Composite nanofibers of poly(caprolactone) (PCL) and gelatin crosslinked with genipin are prepared. The contact angles and mechanical properties of crosslinked PCL-gelatin nanofibers decrease as the gelatin content increases. The proliferation of myoblasts is higher in the crosslinked PCL-gelatin nanofibers than in the PCL nanofibers, and the formation of myotubes is only observed on the crosslinked PCL-gelatin nanofibers. The expression level of myogenin, myosin heavy chain, and troponin T genes is increased as the gelatin content is increased. The results suggest that PCL-gelatin nanofibers crosslinked with genipin can be used as a substrate to modulate proliferation and differentiation of myoblasts, presenting potential applications in muscle tissue engineering.

The 3-dimensional (3D) printing technologies, referred to as additive manufacturing (AM) or rapid prototyping (RP), have acquired reputation over the past few years for art, architectural modeling, lightweight machines, and tissue engineering applications. Among these applications, tissue engineering field using 3D printing has attracted the attention from many researchers. 3D bioprinting has an advantage in the manufacture of a scaffold for tissue engineering applications, because of rapid-fabrication, high-precision, and customized-production, etc. In this review, we will introduce the principles and the current state of the 3D bioprinting methods. Focusing on some of studies that are being current application for biomedical and tissue engineering fields using printed 3D scaffolds.

Electrospinning of pure chitosan was employed to obtain a nanofibrous hemostatic material. Owing to the water-solubility of the resulting acidic chitosan nanofibers, the optimum neutralization conditions were identified by testing various alkaline solutions, so that an insoluble material could be achieved. The pore size and thickness of the neutralized chitosan nanofibers mat could be controlled using ultra-sonication. The porosity of the chitosan mat was increased from 79.9% to 97.2% with ultra-sonication treatment for 1 min, and the water absorption time decreased from 110s to 9s. The blood clotting efficiency measured for the sonicated chitosan nanofiber mat was 1.35- and 3.41-fold better than the efficiencies of the Surgicel(®) and chitosan sponge, respectively. In addition, the proliferation of normal human dermal fibroblasts on the sonicated nanofiber mat was found to be 1.4-fold higher than that on the non-sonicated material after 7 days of culture.

In this study, we demonstrate a method to construct a water-based pharmacophore model which can be utilized in the absence of known ligands. This method utilizes waters found in the binding pocket, sampled through molecular dynamics. Screening of compound databases against this water-based pharmacophore model reveals that this approach can successfully identify known binders to a target protein. The method was tested by enrichment studies of 7 therapeutically important targets and compared favourably to screening-by-docking with Glide. Our results suggest that even without experimentally known binders, pharmacophore models can be generated using molecular dynamics with waters and used for virtual screening.

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