Hydrogel nanotubes with ice helices as exotic nanostructures for diabetic wound healing

Abstract

The slings and arrows of two-dimensional (2D) graphene and one-dimensional (1D) carbon nanotubes embody a high risk-to-benefit ratio, which is challenging for their biocompatibility. Herein, we report for the first time the synthesis of hydrogel nanotubes (HNTs) with ice helices as exotic nanostructures via free radical-mediated aqueous copolymerization. Extensive embryonic 2D polymer nanosheets were produced after 10 h of reaction which buckled out-of-plane into HNTs, inspired by the ancient art of origami. Water drawn into the hydrophobic hollow conduit freezes spontaneously, acting as an epicenter for the genesis of an ice helix trapped in a kinetically stable arrangement with regular periodicity, extending rational synthesis into the nanoscale regime. In this seminal work, the mechanism for the formation of ice helices inside the HNTs was delineated with the aid of transmission electron microscopy (TEM), X-ray diffraction patterns (XRD) and Raman spectroscopy. Endowed with unique biocompatibility, these HNTs aided the rapid establishment of wound barrier properties with concomitant cell proliferation guided by a provisional matrix mimicking the extracellular matrix niche. The HNTs support a permissive milieu for vascular sufficiency with well-proliferated fibroblasts at the wound bed.