Objectives: . A polydioxanone (PDO) stent was developed to treat tracheomalacia in pediatric patients. However, its safety and efficacy need to be verified in animal studies before clinical trials in patients can be conducted. This study evaluated the safety and efficacy of a PDO stent in normal and tracheomalacia-model rabbits. Methods: . In total, 29 New Zealand white rabbits were used: 13 for evaluating the biocompatibility of the PDO stent in normal rabbits and 16 for the creation of a tracheomalacia model. The tracheomalacia model was successfully established in 12 rabbits, and PDO stents were placed in eight of those rabbits. Results: . The PDO stent was successfully positioned in the trachea of the normal rabbits using an endoscopic approach, and its degradation was observed 10 weeks later. The stent fragments did not induce distal airway obstruction or damage, and the mucosal changes that occurred after stent placement were reversed after degradation. The same procedure was performed on the tracheomalacia-model rabbits. The survival duration of the tracheomalacia rabbits with and without stents was 49.0±6.8 and 1.0±0.8 days, respectively. Thus, the PDO stent yielded a significant survival gain (P=0.001). In the tracheomalacia rabbits, stent degradation and granulation tissue were observed 7 weeks after placement, leading to airway collapse and death. Conclusion . We successfully developed a PDO stent and an endoscopic guide placement system. The degradation time of the stent was around 10 weeks in normal rabbits, and its degradation was accelerated in the tracheomalacia model. The mucosal changes associated with PDO stent placement were reversible. Placement of the PDO stent prolonged survival in tracheomalacia-model rabbits.

Objectives: . A polydioxanone (PDO) stent was developed to treat tracheomalacia in pediatric patients. However, its safety and efficacy need to be verified in animal studies before clinical trials in patients can be conducted. This study evaluated the safety and efficacy of a PDO stent in normal and tracheomalacia-model rabbits. Methods: . In total, 29 New Zealand white rabbits were used: 13 for evaluating the biocompatibility of the PDO stent in normal rabbits and 16 for the creation of a tracheomalacia model. The tracheomalacia model was successfully established in 12 rabbits, and PDO stents were placed in eight of those rabbits. Results: . The PDO stent was successfully positioned in the trachea of the normal rabbits using an endoscopic approach, and its degradation was observed 10 weeks later. The stent fragments did not induce distal airway obstruction or damage, and the mucosal changes that occurred after stent placement were reversed after degradation. The same procedure was performed on the tracheomalacia-model rabbits. The survival duration of the tracheomalacia rabbits with and without stents was 49.0±6.8 and 1.0±0.8 days, respectively. Thus, the PDO stent yielded a significant survival gain (P=0.001). In the tracheomalacia rabbits, stent degradation and granulation tissue were observed 7 weeks after placement, leading to airway collapse and death. Conclusion . We successfully developed a PDO stent and an endoscopic guide placement system. The degradation time of the stent was around 10 weeks in normal rabbits, and its degradation was accelerated in the tracheomalacia model. The mucosal changes associated with PDO stent placement were reversible. Placement of the PDO stent prolonged survival in tracheomalacia-model rabbits.

BACKGROUND: Long segmental tracheal repair is challenging in regenerative medicine due to low adhesion of stem cells to tracheal scaffolds. Optimal transplantation of stem cells for tracheal defects has not been established. We evaluated the role of hyaluronic acid (HA) coating of tracheal scaffolds in mesenchymal stem cell (MSC) adhesion and tracheal regeneration in a rabbit model. METHODS: A three-dimensionally printed tubular tracheal prosthesis was incubated with dopa-HA-fluorescein isothiocyanate in phosphate-buffered saline for 2 days. MSCs were incubated with an HA-coated scaffold, and their adhesion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HA coated scaffolds with or without MSC seeding were transplanted at the circumferential tracheal defect in rabbits, and survival, rigid bronchoscopy, radiologic findings, and histologic findings were compared between the two groups. RESULTS: HA-coated scaffolds showed better MSC adhesion than non-coated scaffolds. The HA-coated scaffolds with MSC group showed a wider airway and greater mucosal regeneration compared to the HA-coated scaffolds without MSC group. CONCLUSION HA coating of scaffolds can promote MSC adhesion and tracheal regeneration.

