Dexamethasone loaded bilayered 3D tubular scaffold reduces restenosis at the anastomotic site of tracheal replacement: in vitro and in vivo assessments

Nanoscale ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 4846-4858 ◽  
Author(s):  
Sang Jin Lee ◽  
Ji Suk Choi ◽  
Min Rye Eom ◽  
Ha Hyeon Jo ◽  
Il Keun Kwon ◽  
...  

Despite recent developments in the tracheal tissue engineering field, the creation of a patient specific substitute possessing both appropriate mechanical and biointerfacial properties remains challenging.

2021 ◽  
Vol 12 ◽  
pp. 204173142110037
Author(s):  
Aala’a Emara ◽  
Rishma Shah

The craniofacial region consists of several different tissue types. These tissues are quite commonly affected by traumatic/pathologic tissue loss which has so far been traditionally treated by grafting procedures. With the complications and drawbacks of grafting procedures, the emerging field of regenerative medicine has proved potential. Tissue engineering advancements and the application in the craniofacial region is quickly gaining momentum although most research is still at early in vitro/in vivo stages. We aim to provide an overview on where research stands now in tissue engineering of craniofacial tissue; namely bone, cartilage muscle, skin, periodontal ligament, and mucosa. Abstracts and full-text English articles discussing techniques used for tissue engineering/regeneration of these tissue types were summarized in this article. The future perspectives and how current technological advancements and different material applications are enhancing tissue engineering procedures are also highlighted. Clinically, patients with craniofacial defects need hybrid reconstruction techniques to overcome the complexity of these defects. Cost-effectiveness and cost-efficiency are also required in such defects. The results of the studies covered in this review confirm the potential of craniofacial tissue engineering strategies as an alternative to avoid the problems of currently employed techniques. Furthermore, 3D printing advances may allow for fabrication of patient-specific tissue engineered constructs which should improve post-operative esthetic results of reconstruction. There are on the other hand still many challenges that clearly require further research in order to catch up with engineering of other parts of the human body.


2016 ◽  
Vol 10 (1) ◽  
pp. 900-919 ◽  
Author(s):  
Shima Salmasi ◽  
Leila Nayyer ◽  
Alexander M. Seifalian ◽  
Gordon W. Blunn

BACKGROUNDStatistical reports show that every year around the world approximately 15 million bone fractures occur; of which up to 10% fail to heal completely and hence lead to complications of non-union healing. In the past, autografts or allografts were used as the “gold standard” of treating such defects. However, due to various limitations and risks associated with these sources of bone grafts, other avenues have been extensively investigated through which bone tissue engineering; in particular engineering of synthetic bone graft substitutes, has been recognised as a promising alternative to the traditional methods.METHODSA selective literature search was performed.RESULTSBone tissue engineering offers unlimited supply, eliminated risk of disease transmission and relatively low cost. It could also lead to patient specific design and manufacture of implants, prosthesis and bone related devices. A potentially promising building block for a suitable scaffold is synthetic nanohydroxyapatite incorporated into synthetic polymers. Incorporation of nanohydroxyapatite into synthetic polymers has shown promising bioactivity, osteoconductivity, mechanical properties and degradation profile compared to other techniques previously considered.CONCLUSIONScientific research, through extensive physiochemical characterisation,in vitroandin vivoassessment has brought together the optimum characteristics of nanohydroxyapatite and various types of synthetic polymers in order to develop nanocomposites of suitable nature for bone tissue engineering. The aim of the present article is to review and update various aspects involved in incorporation of synthetic nanohydroxyapatite into synthetic polymers, in terms of their potentials to promote bone growth and regenerationin vitro,in vivoand consequently in clinical applications.


2021 ◽  
Author(s):  
Imran Sheikh

Resection with primary anastomosis can only repair up to 50% of the adult trachea and up to 30% of the pediatric trachea when damaged. There is a strong clinical need for long-segment tracheal replacements. The goal of this research was to create a seamless, scaffold-free cartilage cylinder for tracheal tissue engineering in vitro. Primary bovine articular chondrocytes were seeded onto tracheal moulds for roller bottle culture and the effect of rotational speed, growth factor supplementation, and chondrocyte layering were investigated. After the 4-week culture period, samples were evaluated biochemically, histologically, and biomechanically. The results indicated that rotation was necessary for full tissue coverage, with slower rotational speeds generating thicker tissue with an improved extracellular matrix, IGF-1 supplementation generating thicker tissue rich in glycosaminoglycans with inferior mechanical properties, and chondrocyte layering producing thinner tissue with increased mechanical properties. Overall, scaffold-free tissue engineering can generate seamless cylindrical cartilage constructs using roller bottle culture for future applications in long-segment tracheal replacement.


