Novel Biodegradable Polycaprolactone Occlusion Device Combining Nanofibrous PLGA/Collagen Membrane for Closure of Atrial Septal Defect (ASD)

Abstract

The purpose of this report was to develop novel biodegradable occlusion devices for closure of atrial septal defects (ASD). To manufacture the biodegradable occluders, polycaprolactone (PCL) components were first fabricated by a lab-scale micro-injection molding machine. They were then assembled and hot-spot welded into double umbrella-like devices of 50 mm in diameter. A special mechanism at the axis of the occluder was designed to self-lock the occluder after the two umbrellas were expanded. Furthermore, a nanofibrous matrix of poly-D-L-lactide-glycolide (PLGA)/type I collagen blend was produced via electrospinning to develop biodegradable and biomimetic anti-shunt membranes for the occluders. Characterization of the biodegradable PCL occluders was carried out. PCL occluders exhibited mechanical properties comparable to that of commercially available Amplatzer occluders. The sealing capability of biodegradable occluders was found superior to that of Amplatzer occluders. In addition, the cell attachment and spreading of endothelial cells seeded on the PLGA/collagen nanofibrous matrix and the interaction between cells and PLGA/collagen nanofibers were studied. The nanofibrous membranes made of PLGA/collagen were very effective in promoting cell proliferation during culture.

Study of biodegradable occluder of atrial septal defect in a porcine model

“…So far, some biodegradable ASD occlusion devices have been developed such as partially biodegradable devices including BioSTAR, Biodisk, and Double Biodisc devices, which have been discarded, and fully biodegradable devices including the Chinese Lantern (CL), the DU, PLGA/collagen membrane, and the polydioxanone (PDO), which are in progress . The “Chinese Lantern” device made of fully biodegradable polymers (copolymer of caprolactone and lactate) consists of a soft portion and a structural skeleton .…”

“…However, because the stem of the DU device is longer than septum, the DU device leaves a considerable gap between the umbrella discs and the septum, giving rise to potential thrombosis formation within the gap. The PLGA/collagen membrane was developed with a nanofiber matrix of blend of poly( dl ‐lactide‐glycolide) and type I collagen which has mechanical properties comparable to those of commercial metallic occluders . PLGA starts significant bioresorption after 6 months of postimplantation, and thus degraded faster than PLLA .…”

“…Finally, some patients would prefer not to remaining a foreign body in their heart indefinitely. To address these issues, researchers and clinicians have envisioned a biodegradable septal occluder device …”

New laser soldering-based closures: a promising method in natural orifice transluminal endoscopic surgery

“…42,43 Because bovine albumin serum solders can in some cases induce immunologic responses in humans, we will replace it with human serum albumin for future clinical use.…”

A Novel-Design Poly-<smlcap>L</smlcap>-Lactic Acid Biodegradable Device for Closure of Atrial Septal Defect: Long-Term Results in Swine

“…Due to low elastic modulus, low tensile strength, the limited shape-memory function of PDO, and the diameter of PDO monofilament fibers (0.298 mm) compared with the nickel-titanium wire (only 0.1 mm), the production of a larger occluder may be restricted. Liu et al [20] developed a biodegradable polycaprolactone occluder with a nanofibrous matrix of poly- DL -lactide-glycolide/type I collagen blend. Polycaprolactone occluders have mechanical properties comparable to those of commercially available Amplatzer occluders.…”