Research

Image-based patient specific design utilizes patient imaging data as the basis for designing devices and implants.  Image data, ranging from mobile phone scanning data to Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) data, is segmented into specific patient anatomy.  This data is then converted into .STL surface format.  The STL data can directly be used for 1) input to CAD to assist in patient specific device design, 2) for 3D printing, and 3) to generate Finite Element (FE) and Computational Fluid Dynamics (CFD) simulation models to predict the performance of devices within patient specific anatomy.

Laser sintering (SLS) 

Formiga P110 (EOS): Through laser sintering of powdered polycaprolactone (PCL), this printer produces complex scaffolds and medical devices for research purposes and human clinical applications. This printer provides high specificity and quick printing speeds to manufacture prototypes and scaffolds used in the lab. Our lab uses this device to print research samples for the auxetic scaffold project and for tissue engineering projects related to ear and nose reconstruction. Also used to print splints to help treat tracheomalacia in human pediatric cases. 

Material Extrusion 

3D-Bioplotter (EnvisionTec): Mainly used to print PCL structures for 

research and human clinical applications. This printer can also be used to print other common biomaterials like polylactic acid (PLA) or poly(lactic-co-glycolic) acid (PLGA). This printer uses air pressure to extrude melted resins. (Check with Jeonghun to determine what projects actively use the bioplotter) 

T&R printer (T&R): Used to print PCL structures for research and human clinical applications. Utilizes a temperature and humidity controlled chamber to reduce variability in print conditions for biomaterials. Printer also has a spinning platform to allow for improved printing of circular or cylindrical structures. This printer uses air pressure to extrude melted resins. (Check with Jeonghun to determine what projects actively use the bioplotter) 

Inkredible + Bioprinter (Cellink): Heavily used for printing custom biocompatible APGD resins for research into 3D printing of biodegradable shape memory elastomers for treatment of soft tissue pathologies via minimally invasive procedures. Printer can also be used for cell printing with hydrogel resins. This printer uses air pressure to extrude resins. 

J750 (Stratysys): Uses polyjet technology to print proprietary stratysys resins. These resins cover a range of mechanical behavior, from stiff linear elastic to rubbery viscoelastic behavior. This printer is used to produce high quality surgical models from scanned patient anatomy to assist physicians in preparing for surgery. This printer has also been used to produce prototype prosthetics and non-implantable medical devices. This printer can be used to produce high quality tools as well. 

F170 (Stratysys): A fused deposition model (FDM) 3D printer that can print structures using either PLA or Acrylonitrile butadiene styrene (ABS) filament. Typically used to print simple tools for lab use. 

Vat Photopolymerization 

Lumen X Bioprinter (Cellink): Uses digital light processing (DLP) technology to print biomaterial resins. Originally designed to print poly-ethylene glycol diacrylate (PEG-da) and other hydrogel photoinks, this printer is used to print custom biocompatible APGD resins for research into 3D printing of biodegradable shape memory elastomers for treatment of soft tissue pathologies via minimally invasive procedures. 

Form 2 (Formlabs): These stereolithography (SLA) printers are used to print Formlabs’ proprietary resins. These printers provide of range of resolution parameters based on design needs. This system uses multiple resins based on desired applications like flexible, white, clear, high-temp, durable, etc. While some Formlabs resins have been tested and certified biocompatible for in vitro/in vivo applications, like the Dental SG resin, these printers are typically used to print custom tools (surgical models, molds, grips, etc. ) for in-lab applications.

Poly (glycerol dodecanedioate) is a biodegradable shape memory polymer formulated to exhibit linear elastic or nonlinear hyperelastic and viscoelastic properties elastomer suited for minimally invasive surgical applications in cardiovascular and gastrointestinal domains – with specific focus on pediatric pathologies like atrial septal defect repair and  log gap esophageal atresia repair.

Computationally modeling tissue interaction with devices is important for evaluating surgical repair outcomes and for surgical planning. Experimentally testing the mechanical properties of tissues and materials and evaluating structure and composition provide the empirical inputs for predictive computational models. 

These models can be used to automate screening of various materials and design geometries. Additionally, comparing these models to tissue mimicking materials (Stratasys J750) allows unique models for surgical planning and device testing in patient specific devices in vitro.

Translation of 3D printing medical devices requires applying design control process towards manufacturing medical devices. Nascent manufacturing technologies like 3D printing require significant parameter optimization, verification and validation to ensure high quality and consistent manufacture. This research addresses the regulatory science behind translating personalized devices.