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Cell microencapsulation represents a great promise for long-term drug delivery, but still several challenges need to be overcome before its translation into the clinic, such as the ...long term cell survival inside the capsules. On this regard, graphene oxide has shown to promote proliferation of different cell types either in two or three dimensions. Therefore, we planned to combine graphene oxide with the cell microencapsulation technology. We first studied the effect of this material on the stability of the capsules and next we analyzed the biocompatibility of this chemical compound with erythropoietin secreting C2C12 myoblasts within the microcapsule matrix. We produced 160μm-diameter alginate microcapsules with increasing concentrations of graphene oxide and did not find modifications on the physicochemical parameters of traditional alginate microcapsules. Moreover, we observed that the viability of encapsulated cells within alginate microcapsules containing specific graphene oxide concentrations was enhanced. These results provide a relevant step for the future clinical application of graphene oxide on cell microencapsulation.
Specific relationships among reactive oxygen species, activation pathways, and inflammatory mechanisms involved in kidney injury were assessed in a combined model of obesity and hyperoxaluria. Male ...Wistar rats were divided into four groups: Control, HFD (high fat diet), OX (0.75% ethylene glycol), and HFD + OX (combined model) Changes in basal O
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levels were evaluated by chemiluminescence in renal interlobar arteries and renal cortex. Furthermore, the effect of different inhibitors on NADPH-stimulated O
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generation was assessed in renal cortex. Oxidative stress sources, and local inflammatory mediators, were also determined, in parallel, by RT-PCR, and correlated with measures of renal function, urinary biochemistry, and renal structure. Rats from the HFD group developed overweight without lipid profile alteration. Tubular deposits of crystals were seen in OX and severely enhanced in HFD + OX groups along with a significantly higher impairment of renal function. Basal oxidative stress was increased in renal cortex of OX rats and in renal arteries of HFD rats, while animals from the combined HFD + OX group exhibited the highest levels of oxidative stress in renal cortex, derived from xanthine oxidase and COX-2. NADPH oxidase-dependent O
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generation was elevated in renal cortex of the OX group and markedly enhanced in the HFD + OX rats, and associated to an up-regulation of Nox1 and a down-regulation of Nox4 expression. High levels of oxidative stress in the kidney, of OX and HFD + OX groups were also associated to an inflammatory response mediated by an elevation of TNFα, COX-2, NFκB1 MCP-1, and OPN. Oxidative stress is a key pathogenic factor in renal disease associated to hyperoxaluria and a common link underlying the exacerbated inflammatory response and kidney injury found under conditions of both obesity and hyperoxaluria. Nox1 pathway must be considered as a potential therapeutic target.
Precision oncology continues to challenge the "one-size-fits-all" dogma. Under the precision oncology banner, cancer patients are screened for molecular tumor alterations that predict treatment ...response, ideally leading to optimal treatments. Functional assays that directly evaluate treatment efficacy on the patient's cells offer an alternative and complementary tool to improve the accuracy of precision oncology. Unfortunately, traditional Petri dish-based assays overlook much tumor complexity, limiting their potential as predictive functional biomarkers. Here, we review past applications of microfluidic systems for precision medicine and discuss the present and potential future role of functional microfluidic assays as treatment predictors.
The extracellular matrix (ECM) composition greatly influences cancer progression, leading to differential invasion, migration, and metastatic potential. In breast cancer, ECM components, such as ...fibroblasts and ECM proteins, have the potential to alter cancer cell migration. However, the lack of in vitro migration models that can vary ECM composition limits our knowledge of how specific ECM components contribute to cancer progression. Here, a microfluidic model was used to study the effect of 3D heterogeneous ECMs (i.e., fibroblasts and different ECM protein compositions) on the migration distance of a highly invasive human breast cancer cell line, MDA-MB-231. Specifically, we show that in the presence of normal breast fibroblasts, a fibronectin-rich matrix induces more cancer cell migration. Analysis of the ECM revealed the presence of ECM tunnels. Likewise, cancer-stromal crosstalk induced an increase in the secretion of metalloproteinases (MMPs) in co-cultures. When MMPs were inhibited, migration distance decreased in all conditions except for the fibronectin-rich matrix in the co-culture with human mammary fibroblasts (HMFs). This model mimics the in vivo invasion microenvironment, allowing the examination of cancer cell migration in a relevant context. In general, this data demonstrates the capability of the model to pinpoint the contribution of different components of the tumor microenvironment (TME).
Microfluidic lumen-based systems are microscale models that recapitulate the anatomy and physiology of tubular organs. These technologies can mimic human pathophysiology and predict drug response, ...having profound implications for drug discovery and development. Herein, we review progress in the development of microfluidic lumen-based models from the 2000s to the present. The core of the review discusses models for mimicking blood vessels, the respiratory tract, the gastrointestinal tract, renal tubules, and liver sinusoids, and their application to modeling organ-specific diseases. We also highlight emerging application areas, such as the lymphatic system, and close the review discussing potential future directions.
Lymphatic vessels (LVs) have been suggested as a preferential conduit for metastatic progression in breast cancer, where a correlation between the occurrence of lymph node metastasis and an increased ...extracellular matrix (ECM) density has been reported. However, the effect of ECM density on LV function is largely unknown. To better understand these effects, we used a microfluidic device to recreate tubular LVs in a collagen type I matrix. The density of the matrix was tailored to mimic normal breast tissue using a low-density collagen (LD-3 mg mL
) and cancerous breast tissue using a high-density collagen (HD-6 mg mL
). We investigated the effect of ECM density on LV morphology, growth, cytokine secretion, and barrier function. LVs cultured in HD matrices showed morphological changes as compared to LVs cultured in a LD matrix. Specifically, LVs cultured in HD matrices had a 3-fold higher secretion of the pro-inflammatory cytokine, IL-6, and a leakier phenotype, suggesting LVs acquired characteristics of activated vessels. Interestingly, LV leakiness was mitigated by blocking the IL-6 receptor on the lymphatic ECs, maintaining endothelium permeability at similar levels of LV cultured in a LD matrix. To recreate a more in vivo microenvironment, we incorporated metastatic breast cancer cells (MDA-MB-231) into the LD and HD matrices. For HD matrices, co-culture with MDA-MB-231 cells exacerbated vessel leakiness and secretion of IL-6. In summary, our data suggest that (1) ECM density is an important microenvironmental cue that affects LV function in the breast tumor microenvironment (TME), (2) dense matrices condition LVs towards an activated phenotype and (3) blockade of IL-6 signaling may be a potential therapeutic target to mitigate LV dysfunction. Overall, modeling LVs and their interactions with the TME can help identify novel therapeutic targets and, in turn, advance therapeutic discovery.
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