Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

https://www.mdpi.com/1996-1944/14/12/3197/pdf

Non-Ionic Surfactants for Stabilization of Polymeric Nanoparticles for Biomedical Uses.

A review on carboxylic acid cross-linked polyvinyl alcohol: Properties and applications

Effect of thermal crosslinking process on membrane structure and PEM fuel cell applications performed with SPEEK-PVA blend membranes

Green synthesis of ion-imprinted macroporous composite magnetic hydrogels for selective removal of nickel (II) from wastewater

In this study, scaffolds were prepared via an electrospinning method for application in oral cavities. The hydrophilicity of the fiber mesh is of paramount importance, as it promotes cell spreading; however, the most commonly used polyvinyl alcohol (PVA) and other hydrophilic fiber meshes immediately disintegrate in aqueous media. In contrast, the excessive hydrophobicity of the scaffolds already inhibits cells adhesion on the surface. Therefore, the hydrophilicity of the fiber meshes needed to be optimized. Scaffolds with different polyvinyl alcohol (PVA)/chitosan/citric acid ratios were prepared. The addition of chitosan and the heat initiated cross-linkage of the polymers via citric acid enhanced the scaffolds’ hydrophobicity. The optimization of this property could be followed by contact angle measurements, and the increased number of cross-linkages were also supported by IR spectroscopy results. The fibers’ physical parameters were monitored via low-vacuum scanning electron microscopy (SEM) and atomic force microscopy (AFM). As biocompatibility is essential for dental applications, Alamar Blue assay was used to prove that meshes do not have any negative effects on dental pulp stem cells. Our results showed that the optimization of the fiber nets was successful, as they will not disintegrate in intraoral cavities during dental applications.

The Effect of the PVA/Chitosan/Citric Acid Ratio on the Hydrophilicity of Electrospun Nanofiber Meshes.

The article addresses the formulation and characterization of the polyvinyl alcohol membrane (PVA) with citric acid, succinic acid and their mixing as crosslinking agents. PVA is highly hydrophilic and has excellent film (membrane) properties. Chemical crosslinking is the most common approach to stabilize and produce PVA membranes with enhanced mechanical resistance. Thus, we prepared membranes with variable PVA and crosslinking agents. The thermal properties of the membranes were analyzed using thermogravimetric method (TGA), while the functional groups formed in the membrane were determined using Fourier-transform infrared spectroscopy. The water absorption of the membranes was determined by the degree of swelling. The oxidative stability was obtained using the Fenton test. The ion exchange capacity was also evaluated. Membrane structure, morphology and surface properties were analyzed by topography and adhesion force using atomic force microscopy. The scanning electron microscopy was used to elucidate the fractures. The results indicated that the membranes exhibited roughness uniformly distributed, indicating homogeneous films and excellent crosslinking features allied to enhanced adhesion and strength properties with good stability.

Liz Contino Vianna de Aguiar

Papers

Formulation and characterization of crosslinked polyvinyl alcohol (PVA) membranes: effects of the crosslinking agents