Vascularization strategies for tissue engineering for tracheal reconstruction

2021 ◽  
Author(s):  
Fei Sun ◽  
Yi Lu ◽  
Zhihao Wang ◽  
Hongcan Shi
Keyword(s):  
Tissue Engineering ◽  
Cell Metabolism ◽  
Microvascular Network ◽  
Related Factors ◽  
Engineering Technology ◽  
Term Survival ◽  
Tracheal Reconstruction ◽  
Tracheal Replacement ◽  
Therapy Strategies

Tissue engineering technology provides effective alternative treatments for tracheal reconstruction. The formation of a functional microvascular network is essential to support cell metabolism and ensure the long-term survival of grafts. Although several tracheal replacement therapy strategies have been developed in the past, the critical significance of the formation of microvascular networks in 3D scaffolds has not attracted sufficient attention. Here, we review key technologies and related factors of microvascular network construction in tissue-engineered trachea and explore optimized preparation processes of vascularized functional tissues for clinical applications.

Molecular genetic, host-derived and clinical determinants of long-term survival in glioblastoma: First results from the ETERNITY study (EORTC 1419).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 2056-2056 ◽  
Author(s):  
Michael Weller ◽  
Guido Reifenberger ◽  
Emilie Le Rhun ◽  
Jennifer Leigh Clarke ◽  
Riccardo Soffietti ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Dna Methyltransferase ◽  
Methylation Status ◽  
Related Factors ◽  
Immunological Parameters ◽  
Term Survival ◽  
Long Term Survival ◽  
Large Patient ◽  
The Us

2056 Background: Glioblastoma represents the most aggressive primary brain tumor in adults, and less than 5% of patients survive 5 years from diagnosis. Factors influencing this long-term survival are poorly understood. Methods: In cooperation with the European Organisation for Research and Treatment of Cancer (EORTC) in Brussels, Belgium, more than 20 clinical sites in the US, Europe and Australia have registered patients with centrally confirmed glioblastoma who survived ≥ 5 years, collecting clinical data including therapy and quality of life-related factors, as well as biospecimens allowing to analyse molecular and immunological parameters. Results: At the cut-off of December 31, 2018, 392 patients were registered, of which 232 had glioblastoma confirmed by central pathology review; 59 dropped out due to histology other than glioblastoma. Glioblastomas were isocitrate dehydrogenase (IDH)-wildtype in 70.7% and had a positive O6-methylguanine DNA methyltransferase (MGMT) promotor methylation status in 75.9%. Median age at diagnosis was 52 years (range: 21-77 years). There was enrichment for patients with gross total resection. Further analyses are ongoing. Conclusions: In a comprehensive effort, the consortium funded by the US Brain Tumor Funders’ Collaborative characterizes factors modulating long-term survival in glioblastoma in a unique large patient cohort. Clinical trial information: NCT 03770468.

scholarly journals Advances in Cell Transplantation Therapy for Diseased Myocardium

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Outi M. Villet ◽  
Antti Siltanen ◽  
Tommi Pätilä ◽  
M. Ali A. Mahar ◽  
Antti Vento ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Cultured Cells ◽  
Systolic Function ◽  
Cell Loss ◽  
Engineering Technology ◽  
Term Survival ◽  
3 Dimensional ◽  
Bone Marrow Derived Cells

The overall objective of cell transplantation is to repopulate postinfarction scar with contractile cells, thus improving systolic function, and to prevent or to regress the remodeling process. Direct implantation of isolated myoblasts, cardiomyocytes, and bone-marrow-derived cells has shown prospect for improved cardiac performance in several animal models and patients suffering from heart failure. However, direct implantation of cultured cells can lead to major cell loss by leakage and cell death, inappropriate integration and proliferation, and cardiac arrhythmia. To resolve these problems an approach using 3-dimensional tissue-engineered cell constructs has been investigated. Cell engineering technology has enabled scaffold-free sheet development including generation of communication between cell graft and host tissue, creation of organized microvascular network, and relatively long-term survival afterin vivotransplantation.

scholarly journals Risk Factors for Tooth Loss in Patients with ≥25 Remaining Teeth Undergoing Mid-Long-Term Maintenance: A Retrospective Study

2021 ◽  
Vol 18 (13) ◽  
pp. 7174
Author(s):  
Hiroo Kawahara ◽  
Miho Inoue ◽  
Kazuo Okura ◽  
Masamitsu Oshima ◽  
Yoshizo Matsuka
Keyword(s):  
Risk Factors ◽  
Retrospective Study ◽  
Tooth Loss ◽  
Economic Status ◽  
Significant Risk ◽  
Related Factors ◽  
Term Survival ◽  
Worldwide Population

