Tianyi Shen

Zinc is an essential micronutrient in agricultural systems, fulfilling vital roles in both plant physiology and modern fertilizer formulations. Despite its importance, zinc deficiency has emerged as one of the most prevalent micronutrient limitations in global agriculture. Humic acids (HA) can serve as effective transporters of trace elements for crops, including in foliar fertilization. Our investigation addressed two key aspects: (1) the synthesis of HA-stabilized ZnO nanoparticles, and (2) the assessment of nanoparticle efficacy as zinc sources for foliar fertilization. ZnO and HA-coated ZnO nanoparticles were synthesized via a chemical deposition method and characterized by FTIR, XRD, DLS, ELS, UV-Vis spectroscopy, and TEM. The penetration ability of the nanoparticles through plant leaves was investigated using wheat sprouts. After 24 h of saturation, the plants were dried, and their leaves and seedlings were dissolved in nitric acid; the solution was analyzed by ICP-AES. HA-coated ZnO nanoparticles showed competitive performance compared to conventional zinc chelates used in agriculture. Wheat leaf studies confirmed that nanoparticle accumulation and uptake are pH-dependent, with acidic conditions favoring HA-coated ZnO nanoparticles. These findings provide valuable insights for developing advanced zinc-containing formulations for foliar crop fertilization. The demonstrated effectiveness of HA-stabilized ZnO nanoparticles suggests they represent a promising alternative to traditional zinc supplements in agriculture.

Coatings with xenogenic materials, made of detonation nanodiamonds, provide additional strength and increase elasticity. A functionally developed surface of nanodiamonds makes it possible to apply antibiotics. Previous experiments show the stability of such coatings; however, studies on stability in the bloodstream and calcification of the material in natural conditions have yet to be conducted. Tritium-labeled nanodiamonds (negative and positive) were obtained by the tritium activation method and used to develop coatings for a pork aorta to analyze their stability in a pig’s bloodstream using a radiotracer technique. A chitosan layer was applied from a solution of carbonic acid under high-pressure conditions to prevent calcification. The obtained materials were used to prepare a porcine conduit, which was surgically stitched inside the pig’s aorta for four months. The aorta samples, including nanodiamond-coated and control samples, were analyzed for nanodiamond content and calcium, using the radiotracer and ICP-AES methods. A histological analysis of the materials was also performed. The obtained coatings illustrate a high in vivo stability and low levels of calcification for all types of nanodiamonds. Even though we did not use additional antibiotics in this case, the development of infection was not observed for negatively charged nanodiamonds, opening up prospects for their use in developing coatings.

This research is focused on the adsorption modification of detonation nanodiamond surfaces with antibiotics for their further use as smart materials for cardiovascular surgery purposes, namely as bioprostheses modifiers. Tritium-labeled amikacin and levofloxacin were used as tracers for the adsorption process control. We found that nanodiamonds form adsorption complexes with levofloxacin via physical adsorption, while in the case of amikacin, electrostatic attraction contributes to the formation of more stable complexes, even in the presence of electrolytes and desorbing agents (models of biological fluids). Antimicrobial characterization of nanodiamond–levofloxacin and nanodiamond–amikacin complexes indicates a reduction in the dose of antibiotics that is used as an antimicrobial agent. Therefore, the use of biomaterial based on DND complexes with antibiotics as the basis of bioprostheses will allow one either to avoid or significantly reduce the duration and intensity of antibiotics use in the postoperative period, which is critically important from the viewpoint of the development of antibiotic resistance in pathogens.