This study is an attempt to make a step forward to implement the very immature concept of pumpless transportation of liquid into a real miniaturized device or lab-on-chip (LOC) on a plastic substrate. "Inert" plastic materials such as polypropylene (PP) are used in a variety of biomedical applications but their surface engineering is very challenging. Here, it was demonstrated that with a facile innovative wettability patterning route using fluorosilanized UV-independent TiO nanoparticle coating it is possible to create wedge-shaped open microfluidic tracks on inert solid surfaces for low-cost biomedical devices (lab-on-plastic). For the future miniaturization and integration of the tracks into a device, a variety of characterization techniques were used to not only systematically study the surface patterning chemistry and topography but also to have a clear knowledge of its biological interactions and performance. The effect of such surface architecture on the biological performance was studied in terms of static/dynamic protein (bovine serum albumin) adsorption, bacterial (Staphylococcus aureus and Staphylococcus epidermidis) adhesion, cell viability (using HeLa and MCF-7 cancer cell lines as well as noncancerous human fibroblast cells), and cell patterning (Murine embryonic fibroblasts). Strategies are discussed for incorporating such a confined track into a diagnostic device in which its sensing portion is based on protein, microorganism, or cells. Finally, for the proof-of-principle of biosensing application, the well-known high-affinity molecular couple of BSA-antiBSA as a biological model was employed.

The chemical, temporal, and spatial resolution of chemical signals that are sampled and transported with continuous flow is limited because of Taylor dispersion. Droplets have been used to solve this problem by digitizing chemical signals into discrete segments that can be transported for a long distance or a long time without loss of chemical, temporal or spatial precision. In this review, we describe Taylor dispersion, sampling theory, and Laplace pressure, and give examples of sampling probes that have used droplets to sample or/and transport fluid from a continuous medium, such as cell culture or nerve tissue, for external analysis. The examples are categorized, as follows: (1) Aqueous-phase sampling with downstream droplet formation; (2) preformed droplets for sampling; and (3) droplets formed near the analyte source. Finally, strategies for downstream sample recovery for conventional analysis are described.

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The neutraceutical and pharmaceutical application of essential fatty acids is much cleared. Alpha-linolenic acid (ALA) is omega-3 fatty acid and generally known to have beneficial effects in CVS, CNS and other diseases. The purpose of the present investigation is to produce essential fatty acid, especially ALA by Mucor circinelloides from oil wastes. Five oil wastes collected from food industries were used as carbon sources, and the contents of total lipids, biomass and fatty acids were examined during 168 h. The ability of oil waste degradation was determined by measuring of biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Interestingly, 76 % reduction in BOD and 68 % reduction in COD by this strain were achieved, and M. circinelloides could be a good candidate for oil waste treatment. In order to enhance ALA production, fermentation variables were chosen in accordance with the fractional design and further optimized by the response surface method. The statistical model was constructed via central composite design. Following the optimization step, ALA production increased by approximately 44.3 %, when compared to the screening step. The results indicate that carrying out the fermentation under the conditions of oil waste 4.37 %, yeast extract at 0.65 g/l, (NH 4 ) 2 SO 4 at 0.38 g/l, an agitation rate of 180 rpm and fermentation time of 3 days will increase the ALA production up to 108.57 mg/l. In this study, a new renewable source of ALA was employed and optimized successfully for the production of valuable fatty acids.