Hybrid polymer seed and tablet coating process (more...)

Alginates have been used for decades for the encapsulation of biological molecules, cells and chemicals. The traditional encapsulation process involved dissolving or dispersing the active agent in a sodium alginate solution, forcing the solution through an orifice to form a droplet which was then cross-linked by contact with a calcium chloride solution. This process was not easily scaled-up and was limited to particles larger than 500 μm. Spray-drying would be a commercially viable process to form a calcium alginate matrix particle in the size range of 10 – 20 μm; however, one would have to find a way of cross-linking the sodium alginate solution during atomization. Researchers at the University of California Davis have developed a method that accomplishes this by spray-drying an aqueous formulation that contains sodium alginate, a calcium salt that is only soluble at reduced pH and an organic acid that has been neutralized to a pH just above the pKa with a volatile base. Under these conditions, the calcium salt is insoluble and calcium ions are not available for cross-linking. The solution in this fluid state is pumped through the nozzle of the spray dryer, where it is effectively atomized. Upon atomization, the volatile base is vaporized, which reduces the pH (hydrogen ions are released into solution) and in turn releases calcium ions from the calcium salt that cross-link the alginate. The incorporation of an additional polymer to the formulation allows for the control of hydration properties of the particles to control the release of the encapsulated compounds. This same process can be used for encapsulation using soy protein. (more...)

Emulsions are commonly used in food products, cosmetics, paint, etc. Polymer microspheres have applications in, for example, drug delivery and tissue engineering. A challenge in creating polymer microspheres and emulsions is minimizing the polydispersity of the particles. The particles tend to have inconsistent size, shape and mass distribution. Silk is often used commercially as an emulsion, and has been demonstrated to be an extremely effective polymer for drug delivery. Microfluidic devices that produce microsphere have been demonstrated in the past. However, it has been difficult to produce particles with a consistent size and shape known as monodisperse particles. Researchers at UC Berkeley have developed a microfluidic methodology for producing monodisperse silk microspheres. The unique chemistry and method enables production of exact microsphere diameter and percent of crystallinity. Both the microsphere and crystallinity can be precisely adjusted which can be used in for a variety of applications. It is particularly useful to vary drug release characteristics in a drug delivery system. (more...)

There is great variability among different organisms in their ability to naturally or artificially synthesize and accumulate lipids, hydrocarbons, and polymers. Consequently, many organisms must be screened in order to achieve the desired maximal bio-product accumulation. After an ideal organism is selected, its product content can vary with lifecycle stage, cultivation conditions, cellular stress and/or time. This variability must be understood and controlled during R&D, process development and manufacturing scale-up in order to maximize product yields. The above process of screening and development can be time-consuming and consequently costly.  To address this situation, scientists at UC Berkeley have developed a method for quick and precise estimation of lipid, hydrocarbon or biopolymer content in live cells -- whether grown as single cells or in colonies. This method can be used for screening a variety of microorganisms for product accumulation (microorganism prospecting), and to check yields throughout the production process -- allowing for more rapid improvement of production methods and shortened R&D timelines. (more...)