In the field of tissue engineering, design and fabrication of precisely and
spatially patterned, highly porous scaffolds/matrixes are required to guide
overall shape of tissue growth and replacement. Although rapid prototyping
fabrication techniques have been used to fabricate the scaffolds with desired
design characteristics, controlling the interior architecture of the scaffolds
has been a challenge due to Computer-aided Design (CAD) constrains. Moreover,
thick engineered tissue scaffolds show inadequate success due to the limited
diffusion of oxygen and nutrients to the interior part of the scaffolds. These
limitations lead to improper tissue regeneration. In this work, in order to
overcome these design and fabrication limitations, research has been expanded to
generation of scaffolds which have inbuilt micro and nanoscale fluidic channels.
Branching channels serve as material delivery paths to provide oxygen and
nutrients for the cells. These channels are designed and controlled with
Lindenmayer Systems (L-Systems) which is an influential way to create the
complex branching networks by rewriting process. In this research, through the
computational modeling process, to control the thickness, length, number and the
position of the channels/branches, main attributes of L-Systems algorithms are
characterized and effects of algorithm parameters are investigated. After the
L-System based branching design is completed, 3D tissue scaffolds were
fabricated by “UV-Maskless Photolithography”. In this
fabrication technique, Polyethylene (glycol) Diacrylate (PEGDA), which is
biodegradable and biocompatible polymer, was used as a fabrication material. Our
results show that L-System parameters can be successfully controlled to design
of 3D tissue engineered scaffolds. Our fabrication results also show that
L-System based designed scaffolds with internal branch structures can be
fabricated layer-by-layer fashion by Maskless Photolithography. This technology
can be easily applied to engineering living systems.