Figures & data
Figure 1. Schematic representation of NPs and the progress of preparation. Dox and SPIONs were encapsulated in PLGA matrix via a double emulsion solvent evaporation method (W1/O/W2).
Figure 2. Schematic representation of NPs and the progress of preparation. Dox and SPIONs were encapsulated in PLGA matrix via a single emulsion solvent evaporation method (O/W).
Figure 3. Schematic representation of NPs and the progress of preparation. Dox and SPIONs were encapsulated in PLGA matrix via a modified multiple emulsion solvent evaporation method (O1/W1/O2/W2).
Figure 4. Schematic representation of NPs and the progress of preparation. Dox and SPIONs were encapsulated in PLGA matrix via a modified multiple emulsion solvent evaporation method (W1/O1,2/W2).
Figure 5. Structural formula of Dox-HCl (A) and TEA (B).
Figure 6. Aqueous solutions of Dox-HCl present a red colour at pH < pKa: 8.3 (A). A chemical conservation strategy was utilized to extract Dox-HCl into its free base form (protonated Dox which is hydrophobic) through a chemical reaction with TEA to improve Dox loading into the PLGA nanospheres (B). Whereas aqueous solution of Dox-HCl at pH above 10.5 shows a purple colour (C), Dox in the free base form shows an orange colour (D). Dox-loaded PLGA nanospheres (E) and SPIO/Dox loaded PLGA nanospheres (NPs) (F) with an excellent colloidal stability obtained by W1/O1,2/W2 methods.
Figure 7. Particle size distribution of NPs prepared by W1/O1,2/W2 method. (A, B) The particle size distribution of NPs using DLS and AFM analysis, respectively.
Table 1. Ingredients for preparation of NPs as well as particle size, PDI, LC and EE.
Figure 8. In vitro release profile of Dox from NPs in pH 7.4 PBS and pH 5.5 acetate buffers. (A) For 36 days and (B) for 72 h (n = 3).
