Mouse Embryonic Fibroblasts-Derived Extracellular Matrix Facilitates Expansion of Inner Ear-Derived Cells

Objective: Previous reports showed that mouse embryonic fibroblasts (MEFs) could support pluripotent stem cell selfrenewaland maintain their pluripotency. The goal of this study was to reveal whether the decellularized extracellularmatrix derived from MEFs (MEF-ECM) is beneficial to promote the proliferation of inner ear-derived cells.Materials and Methods: In this experimental study, we prepared a cell-free MEF-ECM through decellularization.Scanning electron microscope (SEM) and immunofluorescent staining were conducted for phenotype characterization.Organs of Corti were dissected from postnatal day 2 and the inner ear-derived cells were obtained. The identificationof inner ear-derived cells was conducted by using reverse transcription-polymerase chain reaction (RT-PCR). Cellcounting kit-8 (CCK-8) was used to evaluate the proliferation capability of inner ear-derived cells cultured on the MEFECMand tissue culture plate (TCP).Results: The MEF-ECM was clearly observed after decellularization via SEM, and the immunofluorescence stainingresults revealed that MEF-ECM was composed of three proteins, including collagen I, fibronectin and laminin. Mostimportantly, the results of CCK-8 showed that compared with TCP, MEF-ECM could effectively facilitate the proliferationof inner ear-derived cells.Conclusion: The discovery of the potential of MEF-ECM in promoting inner ear-derived cell proliferation indicatesthat the decellularized matrix microenvironment may play a vital role in keeping proliferation ability of these cells. Ourfindings indicate that the use of MEF-ECM may serve as a novel approach for expanding inner ear-derived cells andpotentially facilitating the clinical application of inner ear-derived cells for hearing loss in the future

Electrospun Biomimetic Fibrous Scaffold from Shape Memory Polymer of PDLLA-<i>co</i>-TMC for Bone Tissue Engineering

Multifunctional fibrous scaffolds, which combine the capabilities of biomimicry to the native tissue architecture and shape memory effect (SME), are highly promising for the realization of functional tissue-engineered products with minimally invasive surgical implantation possibility. In this study, fibrous scaffolds of biodegradable poly­(d,l-lactide-<i>co</i>-trimethylene carbonate) (denoted as PDLLA-<i>co</i>-TMC, or PLMC) with shape memory properties were fabricated by electrospinning. Morphology, thermal and mechanical properties as well as SME of the resultant fibrous structure were characterized using different techniques. And rat calvarial osteoblasts were cultured on the fibrous PLMC scaffolds to assess their suitability for bone tissue engineering. It is found that by varying the monomer ratio of DLLA:TMC from 5:5 to 9:1, fineness of the resultant PLMC fibers was attenuated from ca. 1500 down to 680 nm. This also allowed for readily modulating the glass transition temperature Tg (i.e., the switching temperature for actuating shape recovery) of the fibrous PLMC to fall between 19.2 and 44.2 °C, a temperature range relevant for biomedical applications in the human body. The PLMC fibers exhibited excellent shape memory properties with shape recovery ratios of <i>R</i>_r > 94% and shape fixity ratios of <i>R</i>_f > 98%, and macroscopically demonstrated a fast shape recovery (∼10 s at 39 °C) in the pre-deformed configurations. Biological assay results corroborated that the fibrous PLMC scaffolds were cytocompatible by supporting osteoblast adhesion and proliferation, and functionally promoted biomineralization-relevant alkaline phosphatase expression and mineral deposition. We envision the wide applicability of using the SME-capable biomimetic scaffolds for achieving enhanced efficacy in repairing various bone defects (e.g., as implants for healing bone screw holes or as barrier membranes for guided bone regeneration)

In Situ Fabrication of CoS and NiS Nanomaterials Anchored on Reduced Graphene Oxide for Reversible Lithium Storage

CoS and NiS nanomaterials anchored on reduced graphene oxide (rGO) sheets, synthesized via combination of hydrothermal with sulfidation process, are studied as high-capacity anode materials for the reversible lithium storage. The obtained CoS nanofibers and NiS nanoparticles are uniformly dispersed on rGO sheets without aggregation, forming the sheet-on-sheet composite structure. Such nanoarchitecture can not only facilitate ion/electron transport along the interfaces, but also effectively prevent metal-sulfide nanomaterials aggregation during the lithium reactions. Both the rGO-supported CoS nanofibers (NFs) and NiS nanoparticles (NPs) show superior lithium storage performance. In particular, the CoS NFs-rGO electrodes deliver the discharge capacity as high as 939 mA h g^–1 after the 100th cycle at 100 mA g^–1 with Coulombic efficiency above 98%. This strategy for construction of such composite structure can also synthesize other metal-sulfide-rGO nanomaterials for high-capacity lithium-ion batteries