Heat Flow Estimation in Polymer Films during Orientational Drawing at the Local Heater.

The optimization of the process of polymer film orientational drawing using the local heater was investigated. One of the problems with this technology is that the strength of the resulting fibers differs significantly from the theoretical estimates. It is assumed that one of the reasons is related to the peculiarity of this technology, when at the point of drawing the film is heated only on one side, which creates a temperature difference between the sides of the film in contact with the heater and the non-contact sides of the film in the air.

Precisely Printable Silk Fibroin/Carboxymethyl Cellulose/Alginate Bioink for 3D Printing.

Three-dimensional (3D) bioprinting opens up many possibilities for tissue engineering, thanks to its ability to create a three-dimensional environment for cells like an extracellular matrix. However, the use of natural polymers such as silk fibroin in 3D bioprinting faces obstacles such as having a limited printability due to the low viscosity of such solutions. This study addresses these gaps by developing highly viscous, stable, and biocompatible silk fibroin-based inks.

A New Approach to Estimating the Parameters of Structural Formations in HDPE Reactor Powder.

The morphology of virgin reactor powder (RP) of high-density polyethylene (HDPE) with M = 160,000 g/mol was investigated using DSC, SEM, SAXS, and WAXS methods. The morphological SEM analysis showed that the main morphological units of RP are macro- and micro-shish-kebab structures with significantly different geometric dimensions, as well as individual lamellae of folded chain crystals. A quantitative analysis of an asymmetric SAXS reflection made it possible to reveal the presence of several periodic morphoses in the RP with long periods ranging from 20 nm to 60 nm, and to correlate them with the observed powder morphology.

Properties of Resorbable Conduits Based on Poly(L-Lactide) Nanofibers and Chitosan Fibers for Peripheral Nerve Regeneration.

New tubular conduits have been developed for the regeneration of peripheral nerves and the repair of defects that are larger than 3 cm. The conduits consist of a combination of poly(L-lactide) nanofibers and chitosan composite fibers with chitin nanofibrils. In vitro studies were conducted to assess the biocompatibility of the conduits using human embryonic bone marrow stromal cells (FetMSCs).