Synthesis of trehalose-grafted poly(ester amide) with potential ice recrystallization inhibition activity

The ice recrystallization inhibition (IRI) activity of a macromolecular cryoprotectant is of great significance for applications in cryopreservation of biosamples. Herein, in order to create a possibly biodegradable trehalose-modified polymer, thiol-monosubstituted trehalose was synthesized by a simplified method, and then tethered to allylated-based poly(ester amide) (PEA) via thiol-ene click reaction. The synthesized PEA-g-trehalose (PEA-g-Tre) was able to inhibit ice recrystallization by 55% at 10 mg mL−1 compared to PBS control, superior to poly(ethylene glycol). Differential scanning calorimetry results showed that PEA-g-Tre exhibited a significantly higher glass transition temperature at 92.4 °C than PEA at 33.5 °C, and had a narrowed ice crystallization temperature range due to introduction of trehalose. Raman spectroscopy indicated that the IRI activity of PEA-g-Tre was attributed to the presence of trehalose residues in the side groups, which disrupted the regular arrangement of freezable water molecules. It is suggested that modification by trehalose can give rise to the IRI activity of the polymer through adsorption and diffusion mechanism with water, and thiol-ene reaction provides a feasible way for preparing polymeric cryoprotectants containing trehalose. Poly(ester amide)-g-trehalose (PEA-g-Tre) was synthesized via thiol-ene click reaction from thiol-monosubstituted trehalose (Tre-SH) and allylated poly(ester amide) (PEA), providing a possible structural design for synthesis of polymeric cryoprotectants with ice recrystallization inhibition (IRI) activity. [Display omitted] •Poly(ester amide)-g-trehalose (PEA-g-Tre) was synthesized via thiol-ene click reaction.•Thiol-monosubstituted trehalose was synthesized through a simplified method.•PEA-g-Tre held ice recrystallization inhibition (IRI) activity relative to PBS control.•Analyses of DSC and Raman spectroscopy confirmed the IRI activity of PEA-g-Tre.•The presence of trehalose in the side chain of PEA-g-Tre contributed to the IRI activity.