[Effect of manual acupuncture on expression of BDNF/TrkB/ERK/CREB signaling in infarcted tissue of cerebral ischemia rats].

OBJECTIVE: To observe the effect of acupuncture on the expression of cortical brain-derived neurothrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) mRNAs, and phosphorylated extracellular regulated protein kinases (p-ERK) 1/2 and phosphorylated cAMP response element binding protein (p-CREB) proteins in cerebral ischemia (CI) rats, so as to explore its neuroprotective mechanism on ischemic brain tissue. METHODS: Thirty male SD rats were randomly divided into sham-operation (control), model and acupuncture groups, with 10 rats in each group. The CI model was established by occlusion of the left middle cerebral artery (MCAO) using thread embolization method. Manual acupuncture was applied to"Baihui"(GV20),"Quchi"(LI11),"Neiguan"(PC6),"Hegu"(LI4),"Zusanli"(ST36),"Sanyinjiao"(SP6) and"Shenmai"(BL62) once daily, 6 days a week for 2 weeks. The modified neurological severity score (mNSS) including motor, sensation, balance, and neural reflex functions (0 point, normal; 18 points, maximal deficit) was used to assess the neurological impairment state. The expression levels of p-ERK 1/2 and p-CREB proteins, and BDNF and TrkB mRNAs in the ischemic cerebral cortex were measured by Western blot and real-time fluorescence quantitative PCR, respectively. RESULTS: The mNSS was significantly increased on day 1, 7 and 14 in the model group compared with the control group (P<0.01), and evidently decreased on day 14 in the acupuncture group in contrast to the model group (P<0.05). The expression levels of BDNF and TrkB mRNAs, and p-ERK1, p-ERK2 and p-CREB proteins on day 7 and 14 were significantly lower in the model group than in the control group (P<0.001). Following acupuncture treatment, the down-regulated expression levels of the two genes and the three proteins on day 14 were reversed (P<0.001, P<0.05, P<0.01). CONCLUSION: Acupuncture may promote neurological recovery in rats with cerebral ischemia, which may be related to its function in up-regulating the activities of BDNF/TrkB-ERK-CREB signaling in the cerebral cortex on the ischemic side.

Liquid-like polymer-based self-cleaning coating for effective prevention of liquid foods contaminations.

Liquid food containers commonly suffer from inevitable contamination and even biofilm formation due to the adhesion of food residuals or saliva, which requires detergents to clean. Although previously reported superhydrophobic and omniphobic coatings can resist the adhesion of liquids, the requirements of specific nanostructures or infused lubricants limit their applications in food containers. Here, by grafting smooth glass containers with "liquid like" polydimethylsiloxane brushes, we developed a unique approach for preparing a slippery coating that could exhibit highly robust repellency to various liquid foods. The coating was highly transparent and did not induce a significant alteration of the smooth surface. The "liquid like" coating could effectively prevent the adhesion of various liquid foods and inhibit the formation of bacterial biofilms, without the use of detergents for cleaning. Moreover, this coating could resist mechanical damage from friction, and displayed high biocompatibility with biological cells. The slipperiness, smoothness, robustness and biocompatibility of the "liquid like" coating was highly beneficial to practical applications as self-cleaning glass container, which has been challenging to achieve by conventional superhydrophobic or omniphobic coatings. Our study introduced a versatile strategy to functionalize biocompatible surfaces for food containers which reduced the contamination of residues and the use of detergents, and may be beneficial to human and environmental health.

Slippery Liquid-Attached Surface for Robust Biofouling Resistance.

Materials for biodevices and bioimplants commonly suffer from unwanted but unavoidable biofouling problems due to the nonspecific adhesion of proteins, cells, or bacteria. Chemical coating or physical strategies for reducing biofouling have been pursued, yet highly robust antibiofouling surfaces that can persistently resist contamination in biological environments are still lacking. In this study, we developed a facile method to fabricate a highly robust slippery and antibiofouling surface by conjugating a liquid-like polymer layer to a substrate. This slippery liquid-attached (SLA) surface was created via a one-step equilibration reaction by tethering methoxy-terminated polydimethylsiloxane (PDMS-OCH3) polymer brushes onto a substrate to form a transparent "liquid-like" layer. The SLA surface exhibited excellent sliding behaviors toward a wide range of liquids and small particles and antibiofouling properties against the long-term adhesion of small biomolecules, proteins, cells, and bacteria. Moreover, in contrast to superomniphobic surfaces and liquid-infused porous surfaces (SLIPS) requiring micro/nanostructures, the SLA layer could be obtained on smooth surfaces and maintain its biofouling resistance under abrasion with persistent stability. Our study offers a simple method to functionalize surfaces with robust slippery and antibiofouling properties, which is promising for potential applications including medical implants and biodevices.