RESUMO
Tuberculosis remains one of the major health problems worldwide. Besides the lungs, tuberculosis affects other organs, including bones and joints. In the case of bone tuberculosis, current treatment protocols include necrectomy in combination with conventional anti-tuberculosis therapy, followed by reconstruction of the resulting bone defects. In this study, we compared autografting and implantation with a biodegradable composite scaffold for bone-defect regeneration in a tuberculosis rabbit model. Porous three-dimensional composite materials were prepared by 3D printing and consisted of poly(ε-caprolactone) filled with nanocrystalline cellulose modified with poly(glutamic acid). In addition, rabbit mesenchymal stem cells were adhered to the surface of the composite scaffolds. The developed tuberculosis model was verified by immunological subcutaneous test, real-time polymerase chain reaction, biochemical markers and histomorphological study. Infected animals were randomly divided into three groups, representing the infection control and two experimental groups subjected to necrectomy, anti-tuberculosis treatment, and plastic surgery using autografts or 3D-composite scaffolds. The lifetime observation of the experimental animals and analysis of various biochemical markers at different time periods allowed the comparison of the state of the animals between the groups. Micro-computed tomography and histomorphological analysis enabled the evaluation of osteogenesis, inflammation and cellular changes between the groups, respectively.
RESUMO
Reconstructive surgery for urethral defects employing tissue-engineered scaffolds represents an alternative treatment for urethroplasty. The aim of this study was to compare the therapeutic efficacy of the bilayer poly-D,L-lactide/poly-ε-caprolactone (PL-PC) scaffold seeded with allogenic mesenchymal stem cells (MSCs) for urethra reconstruction in a rabbit model with conventional urethroplasty employing an autologous buccal mucosa graft (BG). The inner layer of the scaffold based on poly-D,L-lactic acid (PL) was seeded with MSCs, while the outer layer, prepared from poly-ε-caprolactone, protected the surrounding tissues from urine. To track the MSCs in vivo, the latter were labeled with superparamagnetic iron oxide nanoparticles. In rabbits, a dorsal penile defect was reconstructed employing a BG or a PL-PC graft seeded with nanoparticle-labeled MSCs. In the 12-week follow-up period, no complications were detected. Subsequent histological analysis demonstrated biointegration of the PL-PC graft with surrounding urethral tissues. Less fibrosis and inflammatory cell infiltration were observed in the experimental group as compared with the BG group. Nanoparticle-labeled MSCs were detected in the urothelium and muscular layer, co-localizing with the urothelium cytokeratin marker AE1/AE3, indicating the possibility of MSC differentiation into neo-urothelium. Our results suggest that a bilayer MSCs-seeded scaffold could be efficiently employed for urethroplasty.
Assuntos
Células-Tronco Mesenquimais/citologia , Poliésteres/química , Engenharia Tecidual/instrumentação , Uretra/cirurgia , Animais , Células da Medula Óssea/citologia , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Chinchila , Condrócitos/citologia , Compostos Férricos/química , Inflamação , Bicamadas Lipídicas , Masculino , Nanopartículas Metálicas/química , Mucosa Bucal/patologia , Nanopartículas/química , Coelhos , Alicerces Teciduais/química , Transplante Homólogo , Urotélio/metabolismoRESUMO
INTRODUCTION: This nonrandomized study aimed to identify the optimal dose of every-3-week (q3w) and weekly nab-paclitaxel plus q3w carboplatin as first-line therapy in patients with advanced non-small cell lung cancer (NSCLC) for a phase 3 trial. METHODS: Previously untreated patients with advanced NSCLC enrolled sequentially into seven cohorts (25 patients/cohort, N = 175). Cohorts 1 to 4 and 5 to 7 received nab-paclitaxel q3w and weekly, respectively. Patients were evaluated for efficacy and safety. RESULTS: The most common treatment-related > or = grade 3 adverse events were neutropenia (60%), neuropathy (19%), fatigue (9%), and thrombocytopenia (29%) (no grade 4 neuropathy or fatigue). A 100 mg/m(2) weekly nab-paclitaxel produced less serious adverse events than other doses/schedules. Response rate (RR) was greater in the weekly versus q3w cohorts (47% vs. 30%). Median progression-free survival (PFS) ranged from 4.8 to 6.9 months, and overall survival (OS) ranged from 8.3 to 15.0 months (all cohorts). Patients receiving 100 mg/m(2) weekly nab-paclitaxel achieved 48% RR with 6.2 and 11.3 months of PFS and OS, respectively. In a retrospective analysis, patients with nonsquamous cell carcinoma receiving weekly nab-paclitaxel had significantly improved RR (59.4% vs. 23.5%, respectively, p = 0.003), and >2 months longer PFS and OS compared with q3w schedule. In patients with squamous cell carcinoma, the q3w schedule significantly increased PFS by 3 months (p = 0.014) and OS by >2 months (no difference in RR) compared with the weekly schedule. CONCLUSION: nab-Paclitaxel plus carboplatin is an effective therapy for advanced NSCLC. Based on favorable efficacy and safety profiles, a phase 3, randomized, multicenter study comparing 100 mg/m(2) weekly nab-paclitaxel plus q3w carboplatin to solvent-based paclitaxel plus carboplatin has enrolled patients.