română LEVENTE-ZSOLT RÁCZ, LUCIAN-CRISTIAN POP, GHEORGHE TOMOAIA, AURORA MOCANU, CSABA-PÁL RÁCZ, ATTILA-ZSOLT KUN, EDIT FORIZS, MELINDA SÁRKÖZI, CSABA VÁRHELYI JR., MARIA TOMOAIA-COTISEL
Abstract
Gaining basic knowledge on the nanostructure of advanced composites, based on curcumin, CCM, mixed with various bioactive compounds, in polyethylene glycol, PEG6000, will allow better innovative applications of these composites for their importance, particularly as functional foods and supplements for human health care benefits. Our goal is to understand the behavior of curcumin, in the presence of whey protein concentrate, WPC, trans-resveratrol, RES, or silymarin, SIL, within PEG6000 matrix, and the role of biomolecules in making advanced composites, such as PEG6000-CCM, PEG6000-CCM-WPC, PEG6000-CCM-RES-WPC and PEG6000-CCM-SIL-WPC, and thus, developing tailored compositions with multifunctionality. In this study, AFM images: 2D- and 3D-topographies as well as phase and amplitude images provide the surface morphology of nanostructured composites at nanometer resolution and surface roughness as root mean square, RMS, confirming the miscibility of compounds within PEG6000 matrix, and the shape and size of composite nanoparticles. The WPC enhances the stability of these composites through the intermolecular hydrogen bonds with CCM and RES or SIL, leading from small molecules to advanced composite nanostructures within the PEG6000 matrix, as evidenced by AFM investigation. FTIR data for all four composites reveal the interaction between the precursor components within PEG6000 matrix primarily by the formation of new intermolecular hydrogen bonds between their functional groups. Conclusively, the innovative nanocomposites, PEG6000-CCM, PEG6000-CCM-WPC, PEG6000-CCM-RES-WPC and PEG6000-CCM-SIL-WPC, provide an effective strategy for the design of novel promising nanocomposites for biomedical applications, such as drug delivery systems to treat various diseases, especially cancer and for bone regeneration medicine.
Keywords
nanostructured composites, curcumin, whey protein concentrate, resveratrol, silymarin, PEG6000, AFM, FTIR
HAYET MISSOUNI, DJANETTE MERIEM BLIZAK, SOUHEYLA TOUBAL, IMANE DJOUABI, MAHDIA TOUBANE, NADIA BOUKHERROUB
Abstract
Conventional nanoparticle synthesis routes raise growing environmental concerns, making green approaches increasingly relevant. Here, NiO nanoparticles were prepared via hydrothermal synthesis, using Ziziphus Lotus (L.) almond as a natural mediating agent, alongside a control synthesis without extract. According to our investigations, no previous study has used, the almonds of Ziziphus Lotus (L.), for the production of metal oxide nanoparticles. The nanoparticles obtained were characterized by X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM), UV-visible spectroscopy, and zeta potential measurement. The results we obtained showed that the hydrothermal temperature is a crucial parameter in crystallization: samples treated at 140 °C exhibited good crystallization, with crystallites averaging around 34 nm in size, and SEM images revealed a clearly ordered lamellar morphology. The presence of this almond extract had multiple effects on the resulting nanoparticles. Their growth was directed towards anisotropic morphologies, their surface charge was modified, and their optical band gap was considerably widened, reaching 3.75 eV, compared to 3.48 eV in the sample without the extract. The results of this study confirm that hydrothermal biosynthesis is a easy and environmentally friendly method for producing NiO nanoparticles. Thus, these nanoparticles may provide new opportunities in the domain of optoelectronics, energy storage and biomedical applications.
Keywords
NiO nanoparticles, biosynthesis, hydrothermal, Ziziphus Lotus (L.) Lam almond
GEORGE ANDREI PETRESCU, ADRIAN IONUT NICOARA, VLADIMIR LUCIAN ENE, IONELA ANDREEA NEACSU, ANAMARIA BECHIR
Abstract
This study compared the mechanical behavior and chemical evolution of three temporary dental cements—zinc phosphate (FOZ), glass ionomer (CIS), and resin-based (DT)—aged in air and artificial saliva, and explored how microstructural changes relate to their mechanical performance. Cylindrical specimens of FOZ, CIS, and DT were prepared according to manufacturers’ instructions and aged for 3, 14, and 28 days in air or artificial saliva at 25 °C. Compressive strength and elastic response were measured by uniaxial testing. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) were used to characterize crystalline phases and functional groups. FOZ showed marked phase evolution, with XRD revealing a shift from a mixed ZnO–Hopeite composition toward ZnO dominance in air, while saliva preserved higher Hopeite content; these changes were associated with reduced compressive strength in air and increased strength in saliva. CIS remained crystallographically and chemically stable, with BaSO4 as the main crystalline phase and minimal FTIR changes, matching its nearly unchanged compressive strength in air. DT maintained a broadly constant biphasic calcium phosphate–zirconia pattern and a stable resin FTIR signature, consistent with its predominantly elastic behavior and modest variation in elastic force, especially in saliva. The three cements exhibit distinct, material-dependent aging patterns that directly influence their mechanical performance under simulated oral conditions.
Keywords
dental cements, zinc phosphate cement, glass ionomer cement, resin-based cement, artificial saliva aging, provisional prostheses