In vitro and in vivo evaluation of osteogenesis and antibacterial activity of MgGa alloys.

MgGa alloys are considered highly potential biodegradable materials, owing to its good mechanical properties and appropriate corrosion resistance. However, it is still far from application due to the lack of biological evaluation. In the present study, biocompatibility, osteogenesis and antibacterial activity of extruded Mg-xGa (x = 1 and 5 wt%) alloys were investigated by in vitro cell culture experiments and in vivo implantation. The cell adhesion and proliferation of osteoblast precursor cells (MC3T3-E1) showed the excellent cytocompatibility of Mg-1Ga and poor cytocompatibility of Mg-5Ga. The osteogenic activity was evaluated and revealed that Ga3+ in the Mg-1Ga extract had the ability to enhance osteogenic differentiation through the facilitation of its early stages. In vivo studies in a rat femoral condyle model revealed that both Mg-1Ga and Mg-5Ga significantly promoted new bone formation without causing any adverse effects. Mg-5Ga exhibited a much higher corrosion rate in vivo than Mg-1Ga. Its osteogenic activity was better due to the rapid release of Mg2+ and Ga3+, but this caused premature structural integrity loss. Mg-1Ga and Mg-5Ga released Ga3+ to inhibit E. coli and S. aureus, with antibacterial rate increasing with Ga content. Our studies demonstrate that Mg-Ga alloys have the potential to be used as osteogenic and antibacterial implant materials. STATEMENT OF SIGNIFICANCE: This study evaluates the biocompatibility, osteogenesis, and antibacterial activity of Mg-Ga alloys, which are promising biodegradable materials for medical applications. The study finds that Mg-1Ga exhibits excellent cytocompatibility and promotes osteogenic differentiation, facilitating the early stages of osteoblast precursor cell development. In vivo studies in a rat femoral condyle model reveal that Mg-1Ga and Mg-5Ga significantly promote new bone formation without causing any adverse effects. The antibacterial activity of both alloys is evaluated against E. coli and S. aureus, with the inhibition rate increasing with Ga content. These findings suggest that Mg-Ga alloys have the potential to serve as osteogenic and antibacterial implant materials, providing significant insights into the development of novel biomedical implants.

Asymptomatic 3-methylglutaconic aciduria type 1 detected by high C5-OH on newborn screening.

3-Methylglutaconic aciduria type 1 (MGCA1) is an inborn error of leucine catabolism caused by pathogenic variants of the AUH gene. MGCA1 can be identified by newborn screening (NBS) with elevated C5-OH levels. We herein report a girl with MGCA1 detected by NBS. On day 5 after birth, NBS detected high C5-OH levels of 1.17 µmol/L (1.56 µmol/L [retest]). A urinary organic acid analysis revealed the abnormal excretion of 3-methylglutaconic, 3-methylglutaric, and 3-hydroxyisovaleric acids. Two novel heterozygous loss-of-function variants in the AUH gene were identified by genetic testing. We observed the patient without any treatment, such as a leucine-restricted diet. She had episodes of febrile illness several times in infancy but did not develop febrile convulsions or encephalopathy. She is now two years and six months old, and her physical growth and psychomotor development have progressed normally. In a review of the literature and our case, four children with MGCA1 identified during the neonatal period were asymptomatic or exhibited speech delay, regardless of whether or not they had been managed with specific treatments. Treatments such as dietary leucine restriction and carnitine supplementation may have little effect on MGCA1 in childhood; however, further investigation is warranted to evaluate the benefits of specific treatments to prevent potential long-term neurological complications.

Broadband Short-Wave Infrared-Emitting MgGa2O4:Cr3+, Ni2+ Phosphor with Near-Unity Internal Quantum Efficiency and High Thermal Stability for Light-Emitting Diode Applications.

