Additional file 1: Figure S1. of Dental pulp pluripotent-like stem cells (DPPSC), a new stem cell population with chromosomal stability and osteogenic capacity for biomaterials evaluation

Characterization of undifferentiated DPPSC. a Cell morphology of DPPSC from passage 10 observed with optic microscopy. DPPSC are characterized as small-sized cells with large nuclei and low cytoplasm content. b Immunofluorescence analysis of OCT3/4-FITC, SSEA4-PE, and Merge. Hoechst (HT) as a nucleus control. DPPSC were positive for these embryonic markers, and both were located in the nucleus. c FACS analysis of DPPSC. c1 FACS analysis of membrane markers: CD105 (92,15%), CD29 (99,63%), CD146 (15,54%) and CD45 (0.04%). c2 FACS analysis of pluripotency nuclear markers: OCT3/4 (76,72%) and NANOG (30,18%). d RT-PCR of OCT3/4, NANOG and SOX2 expresions in DPPSC and DPMSC. e Western Blot analysis of OCT3/4 in DPPSC and DPMSC at different time points (5, 10 and 15 passages). GAPDH as a housekeeping. (TIF 1031 kb

Effect of Nanocrystalline Domains in Photovoltaic Devices with Benzodithiophene-Based Donor–Acceptor Copolymers

We have investigated the effects of thin-film morphology on the photovolatic performance for a series of donor–acceptor copolymers based on benzodithiophene donor and benzothiadiazole acceptor units. Photovoltaic devices incorporating polymer:fullerene blends show highest efficiencies (up to 6%) for those polymers exhibiting the least degree of crystallinity in X-ray diffraction patterns and a corresponding lowest surface roughness in thin films. We find that the existence of such crystalline domains in thin polymer films correlates well with spectral signatures of polymer chain aggregates already present in solution prior to casting of the film. Polymer solubility and casting conditions therefore appear to be crucial factors for enhancing efficiencies of photovoltaic devices based on such donor–acceptor copolymers. To examine why the presence of crystallite domains lowers device efficiencies, we measured exciton diffusion lengths by modeling the time-dependent photoluminescence from thin polymer films deposited on an exciton quencher layer of TiO₂. We find that exciton diffusion lengths in these materials are substantial (4–7.5 nm) and show some variation with polymer crystallinity. However, ultrafast (1 ps) quenching of the polymer emission from polymer:PCBM blends indicates that the vast majority of excitons rapidly reach the charge-dissociating interface, and hence exciton diffusion does not represent a limiting factor. We therefore conclude that the subsequent charge extraction and lifetimes must be adversely affected by the presence of crystalline domains. We suggest that the formed crystallites are too small to offer significant enhancements in long-range charge carrier mobility but instead introduce domain boundaries which impede charge extraction. For this class of materials, polymer designs are therefore required that target high solubility and chain entropy, leading to amorphous film formation