Multiple functions of microfluidic platforms: Characterization and applications in tissue engineering and diagnosis of cancer

Microfluidic system, or lab-on-a-chip, has grown explosively. This system has been used in research for the first time and then entered in the clinical section. Due to economic reasons, this technique has been used for screening of laboratory and clinical indices. The microfluidic system solves some difficulties accompanied by clinical and biological applications. In this review, the interpretation and analysis of some recent developments in microfluidic systems in biomedical applications with more emphasis on tissue engineering and cancer will be discussed. Moreover, we try to discuss the features and functions of microfluidic systems. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Experimental and numerical studies on microfluidic preparation and engineering of chitosan nanoparticles

Optimization of nanoparticle (NP) characteristics (e.g. size, shape, zeta potential, etc.) is essential to achieve desirable cell responses. In the current study, we intend to introduce an equation representing a prediction about hydrodynamic diameter of microfluidic (MF) preparation of chitosan-tripolyphosphate (CS-TPP) NPs as an influential factor on cell behavior. Both numerical simulation and experimental study have been employed for this study. TPP concentration, channel length and flow ratio (lateral flow to core flow) to find optimum mixing efficiency conditions using a computational fluid dynamics (CFD) in COMSOL 5.5 in a t-shaped MFD were evaluated numerically and consequently in experimental section, a cross-junction MFD was used for preparation of CS-TPP NPs based on optimum conditions obtained from numerical section to find a correlation between NPs hydrodynamic diameter, flow ratios and TPP concentrations. © 2020 Elsevier B.V

Microfluidic fabrication of alendronate-loaded chitosan nanoparticles for enhanced osteogenic differentiation of stem cells

Aims: In this study, we used a cross-junction microfluidic device for preparation of alendronate-loaded chitosan nanoparticles with desired characteristics to introduce a suitable element for bone tissue engineering scaffolds. Main methods: By controlling the reaction condition in microfluidic device, six types of alendronate-loaded chitosan nanoparticles were fabricated which had different physical properties. Hydrodynamic diameter of synthetized particles was evaluated by dynamic light scattering (102 to 215 nm). Nanoparticle morphology was determined by SEM and AFM images. The osteogenic effects of prepared selected nanoparticles on human adipose stem cells (hA-MSCs) were evaluated by assessment of alkaline phosphatase (ALP) activity, calcium deposition, ALP and osteopontin gene expression. Key findings: The highest loading efficiency percentage (LE) was 32.42 ± 2.02. Based on MTT assessment, two samples which had no significant cytotoxicity were chosen for further studies (particle sizes and LE were 142 ± 6.1 nm, 198 ± 16.56 nm, 16.76 ± 3.91 and 32.42 ± 2.02, respectively). In vitro release behavior of nanoparticles displayed pH responsive characteristics. Significant faster release was seen in acidic pH = 5.8 than neutral pH = 7.4. The selected nanoparticles demonstrated higher ALP activity at 14 days in comparison to selected blank sample and osteogenic differentiation media (ODM) and a downregulation at 21 days in comparison to 14 days. Calcium content assay at 21 days displayed significant differences between alendronate-loaded nanoparticles and ODM. ALP and osteopontin mRNA expression was significantly higher than the cells cultured in ODM at 14 and 21 days. Significance: We concluded that our prepared nanoparticles significantly enhanced osteogenic differentiation of hA-MSCs and can be a suitable compartment of bone tissue engineering scaffolds. © 202