Bioactive glasses enriched with zinc and strontium: synthesis, characterization, cytocompatibility with osteoblasts and antibacterial properties.

Purpose: The aim of the presented work was to characterize the new obtained bioglasses and assess their biological performance in vitro. Bioglasses were produced using the sol-gel method in the SiO2-P2O5-CaO system, for the purpose as composite ingredients. Their chemical composition was enriched with ZnO to introduce antibacterial properties and SrO with osteoinductive effect. The properties of bioglasses were compared and the effect of chemical composition and particle size on their biological properties was assessed. Methods: The bioglasses were evaluated via TG-DTA, FTIR, SEM-EDS analyses before and after incubation in SBF solution. LDH and WST-1 tests were used to determine the level of cytotoxicity of the tested bioglasses on hFOB1.19 osteoblasts. Results: The results show that the developed bioglasses release Ca2+, are bioactive in SBF solution, not cytotoxic and show antibacterial activity in contact with Pseudomonas aeruginosa and Staphylococcus aureus strains. Bioglasses enriched with ZnO show the highest bactericidal activity. All tested bioglasses enhanced hFOB 1.19 cells proliferation. Particle size has a lower effect on biological performance of the bioglasses than their chemical composition. Conclusions: The conducted research showed that bioglass modification with SrO and ZnO can be considered particularly for the development of biomaterials supporting bone regeneration and the treatment of infected bone defects.

Light emitting diodes optimisation for secondary metabolites production by Droseraceae plants.

The most abundant active compound in Droseraceae is plumbagin, a naphthoquinone widely used for medical purposes due to its antimicrobial, antitussive, antimalarial and anticancer properties. In this work, we created a light-emitting diode (LED) based culture illumination setup as an alternative to fluorescent lamps traditionally used as a light source in plant in vitro cultures. The plants of Drosera binata and Drosera peltata cultured under LED illumination grew equally well and produced similar amounts of biologically active compounds as plants grown under fluorescent lamps. The plants were cultured on two media differing in mineral composition, sucrose content and pH. Secondary metabolites were extracted with ethanol from the plants after harvesting. The extracts were subjected to HPLC and microbiological analyses. We observed differences in morphology and secondary metabolism between plants of the same species grown on different media. However, we did not note significant changes in secondary metabolite yield under assessed lighting conditions. We propose LEDs as a more efficient, eco-friendly and economically reasonable source of light for big scale in vitro production of plumbagin in Drosera species than fluorescent lamps.