Rapid and cost-effective fabrication of selectively permeable calcium-alginate microfluidic device using “modified” embedded template method

Abstract

In this paper, we have presented a non-lithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. To demonstrate the versatility of the presented method, we have demonstrated two different strategies to fabricate serpentine long delay channels without using any sophisticated microfabrication techniques, in formal lab atmosphere. The procedure presented here, also, enables the preparation of a multilayered microfluidic device with channels of varying dimensions, in a single device without using any sophisticated micromachining instrumentation. In addition, we have also qualitatively studied the diffusion of small and large molecules from a Ca-alginate based microfluidic device and proposed a method to effectively control the out-flow of macro biomolecules from the crosslinked Ca-alginate matrix to create a selectively permeable matrix required for various biological and biomimetic applications, as mentioned in the Introduction section of this work.

Fickian-Based Empirical Approach for Diffusivity Determination in Hollow Alginate-Based Microfibers Using 2D Fluorescence Microscopy and Comparison with Theoretical Predictions

“…For the external gelation fabrication method, the molecular weight cutoff (MWCO) of the membrane has been placed between 60 and 70 kDa (≈3–6 nm) by multiple sources [7,12,20,25,37,47]. It is essential to distinguish pure diffusion from surface erosion, the latter being a combination of hydrodynamic drag and membrane swelling [13,48].…”

“…Due to the versatility of applications, diffusivity quantification across alginate bio-membranes of various geometric shapes and sizes differing by nature and extent of cross-linking and coatings has been extensively researched [6,7,8,9,10,11,12,13]. In conjunction, indirect diffusivity estimations using pore size characterization by various scanning probe microscopy (SPM) methods have been documented [14,15,16].…”

Polystyrene microsphere and 5-fluorouracil release from custom-designed wound dressing films

“…Even after membrane burst, the average release from alginate films ( M AGCa  = 81%) is approximately twice that calculated from chitosan films ( M CD  = 42%) from which, it could be inferred that alginate films are more porous than chitosan films and hence, the justification of using chitosan for slowing down the release rate of compounds from alginate membranes (Gaserod et al 1999; Asthana et al 2012). Theoretically, an increase in CaCl 2 for the alginate films in conjunction with an increase in PG content for the chitosan films, should increase the porosity of the films, and hence the diffusion rate (Madsen et al 2011; Simpliciano & Asi 2012); however, no discernible trends were observed as a result of varying the aforementioned factors.…”

Preface to Special Topic: Selected Papers from the Second Conference on Advances in Microfluidics and Nanofluidics and Asia-Pacific International Symposium on Lab on Chip

“…CO 2 laser was applied to induce glass strip peeling off to form microchannels on soda lime glass substrates, as reported by Wang and Zheng. 20 Asthana et al 21 presented a nonlithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. Finally, surface modification of cyclic olefin copolymer (COC) by 2-methacryloyloxyethyl phosphorylcholine monomer using photografting technique was reported by Jena and Yue, 22 showing the resistance to both protein adsorption and cell adhesion in COC-based microfluidic devices.…”

“…It was a successful conference providing a highly interactive forum that brought together approximately 200 researchers of different disciplines from more than 20 different countries and regions. This special issue is dedicated to the original contributions that were presented at the conference and covers a wide range of research directions from both fundamental and practical application of microfluidics and nanofluidics, including acoustofluidics, 1,2 biosensor 3 and diagnosis, 4 dielectrophorsis, 5-7 droplet microfluidics, [8][9][10][11][12][13][14][15] electrokinetic flow 16,17 and electrophoresis, 18 micro-and nanofabrications, [19][20][21] as well as surface modification. 22 Beginning with acoustofluidics, Wang, Jalikop, and Hilgenfeldt 1 reported a bubble microfluidic device to filter, enrich, and preconcentrate particles of selected sizes through oscillating microbubbles of radius 20-100 lm driven by ultrasound.…”