Heavy metal poisoning is a rare health condition caused by the accumulation of toxic metal ions in the soft tissues of the human body that can be life threatening if left untreated. In the case of severe intoxications, hemodialysis is the most effective method for a rapid clearance of the metal ions from the bloodstream, therefore, the development of hemodialysis membranes with superior metal ions retention ability is of great research interest. In the present study, synthetic polysulfone membranes were modified with reduced graphene oxide functionalized with crown ether, an organic compound with high metal ions complexation capacity. The physico-chemical characteristics of the composite membranes were determined by FT-IR, Raman, XPS and SEM analysis while their efficiency in retaining metal ions was evaluated via ICP-MS analysis. The obtained results showed that the thermal stability of reduced graphene oxide was improved after functionalization with crown ether and that the presence of the carbonaceous filler influenced the membranes morphology in terms of pore dimensions and membrane thickness. Moreover, the ability of Cu²⁺ ions retention from synthetic feed solution was up to three times higher in the case of the composite membranes compared to the neat ones.

Following implantation, infections, inflammatory reactions, corrosion, mismatches in the elastic modulus, stress shielding and excessive wear are the most frequent reasons for orthopedic implant failure. Natural polymer-based coatings showed especially good results in achieving better cell attachment, growth and tissue-implant integration, and it was found that the inclusions of nanosized fillers in the coating structure improves biomineralization and consequently implant osseointegration, as the nanoparticles represent calcium phosphate nucleation centers and lead to the deposition of highly organized hydroxyapatite crystallites on the implant surface. In this study, magnetic nanoparticles synthesized by the co-precipitation method were used for the preparation of cellulose acetate composite coatings through the phase-inversion method. The biomineralization ability of the membranes was tested through the Taguchi method, and it was found that nanostructured hydroxyapatite was formed at the surface of the composite membrane (with a higher organization degree and purity, and a Ca/P percentage closer to the one seen with stoichiometric hydroxyapatite, compared to the one deposited on neat cellulose acetate). The results obtained indicate a potential new application for magnetic nanoparticles in the field of orthopedics.

Polyethersulfone (PES) is one of the most used synthetic polymers for the production of hemodialysis membranes, due to its appropriate features, such as biocompatibility, high permeability for low-molecular-weight proteins, high endotoxin retention ability, and resistance to sterilization processes. However, there is room for improvement regarding their anticoagulant properties when coming into contact with blood. In the present study, commercial PES membranes were plasma-treated and then chemically modified with crown ether, an organic compound that could interfere with the coagulation cascade by complexating Ca²⁺ in the blood. The physico-chemical and morphological characteristics of the membranes were determined by FT-IR, XPS, TGA, SEM, and CT analyses, while their efficiency in retaining calcium ions was evaluated via ICP-MS. The results revealed that plasma treatment with a mixture of argon and ammonia was the most effective in generating nitrogen-containing surface functional groups and that these moieties can be successfully used for the covalent functionalization of the membranes. Also, the Ca²⁺ retention ability of the PES membranes was improved by up to 30% after chemical modification with 4′-aminobenzo-15-crown-5 ether.