Liying Hao

Insight into the Interaction of Graphene Oxide with Serum Proteins and the Impact of the Degree of Reduction and Concentration.

As novel applied nanomaterials, both graphene oxide (GO) and its reduced form (rGO) have attracted global attention, because of their excellent properties. However, the lack of comprehensive understanding of their interactions with biomacromolecules highly limits their biomedical applications. This work aims to initiate a systematic study on the property changes of GO/rGO upon interaction with serum proteins and on how their degree of reduction and exposure concentration affect this interaction, as well as to analyze the possible biomedical impacts of the interaction. We found that the adsorption of proteins on GO/rGO occurred spontaneously and rapidly, leading to significant changes in size, zeta potential, and morphology. Compared to rGO, GO showed a higher ability in quenching intrinsic fluorescence of serum proteins in a concentration-dependent manner. The protein adsorption efficiency and the types of associated proteins varied, depending on the degree of reduction and concentration of graphene. Our findings indicate the importance of evaluating the potential protein adsorption before making use of GO/rGO in drug delivery, because the changed physicochemical properties after protein adsorption will have significant impacts on safety and effectiveness of these delivery systems. On the other hand, this interaction can also be used for the separation, purification, or delivery of certain proteins.

Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells.

Up to now, little research has been focussed on discovering how zeta potential independently affects polymeric nanoparticle (NP) cytotoxicity.

Electrospun P34HB fibres: a scaffold for tissue engineering

Amongst the fourth generation of PHAs is bio‐plasticpoly3‐hydroxybutyrate4‐hydroxybutyrate (P34HB); it is thus appropriate to perform novel research on its uses and applications. The main objective of this study was to determine whether electrospun P34HB fibres would accommodate viability, growth and differentiation of mouse adipose‐derived stem cells (mASCs).

Tea Polyphenol–Functionalized Graphene/Chitosan as an Experimental Platform with Improved Mechanical Behavior and Bioactivity

In this study, water-soluble, one-step highly reduced and functionalized graphene oxide was prepared via a facile, environment-friendly method by using tea polyphenol (TP), which acted as both reducing agent and stabilizer. The product obtained, that is, tea polyphenol-reduced graphene oxide (TPG), was used as a reinforcing building block for the modification of a mechanically weak chitosan (CS), TPG/CS. The morphology and physicochemical and mechanical properties of the composite were examined by various characterizations. The tensile strength and elastic modulus of CS were greatly improved by TPG, as compared to the findings for GO incorporation. Additionally, to our knowledge, this study is an in-depth analysis of the osteoblast functions of CS/TPG, including aspects such as cell cytotoxicity, proliferation, and expression of ossification genes, alkaline phosphatase (ALP), and Runt-related transcription factor (Runx2), which showed advantages in favorably modulating cellular activity. It was concluded that TPG/CS showed a higher elastic modulus, better hydrophilicity, and excellent biocompatibility than the pristine chitosan for promoting the proliferation and differentiation of osteoblasts, as well as for accelerating the expression of ALP and Runx2 (as shown by reverse transcription polymerase chain reaction (RT-PCR)). These results may provide new prospects for the use of TPG in the modification of biomaterials and for broadening the application of TPG in biological fields.

Tea Polyphenol-Reduced Graphene Oxide Deposition on Titanium Surface Enhances Osteoblast Bioactivity

Graphene, a novel carbon-based material, has been widely used as osteogenic agent for the potential effect on the promotion of osteoblast proliferation. Tea polyphenol-reduced graphene oxide (TPG) is a simple and environmental-friendly raw material to obtain graphene. In this study, TPG was deposited on the Ti substrate to promote the bone regeneration. We prepared a honeycomb-like structure by acid and alkali pretreatment and immobilized the TPG layer (Ti-TPG) on the surface via electrochemical deposition. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) were used to identify the immobilization of TPG on the titanium (Ti) successfully. Furthermore, the biological response of the Ti-TPG surface to rat osteoblast was evaluated. We also studied the cell adhesion, proliferation and expression of ossification genes on the sample. The results revealed that Ti-TPG had an advantage over Ti alloys in modulating cellular activity and Ti-TPG may be a promising coating for biological materials.

Synthesis, Characterization, and Biological Study of Carboxyl- and Amino-Rich g-C3N4 Nanosheets by Different Processing Routes

Graphitic-phase carbon nitride (g-C₃N₄) is a graphene analogue, which has attracted much attention for its unique physicochemical properties. The bulk g-C₃N₄ is often fragmented and ionized to nanosheets, obtaining improved performance or confer novel properties. It is reported that g-C₃N₄ nanosheets using different processing methods can be modified with different functional groups, resulting in different electrical characteristics. However, the surface charge of g-C₃N₄ nanosheets is seldom mentioned as a factor influencing their biological applications. In our present study, we prepared two kinds of uniformly dispersed g-C₃N₄ nanosheets of high quality, the carboxyl- and amino-rich g-C₃N₄ nanosheets. Although both the carboxyl- and amino-rich g-C₃N₄ nanosheets displayed good biocompatibility in vitro and in vivo, however, they are at very different levels of surface charge, which are relative to different cellular uptake, penetration mechanism and lysosome escape ability of the nanosheets.

Doxorubicin conjugated carbon dots as a drug delivery system for human breast cancer therapy

Carbon dots (CDs) are one of the most promising carbon‐based materials in bioimaging and drug/gene delivery applications. In this study, we have attempted to study the drug carrying capacity of highly fluorescent CDs for delivery of doxorubicin (DOX) and investigate the therapeutic activity of the CDs‐DOX drug delivery system.

Aptamer-targeted DNA nanostructures with doxorubicin to treat protein tyrosine kinase 7-positive tumours

Aptamer sgc8c is a short DNA sequence that can target protein tyrosine kinase 7 (PTK7), which was overexpressed on many tumour cells. This study aimed to fabricate a novelty DNA nanostructure drug delivery system target on PTK7‐positive cells—CCRF‐CEM (human T‐cell ALL).