Functionalized Biodegradable Polymers via Termination of Ring-Opening Polymerization by Acyl Chlorides

Synthesis of 14C-Labeled Polyethylene Terephthalate and Generation of 14C-Nanoparticles for Fate and Disposition Studies

Polyethylene terephthalate (PET) is one of the most extensively used plastics in daily life. Due to its prevalent use, it is ubiquitous in the environment and a significant contributor to plastic pollution. Continuous exposure to photochemical, thermal, biological, and mechanical processes makes PET susceptible to slow degradation and the production of microsized and/or nanosized particles known as PET microplastic/nanoplastic (MP/NP). MP/NP are widely detected in the environment, including in drinking water and human food; consequently, knowledge gaps on the impacts of MP/NP in human food sources have gained global attention. A large knowledge gap is the bioaccumulation and fate of PET MP/NP in food animals. The application of carbon-14 labeled PET NP in food animals would provide a relatively straightforward approach to understanding the degree of PET absorption and its tissue distribution after absorption. Here, a simple, fast, and efficient synthetic method is described to produce [14C]-PET NP. The method comprises the polycondensation of terephthaloyl chloride and readily accessible [14C]-ethylene glycol followed by nanoprecipitation. The synthesized [14C]-PET and [14C]-PET NP were characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering spectroscopy, thermogravimetric analyzer (TGA), and UV-Vis spectroscopy.

Controlled Polymerization

An amazing variety of polymerization mechanisms enables the creation of polymers with given microstructures and comonomer sequences [...]

Chain-End Functionalization of Poly(ε-caprolactone) for Chemical Binding with Gelatin: Binary Electrospun Scaffolds with Improved Physico-Mechanical Characteristics and Cell Adhesive Properties

Composite biocompatible scaffolds, obtained using the electrospinning (ES) technique, are highly promising for biomedical application thanks to their high surface area, porosity, adjustable fiber diameter, and permeability. However, the combination of synthetic biodegradable (such as poly(ε-caprolactone) PCL) and natural (such as gelatin Gt) polymers is complicated by the problem of low compatibility of the components. Previously, this problem was solved by PCL grafting and/or Gt cross-linking after ES molding. In the present study, composite fibrous scaffolds consisting of PCL and Gt were fabricated by the electrospinning (ES) method using non-functionalized PCL1 or NHS-functionalized PCL2 and hexafluoroisopropanol as a solvent. To provide covalent binding between PCL2 and Gt macromolecules, NHS-functionalized methyl glutarate was synthesized and studied in model reactions with components of spinning solution. It was found that selective formation of amide bonds, which provide complete covalent bonding of Gt in PCL/Gt composite, requires the presence of weak acid. With the use of the optimized ES method, fibrous mats with different PCL/Gt ratios were prepared. The sample morphology (SEM), hydrolytic resistance (FT-IR), cell adhesion and viability (MTT assay), cell penetration (fluorescent microscopy), and mechanical characteristics of the samples were studied. PCL2-based films with a Gt content of 20 wt% have demonstrated the best set of properties.