CHME 690: Graduate Seminar Spring 2017 Elizabeth Cosgriff-Hernandez (Texas A&M University)

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Date/Time
Date(s) - Fri 05/05/17
1:30 pm - 2:30 pm

Location
Guthrie Hall 201

Categories


Biomedical Applications of Emulsion Templating

Tissue engineering has emerged as a potential means to combine the healing potential of autografts with the advantages of synthetic grafts; however, there are several critical challenges in the treatment of bone defects. Current injectable materials are limited by a lack of porosity and biodegradability (e.g. bone cements/putties) or inability to prevent loss of reduction and require significant fixation to stabilize the defect (e.g. hydrogels/colloidal gels). Our laboratory has developed a novel emulsion templating methodology to generate injectable bone grafts that rapidly cure at body temperature to a high porosity foam with compressive properties in the range of trabecular bone. Recently, we utilized this platform to generate curable emulsion inks to form porous polyHIPE foams with hierarchical porosity using fused deposition modeling. Briefly, HIPE material is deposited layer-by-layer using an open source 3D printer equipped with a syringe and motor-actuated plunger. Emulsions inks are rapidly cured after deposition by constant UV irradiation to form rigid constructs with interconnected porosity in a method we term Cure-on-Dispense (CoD) printing. 3D printed polyHIPE constructs benefit from the tunable pore structure of emulsion templated materials and the fine control over complex geometries of 3D printing that is not possible with traditional manufacturing techniques. In order to generate scaffolds with increased permeability without sacrificing mechanical strength, a biomimetic approach to scaffold design was used to reinforce the highly porous emulsion inks with a dense cortical shell of thermoplastic polyester. Herein, we report an open source method for creating hybrid multi-material scaffolds with emulsion inks and reinforced with a shell of thermoplastic poly(ϵ-caprolactone) (PCL) or poly(lactic acid) (PLA). A multi-modal printing setup was first developed that combined paste extrusion and high temperature thermoplastic extrusion with high positional accuracy in the dual deposition. By combining this new paste extrusion of emulsion inks with traditional thermoplastic extrusion printing, we have created scaffolds with superior strength that promote cell viability and proliferation of human mesenchymal stem cells. The development of this technique shows great promise for the fabrication of a myriad of other complex tissue engineered scaffolds. 

Research Interests

Dr. Elizabeth Cosgriff-Hernandez is associate professor in the Department of Biomedical Engineering at Texas A&M University. Her laboratory specializes in the development of polymeric biomaterial scaffolds for tissue engineering applications.

Biomaterial synthesis is complemented by the development of new fabrication strategies that improve the ability to manipulate 3D scaffold architecture. In addition to providing improved scaffolds for tissue repair, these innovative biomaterials and fabrication strategies provide new tools to probe the complex process of tissue remodeling in order to enhance the rational design of biomaterial scaffolds and guide tissue regeneration strategies.

The primary applications investigated by the Cosgriff-Hernandez laboratory include injectable bone grafts, multilayer vascular grafts based on bioactive hydrogels, electrospun grafts for interfacial tissue engineering, wound dressings with tunable moisture control and bioactivity, and porous microspheres for drug delivery.

Education

  • Postdoctoral Fellowship, Bioengineering, Rice University, 2005-2007
  • Ph.D., Macromolecular Science and Engineering, Case Western Reserve University, 2005
  • B.S., Biomedical Engineering, Case Western Reserve University, 2000