Cytoprotective Alginate/Polydopamine Core/Shell Microcapsules in Microbial Encapsulation

Abstract

Chemical encapsulation of microbes in threedimensional polymeric microcapsules promises various applications, such as cell therapy and biosensors, and provides a basic platform for studying microbial communications. However, the cytoprotection of microbes in the microcapsules against external aggressors has been a major challenge in the field of microbial microencapsulation, because ionotropic hydrogels widely used for microencapsulation swell uncontrollably, and are physicochemically labile. Herein, we developed a simple polydopamine coating for obtaining cytoprotective capability of the alginate capsule that encapsulated Saccharomyces cerevisiae. The resulting alginate/ polydopamine core/shell capsule was mechanically tough, prevented gel swelling and cell leakage, and increased resistance against enzymatic attack and UV-C irradiation. We believe that this multifunctional core/shell structure will provide a practical tool for manipulating microorganisms inside the microcapsules.

Microfluidic Production of Alginate Hydrogel Particles for Antibody Encapsulation and Release

“…In contrast, the use of larger (≥30 μm) particles in vivo would be hardly possible due to clogging of the blood vessels. The use of cell‐size particles as delivery systems could also benefit many other biomedical applications such as encapsulation of beneficial microorganisms, preparation of tumor vaccines, or triggering controlled immune response …”

Growth and survival of microencapsulated probiotics prepared by emulsion and internal gelation

“…Usually, a membrane is formed by some compounds, such as polylysine and chitosan, around the alginate micro-beads for better protection of the cells and prevention of cell leakage, especially when the microcapsules are used to protect transplanted cells from attack by the host immune system (Qi et al 2006; Chan et al 2014). Sometimes the microcapsule core is liquefied to offer more space for cell proliferation (Qi et al 2005; Kim et al 2014). Both core liquefaction and membrane formation were omitted in this research, but we did not find obvious leakage of the microbe cells.…”

Library of Norcoclaurine Synthases and Their Immobilization for Biocatalytic Transformations

“…It has to be mentioned that the catalyst preparations turned black over time due to the formation of a precipitate. This is most probably caused by the formation of insoluble polydopamine and eulmelanin derivatives as a result of a side reaction of the substrate . By the addition of ascorbic acid as antioxidant no precipitate could be detected visually (Figure S9, Supporting Information) …”