Compartmentalized bioencapsulated liquefied 3D macro-construct by perfusion-based layer-by-layer technique

Abstract

The biological response of L929 cells encapsulated in individual Ca-Alg beads, non-liquefied 3D constructs, liquefied 3D constructs and was assessed by live-dead and MTS assays. Ca-Alg beads were selected as reference as reference group using an equal number of unbound beads to that in 3D constructs.The green fluorescence detected in live-dead assays revealed that encapsulated cells remained viable up to 7 days of culture both in non-liquefied ( Figure 4A) and liquefied ( Figure 4B) constructs. Figure 4. L929 cell viability up to 7 days of culture. (A) Live-dead fluorescence assay at day 7 of cell culture of non-liquefied and (B) liquefied 3D constructs. Living cells were stained green by calcein-AM and dead cells red by propidium iodide. Scale bars: 200 µm.(C) MTS colorimetric assay of control, nonliquefied and liquefied 3D constructs after 3 and 7 days of culture (* for same sample groups, # for different sample groups, p < 0.05). The error bar for liquefied sample after 3 days is too small to be seen.These observations suggest the process of making these constructs did not jeopardize cell viability, and the flow of culture medium was efficient in providing nutrients to the encapsulated cells. The quantitative MTS assay when comparing the values obtained for the 3 rd and 7 th day showed that whereas in both reference group and non-liquefied constructs cell metabolic activity decreased, it increased significantly A novel biofabrication process based on "perfusion-based layer-by-layer" technique using cell encapsulated hydrogel beads as building blocks is proposed to produce a freeform 3D construct with controllable switching of solid to liquified microenvironment for the use in tissue engineering/organ printing.

Biomimetic Extracellular Environment Based on Natural Origin Polyelectrolyte Multilayers

“…LbL buildup of multilayers occurs through a variety of deposition methods, including dip‐coating, hydrodynamic dip‐coating, spin‐coating, spraying, perfusion, inkjet printing‐assisted LbL, and high‐gravity field . To the date dip‐coating is the most used, besides its inherent shortcomings, namely the large amount of material and total time required for film preparation, which limit their industrial application .…”

Towards the design of 3D multiscale instructive tissue engineering constructs: Current approaches and trends

“…(Tang, et al, 2006;Oliveira, et al, 2013b; Using LbL, multilayered structures can be created around the units, binding and stabilizing the entire set and forming a scaffold (Miranda, et al, 2011;Sher, et al, 2015a;Sher, et al, 2015b), temporary templates to produce high porous foams (Sher, et al, 2010;Silva, et al, 2013a) or hierarchical capsules (Correia, et al, 2013;. Such extension of the LbL methodology towards the fabrication of 3D structures is an example of the application of this technology in the biomedical field.…”

Biomedical Applications of Layer‐by‐Layer Self‐Assembly for Cell Encapsulation: Current Status and Future Perspectives

“…As the most widely utilized method for LbL cell encapsulation, immersive assembly will continue to play an important role in the LbL cell encapsulation. Fluidic assembly technique can perform multilayer assembly on cell surfaces by loading cells into the fluidic channels, then followed by using vacuum or pressure to drive the sequential flow of polymers and washing solutions through the fluidic channels to achieve cell encapsulation . The microfluidic platform is made up of channels with micrometers dimensions, which provides a fast and new method for cell encapsulation and can significantly decrease the reagent consumption and waste production .…”