Self-expandable tubular collagen implants

Abstract

Collagen has been extensively used as a biomaterial, yet for tubular organ repair, synthetic polymers or metals (e.g., stents) are typically used. In this study, we report a novel type of tubular implant solely consisting of type I collagen, suitable to self‐expand in case of minimal invasive implantation. Potential benefits of this collagen scaffold over conventional materials include improved endothelialization, biodegradation over time, and possibilities to add bioactive components to the scaffold, such as anticoagulants. Implants were prepared by compression of porous scaffolds consisting of fibrillar type I collagen (1.0–2.0% (w/v)). By applying carbodiimide cross‐linking to the compressed scaffolds in their opened position, entropy‐driven shape memory was induced. The scaffolds were subsequently crimped and dried around a guidewire. Upon exposure to water, crimped scaffolds deployed within 15–60 s (depending on the collagen concentration used), thereby returning to the original opened form. The scaffolds were cytocompatible as assessed by cell culture with human primary vascular endothelial and smooth muscle cells. Compression force required to compress the open scaffolds increased with collagen content from 16 to 32 mN for 1.0% to 2.0% (w/v) collagen scaffolds. In conclusion, we report the first self‐expandable tubular implant consisting of solely type I collagen that may have potential as a biological vascular implant.

A collagen plug with shape memory to seal iatrogenic fetal membrane defects after fetoscopic surgery

“…When our crimped plug with shape memory comes into contact with PBS, it fully returns to the shape in which it was crosslinked, while the untreated plugs did not show any shape recovery. The mechanism of the shape memory has been proposed before by our laboratory in both self-closing and self-expandable tubular scaffolds [ [33] , [34] , [35] ]. The degree of expansion of the crosslinked solid plugs in solvents with different polarities showed comparable results with the expandable tubular scaffolds [ 33 ].…”

“…Previously, we communicated how shape memory can be given to hollow tubular scaffolds made of exclusively type I collagen fibrils [ [33] , [34] , [35] ]. In this study, we constructed a solid, non-hollow collagen plug with shape memory to expand directly upon employment in order to seal fetal membranes after a fetoscopic procedure.…”

Bioengineered Scaffolds as Substitutes for Grafts for Urethra Reconstruction

“…The results showed that such engineered substitutes successfully displayed elastic-like characteristics. This type of scaffold was described as the first self-expandable tubular implant consisting solely of type I collagen [34].…”

Rifampin‐Releasing Triple‐Layer Cross‐Linked Fresh Water Fish Collagen Sponges as Wound Dressings

“…It has been proven that the use of fresh water fish scale-derived collagen is advantageous due to its enhanced biocompatibility and high level of direct cell adhesion [ 16 ]. Since fish collagen loses stability at body temperature [ 17 ], it has to be cross-linked in order to maintain its spongy consistency when used as a collagen dressing [ 16 , 18 ]; carbodiimide has been demonstrated to provide a highly biocompatible collagen cross-linking agent [ 16 , 19 , 20 ].…”