Substance P combined with epidermal stem cells promotes wound healing and nerve regeneration in diabetes mellitus

Exogenous substance P accelerates wound healing in diabetes,but the mechanism remains poorly understood.Here,we established a rat model by intraperitoneally injecting streptozotocin.Four wounds（1.8 cm diameter） were drilled using a self-made punch onto the back,bilateral to the vertebral column,and then treated using amniotic membrane with epidermal stem cells and/or substance P around and in the middle of the wounds.With the combined treatment the wound-healing rate was 100% at 14 days.With prolonged time,type I collagen content gradually increased,yet type III collagen content gradually diminished.Abundant protein gene product 9.5-and substance P-immunoreactive nerve fibers regenerated.Partial nerve fiber endings extended to the epidermis.The therapeutic effects of combined substance P and epidermal stem cells were better than with amniotic membrane and either factor alone.Our results suggest that the combination of substance P and epidermal stem cells effectively contributes to nerve regeneration and wound healing in diabetic rats.

Thiophene-Conjugated Porous C_(3)N_(4) Nanosheets for Boosted Photocatalytic Nicotinamide Cofactor Regeneration to Facilitate Solar-to-Chemical Enzymatic Reactions

The low catalytic efficiency of redox-active cofactor photoregeneration severely limits the performance of photoenzymatic hybrid systems. Herein, we synthesized thiophene-conjugated porous C3N4 nanosheets(CN-ATCN) exhibiting boosted photoregeneration activity of nicotinamide cofactors(NADH and NADPH), which are the most common redox cofactors of oxidoreductases, with regeneration rates of 59.00 μM/min for NADH and 40.99 μM/min for NADPH, ~ 84.3 and 24.7 times higher than those of bulk g-C3N4, respectively. The thin nanosheet structure of CN-ATCN facilitates the exposure of active sites to reactants and favors the diff usion of reactants and products. Upon conjugation of a thiophene moiety into the carbon nitride framework, the optical and photoelectric properties of CN-ATCN were considerably enhanced by an extended π-conjugation system in the frameworks and molecular type II heterojunctions formed between the incorporated and nonincorporated portions of CN-ATCN. Upon coupling NAD(P)H photoregeneration reaction by CN-ATCN with NAD(P)H-dependent enzymatic systems, sustainable synthesis of L-tert-leucine and styrene oxide was achieved with rates of 964 and 14.9 μM/h, respectively.

Biodegradable magnesium wire promotes regeneration of compressed sciatic nerves

Magnesium（Mg） wire has been shown to be biodegradable and have anti-inflammatory properties. It can induce Schwann cells to secrete nerve growth factor and promote the regeneration of nerve axons after central nervous system injury. We hypothesized that biodegradable Mg wire may enhance compressed peripheral nerve regeneration. A rat acute sciatic nerve compression model was made, and AZ31 Mg wire（3 mm diameter; 8 mm length） bridged at both ends of the nerve. Our results demonstrate that sciatic functional index, nerve growth factor, p75 neurotrophin receptor, and tyrosine receptor kinase A m RNA expression are increased by Mg wire in Mg model. The numbers of cross section nerve fibers and regenerating axons were also increased. Sciatic nerve function was improved and the myelinated axon number was increased in injured sciatic nerve following Mg treatment. Immunofluorescence histopathology showed that there were increased vigorous axonal regeneration and myelin sheath coverage in injured sciatic nerve after Mg treatment. Our findings confirm that biodegradable Mg wire can promote the regeneration of acute compressed sciatic nerves.

Microencapsulation improves inhibitory effects of transplanted olfactory ensheathing cells on pain after sciatic nerve injury

Olfactory bulb tissue transplantation inhibits P2X2/3 receptor-mediated neuropathic pain. However, the olfactory bulb has a complex cellular composition, and the mechanism underlying the action of purified transplanted olfactory ensheathing cells（OECs） remains unclear. In the present study, we microencapsulated OECs in alginic acid, and transplanted free and microencapsulated OECs into the region surrounding the injured sciatic nerve in rat models of chronic constriction injury. We assessed mechanical nociception in the rat models 7 and 14 days after surgery by measuring paw withdrawal threshold, and examined P2X2/3 receptor expression in L4–5 dorsal root ganglia using immunohistochemistry. Rats that received free and microencapsulated OEC transplants showed greater withdrawal thresholds than untreated model rats, and weaker P2X2/3 receptor immunoreactivity in dorsal root ganglia. At 14 days, paw withdrawal threshold was much higher in the microencapsulated OEC-treated animals. Our results confirm that microencapsulated OEC transplantation suppresses P2X2/3 receptor expression in L4–5 dorsal root ganglia in rat models of neuropathic pain and reduces allodynia, and also suggest that transplantation of microencapsulated OECs is more effective than transplantation of free OECs for the treatment of neuropathic pain.

Recent progress in photocatalytic NAD(P)H regeneration for photocatalytic-enzymatic-coupling system

The enzymatic redox reactions in natural photosynthesis rely much on the participation of cofactors,with reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate(NADH/NADPH)or their oxidized form(NAD+/NADP+)as an important redox power.The photocatalytic regeneration of expensive and unstable NADH/NADPH in vitro is an important process in enzymatic reduction and has attracted much research attention.Though different types of photocatalysts have been developed for photocatalytic NADH/NADPH regeneration,the efficiency is still relatively low.To elucidate the key factors affecting the performance of photocatalytic NADH/NADPH regeneration is helpful to rationally design the photocatalyst and improve the photocatalytic efficiency.In this paper,we overview the recent progress in photocatalytic NADH/NADPH regeneration with the focus on the strategies to improve the visible light adsorption,the charge separation and migration efficiency,as well as the surface reaction,which jointly determine the overall photocatalytic regeneration efficiency.The potential development of photocatalytic NADH/NADPH regeneration and photocatalyticenzymatic-coupling system is prospected finally.