Development of a polymeric biomedical device platform with controlled disassembly and in vivo testing in a swine intestinal model.

The aim of this study was to create a surgical guide platform that maintains its integrity while the surgeon performs an intestinal anastomosis or another similar procedure, which then breaks apart and is eliminated from the body in a controlled manner. The device contains mixed polymeric structures that give it a controlled rate of disassembly that could meet the requirements of a specific surgical purpose. The intraluminal anastomotic guide was manufactured as a hollow cylinder composed of layers of porous polyurethane/PCL with polyvinylpyrrolidone as the binding agent similar to a "brick-mortar" architecture. This combination of polymeric structures is a promising manufacturing method from which a variety of tunable devices can be fabricated for specific medical procedures and site-specific indications. The guide was designed to rapidly disassemble within the intestinal lumen after use, reliably degrading while maintaining sufficient mechanical rigidity and stability to support manipulation during complex surgical procedures. The nature of the device's disassembly makes it suitable for use in hollow structures that discharge their contents, resulting in their elimination from the body. A swine model of intestinal anastomosis was utilized to validate the use and function of the device.

Development and in vivo Assessment of a Rapidly Collapsible Anastomotic Guide for Use in Anastomosis of the Small Intestine: A Pilot Study Using a Swine Model.

Various conditions in human and veterinary medicine require intestinal resection and anastomosis, and complications from these procedures are frequent. A rapidly collapsible anastomotic guide was developed for small intestinal end-to-end anastomosis and was investigated in order to assess its utility to improve the anastomotic process and to potentially reduce complication rates. A complex manufacturing method for building a polymeric device was established utilizing biocompatible and biodegradable polyvinylpyrrolidone and polyurethane. This combination of polymers would result in rapid collapse of the material. The guide was designed as a hollow cylinder composed of overlaying shingles that separate following exposure to moisture. An in vivo study was performed using commercial pigs, with each pig receiving one standard handsewn anastomosis and one guide-facilitated anastomosis. Pigs were sacrificed after 13 days, at which time burst pressure, maximum luminal diameter, and presence of adhesions were assessed. Burst pressures were not statistically different between treatment groups, but in vivo anastomoses performed with the guide withstood 10% greater luminal burst pressure and maintained 17% larger luminal diameter than those performed using the standard handsewn technique alone. Surgeons commented that the addition of a guide eased the performance of the anastomosis. Hence, a rapidly collapsible anastomotic guide may be beneficial to the performance of intestinal anastomosis.

Evaluation of a Polyurethane Platform for Delivery of Nanohydroxyapatite and Decellularized Bone Particles in a Porous Three-Dimensional Scaffold.

The complex dynamic nature of bone tissue presents a unique challenge for developing optimal biomaterials within the field of bone tissue engineering. Materials based on biological and physiological characteristics of natural bone have shown promise for inducing and promoting effective bone repair. Design of multicomposite scaffolds that incorporate both malleable and hard mineral components allows for intricate structures with nano- and macrosized mineral components to provide architectural elements that promote osteogenesis. The examined S-1 and S-2 scaffolds are multilayered constructs which differ only in the compositional ratio of nanohydroxyapatite (nHA) and decellularized bone particles (DBPs). The constructs incorporated previously studied nHA/polyurethane films interspersed with macrosized bone DBPs to stimulate integration with native tissue and induce osteogenic activity. In vitro assessment of cytocompatibility and osteostimulatory characteristics indicated that the scaffolds did not negatively impact cell health and demonstrated osteogenic effects. When the constructs were implanted in vivo, in a rat tibial defect model, the biocompatibility and osteogenic impact were confirmed. Material-treated defects were observed to not induce negative tissue reactions and, in those treated with S-1 scaffolds, exhibited greater levels of new bone formation. These results indicate that, while both scaffold designs were biocompatible, S-1 constructs demonstrate more effective biologically relevant nano-/macromineral architectural elements.