Cell activity modulation and its specific function maintenance by bioinspired electromechanical nanogenerator.

The biophysical characteristics of the extracellular matrix (ECM), such as a three-dimensional (3D) network and bioelectricity, have a profound influence on cell development, migration, function expression, etc. Here, inspired by these biophysical cues of ECM, we develop an electromechanical coupling bio-nanogenerator (bio-NG) composed of highly discrete piezoelectric fibers. It can generate surface piezopotential up to millivolts by cell inherent force and thus provide in situ electrical stimulation for the living cells. Besides, the unique 3D space in the bio-NGs provides an ECM-like growth microenvironment for cells. As a result, our bio-NGs effectively promote cell viability and development and, more importantly, maintain its specific functional expression. These advanced in vitro bio-NGs are expected to fill the gap between the inaccurate 2D systems and the expensive and time-consuming animal models, mimicking the complexity of the ECM and the physiological relevance of an in vivo biological system.

Neurogenic differentiation of adipose derived stem cells on graphene-based mat.

Adipose derived stem cells (ADSCs) have been proved as an abundant and accessible cell source with the ability to differentiate into neuron-like cells. However, the low differentiation efficiency puts forward an important challenge to practical applications in clinic. Considering of the good biocompatibility of graphene-based materials and the potential interaction between graphene and cells mentioned in previous studies, herein, we investigated the effect of graphene oxide (GO) and reduced graphene oxide (rGO) mats on neurogenic differentiation of the ADSCs. We demonstrated the excellent capabilities of graphene-based mats, especially GO to support the neural differentiation of ADSCs. By comparing the observation under an optical microscope and fluorescence microscope, the conversion rate of neuron-like cells reached about 90%. We consider that GO mat is better for promoting the differentiation of ADSCs into neuron-like cells, which compared to rGO based platforms. Meanwhile, we made an analysis of the mechanism by which graphene induced the differentiation of ADSCs to neuron-like cells. The data obtained here highlight the effect of GO mat on neurogenic differentiation of ADSCs and implicate the potential of graphene-based materials in application of neural tissue engineering for the limited self-repair capability of nerve cells.

Magnetic electrospun short nanofibers wrapped graphene oxide as a promising biomaterials for guiding cellular behavior.

Magnetic particles show extremely wide application prospects in the biomedical field, particularly in the success of cellular manipulation, drug delivery systems, magnetic hyperthermia and NRI contrast enhancement. Graphene oxide with functional groups has a promising biological effect. In this work, we develop magnetic short-fibers wrapped graphene oxide for guiding cellular behavior with the aid of high-speed shear of nanofibers fabricated through electrospinning technique. The diameter and the length of short-fibers are about 300nm and 80µm, respectively. The short-fibers exhibit superior magnetic properties (saturation magnetization value: 50.33emu/g), which has a strong response appearance to the NdFeB magnet. SEM images and laser confocal images display that there has an extremely tight adhesion between the short-fibers wrapped graphene oxide and cells. The control of cell-fibers structure behavior can be realized by applying external magnet. The results may provide an attractive perspective on the treatment of disease with magnetic field.