High-resolution lithographic biofabrication of hydrogels with complex microchannels from low-temperature-soluble gelatin bioresins

Levato, Riccardo; Lim, Khoon S.; Li, Wanlu; Asua, Ane Urigoitia; Peña, Laura Blanco; Wang, Mian; Falandt, Marc; Bernal, Paulina Núñez; Gawlitta, Debby; Zhang, Yu Shrike; Woodfield, Tim B. F.; Malda, Jos

doi:10.1016/j.mtbio.2021.100162

Cited by 47 publications

(61 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These soft gels are also likely a consequence of the higher sol‐fraction after crosslinking, since unmodified gelMA prepared at the same prepolymer concentration with no optical tuning resulted in stiffer gels (5.04 ± 0.10 kPa) (Figure S11, Supporting Information). Notably, both gelMA resins were shown to remain biodegradable after the photocrosslinking process, as found upon exposure to a collagenase‐laden media, [ 61 ] an essential characteristic of biocompatible materials used in the field of tissue engineering (Figure S12, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Volumetric Bioprinting of Organoids and Optically Tuned Hydrogels to Build Liver‐Like Metabolic Biofactories

et al. 2022

Self Cite

View full text Add to dashboard Cite

Organ‐ and tissue‐level biological functions are intimately linked to microscale cell–cell interactions and to the overarching tissue architecture. Together, biofabrication and organoid technologies offer the unique potential to engineer multi‐scale living constructs, with cellular microenvironments formed by stem cell self‐assembled structures embedded in customizable bioprinted geometries. This study introduces the volumetric bioprinting of complex organoid‐laden constructs, which capture key functions of the human liver. Volumetric bioprinting via optical tomography shapes organoid‐laden gelatin hydrogels into complex centimeter‐scale 3D structures in under 20 s. Optically tuned bioresins enable refractive index matching of specific intracellular structures, countering the disruptive impact of cell‐mediated light scattering on printing resolution. This layerless, nozzle‐free technique poses no harmful mechanical stresses on organoids, resulting in superior viability and morphology preservation post‐printing. Bioprinted organoids undergo hepatocytic differentiation showing albumin synthesis, liver‐specific enzyme activity, and remarkably acquired native‐like polarization. Organoids embedded within low stiffness gelatins (<2 kPa) are bioprinted into mathematically defined lattices with varying degrees of pore network tortuosity, and cultured under perfusion. These structures act as metabolic biofactories in which liver‐specific ammonia detoxification can be enhanced by the architectural profile of the constructs. This technology opens up new possibilities for regenerative medicine and personalized drug testing.

show abstract

Section: Resultsmentioning

confidence: 99%

Volumetric Bioprinting of Organoids and Optically Tuned Hydrogels to Build Liver‐Like Metabolic Biofactories

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Unlike extrusion bioprinting where the GelMA-based bioinks (including our micropore-forming bioinks) could be pre-stored at a lower temperature (e.g., 4 °C) to first allow gelation to enable faithful bioprinting, the stability of the emulsions in the micropore-forming bioinks becomes a critical factor in DLP bioprinting since they would have to be maintained in the liquid state (e.g., room temperature) during the entire process to enable layer-by-layer biofabrication. [36,39,59] Therefore, the stability of our micropore-forming bioinks was evaluated using fluorescently labeled GelMA [27] (Figure S15, Supporting Information). It could be found that an apparent phase-separation started to occur in the micropore-forming bioink made of HF-GelMA (10 wt.%) and PEO (1 wt.%, MW: 1 × 10 5 Da) after ≈10 min of mixing at room temperature, consistent with our previous formulation reported.…”

Section: Resultsmentioning

confidence: 99%

“…Studies have shown that gelatins derived from different sources offer unique material properties. [ 38,39 ] For example, bovine and porcine gelatins have higher tensile strengths and percent elongation values compared to fish gelatin. Fish gelatin has a much lower gelation temperature than those of other species due to fish gelatin having lower concentrations of proline and hydroxyproline.…”

Section: Resultsmentioning

confidence: 99%

Micropore‐Forming Gelatin Methacryloyl (GelMA) Bioink Toolbox 2.0: Designable Tunability and Adaptability for 3D Bioprinting Applications

