Airway stents are often used to maintain patency of the tracheal and bronchial passages in patients suffering from central airway obstruction caused by malignant tumors, scarring, and injury. Like most conventional medical implants, they are designed to perform their functions for a limited period of time, after which surgical removal is often required. Two primary types of airway stents are in general use, metal mesh devices and elastomeric tubes; both are constructed using permanent materials, and must be removed when no longer needed, leading to potential complications. This paper describes the development of process technologies for bioresorbable prototype elastomeric airway stents that would dissolve completely after a predetermined period of time or by an enzymatic triggering mechanism. These airway stents are constructed from biodegradable elastomers with high mechanical strength, flexibility and optical transparency. This work combines microfabrication technology with bioresorbable polymers, with the ultimate goal of a fully biodegradable airway stent ultimately capable of improving patient safety and treatment outcomes.

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In this work, nickel nanoparticles were prepared from nickel chloride solution using the liquid phase plasma reduction technique. A cold plasma jet was used for this purpose. The variation of the concentrations 0.5mM, 1mM and 2 mM and was used to study optimal condition of nickel nanoparticles formation. A concentration of 1 ml was observed to be the best, by using UV-Vis spectroscopy and Field emission scanning electron microscopy (FESEM). The optimum concentration was used to formation nanoparticles solution with variation the exposure time of cold plasma jet at (5 min, 10 min, 15 min ) respectively. The results shown by UV-Vis spectroscopy the nanoparticle peaks produced by surface plasmon absorption were observed around 365-375 nm according the discharge time of cold plasma. The nanoparticles were spherical homogenous as observed by Field emission scanning electron microscopy (FESEM) which also shown the average particle size about 25nm, and by dynamic light scattering (DLS) and also zeta potential (ZP) measurements were observed non-aggregated in the long term, the particles are very stable colloid, also no visible aggregation have been seen on the prepared samples in this concentration (1mM). In contrast to other concentrations which showed a nonhomogeneous morphology and aggregated. X-ray Diffraction (XRD) showed that NiNPs have a face-centered cubic (FCC) structure with a crystalline size of around 12.5 nm, and also Inductively Coupled Plasma mass Spectrometry (ICP-mass) were used to characterize the prepared samples.