The effect of porosity on cell ingrowth in 3D laser-fabricated biodegradable scaffolds for bone regeneration

Abstract

Bone is the second most common transplantation tissue after blood. While the use of bone grafts remains the optimum choice, the problems associated with them has made the use of synthetic implants ever more popular. Over the last decade, there has been a lot research into the development of engineered new bone, to replace damaged tissue. An important part of this research effort has gone into the development of three-dimensional porous scaffolds, to support and guide the new cells.Here, we describe our research into the fabrication and evaluation as bone scaffolds of 3D biodegradable structures made using Direct fs Laser Writing (DLW). The material we use is a photostructurable polylactidebased material (PLA) synthesized for this purpose [1]. We test its degradation in vitro in PBS and we show that the material looses one third of its weight after six weeks, therefore allowing the slow release of an implanted scaffold. We demonstrate the fabrication of artificial scaffolds with precisely controlled geometries and different pore sizes and we test them for up to eight weeks using the mouse pre-osteoblastic cell line MC3T3-E1 [2]. Our results show good cell adhesion and a preference to scaffolds with 86% porosity, compare to other porosities studied (Fig. 1). Our study shows that DLW is a suitable technique for the fabrication of 3D biodegradable scaffolds for bone repair and other tissue engineering applications. Fig. 1Porous wood-pile shaped scaffold with 86% porosity (a) and 82% porosity (b). After three weeks in culture, pre-osteoblastic cells proliferated remarkably more into the 86% porous scaffolds.

Multiphoton 3D Printing of Biopolymer-Based Hydrogels

“…Apart from the biomaterial and the appropriate 3D scaffold architecture, selected for specific TERM applications, the cell type used as well as the bioactive molecules, that guide different biological responses, are crucial. Recent advances in stem cell research have provided the theoretical and experimental background for TERM applications.…”