Human Organs-on-Chips: A Review of the State-of-the-Art, Current Prospects, and Future Challenges

New emerging technologies, remarkably miniaturized 3D organ models and microfluidics, enable simulation of the real in vitro microenvironment ex vivo more closely. There are many fascinating features of innovative organ-on-a-chip (OOC) technology, including the possibility of integrating semipermeable and/or stretchable membranes, creating continuous perfusion of fluids into microchannels and chambers (while maintaining laminar flow regime), embedding microdevices like microsensors, microstimulators, micro heaters, or different cell lines, along with other 3D cell culture technologies. OOC systems are designed to imitate the structure and function of human organs, ranging from breathing lungs to beating hearts. This technology is expected to be able to revolutionize cell biology studies, personalized precision medicine, drug development process, and cancer diagnosis/treatment. OOC systems can significantly reduce the cost associated with tedious drug development processes and the risk of adverse drug reactions in the body, which makes drug screening more effective. The review mainly focus on presenting an overview of the several previously developed OOC systems accompanied by subjects relevant to pharmacy-, cancer-, and placenta-on-a-chip. The challenging issues and opportunities related to these systems are discussed, along with a future perspective for this technology.

Chitosan-based blends for biomedical applications

Polysaccharides are the most abundant naturally available carbohydrate polymers; composed of monosaccharide units covalently connected together. Chitosan is the most widely used polysaccharides because of its exceptional biocompatibility, mucoadhesion, and chemical versatility. However, it suffers from a few drawbacks, e.g. poor mechanical properties and antibacterial activity for biomedical applications. Blending chitosan with natural or synthetic polymers may not merely improve its physicochemical and mechanical properties, but may also improve its bioactivity-induced properties. This review paper summarizes progress in chitosan blends with biodegradable polymers and polysaccharides and their biomedical applications. Blends of chitosan with alginate, starch, cellulose, pectin and dextran and their applications were particularly addressed. The critical and challenging aspects as well as the future ahead of the use of chitosan-based blends were eventually enlightened.

Copper-nickel oxide nanofilm modified electrode for non-enzymatic determination of glucose

CuxO-NiO nanocomposite film for the non-enzymatic determination of glucose was prepared by the novel modifying method. At first, anodized Cu electrode was kept in a mixture solution of CuSO4, NiSO4 and H2SO4 for 15 minutes. Then, a cathodization process with a step potential of -6 V in a mixture solution of CuSO4 and NiSO4 was initiated, generating formation of porous Cu-Ni film on the bare Cu electrode by electrodeposition assisted by the release of hydrogen bubbles acting as soft templates. Optimized conditions were determined by the experimental design software for electrodeposition process. Afterward, Cu-Ni modified electrode was scanned by cyclic voltammetry (CV) method in NaOH solution to convert Cu and Ni nanoparticles to the nano-scaled CuxO-NiO film. The electrocatalytic behavior of the novel CuxO-NiO film toward glucose oxidation was studied by CV and chronoamperometry (CHA) techniques. The calibration curve of glucose was found linear in a wide range of 0.04–5.76 mM, with a low limit of detection (LOD) of 7.3 µM (S/N = 3) and high sensitivity (1.38 mA mM-1 cm-2). The sensor showed high selectivity against some usual interfering species and high stability (loss of only 6.3 % of its performance over one month). The prepared CuxO-NiO nanofilm based sensor was successfully applied for monitoring glucose in human blood serum and urine samples.