Phenolic and flavonoid compounds from the fruit shell of Camellia oleifera.

A new phenolic compound oleiphenol (1), and a new dihydrochalcone oleifechalcone (2) along with seven known compounds (3-9) were isolated from the fruit shell of Camellia oleifera Abel. The planar structures of compounds 1 and 2 were determined on the basis of extensive spectroscopic analyses (IR, UV, NMR, and HR-ESI-MS) and comparison with literature data. The absolute configurations of the new structures were determined by ECD calculations and chemical methods. In addition, compounds 1-9 underwent a series of pharmacological activity tests, including cytotoxic, anti-inflammatory, anti-RSV and antioxidant activities.

Engineered human spinal cord-like tissues with dorsal and ventral neuronal progenitors for spinal cord injury repair in rats and monkeys.

Transplanting human neural progenitor cells is a promising method of replenishing the lost neurons after spinal cord injury (SCI), but differentiating neural progenitor cells into the diverse types of mature functional spinal cord neurons in vivo is challenging. In this study, engineered human embryonic spinal cord-like tissues with dorsal and ventral neuronal characters (DV-SC) were generated by inducing human neural progenitor cells (hscNPCs) to differentiate into various types of dorsal and ventral neuronal cells on collagen scaffold in vitro. Transplantation of DV-SC into complete SCI models in rats and monkeys showed better therapeutic effects than undifferentiated hscNPCs, including pronounced cell survival and maturation. DV-SC formed a targeted connection with the host's ascending and descending axons, partially restored interrupted neural circuits, and improved motor evoked potentials and the hindlimb function of animals with SCI. This suggests that the transplantation of pre-differentiated hscNPCs with spinal cord dorsal and ventral neuronal characteristics could be a promising strategy for SCI repair.

Spinal cord tissue engineering using human primary neural progenitor cells and astrocytes.

Neural progenitor cell (NPC) transplantation is a promising approach for repairing spinal cord injury (SCI). However, cell survival, maturation and integration after transplantation are still major challenges. Here, we produced a novel centimeter-scale human spinal cord neural tissue (hscNT) construct with human spinal cord neural progenitor cells (hscNPCs) and human spinal cord astrocytes (hscAS) on a linearly ordered collagen scaffold (LOCS). The hscAS promoted hscNPC adhesion, survival and neurite outgrowth on the LOCS, to form a linearly ordered spinal cord-like structure consisting of mature neurons and glia cells. When transplanted into rats with SCI, the hscNT created a favorable microenvironment by inhibiting inflammation and glial scar formation, and promoted neural and vascular regeneration. Notably, the hscNT promoted neural circuit reconstruction and motor functional recovery. Engineered human spinal cord implants containing astrocytes and neurons assembled on axon guidance scaffolds may therefore have potential in the treatment of SCI.

Transplantation of neural stem progenitor cells from different sources for severe spinal cord injury repair in rat.

Neural stem progenitor cell (NSPC) transplantation has been regarded as a promising therapeutic method for spinal cord injury (SCI) repair. However, different NSPCs may have different therapeutic effects, and it is therefore important to identify the optimal NSPC type. In our study, we compared the transcriptomes of human fetal brain-derived NSPCs (BNSPCs), spinal cord-derived NSPCs (SCNSPCs) and H9 embryonic stem-cell derived NSPCs (H9-NSPCs) in vitro and subsequently we transplanted each NSPC type on a collagen scaffold into a T8-9 complete SCI rat model in vivo. In vitro data showed that SCNSPCs had more highly expressed genes involved in nerve-related functions than the other two cell types. In vivo, compared with BNSPCs and H9-NSPCs, SCNSPCs exhibited the best therapeutic effects; in fact, SCNSPCs facilitated electrophysiological and hindlimb functional recovery. This study demonstrates that SCNSPCs may be an appropriate candidate cell type for SCI repair, which is of great clinical significance.

Synthesis of a magnetic π-extended carbon nanosolenoid with Riemann surfaces.

Riemann surfaces are deformed versions of the complex plane in mathematics. Locally they look like patches of the complex plane, but globally, the topology may deviate from a plane. Nanostructured graphitic carbon materials resembling a Riemann surface with helicoid topology are predicted to have interesting electronic and photonic properties. However, fabrication of such processable and large π-extended nanographene systems has remained a major challenge. Here, we report a bottom-up synthesis of a metal-free carbon nanosolenoid (CNS) material with a low optical bandgap of 1.97 eV. The synthesis procedure is rapid and possible on the gram scale. The helical molecular structure of CNS can be observed by direct low-dose high-resolution imaging, using integrated differential phase contrast scanning transmission electron microscopy. Magnetic susceptibility measurements show paramagnetism with a high spin density for CNS. Such a π-conjugated CNS allows for the detailed study of its physical properties and may form the base of the development of electronic and spintronic devices containing CNS species.

Synthesis of Giant π-Extended Molecular Macrocyclic Rings as Finite Models of Carbon Nanotubes Displaying Enriched Size-Dependent Physical Properties.

Bottom-up synthesis of π-extended macrocyclic carbon rings is promising for constructing length- and diameter-specific carbon nanotubes (CNTs). However, it is still a great challenge to realize size-controllable giant carbon macrocycles. Herein, a tunable synthesis of curved nanographene-based giant π-extended macrocyclic rings (CHBC[n]s; n=8, 6, 4), as finite models of armchair CNTs, is reported. Among them, CHBC[8] contains 336 all-carbon atoms and is the largest cyclic conjugated molecular CNT segment ever reported. CHBC[n]s were systematically characterized by various spectroscopic methods and applied in photoelectrochemical cells for the first time. This revealed that the proton chemical shifts, fluorescence, and electronic and photoelectrical properties of CHBC[n]s are highly dependent on the macrocycle diameter. The tunable bottom-up synthesis of giant macrocyclic rings could pave the way towards large π-extended diameter- and chirality-specific CNT segments.

A Long π-Conjugated Poly(para-Phenylene)-Based Polymeric Segment of Single-Walled Carbon Nanotubes.

Conjugated polymers have attracted much attention for many years and have applications in various organic devices. Carbon nanotubes can be considered as all-carbon tube-shaped conjugated polymers containing only sp2-bonded atoms, which play an important role in nanotechnology and nanoelectronics. So far, no study has reported the realization of long π-conjugated polymers as diameter-specified carbon nanotube segments. Herein, we report the first synthesis of a π-conjugated polymeric segment (PS1) of armchair single-walled carbon nanotubes (SWCNTs). PS1 is achieved by a rationally designed synthesis of a bifunctionalized cyclo-para-phenylene monomer, followed by inserting these ring-shaped units into the conjugated poly(para-phenylene) backbone. PS1 was fully characterized by gel permeation chromatography (GPC) combined with NMR, FTIR, and Raman spectra. Possessing unique structural and physical properties, this long π-extended polymer PS1 can provide new insight for the development of bottom-up syntheses of uniform carbon nanotube segments and potential applications in electron- and hole-transport devices.

Through-space π-delocalization in a conjugated macrocycle consisting of [2.2]paracyclophane.

Herein, we report the synthesis and characterization of a [2.2]paracyclophane-containing macrocycle (PCMC) as a new through-space conjugated macrocycle using only benzene groups as the skeleton. For comparison, a diphenylmethane-containing nanohoop macrocycle (DCMC) with a non-conjugated linker was also synthesized. Their structures were confirmed by NMR and HR-MS, and their photophysical properties were studied by UV-vis and fluorescence spectroscopies combined with theoretical calculations. The strain energy of PCMC was estimated to be as high as 72.58 kcal mol-1.