Biomimetic design of highly flexible metal oxide nanofibrous membranes with exceptional mechanical performance for superior phosphopeptide enrichment

Developing free-standing and mechanical robust membrane materials capable of superior enrichment of phosphopeptides for analyzing and identifying the specific phosphoproteome of cancer cells is significant in understanding the molecular mechanisms of cancer development and exploring new therapeutic approaches, but still a significant challenge in materials design. To this end, we firstly constructed highly flexible ZrTiO₄ nanofibrous membranes (NFMs) with excellent mechanical stability through a cost-effective and scalable electrospinning and subsequent calcination technique. Then, to further increase the enrichment capacity of the phosphopeptide, the biomimetic TiO₂@ZrTiO₄ NFMs with root hair or leaf like branch microstructure are developed by the hydrothermal post-synthetic modification of ZrTiO₄ NFMs through growing unfurling TiO₂ nanosheets onto the ZrTiO₄ nanofibers. Importantly, remarkable flexibility and mechanical stability enable the resulting TiO₂@ZrTiO₄ NFMs excellent practicability, while the biomimetic microstructure allows it outstanding enrichment ability of the phosphopeptide and identification ability of the specific phosphoproteins in the digest of cervical cancer cells. Specifically, 6770 phosphopeptides can be enriched by TiO₂@ZrTiO₄ NFMs (2205 corresponding phosphoproteins can be identified), and the value is much higher than that of ZrTiO₄ NFMs (6399 phosphopeptides and 2132 identified phosphoproteins) and commercial high-performance TiO₂ particles (4525 phosphopeptides and 1811 identified phosphoproteins). These results demonstrate the super ability of TiO₂@ZrTiO₄ NFMs in phosphopeptide enrichment and great potential for exploring the pathogenesis of cancer.