Honors & Awards

  • Ann Schreiber Mentored Investigator Award, Ovarian Cancer Research Fund (2016-2018)

Professional Education

  • Ph.D., Brandeis University, Chemistry (2014)
  • B.A., Sichuan University, Biomedical Engineering (2007)

Stanford Advisors

All Publications

  • De Novo Chemoattractants Form Supramolecular Hydrogels for Immunomodulating Neutrophils In Vivo BIOCONJUGATE CHEMISTRY Zhao, F., Li, J., Zhou, N., Sakai, J., Gao, Y., Shi, J., Goldman, B., Browdy, H. M., Luo, H. R., Xu, B. 2014; 25 (12): 2116-2122


    Most immunomodulatory materials (e.g., vaccine adjuvants such as alum) modulate adaptive immunity, and yet little effort has focused on developing materials to regulate innate immunity, which get mentioned only when inflammation affects the biocompatibility of biomaterials. Traditionally considered as short-lived effector cells from innate immunity primarily for the clearance of invading microorganisms without specificity, neutrophils exhibit a key role in launching and shaping the immune response. Here we show that the incorporation of unnatural amino acids into a well-known chemoattractant-N-formyl-l-methionyl-l-leucyl-l-phenylalanine (fMLF)-offers a facile approach to create a de novo, multifunctional chemoattractant that self-assembles to form supramolecular nanofibrils and hydrogels. This de novo chemoattractant not only exhibits preserved cross-species chemoattractant activity to human and murine neutrophils, but also effectively resists proteolysis. Thus, its hydrogel, in vivo, releases the chemoattractant and attracts neutrophils to the desired location in a sustainable manner. As a novel and general approach to generate a new class of biomaterials for modulating innate immunity, this work offers a prolonged acute inflammation model for developing various new applications.

    View details for DOI 10.1021/bc5004923

    View details for Web of Science ID 000346682300005

    View details for PubMedID 25398017

    View details for PubMedCentralID PMC4275169

  • L-Rhamnose-containing supramolecular nanofibrils as potential immunosuppressive materials ORGANIC & BIOMOLECULAR CHEMISTRY Zhao, F., Heesters, B. A., Chiu, I., Gao, Y., Shi, J., Zhou, N., Carroll, M. C., Xu, B. 2014; 12 (35): 6816-6819


    An l-rhamnose-based hydrogelator self-assembles to form nanofibrils, which, in contrast to the properties of monomeric l-rhamnose, suppress the antibody response of mice to phycoerythrin (PE), a fluorescent protein antigen. As the first example of the supramolecular assemblies of a saccharide to suppress immunity, this work illustrates a new approach of immunomodulation.

    View details for DOI 10.1039/c4ob01362j

    View details for Web of Science ID 000341024300008

    View details for PubMedID 25078446

    View details for PubMedCentralID PMC4160809

  • Bacteria activate sensory neurons that modulate pain and inflammation NATURE Chiu, I. M., Heesters, B. A., Ghasemlou, N., Von Hehn, C. A., Zhao, F., Tran, J., Wainger, B., Strominger, A., Muralidharan, S., Horswill, A. R., Wardenburg, J. B., Hwang, S. W., Carroll, M. C., Woolf, C. J. 2013; 501 (7465): 52-?


    Nociceptor sensory neurons are specialized to detect potentially damaging stimuli, protecting the organism by initiating the sensation of pain and eliciting defensive behaviours. Bacterial infections produce pain by unknown molecular mechanisms, although they are presumed to be secondary to immune activation. Here we demonstrate that bacteria directly activate nociceptors, and that the immune response mediated through TLR2, MyD88, T cells, B cells, and neutrophils and monocytes is not necessary for Staphylococcus aureus-induced pain in mice. Mechanical and thermal hyperalgesia in mice is correlated with live bacterial load rather than tissue swelling or immune activation. Bacteria induce calcium flux and action potentials in nociceptor neurons, in part via bacterial N-formylated peptides and the pore-forming toxin α-haemolysin, through distinct mechanisms. Specific ablation of Nav1.8-lineage neurons, which include nociceptors, abrogated pain during bacterial infection, but concurrently increased local immune infiltration and lymphadenopathy of the draining lymph node. Thus, bacterial pathogens produce pain by directly activating sensory neurons that modulate inflammation, an unsuspected role for the nervous system in host-pathogen interactions.

    View details for DOI 10.1038/nature12479

    View details for Web of Science ID 000323888300030

    View details for PubMedID 23965627

    View details for PubMedCentralID PMC3773968

  • Novel Anisotropic Supramolecular Hydrogel with High Stability over a Wide pH Range LANGMUIR Zhao, F., Gao, Y., Shi, J., Browdy, H. M., Xu, B. 2011; 27 (4): 1510-1512


    The hydrolysis of the carboxylic ester bond, by a base or catalyzed by an enzyme under weak basic conditions, serves as the only path to obtain a novel anisotropic supramolecular hydrogel that is stable over a wide pH range. This result not only expands the molecular scope of supramolecular hydrogelators but also illustrates the design principles for creating pH-stable supramolecular soft materials.

    View details for DOI 10.1021/la103982e

    View details for Web of Science ID 000287048900042

    View details for PubMedID 21138331

    View details for PubMedCentralID PMC3235788

  • beta-Galactosidase-instructed formation of molecular nanofibers and a hydrogel NANOSCALE Zhao, F., Weitzel, C. S., Gao, Y., Browdy, H. M., Shi, J., Lin, H., Lovett, S. T., Xu, B. 2011; 3 (7): 2859-2861


    Here we report the first example of using β-galactosidase to trigger the formation of cell compatible, supramolecular nanofibers, which ultimately may lead to a new approach for the development of soft nanotechnology.

