Combined effect of Cerium oxide nanoparticles loaded scaffold and photobiomodulation therapy on pain and neuronal regeneration following spinal cord injury: an experimental study

BACKGROUND

Spinal cord injury (SCI) remained one of the challenges to treat due to its complicated mechanisms. Photobiomodulation therapy (PBMT) accelerates neuronal regeneration. Cerium oxide nanoparticles (CeONPs) also eliminate free radicals in the environment. The present study aims to introduce a combined treatment method of making PCL scaffolds as microenvironments, seeded with CeONPs and the PBMT technique for SCI treatment.

METHODS

The surgical hemi-section was used to induce SCI. Immediately after the SCI induction, the scaffold (Sc) was loaded with CeONPs implanted. PBMT began 30 min after SCI induction and lasted for up to 4 weeks. Fifty-six male rats were randomly divided into seven groups. Glial fibrillary acidic protein (GFAP) (an astrocyte marker), Connexin 43 (Con43) (a member of the gap junction), and gap junctions (GJ) (a marker for the transfer of ions and small molecules) expressions were evaluated. The behavioral evaluation was performed by BBB, Acetone, Von Frey, and radiant heat tests.

RESULT

The SC + Nano + PBMT group exhibited the most remarkable recovery outcomes. Thermal hyperalgesia responses were mitigated, with the combined approach displaying the most effective relief. Mechanical allodynia and cold allodynia responses were also attenuated by treatments, demonstrating potential pain management benefits.

CONCLUSION

These findings highlight the potential of PBMT, combined with CeONPs-loaded scaffolds, in promoting functional motor recovery and alleviating pain-related responses following SCI. The study underscores the intricate interplay between various interventions and their cumulative effects, informing future research directions for enhancing neural repair and pain management strategies in SCI contexts.

Magnetic MgFe2O4-CaFe2O4 S-scheme photocatalyst prepared from recycling of electric arc furnace dust

In this research, magnetic MgFe₂O₄-CaFe₂O₄ photocatalyst powder was prepared from recycling of electric arc furnace (EAF) dust as a secondary source through a two-step leaching process followed by co-precipitation method. To maximize the total Fe to Ca recovery ratio (F/C) and evaluate the effective parameters of sulfuric acid concentration and temperature, response surface methodology (RSM) as a design of experiment was used. The best temperature and acid concentration were obtained as 85 °C and 1 M, respectively for the second step of the leaching process. X-ray diffraction (XRD) results indicated that the synthesized nanocomposite sample contains MgFe₂O₄ and CaFe₂O₄ phases together with a small amount of Ca₂Fe₂O₅. The saturation magnetization and optical band gap of the synthesized composite powder were 24 emu/g and 2.17 eV, respectively. X-Ray photoelectron spectroscopy (XPS) result revealed the oxidation states as Fe³⁺, Ca²⁺, Mg²⁺ and O^2-. Energy dispersive X-ray spectroscopy (EDS) showed that the elements were uniformly distributed within the nanostructured particles. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) results indicated the presence of CaFe₂O₄ and MgFe₂O₄ nanoparticles with good contact between them. The nanocomposite sample showed the capability of 45% for degrading methylene blue (MB) dye under 240 min visible light irradiation. The reusability tests showed that the photocatalytic activity of the nanocomposite was not considerably changed after three cycles.

High performance Ni–CNTs catalyst: synthesis and characterization

In this study, a Ni–CNTs nano-composite was synthesized via mechanical milling.

Preparation of magnetic nano-composite: barium hexaferrite loaded in the ordered meso-porous silica matrix (MCM-41)

In this work a magnetic nano-composite was synthesized by modified incorporation of iron-barium complex into ordered meso-porous silica (MCM-41) as a matrix. The MCM-41 was synthesized by silylation treatment which was accompanied by pH adjusting. Low angle XRD patterns of both annealed MCM-41 and resulted composite exhibited the characteristic reflection of high quality hexagonal meso-structures. TEM image of the composite material revealed that the hexagonal ordered meso-structure host material was not affected by wet impregnation and subsequent calcination in order to incorporate with barium hexaferrite. Also, TEM images accompanied by EDS analysis confirmed the formation of second phase consists of barium and iron ions inside the MCM-41 channels. The resulted composite material showed a super-paramagnetic nature at room temperature.

An investigation of the neuroprotective effects of Curcumin in a model of Homocysteine - induced oxidative stress in the rat's brain

BACKGROUND AND THE PURPOSE OF THE STUDY

Aging is the major risk factor for neurodegenerative diseases and oxidative stress is involved in the pathophysiology of them. Oxidative stress can induce neuronal damages and modulate intracellular signaling, ultimately leading to neuronal death by apoptosis or necrosis. In this study, the possible antioxidant and neuroprotective properties of the natural polyphenolic antioxidant compound, curcumin against homocysteine (Hcy) neurotoxicity was investigated.

METHODS

Curcumin (5, 15, 45 mg/kg) was injected intraperitonealy (i.p.) once daily for a period of 10 days beginning 5 days prior to Hcy (0.2 µmol/µl) intracerebroventricular (i.c.v) injection in rats. Biochemical and behavioral studies, including passive avoidance learning and locomotor activity tests were studied 24 hrs after the last curcumin or its vehicle injection. The cell density of hippocampus layers and apoptosis in rats' hippocampi by immunohistochical methods were also studied.

RESULTS AND MAJOR CONCLUSION

Results indicated that Hcy could induce lipid peroxidation and increase Malondialdehyde (MDA) and Super Oxide Anion (SOA) levels in rat's brain. Additionally, Hcy impaired memory retention in passive avoidance learning test. However, curcumin decreased MDA and SOA levels significantly and improved learning and memory in rats. On the other hand Hcy could induce cell death and apoptosis in rats' hippocampi which was inhibited by curcumin. These results suggest that Hcy may induce lipid peroxidation in rat's brain. and polyphenol treatment (curcumin) improves learning and memory deficits by protecting the nervous system against Oxidative stress.