Multivalent polyaspartamide crosslinker for engineering cell-responsive hydrogels with degradation behavior and tunable physical properties

Abstract

Hydrogels possess favorable physical properties ideally suited for various biotechnology applications. To tailor to specific needs, a number of modification strategies have been employed to tune their properties. Herein, a multifunctional polymeric crosslinker based on polyaspartamide is developed, which allows for the facile adjustment of the type and number of reactive functional groups to fit different reaction schemes and control the mechanical properties of the hydrogels. The amine-based nucleophiles containing desired functional groups are reacted with polysuccinimide to synthesize polyaspartamide crosslinkers. The crosslinking density and the concurrent change in mechanical properties of the resulting hydrogels are controlled in a wide range only with the degree of substitution. This multivalency of the polyaspartamide linkers also allowed for the degradation of hydrogels by the unreacted functional groups involved in the chain lysis. Furthermore, the polyaspartamide crosslinker conjugated with cell-recognition molecules via the same conjugation mechanism (i.e. nucleophilic substitution) render the hydrogels cell responsive without the need of additional processing steps. This versatility of polyaspartamide-based crosslinker is expected to provide an efficient and versatile route to engineer hydrogels with controllable properties for biomedical applications.