Long-lasting and efficient tumor imaging using a high relaxivity polysaccharide nanogel magnetic resonance imaging contrast agent

Minnie Chan, Jacques Lux, Tomoki Nishimura, Kazunari Akiyoshi, Adah Almutairi

Research output: Contribution to journalArticle

21 Scopus citations


Clinically approved small-molecule magnetic resonance imaging (MRI) contrast agents are all rapidly cleared from the body and offer weak signal enhancement. To avoid repeated administration of contrast agent and improve signal-to-noise ratios, agents with stronger signal enhancement and better retention in tumors are needed. Therefore, we focused on hydrogels because of their excellent water accessibility and biodegradability. Gadolinium (Gd)-chelating cross-linkers were incorporated into self-assembled pullulan nanogels to both impart magnetic properties and to stabilize this material that has been extensively studied for medical applications. We show that these Gd-chelating pullulan nanogels (Gd-CHPOA) have the highest reported relaxivity for any hydrogel-based particles and accumulate in the 4T1 tumors in mice at high levels 4 h after injection. This combination offers high signal enhancement and lasts up to 7 days to delineate the tumor clearly for longer imaging time scales. Importantly, this long-term accumulation does not cause any damage or toxicity in major organs up to three months after injection. Our work highlights the clinical potential of Gd-CHPOA as a tumor-imaging MRI contrast agent, permitting tumor identification and assessment with a high signal-to-background ratio.

Original languageEnglish (US)
Pages (from-to)2964-2971
Number of pages8
Issue number9
StatePublished - Sep 14 2015


ASJC Scopus subject areas

  • Bioengineering
  • Biomaterials
  • Polymers and Plastics
  • Materials Chemistry

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