Blue InGaN chip-pumped short-wave infrared (SWIR) emitters have aroused tremendous attention and shown emerging applications in diverse fields such as healthcare, retail, and agriculture. However, discovering blue light-emitting diode (LED)-pumped SWIR phosphors with a central emission wavelength over 1000 nm remains a significant challenge. Herein, we demonstrate the efficient broadband SWIR luminescence of Ni2+ by simultaneously incorporating Cr3+ and Ni2+ ions into the MgGa2O4 lattice, with Cr3+ as the sensitizer and Ni2+ as the emitter. Because of the strong blue light absorption of Cr3+ and high energy transfer efficiency to Ni2+, the obtained MgGa2O4:Cr3+, Ni2+ phosphors show intense SWIR luminescence with a peak wavelength at 1260 nm and a full width at half maximum (FWHM) of 222 nm under the excitation of blue light. The optimized SWIR phosphor presents an ultra-high SWIR photoluminescence quantum efficiency of 96.5% and outstanding luminescence thermal stability (67.9%@150 °C). A SWIR light source has been fabricated through a combination of the prepared MgGa2O4:Cr3+, Ni2+ phosphor and a commercial 450 nm blue LED chip, delivering a maximum SWIR radiant power of 14.9 mW at 150 mA input current. This work not only demonstrates the feasibility of developing broadband high-power SWIR emitters using converter technology but also presents new insights into the importance of SWIR technology.

Theoretical investigation of the low lying electronic states of MgGa.

In this work, we investigate the low-lying electronic states correlated to the first and the second dissociation channels of MgGa molecule, neglecting and including the spin-orbit coupling effect. High-level ab initio calculations have been performed by using the icMRCI + Q method. Potential energy curves, spectroscopic constants, electron configurations and dipole moments are derived and discussed. Molecular structures of several magnesium-group 13 diatomics have been probed and analyzed. Information associated with transition dipole moments, Franck-Condon factors, vibrational branching ratios and radiative lifetimes between the Ω states are also well characterized. It is anticipated this work will provide some inspiration for further studies on MgGa.

Physico-Chemical Properties of MgGa Mixed Oxides and Reconstructed Layered Double Hydroxides and Their Performance in Aldol Condensation of Furfural and Acetone.

MgGa layered double hydroxides (Mg/Ga = 2-4) were synthesized and used for the preparation of MgGa mixed oxides and reconstructed hydrotalcites. The properties of the prepared materials were examined by physico-chemical methods (XRD, TGA, NH3-TPD, CO2-TPD, SEM, and DRIFT) and tested in aldol condensation of furfural and acetone. The as-prepared phase-pure MgGa samples possessed hydrotalcite structure, and their calcination resulted in mixed oxides with MgO structure with a small admixture phase characterized by a reflection at 2θ ≈ 36.0°. The interaction of MgGa mixed oxides with pure water resulted in reconstruction of the HTC structure already after 15 s of the rehydration with maximum crystallinity achieved after 60 s. TGA-MS experiments proved a substantial decrease in carbonates in all rehydrated samples compared with their as-prepared counterparts. This allowed suggesting presence of interlayer hydroxyls in the samples. Acido-basic properties of MgGa mixed oxides determined by TPD technique did not correlate with Mg/Ga ratio which was explained by the specific distribution of Ga atoms on the external surface of the samples. CO2-TPD method was also used to evaluate the basic properties of the reconstructed MgGa samples. In these experiments, an intensive peak at T = 450°C on CO2-TPD curve was attributed to the decomposition of carbonates newly formed by CO2 interaction with interlayer carbonates rather than to CO2 desorption from basic sites. Accordingly, CO2-TPD method quantitatively characterized the interlayer hydroxyls only indirectly. Furfural conversion on reconstructed MgGa materials was much larger compared with MgGa mixed oxides confirming that Brønsted basic sites in MgGa catalysts, like MgAl catalysts, were active in the reaction. Mg/Ga ratio in mixed oxides influenced product selectivity which was explained by the difference in textural properties of the samples. In contrast, Mg/Ga ratio in reconstructed catalysts had practically no effect on the composition of reaction products suggesting that the basic sites in these catalysts acted similarly in aldol condensation of acetone with furfural. It was concluded that the properties of MgGa samples resembled in a great extent those of MgAl hydrotalcite-based materials and demonstrated their potential as catalysts for base-catalyzed reactions.