cumulative Percentage (\% \(v/v\)) \(\pm\) St. Dev.**} \\ \cline{2-3}  & **In Ethanol** & **In Sensititre(tm) YeastOne Broth** \\ \hline
1 h & 67.13 \(\pm\) 2.20 & 17.65 \(\pm\) 1.75 \\
4 h & 93.347 \(\pm\) 2.16 & 21.22 \(\pm\) 2.20 \\
24 h & 99.67 \(\pm\) 1.58 & 26.30 \(\pm\) 2.13 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Cumulative percentage of released CIN in ethanol and Sensititre YeastOne broth at 1, 4 and 4 and 24 h. Analyses were performed in triplicate (\(p\) value < 0.0001).  
Figure 2: Representative SEM images of empty-MPs, scale bar 200 \(\upmu\)m (**A**; Mag = 100 X) and 20 \(\upmu\)m (**B**; Mag = 1.00 KX).  
gradual release of CIN by the MPs resulted in the gradual uptake of the molecule by the microorganisms. The difference in CIN release percentage in growth area equal to 0.31 cm\({}^{2}\), at the three concentrations analyzed was statistically significant (\(p\) value < 0.0001).  
Headspace analysis of the vehiculate CIN confirmed the absence of other metabolites. The chromatogram is also reported (Figure 4).  
Figure 4: GC-FID Chromatogram of CIN-MPs.  
Figure 3: In vitro drug release profiles of CIN-MPs in ethanol and culture medium. Results were represented as mean \(\pm\) St. Dev. Analyses were performed in triplicate.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**CIN-MPs Concentrations**} & \multicolumn{2}{c}{**Release Percentage (\% v/\(v\)) \(\pm\) St. Dev.**} \\ \cline{2-3}  & **0.31 cm\({}^{2}\)** & **1.90 cm\({}^{2}\)** \\ \hline
600 \(\mathrm{\SIUnitSymbolMicro m}\) & 61.85 \(\pm\) 1.44 & 85.66 \(\pm\) 2.02 \\
300 \(\mathrm{\SIUnitSymbolMicro m}\) & 74.43 \(\pm\) 1.57 & 92.85 \(\pm\) 1.69 \\
150 \(\mathrm{\SIUnitSymbolMicro m}\) & 89.00 \(\pm\) 1.75 & 93.00 \(\pm\) 1.32 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Release percentage of CIN on a growth area of 0.31 cm\({}^{2}\) and 1.90 cm\({}^{2}\) in 24 h at 600, 300 and 150 \(\mathrm{\SIUnitSymbolMicro g}\)/mL of CIN-MPs. Analyses were performed in triplicate.