Laser ablation imparts controlled micro-scale pores in electrospun scaffolds for tissue engineering applications

Electrospun scaffolds have been used extensively for tissue engineering applications due to the simple processing scheme and versatility. However, many additional benefits can be imparted to these materials via post-processing techniques. Specifically the addition of structured pores on the micro-scale can offer a method to enable patterned cell adhesion, enhanced diffusional properties, and/or guide vascular infiltration upon implantation in vivo. In this study, we laser ablated electrospun poly(L: -lactic acid) (PLA) scaffolds and assessed the ablation process and cellular interaction by examining human adipose-derived stem cell (hASC) viability and proliferation on laser micro-machined scaffolds. Laser ablated pores of 150, 300, and 600 μm diameter were micro-machined through electrospun PLA scaffolds. Laser ablation parameters were varied and it was determined that the aperture and z-travel direction of the laser linearly correlated with the ablated pore diameter. To assess cytocompatibility of the micro-machined scaffolds, hASCs were seeded on each scaffold and cell viability was assessed on day 7. Human ASCs were able to adhere around the micro-machined features. DNA content was quantified on all scaffolds and it was determined that hASCs were able to proliferate on all scaffolds. The process of laser ablation could impart many beneficial features to electrospun scaffolds by increasing mass transport and mimicking micro-scale features and assisting in patterning of cells around micro-machined features.