BACKGROUND: Long segmental tracheal repair is challenging in regenerative medicine due to low adhesion of stem cells to tracheal scaffolds. Optimal transplantation of stem cells for tracheal defects has not been established. We evaluated the role of hyaluronic acid (HA) coating of tracheal scaffolds in mesenchymal stem cell (MSC) adhesion and tracheal regeneration in a rabbit model. METHODS: A three-dimensionally printed tubular tracheal prosthesis was incubated with dopa-HA-fluorescein isothiocyanate in phosphate-buffered saline for 2 days. MSCs were incubated with an HA-coated scaffold, and their adhesion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. HA coated scaffolds with or without MSC seeding were transplanted at the circumferential tracheal defect in rabbits, and survival, rigid bronchoscopy, radiologic findings, and histologic findings were compared between the two groups. RESULTS: HA-coated scaffolds showed better MSC adhesion than non-coated scaffolds. The HA-coated scaffolds with MSC group showed a wider airway and greater mucosal regeneration compared to the HA-coated scaffolds without MSC group. CONCLUSION HA coating of scaffolds can promote MSC adhesion and tracheal regeneration.

Codonopsis lanceolata has been used as an herbal medicine for several lung infl ammatory diseases, such as asthma, tonsillitis, and pharyngitis. Previously, we showed the neuroprotective effect of steamed and fermented C. lanceolata (SFC) in vitro and in vivo. In the current study, the treatment of HT22 cells with SFC decreased glutamate-induced cell death, suggesting that SFC protected HT22 cells from glutamate-induced cytotoxicity. Based on these, we sought to elucidate the mechanisms of the neuroprotective effect of SFC by measuring the oxidative stress parameters and the expression of Bax and caspase-3 in HT22 cells. SFC reduced contents of ROS, Ca2+ and NO. Moreover, SFC restored contents of glutathione and glutathione reductase as well as inhibited Bax and caspase-3 activity in HT22 cells. These results indicate that steamed and fermented C. lanceolata (SFC) extract protected HT22 cells by anti-oxidative effect and inhibition of the expression of Bax and caspase-3.
Asthma ; Caspase 3 ; Cell Death ; Codonopsis* ; Glutathione ; Glutathione Reductase ; Herbal Medicine ; Lung ; Neuroprotective Agents* ; Oxidative Stress ; Palatine Tonsil ; Pharyngitis ; Steam* ; Tonsillitis

Codonopsis lanceolata (Campanulaceae) traditionally have been used as a tonic and to treat patients with lung abscesses. Recently, it was proposed that the extract and some compounds isolated from C. lanceolata reversed scopolamine-induced memory and learning deficits. The purpose of this study was to evaluate the improvement of cognitive enhancing effect of C. lanceolata by steam and fermentation process in scopolamine-induced memory impairment mice models by passive avoidance test and Morris water maze test. The extract of C. lanceolata or the extract of steamed and fermented C. lanceolata (SFCE) was orally administered to male mice at the doses of 100 and 300 mg/kg body weight. As a result, mice treated with steamed and fermented C. lanceolata extract (SFCE) (300 mg/kg body weight, p.o.) showed shorter escape latencies than those with C. lanceolata extract or the scopolamine-administered group in Morris water maze test. Also, it exerted longer step-through latency time than scopolamine treated group in passive avoidance test. Furthermore, neuroprotective effect of SFCE on glutamate-induced cytotoxicity was assessed in HT22 cells. Only SFCE-treated cells showed significant protection at 500 microg/ml. Interestingly, steamed C. lanceolata with fermentation contained more phenolic acid including gallic acid and vanillic acid than original C. lanceolata. Collectively, these results suggest that steam and fermentation process of C. lanceolata increased cognitive enhancing activity related to the memory processes and neuroprotective effect than original C. lanceolata.
Animals ; Body Weight ; Codonopsis* ; Fermentation ; Gallic Acid ; Humans ; Learning ; Lung Abscess ; Male ; Maze Learning ; Memory* ; Mice* ; Neuroprotective Agents ; Phenol ; Scopolamine Hydrobromide ; Steam* ; United Nations ; Vanillic Acid