Cell encapsulation spatially alters crosslink density of poly(ethylene glycol) hydrogels formed from free-radical polymerizations

Chu, Stanley; Maples, Mollie M; Bryant, Stephanie J.

doi:10.1016/j.actbio.2020.03.033

Cited by 29 publications

(30 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of cells within the hydrogel precursor solution can also influence the photo cross-linking reaction and can impact on the mechanical properties of the hydrogel resin, 272 which in turn can result in decreased shape fidelity of the final constructs. However, to date, the effect of embedded cells on shape fidelity of bioresins for lithographic printing has received only little attention and additional research is required.…”

Section: Implications For Lithography-based Printing Technologiesmentioning

confidence: 99%

Printability and Shape Fidelity of Bioinks in 3D Bioprinting

et al. 2020

View full text Add to dashboard Cite

Three-dimensional bioprinting uses additive manufacturing techniques for the automated fabrication of hierarchically organized living constructs. The building blocks are often hydrogel-based bioinks, which need to be printed into structures with high shape fidelity to the intended computer-aided design. For optimal cell performance, relatively soft and printable inks are preferred, although these undergo significant deformation during the printing process, which may impair shape fidelity. While the concept of good or poor printability seems rather intuitive, its quantitative definition lacks consensus and depends on multiple rheological and chemical parameters of the ink. This review discusses qualitative and quantitative methodologies to evaluate printability of bioinks for extrusion- and lithography-based bioprinting. The physicochemical parameters influencing shape fidelity are discussed, together with their importance in establishing new models, predictive tools and printing methods that are deemed instrumental for the design of next-generation bioinks, and for reproducible comparison of their structural performance.

show abstract

Section: Implications For Lithography-based Printing Technologiesmentioning

confidence: 99%

Printability and Shape Fidelity of Bioinks in 3D Bioprinting

et al. 2020

View full text Add to dashboard Cite

show abstract

“…At the time of encapsulation, cells can sequester crosslinker molecules prior to polymerization which lowers the effective crosslink density and hence stiffness. [58] After encapsulation, secretion of MMPs can lead to rapid degradation of the hydrogel before the cells have time to differentiate and deposit their own ECM. [57,59] The modulus of the 3D-printed structure infilled with the soft hydrogel (i.e., the bone layer shown in Figure 1B) was 2.4 (0.5) MPa.…”

Section: Doi: 101002/adhm202001226mentioning

confidence: 99%

A 3D, Dynamically Loaded Hydrogel Model of the Osteochondral Unit to Study Osteocyte Mechanobiology

Wilmoth

Ferguson

Bryant

2020

Adv Healthcare Materials

Self Cite

View full text Add to dashboard Cite

Osteocytes are mechanosensitive cells that orchestrate signaling in bone and cartilage across the osteochondral unit. The mechanisms by which osteocytes regulate osteochondral homeostasis and degeneration in response to mechanical cues remain unclear. This study introduces a novel 3D hydrogel bilayer composite designed to support osteocyte differentiation and bone matrix deposition in a bone-like layer and to recapitulate key aspects of the osteochondral unit's complex loading environment. The bilayer hydrogel is fabricated with a soft cartilage-like layer overlaying a stiff bone-like layer. The bone-like layer contains a stiff 3D-printed hydrogel structure infilled with a soft, degradable, cellular hydrogel. The IDG-SW3 cells embedded within the soft hydrogel mature into osteocytes and produce a mineralized collagen matrix. Under dynamic compressive strains, near-physiological levels of strain are achieved in the bone layer (≤ 0.08%), while the cartilage layer bears the majority of the strains (>99%). Under loading, the model induces an osteocyte response, measured by prostaglandin E2, that is frequency, but not strain, dependent: a finding attributed to altered fluid flow within the composite. Overall, this new hydrogel platform provides a novel approach to study osteocyte mechanobiology in vitro in an osteochondral tissue-mimetic environment. Osteocytes are mechanosensitive cells that help to orchestrate signaling in bone and cartilage across the osteochondral unit. Yet the mechanisms by which osteocytes regulate osteochondral

show abstract

“…Numerous natural and synthetic hydrogels have been successfully designed to enable cartilage restoration by providing a 3D microenvironment for chondrocytes or stem cells [ 7 ]. Many physical characteristics of hydrogels, such as stiffness [ 8 ], degradation profile [ 9 ], crosslinking density [ 10 ], and porous structure [ 11 , 12 ], play a pivotal role in cell behavior regulation and thus influence the efficacy of cartilage regeneration. Traditional dense bulk hydrogels do not meet the requirements for cartilage regeneration [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

3D printed silk-gelatin hydrogel scaffold with different porous structure and cell seeding strategy for cartilage regeneration

Feng

et al. 2021

Bioactive Materials

140

View full text Add to dashboard Cite

Hydrogel scaffolds are attractive for tissue defect repair and reorganization because of their human tissue-like characteristics. However, most hydrogels offer limited cell growth and tissue formation ability due to their submicron- or nano-sized gel networks, which restrict the supply of oxygen, nutrients and inhibit the proliferation and differentiation of encapsulated cells. In recent years, 3D printed hydrogels have shown great potential to overcome this problem by introducing macro-pores within scaffolds. In this study, we fabricated a macroporous hydrogel scaffold through horseradish peroxidase (HRP)-mediated crosslinking of silk fibroin (SF) and tyramine-substituted gelatin (GT) by extrusion-based low-temperature 3D printing. Through physicochemical characterization, we found that this hydrogel has excellent structural stability, suitable mechanical properties, and an adjustable degradation rate, thus satisfying the requirements for cartilage reconstruction. Cell suspension and aggregate seeding methods were developed to assess the inoculation efficiency of the hydrogel. Moreover, the chondrogenic differentiation of stem cells was explored. Stem cells in the hydrogel differentiated into hyaline cartilage when the cell aggregate seeding method was used and into fibrocartilage when the cell suspension was used. Finally, the effect of the hydrogel and stem cells were investigated in a rabbit cartilage defect model. After implantation for 12 and 16 weeks, histological evaluation of the sections was performed. We found that the enzymatic cross-linked and methanol treatment SF 5 GT 15 hydrogel combined with cell aggregates promoted articular cartilage regeneration. In summary, this 3D printed macroporous SF-GT hydrogel combined with stem cell aggregates possesses excellent potential for application in cartilage tissue repair and regeneration.

show abstract

Cell encapsulation spatially alters crosslink density of poly(ethylene glycol) hydrogels formed from free-radical polymerizations

Cited by 29 publications

References 57 publications

Printability and Shape Fidelity of Bioinks in 3D Bioprinting

Printability and Shape Fidelity of Bioinks in 3D Bioprinting

A 3D, Dynamically Loaded Hydrogel Model of the Osteochondral Unit to Study Osteocyte Mechanobiology

3D printed silk-gelatin hydrogel scaffold with different porous structure and cell seeding strategy for cartilage regeneration

Contact Info

Product

Resources

About