Limited permeability through the stratum corneum (SC) is a major obstacle for numerous skin care products. One promising approach is to use lipid nanoparticles as they not only facilitate penetration across skin but also avoid the drawbacks of conventional skin formulations. This review focuses on solid lipid nanoparticles (SLNs), nanostructured lipid nanocarriers (NLCs), and nanoemulsions (NEs) developed for topical and transdermal delivery of active compounds. A special emphasis in this review is placed on composition, preparation, modifications, structure and characterization, mechanism of penetration, and recent application of these nanoparticles. The presented data demonstrate the potential of these nanoparticles for dermal and transdermal delivery.

Agricultural residue-activated carbon and biochar, inexpensive and environmentally friendly adsorbent materials, have recently received significant research attention. This study investigated the potential use of oak cupules in activated carbon form to remove widespread heavy metals (Pb²⁺, Cu²⁺, and Ni²⁺) from wastewater. The oak-activated carbon was prepared from oak cupules and activated with phosphoric acid. Oak-activated carbon was characterized using FTIR, BET analysis, energy-dispersive X-ray spectrometry (EDS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The Freundlich, Langmuir, and Temkin isotherm models were used to assess the equilibrium data. The impact of various parameters, including pH effect, temperature, adsorbent dose, and contact time, was estimated. The Freundlich model was the most agreeable with Pb²⁺ adsorption by oak-based activated carbon, and Langmuir was more compatible with Cu²⁺ and Ni²⁺. Under optimum conditions, the average maximum removal was 63% Pb²⁺, 60% Cu²⁺, and 54% Ni²⁺ when every ion was alone in the aqueous solution. The removal was enhanced to 98% Pb²⁺, 72% Cu²⁺, and 60% Ni²⁺ when found as a mixture. The thermodynamic model revealed that the adsorption of ions by oak-based activated carbon is endothermic. The pseudo-second-order kinetic best describes the adsorption mechanism in this study; it verifies chemical sorption as the rate-limiting step in adsorption mechanisms. The oak-activated carbon was effective in removing Pb²⁺, Cu²⁺, and Ni²⁺ from wastewater and aqueous solutions.

As a potential approach for enhanced energy generation from anaerobic digestion, iron-based conductive nanoparticles have been proposed to enhance the methane production yield and rate. In this study, the impact of two different types of iron nanoparticles, namely the nano-zero-valent-iron particles (NZVIs) and magnetite (Fe₃O₄) nanoparticles (NPs) was investigated, using batch test under mesophilic conditions (35 °C). Magnetite NPs have been applied in doses of 25, 50 and 80 mg/L, corresponding to 13.1, 26.2 and 41.9 mg magnetite NPs/gTS of substrate, respectively. The results reveal that supplementing anaerobic batches with magnetite NPs at a dose of 25 mg/L induces an insignificant effect on hydrolysis and methane production. However, incubation with 50 and 80 mg/L magnetite NPs have instigated comparable positive impact with hydrolysis percentages reaching approximately 95% compared to 63% attained in control batches, in addition to a 50% enhancement in methane production yield. A biodegradability percentage of 94% was achieved with magnetite NP doses of 50 and 80 mg/L, compared to only 62.7% obtained with control incubation. NZVIs were applied in doses of 20, 40 and 60 mg/L, corresponding to 10.8, 21.5 and 32.2 mg NZVIs/gTS of substrate, respectively. The results have shown that supplementing anaerobic batches with NZVIs revealed insignificant impact, most probably due to the agglomeration of NZVI particles and consequently the reduction in available surface area, making the applied doses insufficient for measurable effect.

Global concerns regarding microplastics emerging in the environment have been raised recently. Using samples collected during the OceanXplorer mission in Aqaba, we explored the depth-based and regional variations of microplastics across pelagic and benthic zones. Microplastics (63.0–950.0 μm) from the surface seawater, middle seawater, bottom seawater, and deep-sea sediment were quantified and identified using a dissecting microscope and Fourier Transform Infrared microscope (μ-FTIR). The results revealed that the average abundance of microplastics was 6.7 ± 6.05 particles L⁻¹ in the pelagic zone and 2900 ± 1650 particles kg⁻¹ in the benthic zone. A size gradation of microplastics was observed across depths from 5 to 840 m, accompanied by a shift in particle types: fragments were the most common in the benthic zone, whereas fibers dominated the pelagic zone. μ-FTIR analysis identified the presence of the following polymers: polyethylene (PE), polyvinyl chloride (PVC), polyamide 6 (PA 6), and polypropylene (PP). These findings establish baseline data for future monitoring and management efforts addressing microplastic pollution in the Gulf of Aqaba.