Enhancement of solute release from alginate scaffold with embedded sub-millimeter voids

Alginate scaffold has potential use in the controlled release of drugs, and as 3-D structure for the formation of tissue matrix. This article describes the solute release behavior of alginate scaffold that bears embedded voids of sub-millimeter dimensions. Nitrogen gas was bubbled in a fluidic arrangement to generate uniform and self-aligned bubbles in alginate, prior to the cross-linking by CaCl₂. The cross-linked gel was dried in a vacuum oven, and subsequently, soaked in Vitamin B12 solution. The dimensions of the voids immediately after the cross-linking of gel, and also after complete drying were obtained using a digital microscope and the scanning electron microscope, respectively. The porosity of the gel was measured gravimetrically. The release of Vitamin B12 in water on a shaker was studied. For comparison, the experiment was repeated with a scaffold that did not have any embedded void. The enhancements in uptake and release of Vitamin B12 due to the presence of voids are estimated in this article.