Tooth loss represents a diffused pathologic condition affecting the worldwide population. Risk factors have been identified in both general features (smoking, diabetes, economic status) and local tooth-related factors (caries, periodontitis). In this retrospective study, we examined the data of 366 patients with a large number of remaining teeth (≥25) undergoing maintenance therapy in order to identify specific risk factors for tooth loss. The number of remaining teeth, number of non-vital teeth, and number of occlusal units were investigated for their correlation with tooth loss. The mean follow-up of patients was 9.2 years (range 5 to 14). Statistically significant risk factors for tooth loss were identified as number of remaining teeth at baseline (p = 0.05), number of occlusal units (p = 0.03), and number of non-vital teeth in posterior regions (p < 0.001). Multiple logistic regression showed that the number of occlusal units and number of non-vital teeth in the posterior regions were significantly associated with a greater risk of tooth loss (odds ratio 1.88 and 3.17, respectively). These results confirm that not only the number of remaining teeth, but also their vital or non-vital status and the distribution between the anterior and posterior regions influence the long-term survival.

scholarly journals Decellularized tracheal scaffolds in tracheal reconstruction: An evaluation of different techniques

2021 ◽  
Vol 19 ◽  
pp. 228080002110649
Author(s):  
Chenyang Lei ◽  
Sheng Mei ◽  
Chun Zhou ◽  
Chen Xia
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Structure And Function ◽  
Future Research ◽  
Natural Structure ◽  
Tracheal Reconstruction ◽  
Good Biocompatibility ◽  
And Function ◽  
The Impact

In humans, the trachea is a conduit for ventilation connecting the throat and lungs. However, certain congenital or acquired diseases may cause long-term tracheal defects that require replacement. Tissue engineering is considered a promising method to reconstruct long-segment tracheal lesions and restore the structure and function of the trachea. Decellularization technology retains the natural structure of the trachea, has good biocompatibility and mechanical properties, and is currently a hotspot in tissue engineering studies. This article lists various recent representative protocols for the generation of decellularized tracheal scaffolds (DTSs), as well as their validity and limitations. Based on the advancements in decellularization methods, we discussed the impact and importance of mechanical properties, revascularization, recellularization, and biocompatibility in the production and implantation of DTS. This review provides a basis for future research on DTS and its application in clinical therapy.

scholarly journals Surgical and Surgeon-Related Factors Related to Long-Term Survival in Esophageal Cancer: A Review

2019 ◽  
Vol 27 (3) ◽  
pp. 718-723 ◽  
Author(s):  
Sheraz R. Markar ◽  
Jesper Lagergren
Keyword(s):  
Esophageal Cancer ◽  
Prognostic Factors ◽  
Critical Role ◽  
Survival Rates ◽  
Surgical Approaches ◽  
Related Factors ◽  
Term Survival ◽  
Long Term Survival ◽  
The Individual

Abstract Esophagectomy is the mainstay of curative treatment for most patients with a diagnosis of esophageal cancer. This procedure needs to be optimized to secure the best possible chance of cure for these patients. Research comparing various surgical approaches of esophagectomy generally has failed to identify any major differences in long-term prognosis. Comparisons between minimally invasive and open esophagectomy, transthoracic and transhiatal approaches, radical and moderate lymphadenectomy, and high and moderate hospital volume generally have provided only moderate alterations in long-term survival rates after adjustment for established prognostic factors. In contrast, some direct surgeon-related factors, which remain independent of known prognostic factors, seem to influence the long-term survival more strongly in esophageal cancer. Annual surgeon volume is strongly prognostic, and recent studies have suggested the existence of long surgeon proficiency gain curves for achievement of stable 5-year survival rates and possibly also a prognostic influence of surgeon age and weekday of surgery. The available literature indicates a potentially more critical role of the individual surgeon’s skills than that of variations in surgical approach for optimizing the long-term survival after esophagectomy for esophageal cancer. This finding points to the value of paying more attention to how the skills of the individual esophageal cancer surgeon can best be achieved and maintained. Careful selection and evaluation of the most suitable candidates, appropriate and structured training programs, and regular peer-review assessments of experienced surgeons may be helpful in this respect.

scholarly journals Determinants of two-year mortality among HIV positive patients with Cryptococcal meningitis initiating standard antifungal treatment with or without adjunctive dexamethasone in Uganda

2020 ◽  
Vol 14 (11) ◽  
pp. e0008823
Author(s):  
Jonathan Kitonsa ◽  
Rebecca Nsubuga ◽  
Yunia Mayanja ◽  
Julius Kiwanuka ◽  
Yofesi Nikweri ◽  
...  
Keyword(s):  
Cryptococcal Meningitis ◽  
Cox Regression ◽  
Sub Saharan Africa ◽  
Term Survival ◽  
Long Term Survival ◽  
Factors Affecting ◽  
Short Term Mortality ◽  
Sub Saharan ◽  
Therapy Strategies

