Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, β-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin). These complexes increase the bioactivity and bioavailability of curcumin. The current review provides these derivatization strategies for curcumin in terms of biological and physico-chemical aspects with a strong focus on different type of proteins, characterization methods, and thermodynamic features of protein–curcumin complexes, and with the aim of evaluating the best performances. The current literature review offers, taking into consideration various biological effects of the CCM, a whole approach for CCM-biomolecules interactions such as CCM-proteins, CCM-nanomaterials, and CCM-natural compounds regarding molecular strategies to improve the bioactivity as well as the bioavailability of curcumin in biological systems.

Curcumin is among the most well-studied natural substances, known for its biological actions within the central nervous system, its antioxidant and anti-inflammatory properties, and human health benefits. However, challenges persist in effectively utilising curcumin, addressing its metabolism and passage through the blood–brain barrier (BBB) in therapies targeting cerebrovascular diseases. Current challenges in curcumin’s applications revolve around its effects within neoplastic tissues alongside the development of intelligent formulations to enhance its bioavailability. Formulations have been discovered including curcumin’s complexes with brain-derived phospholipids and proteins, or its liposomal encapsulation. These novel strategies aim to improve curcumin’s bioavailability and stability, and its capability to cross the BBB, thereby potentially enhancing its efficacy in treating cerebrovascular diseases. In summary, this review provides a comprehensive overview of molecular pathways involved in interactions of curcumin and its metabolites, and brain vascular homeostasis. This review explores cellular and molecular current aspects, of curcumin-based effects with an emphasis on curcumin’s metabolism and its impact on pathological conditions, such as neurodegenerative diseases, schizophrenia, and cerebral angiopathy. It also highlights the limitations posed by curcumin’s poor bioavailability and discusses ongoing efforts to surpass these impediments to harness the full therapeutic potential of curcumin in neurological disorders.

This work aimed to compare the effect of four new toothpastes (P1–P4) based on pure and biomimetic substituted nano-hydroxyapatites (HAPs) on remineralization of human enamel. Artificially demineralized enamel slices were daily treated for ten days with different toothpastes according to the experimental design. Tooth enamel surfaces were investigated using atomic force microscope (AFM) images and surface roughness (Ra) determined before and after treatment. The surface roughness of enamel slices was statistically analyzed by one-way ANOVA and Bonferroni’s multiple comparison test. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) data revealed the HAP structure with crystal sizes between 28 and 33 nm and crystallinity between 29 and 37%. The average size of HAP particles was found to be between 30 and 40 nm. The Ra values indicated that P3 (HAP-Mg-Zn-Sr-Si) toothpaste was the most effective after 10 days of treatment, leading to the lowest mean roughness. The P3 and P2 (HAP) toothpastes were found to be effective in promoting remineralization. Specifically, their effectiveness can be ranked as follows: P3 = P2 > P4 (HAP-Mg-Zn-Si) > P1 (HAP-Zn), considering both the chemical composition and the size of their constitutive nanoparticles. The proposed toothpastes might be used successfully to treat early tooth decay.

In this work, new optical properties of composites based on polystyrene (PS) microspheres and graphene oxide (GO) are reported. The radical polymerization of styrene in the presence of benzoyl peroxide, pentane and GO induces the appearance of new ester groups in the PS macromolecular chains remarked through an increase in the absorbance of the infrared (IR) band at 1743 cm⁻¹. The decrease in the GO concentration in the PS/GO composites mass from 5 wt.% to 0.5 wt.% induces a diminution in the intensities of the D and G Raman bands of GO simultaneous with a down-shift of the D band from 1351 to 1322 cm⁻¹. These variations correlated with the covalent functionalization of the GO layers with PS. For the first time, the photoluminescent (PL) properties of PS/GO composites are reported. The PS microspheres are characterized by a PL band at 397 nm. Through increasing the GO sheets’ concentration in the PS/GO composite mass from 0.5 wt.% to 5 wt.%, a PS PL quenching process is reported. In addition, in the presence of ultraviolet A (UVA) light, a photo-degradation process of the PS/GO composite having the GO concentration equal to 5 wt.% is demonstrated by the PL studies.

Curcumin (CCM) is a natural polyphenol with promising pharmacological potential. This potential is severely restricted, however, due to its limited bioavailability, poor solubility and stability. To address this, several systems of curcumin and polyethylene glycol, PEG (PEG4000 or PEG6000), were synthetized, with or without whey protein concentrate (WPC), trans-resveratrol (RES) or silymarin (SIL) using solid dispersion technique. Firstly, CCM-PEG composites were synthesized using PEG4000 or PEG6000 for 1:8 mol ratio by polymer melting method. Further, the CCM-WPC-PEG4000 composite for 1:0.4:8 mol ratio and CCM-WPC-PEG6000 composite for 1:0.5:10 mol ratio were synthesized. Furthermore, CCM-RES-WPC-PEG and CCM-SIL-WPC-PEG composites were prepared for 1:2.5:0.4:10 mol ratio for PEG4000 or PEG6000. The composite formation was investigated by Fourier transform infrared spectroscopy (FTIR). The thermal stability of synthesized composites was analyzed through thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealing a high stability up to 200 °C. Thus, each composite formulation was optimized to carry CCM, RES and WPC or CCM, SIL and WPC within PEG matrix primarily by hydrogen bonds and van der Waals interactions. This study demonstrated that all synthesized composites may have potential advantages for applications such as nutraceuticals, functional foods, supplements and pharmaceuticals.

Magnetically separable TiO₂-based composite photocatalysts have gained significant interest in the past two decades; however, the optimization of their synthesis and the stabilization of the magnetic iron oxide within the composite is still an open challenge. The present study investigates the photocatalytic behavior and recyclability of TiO₂-Fe₃O₄ composites, with emphasis on a possible correlation between pollutant degradation efficiency, recyclability, iron oxide stability, and the phase composition of the chosen TiO₂ base. Magnetite nanoparticles were synthesized under varied temperature and alkaline conditions to identify optimal parameters for achieving the desirable magnetic properties. The magnetic nanoparticles were integrated into composite systems with either commercial TiO₂ (Evonik Aeroxide P25 with anatase–rutile mixed phase) or a hydrothermally synthesized anatase TiO₂. The P25-based composite removed 99% paracetamol from aqueous solutions under UV-A irradiation and demonstrated successful recyclability, maintaining 96% paracetamol degradation efficiency after four uses. In contrast, the anatase TiO₂-based magnetic composite exhibited a lower performance (70%) and a significantly hindered recyclability (45% after four cycles). The difference in performance was attributed to variations in the phase composition of the employed TiO₂ in the composites and, consequently, in their charge separation mechanisms.