Inkjet-printed PEDOT:PSS multi-electrode arrays for low-cost in vitro electrophysiology.

Multi-electrode arrays (MEAs) have become a key element in the study of cellular phenomena in vitro. Common modern MEAs are still based on costly microfabrication techniques, making them expensive tools that researchers are pushed to reuse, compromising the reproducibility and the quality of the acquired data. There is a need to develop novel fabrication strategies, able to produce disposable devices that incorporate advanced technologies beyond the standard metal electrodes on rigid substrates. Here we present an innovative fabrication process for the production of polymer-based flexible MEAs. The device fabrication exploited inkjet printing, as this low-cost manufacturing method allows for an easy and reliable patterning of conducting polymers. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) was used as the sole conductive element of the MEAs. The physical structure and the electrical properties of the plastic/printed MEAs (pMEAs) were characterised, showing a low impedance that is maintained also in the long term. The biocompatibility of the devices was demonstrated, and their capability to successfully establish a tight coupling with cells was proved. Furthermore, the pMEAs were used to monitor the extracellular potentials from cardiac cell cultures and to record high quality electrophysiological signals from them. Our results validate the use of pMEAs as in vitro electrophysiology platforms, pushing for the adoption of innovative fabrication techniques and the use of new materials for the production of MEAs.

Cost-utility analysis of sodium polystyrene sulfonate vs. potential alternatives for chronic hyperkalemia.

PURPOSE: Hyperkalemia during renin-angiotensin-aldosterone system inhibition (RAAS-I) may prevent optimum dosing. Treatment options include sodium polystyrene sulfonate potassium binding resins, but safety and efficacy concerns exist, including associated colonic necrosis (CN). Alternative agents have been studied, but cost-utility has not been estimated. METHODS: We performed a cost-utility analysis of outpatients ≥ 18 years of age receiving chronic RAAS-I, with a history of hyperkalemia or chronic kidney disease, prescribed either sodium polystyrene sulfonate or a theoretical "drug X" binding resin for chronic hyperkalemia. Data were obtained from existing literature. We used a decision analytic model with Monte Carlo probabilistic sensitivity analyses, from a health care payer perspective and a 12-month time horizon. Costs were measured in US dollars. Effectiveness was measured in quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). RESULTS: Drug X could cost no more than $ 10.77 per daily dose to be cost-effective, at a willingness-to- pay (WTP) threshold of $ 50,000/QALY. At $ 40.00 per daily dose, drug X achieved an incremental cost effectiveness ratio of $26,088,369.00 per QALY gained. One-way sensitivity analysis showed sodium polystyrene sulfonate to be the cost-effective option for CN incidences ≤ 19.9%. Limitations include incomplete information on outpatient outcomes and lack of data directly comparing sodium polystyrene sulfonate to potential alternatives. CONCLUSIONS: Alternatives may not be cost-effective unless priced similarly to sodium polystyrene sulfonate. This analysis may guide decisions regarding adoption of alternative agents for chronic hyperkalemia control, and suggests that sodium polystyrene sulfonate be employed as an active control in clinical trials of these agents.