Injectable Ozone-Rich Nanocomposite Hydrogel Loaded with D-Mannose for Anti-Inflammatory and Cartilage Protection in Osteoarthritis Treatment.

Osteoarthritis (OA) is a dynamic condition characterized by cartilage damage and synovial inflammation. Ozone (O3 ) shows potential therapeutic effects owing to its anti-inflammatory properties; however, its high reactivity and short half-life substantially limit its effectiveness in OA treatment. In this study, an ozone-rich thermosensitive nanocomposite hydrogel loaded with D-mannose is developed for OA treatment. Briefly, O3 is encapsulated in nanoparticles (NPs) composed of perfluorotributylamine and fluorinated hyaluronic acid to improve its stability. Next, D-mannose is conjugated with α-amino of the hydroxypropyl chitin (HPCH) via Schiff base to prepare MHPCH. These nanoparticles are encapsulated in MHPCH to produce O3 NPs@MHPCH. In vitro cell experiments demonstrate that the O3 NPs@MHPCH treatment significantly reduced VEGF and inflammation levels, accompanied by a decrease in inflammatory factors such as IL-1ß, IL-6, TNF-α, and iNOS. Furthermore, O3 NPs@MHPCH promotes the expression of collagen II and aggrecan and stimulates chondrocyte proliferation. Additionally, in vivo studies show that O3 NPs@MHPCH significantly alleviated OA by reducing synovial inflammation, cartilage destruction, and subchondral bone remodeling. O3 NPs@MHPCH offers a promising option for improving the efficacy of O3 therapy and reducing the risk of synovial inflammation and cartilage degeneration in OA.

[Serum levels of homocysteine and folate in neonates with asphyxia].

OBJECTIVE: To determine whether serum homocysteine and folate levels are correlated with the occurrence of neonatal asphyxia and to study the effects of gender and gestational age on serum homocysteine and folate levels. METHODS: Thirty-five neonates with mild asphyxia (19 males and 16 females) and 40 normal neonates (control group,18 males and 22 females) were enrolled in this study. The asphyxia and the control groups consisted of 10 and 11 cases of preterm infants respectively. Serum homocysteine levels were measured using ELASA. Serum folate levels were measured using radioimmunity assay. RESULTS: Serum homocysteine level (14.66+/-2.61 micromol/L vs 7.55+/-0.50 mumol/L; P<0.05) was significantly higher and serum folate level (2.47+/-0.24 ng/mL vs 3.28+/-0.28 ng/mL; P<0.05) was significantly lower in the asphyxia group than that in the control group. There were no significant differences in serum levels of homocysteine and folate between males and females either in the asphyxia group or the control group. The asphyxiated neonates born at premature showed increased serum homocysteine level compared with the full-term neonates with asphyxia (21.25+/-5.01 micromol/L vs 12.34+/-2. 01 micromol/L; P<0.05). CONCLUSIONS: The increased serum homocysteine level and decreased serum folate level are correlated with the occurrence of neonatal asphyxia. Serum homocysteine and folate levels are not associated with the gender. A more significantly increased serum homocysteine level may be found in asphyxiated neonates born at premature.

P2 receptor antagonist PPADS confers neuroprotection against glutamate/NMDA toxicity.

The present study investigated the role of pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid tetrasodium salt (PPADS), a P2 receptor antagonist, in protecting mouse cerebellar granule neurons (CGNs) against glutamate/NMDA-induced neuronal death. Neurotoxicity caused by 50 microM glutamate or 200 microM NMDA was significantly reduced in CGNs treated with PPADS. Such neuroprotection was in a time- and dose-dependent manner. The possibility that PPADS may block glutamate/NMDA-mediated intracellular Ca2+ influx to CGNs was investigated using temperature-controlled platereader measurements of fluorescence intensity of CGNs loaded with Ca2+-sensitive fluorescent dye Fluo-4AM. Interestingly, the rapid increase of calcium influx following glutamate/NMDA treatment was not significantly affected by prior treatment with PPADS. In contrast, MK801, a specific NMDA receptor antagonist, completely blocked intracellular Ca2+ influx. Taken together, these data suggest that inhibition of the P2 receptor may directly modulate NMDA receptor-mediated neurotoxicity through a Ca2+-independent mechanism.

Group B vitamins protect murine cerebellar granule cells from glutamate/NMDA toxicity.

The role of B group vitamins in preventing neuronal death against excitotoxicity was investigated. Neuronal death of cultured mouse cerebellar granule neurons (CGNs) caused by glutamate (50 microM) or NMDA (200 microM) was delayed in CGNs that had been treated with riboflavin (B2), folic acid (B9) or cynocobalamin (B12) for 18 h. Such neuroprotection by B2, B9 and B12 was in a dose- and time-dependent manner. In contrast, application of thiamin (B1), nicotinamide (B3), d-pantothenic acid (B5), pyridoxine (B6) or carnitine (BT) did not ameliorate glutamate or NMDA-mediated excitotoxicity to CGCs. These results are the first indication that certain B group vitamins are not only required for the normal brain function, but can also play a protective role against excitotoxicity to the brain.