PAPER: Polysuccinimide and Polyaspartamide for Functional Fibers: Synthesis, Characterization, and Properties

July 22, 2022 

Abstract: This chapter discusses the synthesis and characterization of polysuccinimide and polyaspartamide functional fibers made by electrospinning. Polysuccinimide is a biodegradable and tissue-friendly polymer made from L-aspartic acid. Under physiological conditions (pH = 7.4) it hydrolyzes to form water-soluble poly(aspartic acid). The poly(amino acid) structure provides biocompatibility and biodegradability to poly(aspartic acid)- based fibers and networks making them promising materials for biomedical applications such as soft tissue and drug delivery implants. However, the hydrolysis and the dissolution of the polysuccinimide fibers is fast, prohibiting their use as implants. To prevent dissolution, crosslinks between the polymer chains and thus a polymer network inside the electrospun fibers can be created. Then these fibers will swell, forming hydrogel fiber membranes. Polysuccinimide can easily be modified with primary amines, therefore a wide variety of polysuccinimides and poly(aspartic acids) with various properties can be synthesized. Three methods were successful for the synthesis of poly(aspartic acid) based hydrogel fiber networks: reactive electrospinning based on thiol–disulfide exchange, plasma-induced crosslinking of allyl-functionalized polysuccinimide followed by hydrolysis and submerging in 2,2,4(2,4,4)-trimethyl-1,6-hexanediamine/methanol solution to crosslink post-electrospinning. These synthetic strategies can be used with other polymers as well.