Development of a biomimetic liver tumor-on-a-chip model based on decellularized liver matrix for toxicity testing

Cancer poses a great health threat to both developed and developing countries, and anti-cancer drugs are of important interest for improved clinical outcomes. Although tumor-on-a-chip technologies offer a feasible approach to screening drug toxicity, their capability to mimic the native tumor microenvironment (TME) is still limited. For better mimicry of the TME, we developed a biomimetic three-dimensional (3D) liver tumor-on-a-chip with the integration of essential components derived from decellularized liver matrix (DLM) with gelatin methacryloyl (GelMA) in a microfluidics-based 3D dynamic cell culture system. The biomimetic liver tumor-on-a-chip based on the integration of DLM components with GelMA, as opposed to GelMA only, had an increased capability to maintain cell viability and to enhance hepatocyte functions under flow conditions. The improved performance of the DLM-GelMA-based tumor-on-a-chip may be attributed to the provision of biochemical factors (e.g., growth factors), the preservation of scaffold proteins, and the reestablishment of biophysical cues (e.g., stiffness and shear stress) for better recapitulation of the 3D liver TME. Furthermore, this DLM-GelMA-based tumor-on-a-chip exhibited linear dose-dependent drug responses to the toxicity of acetaminophen and sorafenib. Taken together, our study demonstrates that the DLM-GelMA-based biomimetic liver tumor-on-a-chip better mimics the in vivo TME and holds great promise for a breadth of pathological and pharmacological studies.

An integrated double-filtration microfluidic device for isolation, enrichment and quantification of urinary extracellular vesicles for detection of bladder cancer

Extracellular vesicles (EVs), including exosomes and microvesicles, are present in a variety of bodily fluids, and the concentration of these sub-cellular vesicles and their associated biomarkers (proteins, nucleic acids, and lipids) can be used to aid clinical diagnosis. Although ultracentrifugation is commonly used for isolation of EVs, it is highly time-consuming, labor-intensive and instrument-dependent for both research laboratories and clinical settings. Here, we developed an integrated double-filtration microfluidic device that isolated and enriched EVs with a size range of 30–200 nm from urine, and subsequently quantified the EVs via a microchip ELISA. Our results showed that the concentration of urinary EVs was significantly elevated in bladder cancer patients (n = 16) compared to healthy controls (n = 8). Receiver operating characteristic (ROC) analysis demonstrated that this integrated EV double-filtration device had a sensitivity of 81.3% at a specificity of 90% (16 bladder cancer patients and 8 healthy controls). Thus, this integrated device has great potential to be used in conjunction with urine cytology and cystoscopy to improve clinical diagnosis of bladder cancer in clinics and at point-of-care (POC) settings.

Advances in addressing technical challenges of point-of-care diagnostics in resource-limited settings

The striking prevalence of HIV, TB and malaria, as well as outbreaks of emerging infectious diseases, such as influenza A (H7N9), Ebola and MERS, poses great challenges for patient care in resource-limited settings (RLS). However, advanced diagnostic technologies cannot be implemented in RLS largely due to economic constraints. Simple and inexpensive point-of-care (POC) diagnostics, which rely less on environmental context and operator training, have thus been extensively studied to achieve early diagnosis and treatment monitoring in non-laboratory settings. Despite great input from material science, biomedical engineering and nanotechnology for developing POC diagnostics, significant technical challenges are yet to be overcome. Summarized here are the technical challenges associated with POC diagnostics from a RLS perspective and the latest advances in addressing these challenges are reviewed.