Melatonin for the treatment of spinal cord injury

Spinal cord injury（SCI） from trauma or disease severely impairs sensory and motor function. Neurorehabilitation after SCI is a complex medical process that focuses on improving neurologic function and repairing damaged connections in the central nervous system. An increasing number of preclinical studies suggest that melatonin may be useful for the treatment of SCI. Melatonin is an indolamine that is primarily secreted by the pineal gland and known to be regulated by photoperiodicity. However, it is also a versatile hormone with antioxidative, antiapoptotic, neuroprotective, and anti-inflammatory properties. Here, we review the neuroprotective properties of melatonin and the potential mechanisms by which it might be beneficial in the treatment of SCI. We also describe therapies that combine melatonin with exercise, oxytetracycline, and dexamethasone to attenuate the secondary injury after SCI and limit potential side effects. Finally, we discuss how injury at different spinal levels may differentially affect the secretion of melatonin.

Effect of low-level laser irradiation(LLLI)combined with ferulic acid on the osteoblast differentiation and maturation as well as osteogenesis signaling pathway expression

Objective: To study the effect of low-level laser irradiation (LLLI) combined with ferulic acid on the osteoblast differentiation and maturation as well as osteogenesis signaling pathway expression. Methods: The cranium was collected from the SD rats born within 24 h, osteoblasts were separated, cultured and then divided into control group, ferulic acid group, LLLI group, ferulic acid + LLLI group, and the expression osteoblast differentiation markers, proliferation molecules and signaling pathway molecules were detected after continuous treatment with different conditions for three days. Results: 3 d after treatment, the Bax and Bid mRNA expression in ferulic acid group, LLLI group and ferulic acid + LLLI group of cells were significantly lower than those in control group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in control group;Bax and Bid mRNA expression in ferulic acid + LLLI group of cells were significantly lower than those in ferulic acid group and LLLI group while Bcl-2, CyclinD1, E2F, Col-I, OC and ALP mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were significantly higher than those in ferulic acid group and LLLI group;Col-I, OC, ALP, Bax, Bid, Bcl-2, CyclinD1 and E2F mRNA expression as well as Wnt, β-catenin, Runx2, cAMP and PKA protein expression were not significantly different between ferulic acid group and LLLI group. Conclusion: Low-level laser irradiation (LLLI) combined with ferulic acid can promote osteoblast differentiation and maturation and activate osteogenesis signaling pathway.

A Facile Strategy to Enhance the Formation of Stereocomplex Crystallites in Poly(L-lactic acid)/Poly(D-lactic acid) Blend with High Molecular Weights

Blending of poly(levorotatory-lactic acid) (PLLA) and poly(dextrorotatory-lactic acid) (PDLA) produces the stereocomplex crystallites (PLA SC), which present higher melting temperature and mechanical properties than that of neat PLLA or PDLA. However, in the PLLA/PDLA blends with higher molecular weights, the phase separation occurs and the SC exhibits weak memory after melting, which lead to a small amount of SC together with a large amount of homochiral crystallites (HC) develop during crystallization from the melt. In this study, a small content of graphite oxide was blended with PLLA and PDLA to form ternary blends, and it was exciting to find that the formation of SC was enhanced gradually with the content of graphite oxide. The SC exclusively developed when 2 wt% graphite oxide was incorporated into the PLLA/PDLA, and the crystallinity with ∼50% was received even during fast cooling from the melt (−50 ℃/min). The acceleration formation of SC was speculated due to the interaction between PLA molecular chains and the hydroxyl groups on the surface of graphite oxide and the obstruction of proliferation of graphite oxide.

Antibacterial Thermoplastic Polyurethane/PL-DOSS Composite Films

Medical devices-related infections pose a great threat to patients and cause an increased morbidity and mortality. Herein, we prepare an antibacterial composite(TPU-x) through blending medical grade thermoplastic polyurethane(TPU) and the complex(PL-DOSS) of ε-polylysine(ε-PL) and docusate sodium(DOSS). >99% reduction of colony forming unit(CFU) can be obtained in TPU-x composite films even at relatively low content of PL-DOSS, e.g. 0.13% for Methicillin resistant S. aureus(MRSA) and 0.5% for E. coli. The excellent antibacterial activity is mainly attributed to the formation of PL-DOSS nanoparticles that are uniformly dispersed in the TPU matrix with a size of ~100 nm. TPU-x composite films exhibit long-term stability in saline and good biocompatibility, and retain mechanical properties of TPU.

Effects of oceanic ice cover and density stratification on the propagation of hydroacoustic waves

The propagation characteristic of hydroacoustic waves is studied for an ideal compressible two-layer fluid with different densities covered by an elastic ice sheet.Boundary conditions are simplified by adopting linear assumption and then the dispersion relation is derived.The analysis and visualization of the dispersion relation present the introduction of compressibility leads to the appearance of hydroacoustic wave modes while the density stratification leads to the appearance of interfacial wave mode.Larger ice thickness and the density ratio of the two fluid layers increase the wave number and group speed of hydroacoustic waves at the same frequency while the phase speed decreases.