Dr Xiaokun Wang
Translational Tissue Engineering Centre
Johns Hopkins University
Dr Xiaokun Wang received her PhD degree in Biomedical Engineering from Peking University / Georgia Institute of Technology / Emory University joint PhD program in 2013, and she is currently a Research Associate at Johns Hopkins University. Her research focuses on biomaterial engineering and regenerative medicine, with the aim of developing scaffolds that provide better regenerative microenvironments for repairing various types of tissues. Such biomaterial scaffolds play a critical role in supporting (three dimensional) cell growth, as well as providing biological cues to direct cell differentiation and enhance regeneration. Not all tissue are made equal, while many tissues like bone and muscle have a high capacity for cellular regeneration, others like cartilage and cornea are far more difficult to self-renew after damage. In response to this, different strategies are needed to effectively repair various types of target tissue. With this aim, Dr Wang has developed different biomaterial approaches to promote tissue repair, including utilizing structural cues to enhance osseointegration, engineering biosynthetic collagen membranes to reconstruct traumatized corneas, and modulating immune response to stimulate tissue-self-repair.Corneal Mimetic Materials, Mechanical Reinforcement and Wound Healing
The unique ulstrastruacture that gives corneal stroma superior transparency and mechanical strength is the specific collagen fibril size, interfibrillar spacing as well as the lamellar structure. Proteoglycans such as decorin and lumican contribute to the collagen size and spacing. In order to mimic the unique structure and to obtain a transparent, mechanically robust artificial cornea, we incorporated small functionalized oligosaccharides and their derivatives that bind to collagen molecules to regulate the fibril growth and spacing, to eventually obtain a lamellae structure very similar to corneal stroma. The final product has great suturability, optical transparency and biocompatibility. Pilot animal trials showed corneal epithelial cell migration and good material/host tissue integration. Besides corneal mimetics, we also developed glycosaminoglycan-based crosslinkers to form interpenetrating networks with corneal stroma to reinforce corneal mechanics, in order to reduce the complications of current UV-irradiation crosslinking systems for keratoconus patients. In the mean time, we have studied the anti-fibrosis effects of tissue-derived extracellular matrix materials during corneal wound healing. We discovered anti-inflammatory impact of the ECM materials from in vitro culture of various cell types. When administrated to injured corneas, the ECM treatment significantly reduced cornea haze formation at 1 month post-injury compared to non-treated control, indicating the pro-regenerative potential of these tissue-derived materials. In summary, different approaches have been taken including traditional biomaterial scaffold fabrication, bioactive molecules incorporation, and pro-regenerative immunomodulation to access ocular repair and regeneration.