UC Berkeley

The intricate interplay between cellular microenvironments and the development of tissue constructs, particularly the dynamics of cell proliferation and vascular formation within hydrogel matrices, has attracted great interest in the tissue engineering field and motivated numerous innovations from the biofabrication community. In particular, the recent invention of volumetric additive manufacturing (VAM) opens unique opportunities in bioprinting because it offers geometric freedom, enables overprinting, and imposes fewer rheological constraints on the printing material than traditional bioprinting methods do.This dissertation presents the use of Computed Axial Lithography (CAL), an implementation of tomographic VAM, to fabricate complex, perfusable structures within biomaterial hydrogels. These hydrogels, exhibiting storage moduli as low as a few hundred pascals, support the formation of extensive microcapillary networks, indicating their potential to replicate tissue systems. Additionally, this dissertation introduces an innovative perfusion device designed for contact-free CAL printing and subsequent processing of these hydrogel constructs. This device also demonstrates CAL's ability to intricately overprint soft structures onto pre-existing solid components. This dissertation concludes by presenting a novel print visualization method that leverages the temperature and curing-sensitive fluorescent properties of Rhodamine B (RhB). This technique, a first in the field, demonstrates real-time sensing capabilities in VAM, paving the way for advanced measurement systems that can precisely gauge both temperature and degree of conversion (DOC) during the printing process. This innovation lays foundational work for future research in the domain.