Liquefied microcapsules as dual-Mmcrocarriers for 3D+3D bottom-up tissue engineering

Cell encapsulation systems must ensure the diffusion of molecules to avoid the formation of necrotic cores. The architectural design of hydrogels, the gold standard tissue engineering strategy, is thus limited to a microsize range. To overcome such a limitation, liquefied microcapsules encapsulating cells and microparticles are proposed. Microcapsules with controlled sizes with average diameters of 608.5 ± 122.3 µm are produced at high rates by electrohydrodynamic atomization, and arginyl-glycyl-aspartic acid (RGD) domains are introduced in the multilayered membrane. While cells and microparticles interact toward the production of confined microaggregates, on the outside cell-mediated macroaggregates are formed due to the aggregation of microcapsules. The concept of simultaneous aggregation is herein termed as 3D+3D bottom-up tissue engineering. Microcapsules are cultured alone (microcapsule1 ) or on top of 2D cell beds composed of human umbilical vein endothelial cells (HUVECs) alone (microcapsule2 ) or cocultured with fibroblasts (microcapsule3 ). Microcapsules are able to support cell encapsulation shown by LiveDead, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphofenyl)-2H-tetrazolium (MTS), and dsDNA assays. Only microcapsule3 are able to form macroaggregates, as shown by F-actin immunofluorescence. The bioactive 3D system also presented alkaline phosphatase activity, thus allowing osteogenic differentiation. Upon implantation using the chick chorioallontoic membrane (CAM) model, microcapsules recruit a similar number of vessels with alike geometric parameters in comparison with CAMs supplemented with basic fibroblast growth factor (bFGF).publishe

Cancer Stem Cell Microenvironment Models with Biomaterial Scaffolds In Vitro

Defined by its potential for self-renewal, differentiation and tumorigenicity, cancer stem cells (CSCs) are considered responsible for drug resistance and relapse. To understand the behavior of CSC, the effects of the microenvironment in each tissue are a matter of great concerns for scientists in cancer biology. However, there are many complicated obstacles in the mimicking the microenvironment of CSCs even with current advanced technology. In this context, novel biomaterials have widely been assessed as in vitro platforms for their ability to mimic cancer microenvironment. These efforts should be successful to identify and characterize various CSCs specific in each type of cancer. Therefore, extracellular matrix scaffolds made of biomaterial will modulate the interactions and facilitate the investigation of CSC associated with biological phenomena simplifying the complexity of the microenvironment. In this review, we summarize latest advances in biomaterial scaffolds, which are exploited to mimic CSC microenvironment, and their chemical and biological requirements with discussion. The discussion includes the possible effects on both cells in tumors and microenvironment to propose what the critical factors are in controlling the CSC microenvironment focusing the future investigation. Our insights on their availability in drug screening will also follow the discussion

Geometrically controlled liquefied capsules for modular tissue engineering strategies

A plethora of bioinspired cell-laden hydrogels are being explored as building blocks that once assembled are able to create complex and highly hierarchical structures recapitulating the heterogeneity of living tissues. Yet, the resulting 3D bioengineered systems still present key limitations, mainly related with limited diffusion of essential molecules for cell survival, which dictates the failure of most strategies upon implantation. To maximize the hierarchical complexity of bioengineered systems, while simultaneously fully addressing the exchange efficiency of biomolecules, the high-throughput fabrication of liquefied capsules is proposed using superhydrophobic-superhydrophilic microarrays as platforms to produce the initial structures with high fidelity of geometry and size. The liquefied capsules are composed by i) a permselective multilayered membrane; ii) surface-functionalized poly(ε-caprolactone) microparticles loaded into the liquefied core acting as cell adhesion sites; and iii) cells. It is demonstrated that besides the typical spherical liquefied capsules, it is also possible to obtain multi-shaped blocks with high geometrical precision and efficiency. Importantly, the internal gelation approach used to produce such blocks does not jeopardize cell viability, evidencing the mild conditions of the proposed cell encapsulation technique. The proposed system is intended to be used as hybrid devices implantable using minimally invasive procedures for multiple tissue engineering applications.publishe

Cigarette smoke extract impairs gingival epithelial barrier function

We previously showed that junctional adhesion molecule 1 (JAM1) and coxsackievirus and adenovirus receptor (CXADR), tight junction-associated proteins, have important roles to maintain epithelial barrier function in gingival tissues. Smoking is considered to be a significant risk factor for periodontal disease. The present study was conducted to examine the effects of cigarette smoke extract (CSE) on JAM1 and CXADR in human gingival epithelial cells. CSE was found to cause translocation of JAM1 from the cellular surface to EGFR-positive endosomes, whereas CXADR did not. Using a three-dimensional multilayered gingival epithelial tissue model, CSE administration was found to increase permeability to lipopolysaccharide and peptidoglycan, whereas overexpression of JAM1 in the tissue model prevented penetration by those substrates. Furthermore, vitamin C increased JAM1 expression, and inhibited penetration of LPS and PGN induced by CSE. These findings strongly suggest that CSE disrupts gingival barrier function via dislocation of JAM1, thus allowing bacterial virulence factors to penetrate into subepithelial tissues. Furthermore, they indicate that vitamin C increases JAM1 expression and prevents disruption of gingival barrier function by CSE.Yamaga S., Tanigaki K., Nakamura E., et al. Cigarette smoke extract impairs gingival epithelial barrier function. Scientific Reports 13, 9228 (2023); https://doi.org/10.1038/s41598-023-36366-z

A four-dimensional organoid system to visualize cancer cell vascular invasion

Yanagisawa, K.; Konno, M.; Liu, H.; Irie, S.; Mizushima, T.; Mori, M.; Doki, Y.; Eguchi, H.; Matsusaki, M.; Ishii, H. A Four-Dimensional Organoid System to Visualize Cancer Cell Vascular Invasion. Biology 2020, 9, 361