Liu

Luo

et al. 2022

Small

Self Cite

View full text Add to dashboard Cite

It is well‐known that tissue engineering scaffolds that feature highly interconnected and size‐adjustable micropores are oftentimes desired to promote cellular viability, motility, and functions. Unfortunately, the ability of precise control over the microporous structures within bioinks in a cytocompatible manner for applications in 3D bioprinting is generally lacking, until a method of micropore‐forming bioink based on gelatin methacryloyl (GelMA) was reported recently. This bioink took advantage of the unique aqueous two‐phase emulsion (ATPE) system, where poly(ethylene oxide) (PEO) droplets are utilized as the porogen. Considering the limitations associated with this very initial demonstration, this article has furthered the understanding of the micropore‐forming GelMA bioinks by conducting a systematic investigation into the additional GelMA types (porcine and fish, different methacryloyl‐modification degrees) and porogen types (PEO, poly(vinyl alcohol), and dextran), as well as the effects of the porogen concentrations and molecular weights on the properties of the GelMA‐based ATPE bioink system. This article exemplifies not only the significantly wider range of micropore sizes achievable and better emulsion stability, but also the improved suitability for both extrusion and digital light processing bioprinting with favorable cellular responses.

show abstract

“…Several studies tried to pattern GelMA hydrogels using DMDs ( Grogan et al, 2013 ; Wang et al, 2018 , 2021 ), but this is, to our knowledge, the first example where the stiffness of GelMA has been patterned using projected visible light. Several studies have successfully 3D printed precise structures with GelMA hydrogels using visible light ( Lim et al, 2018 ; Wang et al, 2018 ; Kumar et al, 2021 ; Levato et al, 2021 ), but without trying to control at the same time the stiffness of the scaffolds. In terms of achievable gradients, our system can generate stiffness gradients with slopes ranging from several hundreds of kPa/mm (at boundaries between areas of defined stiffness) to a few kPa/mm, which spans physiological and pathological gradients in tissues and at tissue interfaces ( Vincent et al, 2013 ).…”

Section: Resultsmentioning

confidence: 99%

“…Photopatterning the stiffness of GelMA hydrogels with UV light has been extensively studied using some of the methods cited above ( O’Connell et al, 2018 ; Ko et al, 2019 ; Li et al, 2019 ; Kim et al, 2020 ; Lavrentieva et al, 2020 ). To date, several studies have stiffness-patterned hydrogels through visible light ( Rape et al, 2015 ; He et al, 2018 ) and used projection-based patterning of GelMA ( Levato et al, 2021 ), but to our knowledge, this is the first study employing visible light projection-based patterning to control and pattern the stiffness of GelMA hydrogels.…”

Section: Introductionmentioning

confidence: 99%

Visible-Light Stiffness Patterning of GelMA Hydrogels Towards In Vitro Scar Tissue Models

Chalard

Dixon

Taberner

et al. 2022

Front. Cell Dev. Biol.

View full text Add to dashboard Cite

Variations in mechanical properties of the extracellular matrix occurs in various processes, such as tissue fibrosis. The impact of changes in tissue stiffness on cell behaviour are studied in vitro using various types of biomaterials and methods. Stiffness patterning of hydrogel scaffolds, through the use of stiffness gradients for instance, allows the modelling and studying of cellular responses to fibrotic mechanisms. Gelatine methacryloyl (GelMA) has been used extensively in tissue engineering for its inherent biocompatibility and the ability to precisely tune its mechanical properties. Visible light is now increasingly employed for crosslinking GelMA hydrogels as it enables improved cell survival when performing cell encapsulation. We report here, the photopatterning of mechanical properties of GelMA hydrogels with visible light and eosin Y as the photoinitiator using physical photomasks and projection with a digital micromirror device. Using both methods, binary hydrogels with areas of different stiffnesses and hydrogels with stiffness gradients were fabricated. Their mechanical properties were characterised using force indentation with atomic force microscopy, which showed the efficiency of both methods to spatially pattern the elastic modulus of GelMA according to the photomask or the projected pattern. Crosslinking through projection was also used to build constructs with complex shapes. Overall, this work shows the feasibility of patterning the stiffness of GelMA scaffolds, in the range from healthy to pathological stiffness, with visible light. Consequently, this method could be used to build in vitro models of healthy and fibrotic tissue and study the cellular behaviours involved at the interface between the two.

show abstract

High-resolution lithographic biofabrication of hydrogels with complex microchannels from low-temperature-soluble gelatin bioresins

Cited by 47 publications

References 62 publications

Volumetric Bioprinting of Organoids and Optically Tuned Hydrogels to Build Liver‐Like Metabolic Biofactories

Volumetric Bioprinting of Organoids and Optically Tuned Hydrogels to Build Liver‐Like Metabolic Biofactories

Micropore‐Forming Gelatin Methacryloyl (GelMA) Bioink Toolbox 2.0: Designable Tunability and Adaptability for 3D Bioprinting Applications

Visible-Light Stiffness Patterning of GelMA Hydrogels Towards In Vitro Scar Tissue Models

Contact Info

Product

Resources

About