Histological and structural effects of biodegradable polydioxanone stents in the rabbit trachea

Abstract

Objectives The aim of this study was to evaluate the potential biologic effects caused by successive placement of biodegradable polydioxanone (PDO) stents in the rabbit trachea. PDO stents could eventually induce a fibroproliferative reaction in the submucosa that could be beneficial in the treatment of malacia due to an increase in its consistency without impairing the tracheal lumen. Methods Sixteen adult NZ rabbits were distributed into 3 groups with different survival times according to the number of stents placed: One stent (14 weeks), 2 stents (28 w.), and 3 stents (42 w.). Stent insertion was performed endoscopically in the cervical trachea of the animal. Histopathological studies included Masson’s trichrome staining for submucosal fibrosis and Safranin O to assess structural integrity of cartilage. Potential inflammatory changes were analysed by means of immunohistochemistry determining the number of CD45 positive cells. Results Stent placement was successful in every case. Histological studies did not show a statistically significant increase in tracheal wall collagen area and cartilage structure was not modified in those rabbits with one or more PDO stents inserted compared to non-stented tracheal sections. Furthermore, no statistically significant changes in the number of CD45+ cells were observed in stented tracheal segments compared to normal tracheal tissues. Conclusions According to our data, successive PDO stenting caused mild inflammatory changes in the tracheal wall, no increase in the collagen matrix, and the cartilaginous support was not modified during a long follow-up period (up to 42 weeks). These findings suggest that they may be safe and show good biocompatibility in the long-term.

Biodegradable tracheal stents: our ten-year experience with adult patients

“…Hyperplasia of goblet cells resulting in hypersecretion was also observed [ 2 ]. Valverde et al [ 22 ] showed that successive stenting caused mild inflammatory changes in the tracheal wall and no increase in the collagen matrix or modifications in the cartilage structure. Generally, the response to damage is the formation of granulation tissue.…”

Progress of biodegradable polymer application in cardiac occluders

“…70,124,125 Given the persistent good mechanical properties, machinability, non-antigenity, low inflammatory reaction, and predictable degradation rate, it has been widely used in various medical applications, such as sutures, drug carriers, airway stents, biliary stents, tissue engineering scaffolds. 51,124,[126][127][128][129][130][131] Both the Pansy occluder and Memsorb occluder used PDO as the skeleton material, and clinical trial results were satisfactory. 51,52,[68][69][70][71][72] The complete degradation took around 6-24 months, and the loss of support strength was slow during degradation, hence, it could provide good support for 5-6 weeks.…”

“…Compared with other biodegradable polymers, like PGA and PLA, PDO produces less acidic products, elicits weaker inflammatory reactions, and has better flexibility and tensile strength 70,124,125 . Given the persistent good mechanical properties, machinability, non‐antigenity, low inflammatory reaction, and predictable degradation rate, it has been widely used in various medical applications, such as sutures, drug carriers, airway stents, biliary stents, tissue engineering scaffolds 51,124,126–131 …”

Microinjection Molded Biopolymeric Airway Stent with Antibacterial and Anti‐Hyperplastic Properties

“…reported the successful application of poly (L‐lactide‐ co ‐ ε ‐caprolactone) (PLCL) and PLGA loaded with rapamycin to inhibit fibroblast proliferation and collagen generation in mouse models. [ 16–20 ] Paunović et al. described a 3D printed poly (D, L‐lactide‐ co ‐ ε ‐caprolactone)‐based airway stent with excellent mechanical properties, biocompatibility, and degradation characteristics comparable to the advanced commercial silicone stents.…”

“…[4,15] The safety and efficacy of polydioxanone stents have been evaluated in animal models and the clinic, while Duvvuri et al reported the successful application of poly (L-lactide-co-𝜖-caprolactone) (PLCL) and PLGA loaded with rapamycin to inhibit fibroblast proliferation and collagen generation in mouse models. [16][17][18][19][20] Paunović et al described a 3D printed poly (D, L-lactide-co-𝜖caprolactone)-based airway stent with excellent mechanical properties, biocompatibility, and degradation characteristics comparable to the advanced commercial silicone stents. [21] Zhu et al reported a PLCL-based airway stent eluted with mitomycin in a spiral or tubular form for the prevention of tracheal stenosis.…”