The Development of 3D Tissue and Novel Photonics Technologies for Bio-Medical Theragnostic

Abstract

3D in-vitro models have emerged as substitutes of complex tissue structures of human body. These models can depict in-vivo conditions of real tissues and can be utilized as valuable tools for per-clinical applications. This work presented development of 3D in-vitro tissue models of full-thickness skin equivalents (FSE) and Melanoma full-thickness skin equivalents (Melanoma-FSE). The development of 3D architecture of FSE and Melanoma-FSE are crucial requirement for investigation of skin pathologies, personalized skin disease treatments, disease modelling, drug testing. We designed high-resolution 3D scaffolds to support the growth and maturation of these skin models. Additionally, we developed and validated a cost-effective, custom-built system combining fluorescence spectroscopy (FS) and optical coherence tomography (OCT) for non-destructive analysis of the metabolism and morphology of 3D FSEs. This system proved highly sensitive in detecting fluorescence from key metabolic co-enzymes (NADH/NADPH and FAD) in solutions and cell suspensions, while OCT provided adequate resolution to observe the morphology of FSEs. As a result, both the 3D FSE model and the dual-mode optical system hold significant potential for use in 3D bioprinting of biological tissues, as well as in the development of cosmetics, drugs, and in monitoring their maturation over time. In scaffold fabrication, we explored two latest emerging bioprinting technologies: Digital Light Processing (DLP) and Two-Photon Polymerization (2PP). The difference between 3D tissue engineered constructs by using these two methods are presented to demonstrate the selection of technology considering to the specific application and tissue construction. For microscale functional tissue structures, 2PP is unique and precise method but having some limitations as compared to DLP. Furthermore, due to therapeutic potential of 1267nm laser irradiation, it is used for generation of singlet oxygen without using photosensitizer (PS). 1267nm laser-induced 1O2 production can cause massive oxidative effect on cellular functions, e.g., mitochondrial dysfunction with mtDNA degradation, cancer cell death. In this study, we investigated real time monitoring of production and role of 1O2 in apoptosis with the aim of optimizing therapeutic outcomes. We found that 1O2 caused the initiation of apoptosis in melanoma cancer cell line more effectively as compared to the primary human fibroblasts and HaCaT cells. Collectively, this work demonstrates the integration of tissue engineering, optical diagnostics and phototherapy for advancing diagnostics and treatment.