Controlled‐release fertilizer is one of the most critical tools in agribusiness for decreasing environmental impacts. Thus, the development of bio‐based systems able to induce the slow release of fertilizers has become the focus of numerous researchers. In this sense, this work presents a slow‐release fertilizer prepared by melt mixing of poly(butylene succinate) filled with 30 wt % urea and 5 wt % montmorillonite clay. The obtained materials were characterized using FTIR, XRD, and SAXS. Also, the release of urea was investigated using gravimetric and spectrophotometric tests. Finally, a vegetable growth analysis was performed to evaluate the development of lettuce (Lactuca sativa L.). The best composite material can increase the diameter of the lettuce by 67%, whereas the conventional use of urea increased this diameter by 48%. Therefore, the presented materials are useful as fertilizer systems.

In this work, an extrinsically magnetic composite based on modified magnetite and poly (butylene succinate) (PBS) is prepared. The magnetic composite is obtained by the emulsion–solvent evaporation method. Several analytical tests confirm the synthesis of the composites. Among them, Nuclear magnetic resonance (NMR) results in comparison with literature confirms the synthesis of PBS. X‐Ray Diffraction (XRD) shows the characteristic peaks of PBS, in its monoclinic structure. The crystallite size (Lc) of magnetic particles inside the composite, is equal to 13 nm. Thermogravimetric analysis (TGA) reveals the presence of 5.3 wt% magnetite in the composite and demonstrates that the inclusion of magnetite does not affect the thermal stability of the polymer. The analysis of Fourier transform infrared attenuated total reflection spectra (FTIR‐ATR) indicates the synthesis of desired products as well as the encapsulation of magnetite in PBS polymer matrix. The composite presents magnetic force, which allows its magnetic guidance to a target area. Besides, the magnetic induction heating test promotes heating within the therapeutic range from 40 to 45 °C, being able, according to literature, to promote the death of several types of cancer's cells. Therefore, the material here presented possesses potential to be deeply researched as a future cancer treatment tool.

Chitosan (CS) microparticles loaded with dexamethasone were prepared by spray drying, followed by coating with a pH-dependent interpolymer complex based on poly(acrylic acid)/poly(vinyl pyrrolidone) using an water-in-oil emulsion technique. The aim of this research was to evaluate the influence of PAA/PVP coating on the release of dexamethasone from loaded chitosan microparticles, in simulated gastric fluid (SGF, pH=1.2) and simulated intestinal fluid (SIF, pH=6.8). The release of dexamethasone from uncoated loaded CS microparticles was similar in both fluids, and almost complete release of the drug was achieved in 5 hours. In the coated loaded CS microparticles, the release of dexamethasone in SGF was reduced considerably, very close to zero, due to the interpolymer complex formation at low pH, demonstrating that this system applied as pH-dependent coating has a potential as a site-specific delivery system.