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Electrical signals are a key factor to promote nerve cell neurogenesis. However, the traditionally used exogenous electrical stimulus mode requires additional equipment and complicated wiring, which is very inconvenient. To date, it has been challenging to provide electrical signals to nerve cells in a non-invasive and wireless controllable way, accompanied by the construction of a biomimetic cell microenvironment for supporting nerve cell survival and functional expression. Herein, a new concept of a light-powered oriented bioactive scaffold for remote and wireless electrical stimulation has been developed. By combining electrospinning and electrospraying, the highly oriented polycaprolactone (PCL) microfibrous scaffold with co-sprayed bioactive collagen and photoelectric poly-3-hexylthiophene nanoparticles (P3HT NPs) was obtained, named as PCL–P3HT–Col, which exhibits a considerable photoelectric effect and vital characteristics of the native nerve extracellular matrix. The results show that a photocurrent ranging from 20–80 pA was obtained by changing the light density of a 530 nm green light source. Further, the specific photoelectric conversion effect trigged by the P3HT NPs promotes the oriented elongation and up-regulation of neuronal characteristic factors in rat pheochromocytoma cells (PC12 cells), which is controlled by L-type voltage-gated calcium channel (L-VGCC) activity. This study provides new insights to engineer self-powered scaffolds towards the non-invasive and wireless-controlled stimulation mode of a variety of cells and tissues. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effectiveness of human placental decidua basalis derived mesenchymal stem cells (PDB-MSCs) in repairing full-thickness skin defect of nude mice., Methods: Human placenta samples were obtained from healthy donor mothers with written informed consent. PDB-MSCs were isolated through enzymic digestion and density gradient centrifugation; the 4th passage cells were identified by cellular morphology, cell adipogenic and osteogenic differentiation, and phenotype evaluation. Forty-two 4-5-week-old BALB/c female nude mice were randomly divided into experimental group ( n =21) and control group ( n =21). The 4th passage PDB-MSCs solution (200 μL, 5×10 6 /mL) was injected into the mice of experimental group via caudal vein; the mice of control group were given equal volume of PBS. The full-thickness skin defect model of 1.5 cm×1.5 cm in size was made after 3 days. The wound healing was observed generally at 1, 2, 4, 7, 14, 18, 21, 25, and 30 days after operation, and the wound healing rate was calculated after wound decrustation. HE staining was used to observe the wound repair at 1, 7, 14, 21, and 31 days; immunofluorescent staining was used for cellular localization at 7, 14, and 31 days after operation., Results: Cells isolated from human placenta were MSCs which had multipotential differentiation ability and expressed MSCs phenotype. Animals survived to the end of the experiment. The general observation showed that the experimental group had a faster skin repairing speed than the control group; the time for decrustation was 12-14 days in experimental group and was 14-17 days after operation in the control group. The wound healing rate of experimental group was significantly higher than that of control group at 14, 18, and 21 days ( t =4.001, P =0.016; t =3.380, P =0.028; t =3.888, P =0.018), but no significance was found at 25 and 30 days ( t =1.565, P =0.193; t =1.000, P =0.423). HE staining showed lower inflammatory reaction, and better regeneration of the whole skin and glands with time in the experimental group. The immunofluorescent staining was positive in skin defect area of experimental group at different time points which displayed that human PDB-MSCs existed., Conclusions: Through enzymic digestion and density gradient centrifugation, PDB-MSCs can be obtained. Pre-stored PDB-MSCs can mobilize to the defect area and participate in repair of nude mice skin.