PLA/PLLA scaffold for vascular tissue engineering applications

Abstract

A critical obstacle encountered by tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions to host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. Another task in this research field is the possibility to tune the biodegradability of the scaffold. After implantation, the scaffold must be gradually populated by cells and replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with appropriate dynamics and a well-defined timescale. A premature degradation, in fact, could lead to a collapse of the structure as the newly generated tissue could not have reached yet the suitable mechanical properties. Conversely, a long degradation time could delay or completely interrupt the development of the new tissue. In this work scaffolds for vascular tissue engineering were produced by dip-coating followed by Diffusion Induced Phase Separation (DIPS). Several PLA-PLLA blends (100/0, 75/25, 25/75, 10/90 wt/wt) were utilized to produce the scaffolds. Moreover preliminary biodegradation tests were carried out in order to evaluate the degradation rates.