Femtosecond Laser Patterning of Cell Scaffold Materials for 3D Vascularization Modelling

Femtosecond Laser Patterning of Cell Scaffold Materials

 for 3D Vascularization Modeling

Sabrina McCarthy¹, Nannette Hernandez¹, Alessandro Enrico²,

Anna Herland³, Frank Niklaus² , Gšran Stemme²

1 Department of Chemical Engineering, City College of New York

2 Department of Micro and Nanosystems, School of Electrical Engineering, Royal Institute of Technology

3 Department of Physiology and Pharmacology, Karolinska Institutet

Creating functional, biological tissue constructs is essential for drug screening. Current approaches consist in cell-based vascularization, or scaffold molding and subsequent channel perfusion. However, the first is difficult to achieve and to control, while the second often break sterile conditions because of the molding procedure, and is still limited in terms of 3D geometry of the possible vascular network.

Here we propose 3D patterning of channels by using a femtosecond laser. As non-contact technique, sterility of the sample is maintained, and design freedom in terms of patterning is provided by the nonlinear nature of multiphoton absorption that leads to point-like modification in correspondence of the focal spot of the laser beam.

Recent interests have been devoted to achieving vascularization in ECM based scaffolds such as collagen. When creating these constructs, providing sterility to cells while also creating a mechanically stable ECM based scaffold in a time and cost efficient manner is crucial. Femtosecond laser technology, as opposed to UV molding and soft lithography, allows for a non-contact technique and the freedom to pattern in 3D geometry.

Experiments using femtosecond laser technology to pattern vessel like structures in collagen can provide more insight into what parameters are needed to ablate through a liquid medium. By adjusting power, repetition rate, and feed rate ablation in collagen immersed in liquid is possible without modifying the layers above.