Alteration of monocytic cell oxidative burst caused by methacrylic monomers present in dental materials: a chemiluminescence study

A protein chimera self-assembling unit for drug delivery

In the modern view of selective drug delivery of bioactive molecules, the attention is moving onto the setup of the perfect carrier more than in the optimization of the active compound. In this respect, virus-like particles constitute bioinspired nanodevices with the intrinsic ability to transport a large class of molecules, ranging from smart drugs to small interfering RNAs. In this work, we demonstrate the efficacy of a novel construct obtained by fusing a self-assembling protein from the human Rotavirus A, VP6, with the Small Ubiquitin Modifier domain, which maintains the ability to form nanoparticles and nanotubes and is able to be used as a drug carrier, even without specific targeting epitopes. The high expression and purification yield, combined with low toxicity of the empty particles, clearly indicate a good candidate for future studies of selective drug delivery. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2769, 2019.

Biocompatibility of Root Canal Filling Materials: Differences between Vitality and Functionality Tests

Biocompatibility of root canal filling materials is of great interest because they can come into permanent contact with the living periapical tissue, and induce mild or severe inflammatory responses. Usually biocompatibility tests only determine non-cytotoxic effects of dental materials, even if their functional interactions with cells also play a role in the host responses. The purpose of this study is to evaluate peripheral blood monocyte (PBM) vitality and functionality after contact with 5 different root canal filling materials: Thermafil (gutta-percha), Real Seal and Real Seal 1 (methacrylic resins), AureoSeal (MTA) and SuperSeal (EBA). Cellular vitality was determined by MTT test and cellular functionality by Chemiluminescence (CL) technique. Dishes of the materials were covered with cell culture medium (0.5 cm2/mL) and incubated for 24 h. The extracts were added to PBMs and the latter, after 2 h of incubation, were analysed by MTT and by Chemiluminescence (CL). All results are expressed as mean ± SEM. The group means were compared by analysis of variance. Results showed that SuperSeal and AuroSeal exhibited a moderate cytotoxic effect, while the toxicity induced by RealSeal, RealSeal 1 and Thermafil was lower. SuperSeal and AuroSeal induced a significant decrease of both oxidative burst and basal reactive oxygen species (ROS) production. RealSeal 1 caused a doubling of basal ROS production in respect to control. The results demonstrate that a low cytotoxic effect does not guarantee a total integrity of cellular functionality and more differences among biocompatibility of root canal materials can be detected when a functionality test is used.

[The metabolic activity of neutrophils and monocytes as the model for the study of the organism biocompatibility with different materials]

In stimulated status neutrophils and monocytes in the foci of introduction the different materials are capable to excrete of biologically active substances by means of which if influence on processes of reparation. The express changes of blood leukocytes activity in response on the introduction of stimulated agents are assume as a basis of the proposed model of the organism biocompatibility with different materials. On example of the influence of different materials (ceramics, titanium, latex, surgical steel and copper), from which can be made implant and surgical instruments it was showed that the leukocytes were showed the different reaction of enzyme systems. This model allows the completely and objectively to study the influence of different materials on the neutrophyls and monocytes--the effected cells of the inflammatory process. Moreover, the activity of cation proteins and plasma membrane enzymes of leukocytes is the most expressed factor.