3D printing of personalized catheters with smart pH-responsive coating for improved functionality, cytocompatibility, and anti-bacterial characteristics

Hydrocephalus is one of the most common brain disorders and remains an incurable condition throughout life. The existing gold standard treatment method for hydrocephalus includes surgical cerebrospinal fluid shunting with the help of “one-size-fits-all” catheters. Although this method is very efficient, following their insertion, catheters are subjected to various complications, including flow resistance, blockage, mechanical malfunctions, and being subjected to host-immune response as well as microbial infection. To overcome these complications, we proposed implementing three-dimensional (3D) printing technology to develop the next generation of catheters with improved functionality and liquid flowability. Our suggested technology is based on imaging data on the final destination site (via computed tomography scan or magnetic resonance imaging) in such a way that it fits the needs of the body in a personalized manner. Herein we report for the first time, digital light processing (DLP) 3D printing of helical-shaped, flexible catheters using commercially available KeySplint soft resin. These catheters offer fully customizable features such as diameter, the number and placement of drainage holes tailored to individual patient needs. In vitro stability study of the 3D printed KeySplint samples suggested that the 3D printed catheters may remain structurally stable under physiological conditions for atleast 3240 hrs (135 days). Moreover, to further enhance catheter’s functionality, a pH-responsive smart surface chemistry was introduced on the catheter surface using two strategies (via plasma coating and by simply mixing with 3D printing resin) that can respond dynamically to tackle two critical challenges related to catheters: blockage of the catheters by undesired proteins, choroid plexus, blood clots and infection/biofilm prevention via chemical intramolecular rearrangement in the functional moieties of the coating. Both CB-OH coated and 5 % CB-OH mixed 3D printed catheters significantly inhibited bacterial biofilm formation at 24, 48, and 72 hrs compared to pristine catheters. On top of that, the CB-OH coated 3D printed helical catheters showed a 37-folds reduction in particles deposition per unit volume relative to conventional 3D printed linear catheters. These results suggest that the proposed surface-functionalized 3D printed personalized catheters could provide a promising solution for medical implants treating hydrocephalus.