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

Femtosecond Laser Patterning of Cell Scaffold Materials

 for 3D Vascularization

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.