In this paper we report a microfluidic model to simulate the bronchi of a cystic fibrosis (CF) patient. The biochip is comprised of two cell culture chambers separated by a membrane. On top of the membrane an alginate hydrogel is formed in order to simulate the thick mucus layer spotted in a CF bronchi. In the bottom chamber a monolayer of epithelial cells are cultured to simulate the bronchi t...

Sodium alginate (SA) and gelatine (G) based hydrogels for biomedical applications, such as wound dressing, were crosslinked by calcium chloride (CaCl2) or glutaraldehyde (GTA) in order to overcome their exudates solubility. Swelling behaviour of prepared hydrogels in phosphate buffered saline with different pH value at 37 ° C was compared. It was proved that the crosslinking agent concentration...

This article reports the investigation of mechanical properties of alginate-chitosan microcapsules and the relation to protein delivery. For microscale compression testing, a system based on a microelectromechanical systems (MEMS) capacitive force sensor was developed. The bulk microfabricated capacitive force sensors are capable of resolving forces up to 110 microN with a resolution of 33.2 nN...

Using strong fibers to reinforce a hydrogel is highly desirable but difficult. Such a composite would combine the attributes of a solid that provides strength and a liquid that transports matter. Most hydrogels, however, are brittle, allowing the fibers to cut through the hydrogel when the composite is loaded. Here we circumvent this problem by using a recently developed tough hydrogel. We fabr...

Cell distribution and nutrient supply in 3D cell-laden hydrogel scaffolds are critical and should mimic the in vivo cellular environment, but been difficult to control with conventional fabrication methods. Here, we present a microfluidic direct writer (MFDW) to construct 3D cell-laden hydrogel structures with openings permitting media exchange. The MFDW comprises a monolithic microfluidic head...

Biopolymers such as alginate and pectin are well known for their ability to undergo gelation upon addition of multivalent cations such as calcium (Ca(2+)). Here, we report a simple way to activate such ionic gelation by UV irradiation. Our approach involves combining an insoluble salt of the cation (e.g., calcium carbonate, CaCO(3)) with an aqueous solution of the polymer (e.g., alginate) along...

Heart valve disease is a serious and growing public health problem for which prosthetic replacement is most commonly indicated. Current prosthetic devices are inadequate for younger adults and growing children. Tissue engineered living aortic valve conduits have potential for remodeling, regeneration, and growth, but fabricating natural anatomical complexity with cellular heterogeneity remain c...

We demonstrate the additive manufacturing of complex three-dimensional (3D) biological structures using soft protein and polysaccharide hydrogels that are challenging or impossible to create using traditional fabrication approaches. These structures are built by embedding the printed hydrogel within a secondary hydrogel that serves as a temporary, thermoreversible, and biocompatible support. Th...

Microalgae, a group of microorganisms that grow using sunlight as the sole energy source and carbon dioxide as an only carbon source, have been considered as a feedstock of choice for the production of biofuels such as biodiesel. To explore the economic feasibility of such application, however, many technical hurdles must first be overcome; the selection and/or screening of competent species ar...

Hydrogel nanomaterials, especially those that are of non-human and non-animal origins, have great potential in biomedical and pharmaceutical sciences due to their versatility and inherent soft-tissue like properties. With the ability to simulate native tissue function, hydrogels are potentially well suited for cellular therapy applications. In this study, we have fabricated nanofibrillar cellul...