## 4 Bionanosystems
### Bionanosystems for RA
#### 4.1.2. Bionanosystems Based on Inorganic Carriers
The hybrid systems (i.e., rosmarinate-LDH and salicate-LDH) were successfully dispersed into linear low-density polyethylene (LDPE) (Figure 9), demonstrating that the nanocomposite material containing rosmarinate-LDH was selective and strongly inhibitory toward _Staphylococcus aureus_. Additionally, the overall migration of rosmarinate from films immersed in 95% ethanol solution was followed by fluorescence spectroscopy showing a controlled release of the active compound. Furthermore, a significant effect of stabilization of LDPE thermal-oxidation degradation was observed for nanocomposites due to the antioxidant power of RA. These results encourage future studies by using RA extracted from residual biomasses to improve the economic feasibility of the process. Moreover, fluorescence emission of the materials is an interesting feature that could be exploited for traceability in packaging applications. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Type of Carrier** & **Host-Guest System** & **Main Features** & **Refs.** \\ \hline \multirow{8}{*}{Montmorillonite (MMT)} & \multirow{8}{*}{Intercalated and adsorbed RA-MMT} & \multirow{8}{*}{RA contained in thyme, oregano and basil EOs is immobilized on the external surface of Na-MMT and intercalated in organo-MMT; RA-MMT is a green inhibitive nanocarrier releasing RA and protecting against steel corrosion due to the precipitation of Fe\({}^{2+}\)/RA chelates. \\ \hline \multirow{2}{*}{Halloying nanotubes (HNTs)} & \multirow{2}{*}{Encapsulated RA-HNTs} & \multirow{2}{*}{RA is gradually released from films containing rosmary EO-HNT} & [144] \\  & & & \\ \hline \multirow{8}{*}{Layered double hydroxides (LDHs)} & \multirow{8}{*}{Intercalated RA-LDH} & \multirow{8}{*}{*} & \multirow{8}{*}{Mono-deprotonated RA is intercalated in LDH;} \\  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \multirow{8}{*}{Mellographicographic} & \multirow{8}{*}{Intercalated RA-LDH} & \multirow{8}{*}{*} & \multirow{8}{*}{[156]} \\  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \multirow{8}{*}{Mellographic} & \multirow{8}{*}{LDPE nanocomposites containing RA-LDH} & \multirow{8}{*}{[156]} \\  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \multirow{8}{*}{Mellographic} & \multirow{8}{*}{LDPE nanocomposites containing RA-LDH are fluorescent.} & \multirow{8}{*}{[157]} \\  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \multirow{8}{*}{Silica nanoparticles} & \multirow{8}{*}{Covalently grafted or adsorbed RA silica nanoparticles} & \multirow{8}{*}{*} & The system has antioxidant activity; \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \multirow{8}{*}{Metal organic framework (MOF)} & \multirow{8}{*}{RA-loaded UiO-66-NH2@N-CNDs nanoparticles} & \multirow{8}{*}{\(\bullet\)} & Bionanosystem with possible \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \end{tabular}
\end{table} 
Table 2: Encapsulation of RA in in organic nano and microsystems. Figure 9: Rosmarinate-LDH and salicate-LDH, their dispersion into LDPE, and main properties of LDPE/rosmarinate-LDH and LDPE/salicylate-LDH nanocomposites. Porous silica nanoparticles, with interesting applications in pharmaceutical formulations, in biomedical devices and in early diagnosis of diseases, have also been proposed as alternative nanocarriers of bioactive molecules. However, despite their excellent properties, such as biocompatibility, high specific surface area and versatility on its surface functionalization, some issues related to their toxicity in some tissues, industrial scaling, and optimization in specific drug delivery, still remain. To overcome some of these challenges, the development of systems called nanoantioxidants is an interesting approach.