Globally, early initiation of antiretroviral therapy for HIV led to a reduction in the estimated mortality from cryptococcal meningitis (CCM) from 624,700 in 2009 to 181,100 in 2014. However, CCM remains one of the leading causes of mortality among HIV infected patients especially in sub-Saharan Africa where 75% of the deaths occur. Most of the studies evaluating mortality have reported short-term mortality (at or before 10 weeks of therapy). We determined mortality and associated factors among patients treated for CCM in the CryptoDex trial (ISRCTN59144167) in Uganda, and the effect of dexamethasone adjunctive therapy on mortality at two years. We conducted a retrospective cohort study between May 2017 and July 2017 to determine the long term survival (up to 2 years post-randomization) of all patients who had been enrolled into the CryptoDex trial in Uganda. The CryptoDex trial recruited between April 2013 and February 2015. We estimated mortality rates and determined factors affecting mortality at two years using Cox regression. The study followed up 211 participants, 127 (60.2%) of whom were male. Sixteen participants (7.58%) were diagnosed with HIV at the same admission when CCM was diagnosed. By two years following randomization 127 (60%) participants had died, a mortality rate of 67 deaths per 100 person-years. Mortality was associated with Glasgow coma score (GCS) below 15 (adjusted Hazard ratio (aHR) 1.77, 95% CI: 1.02–2.44), p = 0.040; weight (aHR 0.97, per 1 Kg increase; 95% CI: 0.94–0.99), p = 0.003; and presence of convulsions (aHR 2.31, 95% CI: 1.32–4.04), p = 0.004, while dexamethasone use and fungal burden had no effect. Long-term mortality in CCM patients remains high even among patients receiving recommended therapy. Strategies to improve long-term survival in CCM patients are urgently needed, especially targeting those with reduced GCS, low weight, and convulsions.

Synthesis of Bioactive Hydroxyapatite-Zirconia Toughened Composites for Bone Replacement

2008 ◽  
Vol 57 ◽  
pp. 31-36 ◽  
Author(s):  
Beatrice Cioni ◽  
Andrea Lazzeri ◽  
Giuseppe Gallone ◽  
Giovanni Levita
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Antibacterial Properties ◽  
Inorganic Component ◽  
Term Survival ◽  
Bone Replacement ◽  
Mineral Phases ◽  
Hard Tissues

Hydroxyapatite (HAp) is a major inorganic component of human hard tissues, such as bones and teeth, and its content determines their microstructures and physical properties. Artificial HAp shows strong biocompatibility and bioactivity and thus it has found broad applications in tissue engineering for replacing damaged hard tissues. The artificial HAp, however, suffers from its intrinsic low mechanical properties, so to meet mechanical requirements, HAp can be incorporated with stiff mineral phases (mullite, zirconia, alumina). The performance and long-term survival of these biomedical devices are also dependent on the presence of bacteria surrounding the implants. In order to reduce the incidence of implant-associated infections, several treatments have been proposed, e.g. introduction of silver or fluoride in the HAp. The objective of this research is the sintering of composites based on calcium phosphate, mainly HAp supported on zirconia, for bone replacement with better microstructural features. In fact the use of zirconia can enhance the mechanical properties of bioceramics. Moreover the introduction of small amounts of silver, which should improve the antibacterial properties, will be taken into consideration since it is expected also to further toughen the whole structure.

scholarly journals Tracheal replacement

2018 ◽  
Vol 51 (2) ◽  
pp. 1702211 ◽  
Author(s):  
Harry Etienne ◽  
Dominique Fabre ◽  
Abel Gomez Caro ◽  
Frederic Kolb ◽  
Sacha Mussot ◽  
...  
Keyword(s):  
Clinical Results ◽  
Research Field ◽  
Long Term Results ◽  
Malignant Tumours ◽  
Autologous Tissue ◽  
Tracheal Reconstruction ◽  
Working Solution ◽  
Tracheal Tissue ◽  
Tracheal Replacement

Tracheal reconstruction is one of the greatest challenges in thoracic surgery when direct end-to-end anastomosis is impossible or after this procedure has failed. The main indications for tracheal reconstruction include malignant tumours (squamous cell carcinoma, adenoid cystic carcinoma), tracheoesophageal fistula, trauma, unsuccessful surgical results for benign diseases and congenital stenosis. Tracheal substitutes can be classified into five types: 1) synthetic prosthesis; 2) allografts; 3) tracheal transplantation; 4) tissue engineering; and 5) autologous tissue composite. The ideal tracheal substitute is still unclear, but some techniques have shown promising clinical results. This article reviews the advantages and limitations of each technique used over the past few decades in clinical practice. The main limitation seems to be the capacity for tracheal tissue regeneration. The physiopathology behind this has yet to be fully understood. Research on stem cells sparked much interest and was thought to be a revolutionary technique; however, the poor long-term results of this approach highlight that there is a long way to go in this research field. Currently, an autologous tissue composite, with or without a tracheal allograft, is the only long-term working solution for every aetiology, despite its technical complexity and setbacks.

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