Composite Nanogels Based on Zeolite-Poly(ethylene glycol) Diacrylate for Controlled Drug Delivery

This study presents the design of novel composites nanogels, based on poly(ethylene glycol) diacrylate and natural zeolite particles, that are able to act as materials with controlled drug delivery properties. Natural zeolite‒nanogels composite, with varying zeolite contents, were obtained by an inverse mini-emulsion technique and loaded with 5-fluorouracil, a widely used chemotherapeutic drug. Herein, the possibility of adjusting final properties by means of modifying the preparation conditions was investigated. The prepared composite nanogels are characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). In light of this tunable drug-loading capability, swelling behaviour, and cytotoxicity, these composite nanogels could be highly attractive as drug reservoirs.

Functionalized 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) as Novel Organocatalyst for Efficient Depolymerization of Polyethylene Terephthalate (PET) Wastes

Poly(ethyleneterephthalate) waste was efficiently depolymerized through glycolysis and aminolysis reactions in the presence of functionalized 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) catalyst. The new catalyst of monoamide-ester type, was synthesized through reaction of dimethylterephthalate (DMT) with TBD in refluxing benzene. It was developed as a consequence of the mechanistic investigations of the transesterification reaction of isosorbide with DMT. To test the stability of functionalized TBD compound towards possible amide bond breakage, reactions with primary and secondary glycols as well as primary amines were performed when only the carboxymethyl group reacted. Moreover, it was found that the depolymerization of poly(ethyleneterephthalate) wastes proceeds faster in the presence of this novel organocatalyst by comparison with the hygroscopic TBD precursor.