Conductive nanostructures, such as metal nanoparticles

and carbon nanostructures, may modulate the electrical properties of biomaterials, Selleckchem Selumetinib affecting stem cell functions [73] and [74]. Scaffold morphology, e.g., pore size and shape, is critical for cell–biomaterial interactions in terms of mimicking the morphology of surrounding tissue. High porosity and an adequate pore size in particular are key conditions for increasing the surface area available for cell attachment and growth. In the following sections, the interactions between PDL cells and each parameter of the scaffold design discussed above will be covered in detail using our findings. Cell sheet technology is a concept of tissue engineering that provides a mass of cells to the site of regeneration by the transplantation of an in vitro cultured multilayered cell sheet. This technology has already been applied to the regeneration of many organs in clinical settings, including corneal surface reconstruction, endoscopic treatment of esophageal ulceration, and myocardial tissue reconstruction [75]. The cell sheet was successfully prepared from PDL cells, and scaffold-free sheet transplantation could regenerate a complete periodontium in a canine Fulvestrant model [29]. Cell sheet engineering

is also applicable to 3D-tissue reconstruction of tissue by applying an appropriate scaffold material to increase the number of cell layers [76]. Skin reconstruction is another medical field applicable to cell sheet-based tissue engineering. The honeycomb biodegradable collagen scaffold has been shown to be suitable for 3D cell cultures [77] because the honeycomb structure has many advantages, such as mechanical stability under various physical conditions, the capability to exchange nutrients and waste products through

the honeycomb pores, and the ability to retain its structure without a deformity nearly or collapse until its biodegradation [78]. However, the pore size of natural polymers such as collagen is difficult to control. The honeycomb pattern was also prepared on various types of polymers by a simple casting method [79], [80] and [81]. Briefly, the hydrophobic polymer solution was casted on a basal plate, water droplets self-assembled on the polymer solution with the addition of humid air, and the honeycomb pattern was observed on the polymer film after drying. We could control the pore size of the honeycomb structure and fabricate uniform pores using the casting method. This casting method is applicable for biodegradable polyester films made from poly(lactic acid) and poly(ɛ-caprolactone) (PCL) [82], which is useful as a cell culture substrate. We cultured PDL cells on the honeycomb-patterned polymer films fabricated by the casting method with different pore sizes. PDL cells were obtained from extracted molars with a healthy periodontium, and subjected to experiments during 3–5 passages. PDL cells were cultured on flat (control) and honeycomb PCL films with 5- and 10-μm pores for 72 h.