title: A microgel construction kit for bioorthogonal encapsulation and pH-controlled release of living cells.
abstract: pH-Cleavable cell-laden microgels with excellent long-term viabilities were fabricated by combining bioorthogonal strain-promoted azide-alkyne cycloaddition (SPAAC) and droplet-based microfluidics. Poly(ethylene glycol)dicyclooctyne and dendritic poly(glycerol azide) served as bioinert hydrogel precursors. Azide conjugation was performed using different substituted acid-labile benzacetal linkers that allowed precise control of the microgel degradation kinetics in the interesting pH range between 4.5 and 7.4. By this means, a pH-controlled release of the encapsulated cells was achieved upon demand with no effect on cell viability and spreading. As a result, the microgel particles can be used for temporary cell encapsulation, allowing the cells to be studied and manipulated during the encapsulation and then be isolated and harvested by decomposition of the microgel scaffolds.
authors.affiliation: Freie Universität Berlin, Institute for Chemistry and Biochemistry, Takustrasse 3, 14195 Berlin (Germany).
authors.forename: Dirk
authors.initials: D
authors.lastname: Steinhilber
authors.forename: Torsten
authors.initials: T
authors.lastname: Rossow
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wedepohl
authors.forename: Florian
authors.initials: F
authors.lastname: Paulus
authors.forename: Sebastian
authors.initials: S
authors.lastname: Seiffert
authors.forename: Rainer
authors.initials: R
authors.lastname: Haag
mesh_terms: D002470:Cell Survival / Q000502:physiology*; D057930:Click Chemistry; D044085:Microfluidics / Q000379:methods*; D018613:Microscopy, Confocal; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D011092:Polyethylene Glycols
keywords: click chemistry; gels; hydrolysis; pH-cleavable linkers; reversible cell encapsulation