Microfluidic encapsulation of cells in alginate capsules for high throughput screening

Preparation of alginate hydrogel microparticles by gelation introducing cross-linkers using droplet-based microfluidics: a review of methods

This review examines the preparation of alginate hydrogel microparticles by using droplet-based microfluidics, a technique widely employed for its ease of use and excellent control of physicochemical properties, with narrow size distribution. The gelation of alginate is realized "on-chip" and/or "off-chip", depending on where cross-linkers are introduced. Various strategies are described and compared. Microparticle properties such as size, shape, concentration, stability and mechanical properties are discussed. Finally, we consider future perspectives for the preparation of hydrogel microparticles and their potential applications.

Design of an Adhesive Film-Based Microfluidic Device for Alginate Hydrogel-Based Cell Encapsulation

To support the increasing translational use of transplanted cells, there is a need for high-throughput cell encapsulation technologies. Microfluidics is a particularly promising candidate technology to address this need, but conventional polydimethylsiloxane devices have encountered challenges that have limited their utility, including clogging, leaking, material swelling, high cost, and limited scalability. Here, we use a rapid prototyping approach incorporating patterned adhesive thin films to develop a reusable microfluidic device that can produce alginate hydrogel microbeads with high-throughput potential for microencapsulation applications. We show that beads formed in our device have high sphericity and monodispersity. We use the system to demonstrate effective cell encapsulation of mesenchymal stem cells and show that they can be maintained in culture for at least 28 days with no measurable reduction in viability. Our approach is highly scalable and will support diverse translational applications of microencapsulated cells.

Can microfluidics address biomanufacturing challenges in drug/gene/cell therapies?

Translation of any inventions into products requires manufacturing. Development of drug/gene/cell delivery systems will eventually face manufacturing challenges, which require the establishment of standardized processes to produce biologically-relevant products of high quality without incurring prohibitive cost. Microfluidicu technologies present many advantages to improve the quality of drug/gene/cell delivery systems. They also offer the benefits of automation. What remains unclear is whether they can meet the scale-up requirement. In this perspective, we discuss the advantages of microfluidic-assisted synthesis of nanoscale drug/gene delivery systems, formation of microscale drug/cell-encapsulated particles, generation of genetically engineered cells and fabrication of macroscale drug/cell-loaded micro-/nano-fibers. We also highlight the scale-up challenges one would face in adopting microfluidic technologies for the manufacturing of these therapeutic delivery systems.

Microfluidic synthesis of cell-type-specific artificial extracellular matrix hydrogels

Droplet microfluidic technology is applied for the high-throughput synthesis via Michael-type addition of reactive, micrometer-sized poly(ethylene glycol) (PEG) hydrogels ("microgels") with precisely controlled dimension and physicochemical properties. A versatile chemical scheme is used to modify the reactive PEG microgels with tethered biomolecules to tune their bioactive properties for the bioreactor culture and manipulation of various (stem) cell types.