People in Research

Hua Wang

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Advisor: Prof. Shaoyi Jiang/Buddy D. Ratner

Department/status: Dept. of Chemical Engineering/fourth year graduate student

Project overview: Probing the orienation of surface-immoblized IgG by ToF-SIMS. Interactions of SPARC(osteonectin,BM40) with ECM proteins identified by surface plasmon resonace biosensor. Engineering cell adhesive surface: Control the orientaion/conformation of fibronectin/FnIII7-10 by modulating surface chemistry.

Project details:

1. In this research, a unique probing technique is developed to directly probe the orientation of surface-immobilized IgG using Time-of-flight Secondary Ion Mass Spectrometry (ToF-SIMS). This technique is capable of providing direct information regarding the orientation of surface-immobilized IgG by the analysis of its amino acid composition at the extreme surface (1-1.5nm). This technique overcomes several scientific and engineering barriers that currently prevent accurate estimation of the performance of biosensor technologies. This study, as the first to utilize ToF-SIMS for protein orientation studies, also expands the frontiers of state-of-the-art surface analysis tools for general biomedical research.
2. In this research, a mechanism in wound healing is established by the identification of the interactions between a matricellular protein SPARC with an extracelullar matrix protein fibrinogen under proteolytical conditions that mimic the injured tissue. This research discovered the SPARC's potential participation in a positive feedback loop for the regulation of the fibrin clot lysis through its increased affinity for fibrin degradative products (FDPs) and its upregulation of two enzymes plasmin and MMPs, which will produce more FDPs, and in turn, bind more SPARC.
3. In this research, a fibronectin fragment (FnIII7-10) capable of inducing cell adhesion and migration are immobilized with a controlled orientation by a charge-driven method, compared to the commonly used non-specific adsorption method, which results in random orientation. Thus, the decorated surface will present the body the optimal biosignal and initiate the desired biological response. The results of this research could be applied for the intelligent design of biocompatible biomaterials and scaffolds that are intended for tissue engineering applications.

   Skills: Various surface analysis techniques including SPR, AFM, ToF-SIMS and ESCA
   Handling of proteins, various protein assays
   Cell culture, cell-protein interaction assays, microscopy
   Surface functionalization for biosensors
   Thin film preparation techniques such as self-assembled monolayer (SAMs), spin coating and chemical vapor deposition

   Relevant honors or funding:
   NIH, NSF, DARPA, UWEB

   Names of others on the project:
   David G. Castner, E. Helene Sage