Mechanistic Insights into Interactions at Urea-Hydroxyapatite Nanoparticle Interface

Advances of Hydroxyapatite Nanoparticles in Dental Implant Applications

Hydroxyapatite nanoparticles (HANPs) are becoming increasingly crucial in dental implant applications as they are highly compatible with biological systems, actively support biological processes, and closely resemble bone minerals. This review covers the latest progress in how HANPs are made, studied, and used in dentistry. It looks at critical methods for creating HANPs, such as sol-gel, microwave hydrothermal synthesis, and biomimetic approaches, and how they affect the particles' size, structure, and activity. The green synthesis method illustrated a new door to synthesize HAp for maintaining biocompatibilityand increasing antibacterial properties. The review also explores how HANPs improve the integration of implants with bone, support bone growth, and help treat sensitive teeth based on various laboratory and clinical studies. The usage of HAp in dentin and enamel shows higher potentiality through FTIR, XPS, XRD, EDS, etc., for mechanical stability and biological balance compared to natural teeth. Additionally, the use of HANPs in dental products like toothpaste and mouthwash is discussed, highlighting its potential to help rebuild tooth enamel and fight bacteria. There are some challenges for long-term usage against oral bacteria, but doping with inorganic materials, like Zn, has already solved this periodontal problem. Much more research is still essential to estimate the fabrication variation based on patient problems and characteristics. Still, it has favorable outcomes regarding its bioactive nature and antimicrobial properties. Due to their compatibility with biological tissues and ability to support bone growth, HANPs hold great promise for advancing dental materials and implant technology, potentially leading to better dental care and patient outcomes.

Facet-engineering strategy of phosphogypsum for production of mineral slow-release fertilizers with efficient nutrient fixation and delivery

Phosphogypsum (PG) presents considerable potential for agricultural applications as a secondary primary resource. However, it currently lacks environmentally friendly, economically viable, efficient, and sustainable reuse protocols. This study firstly developed a PG-based mineral slow-release fertilizer (MSRFs) by internalization and fixation of urea within the PG lattice via facet-engineering strategy. The molecular dynamics simulations demonstrated that the binding energy of urea to the (041) facet of PG surpassed that of the (021) and (020) facets, with urea's desorption energy on the (041) facet notably higher than on the (021) and (020) facets. Guided by these calculations, we selectively exposed the (041) dominant facet of PG, and then achieving complete urea fixation within the PG lattice to form urea-PG (UPG). UPG exhibited a remarkable 48-fold extension in N release longevity in solution and a 45.77% increase in N use efficiency by plants compared to conventional urea. The facet-engineering of PG enhances the internalization and fixation efficiency of urea for slow N delivery, thereby promoting nutrient uptake for plant growth. Furthermore, we elucidated the intricate interplay between urea and PG at the molecular level, revealing the involvement of hydrogen and ionic bonding. This specific bonding structure imparts exceptional thermal stability and water resistance to the urea within UPG under environmental conditions. This study has the potential to provide insights into the high-value utilization of PG and present innovative ideas for designing efficient MSRFs.

Synthesis of zeolite A from fly ash and its application in the slow release of urea

The study focused on the transformation of coal fly ash to zeolite A (ZA) as a potential carrier for the slow release of urea. After being treated with HCl aqueous solution and NaOH successively, SiO₂ and Al₂O₃ were converted into sodium silicoaluminate. The obtained silicoaluminate was then heated with NaAlO₂ in an aqueous NaOH solution at 70-110 °C for 3-18 h and zeolite A was successfully prepared according to the X-ray diffraction measurements. By changing the hydrothermal temperature and time, ZA could reach 237.3 mmol/100 g in maximum cation exchange capacity. ZA impregnated with urea (ZA-U) at a mass ratio of more than 5:1 exhibited slow release of urea and the kinetics release mechanism of ZA-U was proposed. The plant growth test proved that the slow release of urea from ZA-U can promote the growth of maize seedling.

Synergistic and non-synergistic impact of HAP-based nano fertilizer and PGPR for improved nutrient utilization and metabolite variation in hemp crops

Nanofertilizer prepared with urea-hydroxyapatite amalgamation along with PGPR promotes urea availability over longer period of plant growth and reduces wasteful urea expense in soil, curtailing environmental pollution.