In Vitro Cytotoxicity Screening as a Criterion for the Rational Selection of Tear Substitutes

A large number of artificial tears are currently available in the pharmaceutical market. Selecting the right drug for the patient remains a challenge for both the doctor and the patient. Comparing the cytotoxicity of artificial tears is one of the criteria for the rational selection of a drug that promotes maximum clinical efficacy and a higher safety profile. It is known that cells grown in vitro retain many metabolic features of the parent host tissues and at the same time lack tissue and organ interrelations and regulatory effects of the nervous and endocrine systems and have very limited compensatory capabilities. These features of cell cultures provide an opportunity to investigate the interaction of chemical agents directly with the cell itself, to identify changes in cellular and subcellular structures that can be masked in whole-organism settings. This study presents the results of assessing the cytotoxicity of tear substitutes, which demonstrate that these drugs can have a cytostatic effect in vitro and differ in their cytotoxic potential. In recent years, the problem of drug therapy of patients with dry eye syndrome has been attracting increasing attention of ophthalmologists, so screening the cytotoxicity of a wide range of tear substitutes using cell culture-based test systems can promote the rational selection of these drugs

Porous composite prosthetic pylon for integration with skin and bone

This article presents results of the further development and testing of the skin and bone integrated pylon (SBIP-1) for percutaneous (through skin) connection of the residual bone with an external limb prosthesis. We investigated a composite structure (called the SBIP-2) made of titanium particles and fine wires using mathematical modeling and mechanical testing. Results showed that the strength of the pylon was comparable with that of anatomical bone. In vitro and in vivo animal studies on 30 rats showed that the reinforcement of the composite pylon did not compromise its previously shown capacity for inviting skin and bone cell ingrowth through the device. These findings provide evidence for the safe and reliable long-term percutaneous transfer of vital and therapeutic substances, signals, and necessary forces and moments from a prosthetic device to the body