Honglin Luo

Layer-by-Layer Assembled Bacterial Cellulose/Graphene Oxide Hydrogels with Extremely Enhanced Mechanical Properties

Uniform dispersion of two-dimensional (2D) graphene materials in polymer matrices remains challenging. In this work, a novel layer-by-layer assembly strategy was developed to prepare a sophisticated nanostructure with highly dispersed 2D graphene oxide in a three-dimensional matrix consisting of one-dimensional bacterial cellulose (BC) nanofibers. This method is a breakthrough, with respect to the conventional static culture method for BC that involves multiple in situ layer-by-layer assembly steps at the interface between previously grown BC and the culture medium. In the as-prepared BC/GO nanocomposites, the GO nanosheets are mechanically bundled and chemically bonded with BC nanofibers via hydrogen bonding, forming an intriguing nanostructure. The sophisticated nanostructure of the BC/GO leads to greatly enhanced mechanical properties compared to those of bare BC. This strategy is versatile, facile, scalable, and can be promising for the development of high-performance BC-based nanocomposite hydrogels.

Magnetic Lamellar Nano-Hydroxyapatite as a Vector for Gene Transfection in Three-Dimensional Cell Culture

Compared to two-dimensional (2D) conditions, investigation on gene transfection in three-dimensional (3D) conditions is much less extensive. In this work, lamellar nano-hydroxyapatite (L-HAp) with and without magnetism were used as the vectors and gene transfection in 2D and 3D cell culture was carried out and compared. We found that the transfection efficiency in 3D conditions was much higher than 2D cell culture. Additionally, magnetism enhanced transfection efficiency under both 2D and 3D conditions. The findings presented in this study demonstrated that the magnetic L-HAp could be a promising vector in 3D gene transfection.

Porous nanoplate-like hydroxyapatite–sodium alginate nanocomposite scaffolds for potential bone tissue engineering

Weak mechanical properties and poor protein adsorption capacity of sodium alginate (SA) limit its use in tissue engineering. In this study, glucosamine-grafted nanoplate-like hydroxyapatite (gHAp)–SA nanocomposite scaffolds were fabricated via solution mixture and freeze-drying method. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared, and thermogravimetric analysis were used to characterize the gHAp/SA nanocomposites. The porosity, mechanical properties, and preliminary cell behaviour of the gHAp/SA nanocomposites were examined and compared with neat SA. The gHAp/SA nanocomposites show improved mechanical properties and superior cell viability to neat SA. Furthermore, both the mechanical and biological behaviours of the gHAp/SA nanocomposites are related to the content of gHAp. It has been demonstrated that the highly porous and mechanically robust gHAp/SA nanocomposite scaffolds hold promise in tissue engineering applications.