    View details for DOI 10.1039/c1nr10333d

    View details for Web of Science ID 000292776300022

    View details for PubMedID 21637882

    View details for PubMedCentralID PMC3235787

  • Molecular hydrogels of therapeutic agents CHEMICAL SOCIETY REVIEWS Zhao, F., Ma, M. L., Xu, B. 2009; 38 (4): 883-891


    This tutorial review aims to introduce a new kind of biomaterials-molecular hydrogels of therapeutic agents. Based on the molecular self-assembly in water, it is possible to transform therapeutic agents into analogues that form hydrogels without compromising their pharmacological efficacy. This transformation can be beneficial in three aspects: (i) the therapeutic agents become "self-deliverable" in the form of hydrogels; (ii) the self-assembly of hydrogelators of drugs might confer new and useful properties such as multivalency or high local densities; (iii) the exploration of molecular hydrogels of drugs may ultimately lead to bioactive molecules that have dual or multiple roles. By summarizing the reports on the molecular hydrogels made from clinical used drugs or other bioactive molecules, this article presents representative molecular hydrogels of therapeutics and outlines the promises and challenges for developing this new class of biomaterials.

    View details for DOI 10.1039/b806410p

    View details for Web of Science ID 000264523700003

    View details for PubMedID 19421568

  • Preparation of Cu2+-loaded porous chitosan particles for immunoglobulin g adsorption THERAPEUTIC APHERESIS AND DIALYSIS Yue, R., Liu, T., Su, B., Fu, P., Zhao, F., Zhao, C. 2008; 12 (3): 209-215


    Chitosan porous particles were prepared using a precipitation technique. The porous particles could bind Cu(2+), from which Cu(2+)-loaded porous particles were prepared. The Cu(2+)-loaded porous chitosan particles could remove immunoglobulin (Ig) G more selectively than albumin, IgA and IgM from aqueous solutions and human plasma. The effect of the volume ratio of plasma to particles on protein adsorption was studied, with the results indicating that a volume ratio of 3:1 might be a good choice for clinical use. The particles could be easily incorporated into a column. When human plasma was applied to the particle column, higher removal efficiency was obtained. These results suggested that Cu(2+)-loaded porous particles may be a potentially good sorbent for IgG removal from plasma.

    View details for DOI 10.1111/j.1744-9987.2008.00576.x

    View details for Web of Science ID 000256124200004

    View details for PubMedID 18503698

  • Chitosan gel beads immobilized Cu (II) for selective adsorption of amino acids JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS Bai, P., Cao, F., Lan, X., Zhao, F., Ma, Y., Zhao, C. 2008; 70 (6): 903-908


    Chitosan (CS) gel beads were prepared by using phase inversion and precipitation technique. The gel beads could bind copper (II), by which Cu (II) ion-immobilized chitosan gel beads (CS-Cu2+ gel beads) were prepared, and the amount of the immobilized Cu (II) was about 35 mg/g when the CS gel beads were incubated in 150 ppm cupric sulfate solution. The CS-Cu2+ gel beads could selectively adsorb histidine (His) from the mixed solution containing His and tryptophan (Trp); and the selective coefficient which was defined as the adsorbed amount ratio of His to Trp was about 8.0 at the pH value of 7.4. The effect of the pH value on the amino acid adsorption was also studied. In order to investigate the relationship of the amino acid adsorption and protein adsorption, the adsorbed amounts for IgG and albumin were determined; and the results indicated that the CS-Cu2+ gel beads could adsorb a larger amount of IgG than albumin due to the larger amount of the exposed residual His. The study provided a sorbent and a method to selectively remove His and IgG.

    View details for DOI 10.1016/j.jprot.2008.01.001

    View details for Web of Science ID 000256393200017

    View details for PubMedID 18262653

  • Preparation of porous chitosan gel beads for copper(II) ion adsorption JOURNAL OF HAZARDOUS MATERIALS Zhao, F., Yu, B., Yue, Z., Wang, T., Wen, M., Liu, Z., Zhao, C. 2007; 147 (1-2): 67-73


    In this paper, chitosan porous beads were prepared by using a phase inversion technique, and then used for the adsorption and removal of copper(II) ions. The porosity, diameter and other characteristics were characterized. With the increase of chitosan and NaOH concentration used to prepare the beads, the amount of adsorbed Cu2+ per gram of the beads decreased. A maximum adsorption amount was observed at a pH value of 6.0 for the cross-linked porous chitosan beads. The amount of the adsorbed Cu2+ increased with the Cu2+ concentration used in the adsorption experiments. By the relationship of the ratio of the equilibrium Cu2+ concentration in the solution (C(e)) to the adsorbed equilibrium amount (P(e)) (C(e)/P(e)) and C(e), we concluded that the adsorption of Cu2+ to the porous chitosan beads was Langmuir adsorption. The Cu2+-loaded porous chitosan beads were stable in water, which is useful for further study on selectively adsorption of IgG. The results suggested that the porous chitosan beads were useful adsorbents for copper ions removal in water treatment, and the Cu2+-loaded beads may be good sorbents for IgG removal in blood purification.

    View details for DOI 10.1016/j.jhazmat.2006.12.045

    View details for Web of Science ID 000249136200009

    View details for PubMedID 17258856

  • Poly(ether sulfone)/activated carbon hybrid beads for creatinine adsorption JOURNAL OF APPLIED POLYMER SCIENCE Deng, X., Wang, T., Zhao, F., Li, L., Zhao, C. 2007; 103 (2): 1085-1092

    View details for DOI 10.1002/app.25344

    View details for Web of Science ID 000242468700056