Mesenchymal stem cell printing and process regulated cell properties

Abstract

This topical review with original analysis and empirical results compares cell sensitivity to physical stress during printing. The objective is to frame a reproducible causation between printing environment and printed cell morphology, viability and phenotype stability. Content includes: (1) a topical review classifies the overlap between physical stress vectors during printing and mesenchymal stem cell sensitivities. (2) Original flow analysis frames the feasible range of stress duration and intensity during manufacturing. (3) Preliminary empirical results define cell properties as a function of minimum, mean and maximum stress conditions. The review and analytical characterization serve as an essential precursor to interpret surprising empirical results. Results identify key cell properties are stress-dependent and controllable based on printing process parameter selection. Printing's minimum stress condition preserves cell viability. The maximum stress increases heterogeneity of cell response, induces inelastic ultra-structural distortion of the cell membrane and chromatin, and increases necrotic subpopulations post-printing. The review, analysis and preliminary results support the feasibility of modulating cell properties during fabrication by prescriptively tuning the stress environment. The process control over cell morphology, health and the rate of differentiation is both a direct result of strain during printing and an in-direct result of increased distress signaling from necrotic sub-populations.

Combining Innovative Bioink and Low Cell Density for the Production of 3D-Bioprinted Cartilage Substitutes: A Pilot Study

“…Conversely, cell viability could be affected by shear forces applied during the mixing of the bioink or during long postprinting cross-linking processes [69]. Currently, live/dead cell viability is often the only assay performed to evaluate the safety of a bioprinting process [53,70]. In our experimental conditions, longitudinal real-time measurement of mitochondrial activity for up to 28 days, with or without TGF-β1, showed no alteration of the cells within the substitutes.…”

Computational simulation of static/cyclic cell stimulations to investigate mechanical modulation of an individual mesenchymal stem cell using confocal microscopy

“…Based on the aforementioned findings, the use of AFM can be important to determine cell mechanical behavior [40]. Laboratory analysis of MSCs differentiation showed phenotype of linage such as neural (0.1-1 kPa), myogenic (8-17 kPa) or osteogenic (>34 kPa) [41]. MSCs, under compressive loading, have the potential to differentiate into cartilage cells [33].…”

Bioimpressão e produção de mini-órgãos com células tronco

“…Dessa forma, as células são colocadas numa matriz juntamente com fatores de crescimento adequados, e em seguida são injetados ou colocados no local da regeneração (Jabbari 2011). Contudo, esses processos exercem influência sobre a morfologia celular, saúde e taxa de diferenciação, que são consequências diretas da pressão durante a impressão dessas células, aumentando os sinais de sofrimento celular e populações necróticas (Snyder et al 2015).…”

“…Entretanto, Snyder et al (2015) identificaram que impressões 3D que condicionam um estresse mínimo podem preservar a viabilidade celular.…”

“…Nessa perspectiva, estudos têm sido realizados na tentativa de produzir células-tronco a partir de bioimpressão para maximizar a viabilidade celular, estimulando as propriedades das células, incluindo a diferenciação pós-impressão (Snyder et al 2015). Durante as três últimas décadas a engenharia de tecidos conseguiu produzir terapias de pele e cartilagem para substituir tecidos funcionalmente danificados, além de outros tecidos como ossos, fígado e coração como substitutos de tecidos.…”