Exchanges period 1

From April 11th till April 25th Dr. Volodymyr Deineka visited Vilnius University, Vilnius, Lithuania.

This visit aimed to conduct a structural description of the Ti3C2 and Nb2C Mxenes. Data between these two types of MXenes will be compared, and patterns of characteristics associated with the size of nanoparticles will be determined. During the implementation, Dr. Deineka received intensive training on working with SEM. Vilnius University staff demonstrated best practices in studying nanomaterials.

After obtaining the structural characterization results, the data were discussed to select the best samples to be coupled to the nanofibrous 3D membranes. Dr. Deineka demonstrated different types of polymer membranes obtained by electrospinning and spoke about the features of producing these materials. As a result of the discussion, the optimal parameters of the membrane were selected as a scaffold for applying Mexene.

The results of the visiting studies will be used in further studies of polymer-MXene membranes on experimental models in vitro.

Dr. Sergiy Kyrylenko from Sumy State University conducted a research secondment to University of Campinas UNICAMP, from February 21 to April 20, 2024. During the secondment, the electro-conductive polycaprolactone (PCL) electrospun nanofibrous membranes with Ti3C2 MXene surface layers, produced by Sum State University in collaboration with Materials Research Center – MRC, were first tested in the conditions in-vivo to support neuronal regeneration in animal model of sciatic nerve injury in rats. To obtain more reliable and reproducible results, the similar membranes were produced also at the University of Latvia in Riga, Latvia. At the UNICAMP, together with Prof. Alexandre Oliveira and his team, we conducted a series of experiments to investigate how neuronal conduits, made out of MXene covered PCL nanofibrous membranes, could be used in design of neuronal conduits to support regeneration of sciatic nerves in the animal model of neuronal injury in rats. For this, the sciatic nerve was dissected and sutured by neurorrhaphy in conjunction with axon fusion technique. Functional recovery was monitored by CatWalk system during 4 weeks post operation. After that, the neuronal fibers together with the conduits and surrounding tissues were examined and prepared for transmission electron microscopy (TEM) investigations.

As a result, while the data processing is still in progress, we showed that the functional regeneration occurred much faster than after the traditional neurorrhaphy. Importantly, we also observed that the new conduits did not induce adverse accumulation of connective tissues at the site of treatment. Currently, experiments are in progress to show the microstructure of the axonal fusion and the state of the MXenes and the PCL nanofibers after 4 weeks in the animal’s body. In addition, currently we are planning a second series of experiments to investigate functional recovery during 8 weeks post operation, as well as histological examination of the treatment sites.

From November 25th till January 8th Dr. Sergiy Kyrylenko visited Department of Technical Physics, University of Eastern Finland in Kuopio, Finland.

The visit started with intensive exchange of knowledge in the truly interdisciplinary fields. The objective of the visit was to evaluate if the technique of electric impedance tomography could be applied to study conductivity of the polymer-MXene membranes. As a result, the experimental setup was brain-stormed and the design of the experiment was put together. To the best of our knowledge, that was the first approach to evaluate the spatial distribution of the conductivity of the polymer-MXene membranes.

Despite the extreme winter weather conditions, the visit was a complete success. During the visit the secondee received training in non-destructive electrical imaging techniques; while the host Department obtained new directions in working with MXenes and other nanoparticles. The research results of the visit will be utilized in the further investigations of the polymer-MXene membranes in the in-vivo experimental models.