Experimental use of new absorbable tracheal stent.

BACKGROUND/PURPOSE: Silicone and metallic stents are not effective in children with tracheobronchial stenosis or tracheomalacia. Herein, we aimed to evaluate the clinical manifestations and histological reaction of rabbit trachea to the presence of a new poly(lactic-co-glycolic acid) with polyisoprene (PLGA/PI) polymer absorbable stent. METHODS: Fourteen adult white rabbits (weight, 3.0-3.5kg) were randomly assigned to three groups: Group I (n=6): PLGA/PI spiral stent; Group II (n=6): PLGA/PI fragment; and Group III (n=2): controls. After a longitudinal incision on three cervical tracheal rings, the stents and fragments were inserted into the trachea and fixed onto the lateral wall with nonabsorbable sutures. RESULTS: The stented group showed significantly more stridor at rest (p=0.0041), agitation (p=0.014), and use of accessory muscles (p=0.0002) and required more emergency endoscopies than the fragment group. Further, it showed significantly more remarkable histological inflammatory damage than the fragment and control groups (p=0.002). CONCLUSIONS: The new PLGA/PI polymeric stent implanted into the trachea of rabbits caused more clinical manifestations and histologically verified inflammatory reaction than the PLGA/PI polymeric fragment. Future studies should be aimed at reducing the stent-wall thickness.

In vitro evaluation of poly (lactic-co-glycolic acid)/polyisoprene fibers for soft tissue engineering.

The polymeric blend of poly (lactic-co-glycolic acid) (PLGA) and polyisoprene (PI) has recently been explored for application as stents for tracheal stenosis and spring for the treatment of craniosynostosis. From the positive results presented in other biomedical applications comes the possibility of investigating the application of this material as scaffold for tissue engineering (TE), acquiring a deeper knowledge about the polymeric blend by exploring a new processing technique while attending to the most fundamental demands of TE scaffolds. PLGA/PI was processed into randomly oriented microfibers through the dripping technique and submitted to physical-chemical and in vitro characterization. The production process of fibers did not show an effect over the polymer's chemical composition, despite the fact that PLGA and PI were observed to be immiscible. Mechanical assays reinforce the suitability of these scaffolds for soft tissue applications. Skeletal muscle cells demonstrated increases in metabolic activity and proliferation to the same levels of the control group. Human dermal fibroblasts didn't show the same behaviour, but presented cell growth with the same development profile as presented in the control group. It is plausible to believe that PLGA/PI fibrous three-dimensional scaffolds are suitable for applications in soft tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2581-2591, 2017.