Author(s):  
Jessica Nulty ◽  
Ross Burdis ◽  
Daniel J. Kelly

Bone tissue engineering (TE) has the potential to transform the treatment of challenging musculoskeletal pathologies. To date, clinical translation of many traditional TE strategies has been impaired by poor vascularisation of the implant. Addressing such challenges has motivated research into developmentally inspired TE strategies, whereby implants mimicking earlier stages of a tissue’s development are engineered in vitro and then implanted in vivo to fully mature into the adult tissue. The goal of this study was to engineer in vitro tissues mimicking the immediate developmental precursor to long bones, specifically a vascularised hypertrophic cartilage template, and to then assess the capacity of such a construct to support endochondral bone formation in vivo. To this end, we first developed a method for the generation of large numbers of hypertrophic cartilage microtissues using a microwell system, and encapsulated these microtissues into a fibrin-based hydrogel capable of supporting vasculogenesis by human umbilical vein endothelial cells (HUVECs). The microwells supported the formation of bone marrow derived stem/stromal cell (BMSC) aggregates and their differentiation toward a hypertrophic cartilage phenotype over 5 weeks of cultivation, as evident by the development of a matrix rich in sulphated glycosaminoglycan (sGAG), collagen types I, II, and X, and calcium. Prevascularisation of these microtissues, undertaken in vitro 1 week prior to implantation, enhanced their capacity to mineralise, with significantly higher levels of mineralised tissue observed within such implants after 4 weeks in vivo within an ectopic murine model for bone formation. It is also possible to integrate such microtissues into 3D bioprinting systems, thereby enabling the bioprinting of scaled-up, patient-specific prevascularised implants. Taken together, these results demonstrate the development of an effective strategy for prevascularising a tissue engineered construct comprised of multiple individual microtissue “building blocks,” which could potentially be used in the treatment of challenging bone defects.


Author(s):  
Alan Isaac Valderrama-Treviño ◽  
Karen Uriarte-Ruiz ◽  
Juan José Granados Romero ◽  
Andrés Eliú Castell Rodriguez ◽  
Alfredo Maciel-Cerda ◽  
...  

Tissue engineering has been widely used for its great variety of functions. It has been seen as a solution to satisfy the need for vascular substitutes like small diameter vessels, veins, and nerves. One of the most used methods is electrospinning, due to the fact that it allows the use of various polymers, sizes, mandrels and it can adjust the conditions to create personalized scaffolds. For the creation of scaffolds is fundamental to understand the advantages and disadvantages of each polymer, of this, will depend the biodegradability, biocompatibility, porosity, cellular adhesion, and cell proliferation as it is essential to mimic the extracellular matrix and provide structural support for the cells. The aim of this review was to investigate which materials are being used for the creation of tubular scaffolds by electrospinning. Here we selected only in vivo evaluation to demonstrate remodeling of the grafts into native-like tissues, in vitro evaluations had been excluded from this review. We analyze the conditions like speed, distance and voltage and the modifications like growth factors and combinations of natural and synthetic polymers that allow the authors to have a functional scaffold that will suit its purpose.


2021 ◽  
Author(s):  
Imran Sheikh

Resection with primary anastomosis can only repair up to 50% of the adult trachea and up to 30% of the pediatric trachea when damaged. There is a strong clinical need for long-segment tracheal replacements. The goal of this research was to create a seamless, scaffold-free cartilage cylinder for tracheal tissue engineering in vitro. Primary bovine articular chondrocytes were seeded onto tracheal moulds for roller bottle culture and the effect of rotational speed, growth factor supplementation, and chondrocyte layering were investigated. After the 4-week culture period, samples were evaluated biochemically, histologically, and biomechanically. The results indicated that rotation was necessary for full tissue coverage, with slower rotational speeds generating thicker tissue with an improved extracellular matrix, IGF-1 supplementation generating thicker tissue rich in glycosaminoglycans with inferior mechanical properties, and chondrocyte layering producing thinner tissue with increased mechanical properties. Overall, scaffold-free tissue engineering can generate seamless cylindrical cartilage constructs using roller bottle culture for future applications in long-segment tracheal replacement.


2020 ◽  
Vol 48 (3) ◽  
pp. 755-764
Author(s):  
Benjamin B. Rothrauff ◽  
Rocky S. Tuan

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.


2004 ◽  
Vol 83 (02) ◽  
Author(s):  
A Haisch ◽  
A Evers ◽  
K Jöhrens-Leder ◽  
S Jovanovic ◽  
B Sedlmaier ◽  
...  
Keyword(s):  

2020 ◽  
Vol 27 (10) ◽  
pp. 1634-1646 ◽  
Author(s):  
Huey-Shan Hung ◽  
Shan-hui Hsu

Treatment of cardiovascular disease has achieved great success using artificial implants, particularly synthetic-polymer made grafts. However, thrombus formation and restenosis are the current clinical problems need to be conquered. New biomaterials, modifying the surface of synthetic vascular grafts, have been created to improve long-term patency for the better hemocompatibility. The vascular biomaterials can be fabricated from synthetic or natural polymers for vascular tissue engineering. Stem cells can be seeded by different techniques into tissue-engineered vascular grafts in vitro and implanted in vivo to repair the vascular tissues. To overcome the thrombogenesis and promote the endothelialization effect, vascular biomaterials employing nanotopography are more bio-mimic to the native tissue made and have been engineered by various approaches such as prepared as a simple surface coating on the vascular biomaterials. It has now become an important and interesting field to find novel approaches to better endothelization of vascular biomaterials. In this article, we focus to review the techniques with better potential improving endothelization and summarize for vascular biomaterial application. This review article will enable the development of biomaterials with a high degree of originality, innovative research on novel techniques for surface fabrication for vascular biomaterials application.


2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.


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