Vat polymerization-based bioprinting—process, materials, applications and regulatory challenges

Abstract

Over the years, the field of bioprinting has attracted attention for its highly automated 16 fabrication system that enables the precise patterning of living cells and biomaterials at pre-17 defined positions for enhanced cell-matrix and cell-cell interactions. Notably, vat polymerization 18 (VP)-based bioprinting is an emerging bioprinting technique for various tissue engineering 19 applications due to its high fabrication accuracy. Particularly, different photo-initiators (PIs) are 20 utilized during the bioprinting process to facilitate the crosslinking mechanism for fabrication of 21 high-resolution complex tissue constructs. The advancements in VP-based printing have led to a 22 paradigm shift in fabrication of tissue constructs from cell-seeding of tissue scaffolds (non-23 biocompatible fabrication process) to direct bioprinting of cell-laden tissue constructs 24 (biocompatible fabrication process). This paper, presenting a first-time comprehensive review of 25 the VP-based bioprinting process, provides an in-depth analysis and comparison of the various 26 biocompatible PIs and highlights the important considerations and bioprinting requirements. This 27 review paper reports a detailed analysis of its printing process and the influence of light-based 28 curing modality and PIs on living cells. Lastly, this review also highlights the significance of VP-29 based bioprinting, the regulatory challenges and presents future directions to transform the VP-30 Page 1 of 47 AUTHOR SUBMITTED MANUSCRIPT -BF-102156.R2based printing technology into imperative tools in the field of tissue engineering and regenerative 31 medicine. The readers will be informed on the current limitations and achievements of the VP-32 based bioprinting techniques. Notably, the readers will realize the importance and value of 33 highly-automated platforms for tissue engineering applications and be able to develop objective 34 viewpoints towards this field.

Synthesis and Characterisation of Acrylic Resin-Al Powder Composites Suitable for Additive Manufacturing

“…This building concept is one of the most versatile AM techniques as it allows to obtain thinner laminate layers, which leads to producing parts with low porosity [18]. Despite being limited by many factors such as poor mechanical properties [18], one of the highlighting applications of SLA lies in the field of tissue engineering applications [19,20]. For this reason, SLA has recently attracted research interest in obtaining composite materials with improved properties compared with pristine photocurable resins [21,22].…”

Applications of 3D Bioprinted-Induced Pluripotent Stem Cells in Healthcare

“…Moreover, the use of photo-initiator resins may be cytotoxic to the cells[ 74 ]. Vat polymerization (VP) based bioprinting is a novel and accurate bioprinting method tissue engineering applications[ 75 ]. Various types of photo-initiators are used for the cross-linking of the printed tissues in the VP based bioprinting.…”

Bioprinting for combating infectious diseases

“…This approach allows for a smoother surface, removes the need for a coating blade and reduces the volume of material required [ 22 ]. The use of a support material may be required for both bottom-up and top-down printing [ 23 ]. Bioprinting can be accomplished using SLA by filling the reservoir with cells and photocurable hydrogel, while using a laser with a specific wavelength to avoid damaging the cellular materials [ 19 ].…”

“…SLA and other vat-polymerization techniques are limited in material choices, as the solution used must be photo-reactive and photocurable, and the process required to ensure biocompatibility may cause loss of drug activity [ 14 ]. Exposure to excessive external light sources may also reduce printing accuracy [ 23 ].…”