Tuneable hydrogel patterns in pillarless microfluidic devices

Organ-on-chip (OOC) technology has recently emerged as a powerful tool to mimic physiological or pathophysiological conditions through cell culture in microfluidic devices. One of its main goals is bypassing animal testing and encouraging more personalized medicine. The recent incorporation of hydrogels as 3D scaffolds into microfluidic devices has changed biomedical research since they provide a biomimetic extracellular matrix to recreate tissue architectures. However, this technology presents some drawbacks such as the necessity for physical structures as pillars to confine these hydrogels, as well as the difficulty in reaching different shapes and patterns to create convoluted gradients or more realistic biological structures. In addition, pillars can also interfere with the fluid flow, altering the local shear forces and, therefore, modifying the mechanical environment in the OOC model. In this work, we present a methodology based on a plasma surface treatment that allows building cell culture chambers with abutment-free patterns capable of producing precise shear stress distributions. Therefore, pillarless devices with arbitrary geometries are needed to obtain more versatile, reliable, and biomimetic experimental models. Through computational simulation studies, these shear stress changes are demonstrated in different designed and fabricated geometries. To prove the versatility of this new technique, a blood-brain barrier model has been recreated, achieving an uninterrupted endothelial barrier that emulates part of the neurovascular network of the brain. Finally, we developed a new technology that could avoid the limitations mentioned above, allowing the development of biomimetic OOC models with complex and adaptable geometries, with cell-to-cell contact if required, and where fluid flow and shear stress conditions could be controlled.

Tetralol derivative NNC-55-0396 targets hypoxic cells in the glioblastoma microenvironment: an organ-on-chip approach

Glioblastoma (GBM) is a highly malignant brain tumour characterised by limited treatment options and poor prognosis. The tumour microenvironment, particularly the central hypoxic region of the tumour, is known to play a pivotal role in GBM progression. Cells within this region adapt to hypoxia by stabilising transcription factor HIF1-α, which promotes cell proliferation, dedifferentiation and chemoresistance. In this study we sought to examine the effects of NNC-55-0396, a tetralol compound which overactivates the unfolded protein response inducing apoptosis, using the organ-on-chip technology. We identified an increased sensitivity of the hypoxic core of the chip to NNC, which correlates with decreasing levels of HIF1-α in vitro. Moreover, NNC blocks the macroautophagic process that is unleashed by hypoxia as revealed by increased levels of autophagosomal constituent LC3-II and autophagy chaperone p62/SQSTM1. The specific effects of NNC in the hypoxic microenvironment unveil additional anti-cancer abilities of this compound and further support investigations on its use in combined therapies against GBM.

A single-arm phase II trial to evaluate the combination of cetuximab plus docetaxel, cisplatin, and 5-fluorouracil (TPF) as induction chemotherapy (IC) in patients (pts) with unresectable SCCHN

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Background: TPF combination is the new standard IC. Adding cetuximab to PF chemotherapy is superior to PF alone in metastatic disease. We incorporated cetuximab into IC with TPF and subsequent radiotherapy (RT) in unresectable SCCHN. Methods: Phase II trial conducted in 7 Spanish hospitals. Previously untreated pts aged 18–70 yrs, ECOG PS 0–1 with unresectable SCCHN were eligible. Induction comprised T 75mg/m2 day 1, P 75mg/m2 day 1, F 750mg/m2 days 1–5, and cetuximab 250mg/m2 days 1, 8, and 15 (initial dose 400mg/m2 on cycle (C) 1, day 1), repeated every 21 days x 4 C, with prophylactic antibiotics and G-CSF support. Subsequently, pts received accelerated RT with a concomitant boost (69.9Gy) and cetuximab 250mg/m2 weekly. The primary endpoint was the objective response rate (RR) to cetuximab TPF as neoadjuvant therapy. Simon's optimal two-stage design was used to calculate the sample size of 49 evaluable pts. Results: 50 pts were enrolled: median age 54 yrs (33–68); 44 male; all stage IV (T4=31, N2–3=40). Primary sites were: oropharynx, 23; hypopharynx, 16; oral cavity, 5; larynx, 4.41(82%) pts received all 4 cycles of cetuximab TPF; 47 pts received ≥2 C and were evaluable for response using RECIST. 3 pts received <2 C (2 deaths from intercurrent disease and febrile neutropenia, 1 secondary neoplasm diagnosed). The table shows RR. Serious grade 3/4 adverse events (AEs) were: neutropenia 24%; neutropenic fever 20%; infection 6%; thrombocytopenia 4%; diarrhea 12%; hepatotoxicity 4%; hypomagnesemia 2%. Grade 3 AEs were: nausea/vomiting 2%; mucositis 6%; renal failure 4%; asthenia 4%; rash 4%; hypotension 4%. There were 2 AE-related deaths (febrile neutropenia and hepatic insufficiency). Conclusions: The addition of cetuximab to TPF IC in pts with unresectable SCCHN yields a high RR, mainly CR, potentially prolonging survival. Cetuximab TPF combination should be given to pts with good PS with specialized support provided.

[Table: see text]

[Table: see text]

[Compliance rate of antibiotic therapy in patients with acute pharyngitis is very low, mainly when thrice-daily antibiotics are given]

OBJECTIVE

To assess drug-compliance observed among patients with suspected streptococcal pharyngitis treated with twice-daily antibiotic regimens (b.i.d.) and others with thrice-daily regimens (t.i.d.).

METHODS

A prospective study in the primary care setting was designed in which patients with pharyngitis and three or more Centor criteria, non-allergic to beta-lactam agents, treated with several b.i.d and t.i.d antibiotic regimens based on doctor's choice, were recruited. Patient compliance was assessed with electronic monitoring.

RESULTS

A total of 113 patients were enrolled (64 in the t.i.d. group and 49 in the b.i.d. group). Mean openings ranged from 70.3 to 83.3% of the total amount of pills. All the parameters analysed indicated significantly worse compliance with the t.i.d. regimens. Eleven patients allocated to the t.i.d. group took at least 80% of the pills (17.2%), this being significantly lower than those who received b.i.d. antibiotics (59.2%; p < 0.001). The percentage of patients who opened the Medication Event Monitoring System (MEMS) container the satisfactory number of times a day was systematically lower among t.i.d. regimens, this being statistically significant from day three (p < 0.05). Patients assigned to t.i.d. regimens more frequently forgot the afternoon dose.

CONCLUSION

Compliance rate was very low, mainly when patients are given t.i.d antibiotic regimens. This may lead to storage of antibiotics and subsequent self-medication. New strategies addressed to improve drug-compliance with antibiotics among outpatients are therefore necessary.