Search results for "tissue engineering"
showing 10 items of 370 documents
In situ crosslinkable hyaluronan hydrogels for tissue engineering
2003
We describe the development of an injectable, cell-containing hydrogel that supports cell proliferation and growth to permit in vivo engineering of new tissues. Two thiolated hyaluronan (HA) derivatives were coupled to four alpha,beta-unsaturated ester and amide derivatives of poly(ethylene glycol) (PEG) 3400. The relative chemical reactivity with cysteine decreased in the order PEG-diacrylate (PEGDA)>>PEG-dimethacrylate>PEG-diacrylamide>PEG-dimethacrylamide. The 3-thiopropanoyl hydrazide derivative (HA-DTPH) was more reactive than the 4-thiobutanoyl hydrazide, HA-DTBH. The crosslinking of HA-DTPH with PEGDA in a molar ratio of 2:1 occurred in approximately 9 min, suitable for an in situ cr…
Cycloastragenol as an Exogenous Enhancer of Chondrogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells. A Morphological Study
2020
Stem cell therapy and tissue engineering represent a promising approach for cartilage regeneration. However, they present limits in terms of mechanical properties and premature de-differentiation of engineered cartilage. Cycloastragenol (CAG), a triterpenoid saponin compound and a hydrolysis product of the main ingredient in Astragalus membranaceous, has been explored for cartilage regeneration. The aim of this study was to investigate CAG&rsquo
Regeneration of lingual musculature in rats using myoblasts over porcine bladder acellular matrix
2020
To use tissue engineering muscle repair (TEMR) for regenerating the lingual musculature of hemiglossectomized rats using neonatal myoblasts (NM) on porcine acellular urinary bladder matrix (AUBM).The study used 80 male rats. A volumetric muscle loss (VML) injury was created on the left side of the tongue. The rats were randomized into four groups: Group 1 (AUBM + myoblasts); Group 2 (AUBM); Group 3 (myoblasts); and Group 4 (control). NM were obtained from neonatal rats. The animals were weighed on day 0 and just before euthanasia. Five rats in each group were euthanized at days 2, 14, 28, and 42; the tongues were prepared for morphometric analysis, postoperative left hemitongue weight, and …
Developing cellular systems in vitro to simulate regeneration.
2014
In the past two decades, cellular systems in vitro have progressed from predominantly monocellular testing models to study the toxic effects of new biomaterials for replacement to relevant human coculture systems for regeneration, often a combination of progenitor cells with novel biomaterials. Considerable progress has been made in understanding cellular cross talk and its contribution to the vascularization of bone. Future challenges include using the established physiological, that is, nonactivated, stem cell niches as a platform to develop coculture models, which will enable the true in situ regenerative niche to be investigated. Hypoxia and a changing inflammatory status are factors th…
Crosstalk between osteoblasts and endothelial cells co-cultured on a polycaprolactone-starch scaffold and the in vitro development of vascularization.
2009
The reconstruction of bone defects based on cell-seeded constructs requires a functional microvasculature that meets the metabolic demands of the engineered tissue. Therefore, strategies that augment neovascularization need to be identified. We propose an in vitro strategy consisting of the simultaneous culture of osteoblasts and endothelial cells on a starch-based scaffold for the formation of pre-vascular structures, with the final aim of accelerating the establishment of a vascular bed in the implanted construct. Human dermal microvascular endothelial cells (HDMECs) were co-cultured with human osteoblasts (hOBs) on a 3D starch-based scaffold and after 21 days of culture HDMEC aligned and…
Engineered microenvironments for synergistic VEGF - Integrin signalling during vascularization
2017
We have engineered polymer-based microenvironments that promote vasculogenesis both in vitro and in vivo through synergistic integrin-growth factor receptor signalling. Poly(ethyl acrylate) (PEA) triggers spontaneous organization of fibronectin (FN) into nanonetworks which provide availability of critical binding domains. Importantly, the growth factor binding (FNIII12-14) and integrin binding (FNIII9-10) regions are simultaneously available on FN fibrils assembled on PEA. This material platform promotes synergistic integrin/VEGF signalling which is highly effective for vascularization events in vitro with low concentrations of VEGF. VEGF specifically binds to FN fibrils on PEA compared to …
Human nasoseptal chondrocytes maintain their differentiated phenotype on PLLA scaffolds produced by thermally induced phase separation and supplement…
2018
Damage of hyaline cartilage such as nasoseptal cartilage requires proper reconstruction, which remains challenging due to its low intrinsic repair capacity. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. Despite so far mostly tested for bone tissue engineering, bioactive glass (BG) could exert stimulatory effects on chondrogenesis. The aim of this work was to produce and characterize composite porous poly(L-lactide) (PLLA)/1393BG scaffolds via thermally induced phase separation (TIPS) technique and assess their effects on chondrogenesis of nasoseptal chondrocytes. The PLLA scaffolds without or…
Decellularized tracheal prelamination implant: A proposed bilateral double organ technique
2021
Introduction In tracheal replacement transplantation, prelamination is a critical stage. Nowadays, the most widely used prelamination technique is the prethoracic fascia flap with lateral thoracic artery. We propose a flap based on the internal thoracic artery, which allows a relatively non-aggressive double organ implant, and we have tested its efficacy in decellularized tracheas. Material and methods Tracheas of albino New Zealand rabbits were decellularized following a protocol that uses detergents and cryogenization, sterilized with 1kGy gamma radiation and tutorized with a stent. Bilateral pedicled flaps made of pectoral fascia and a muscular component were harvested through a longitud…
Use of engineered bone for sinus augmentation.
2008
Tissue-engineered bone grafts represent an appealing alternative for maxillary sinus augmentation because they eliminate the significant drawbacks associated with extra- and intraoral bone-harvesting procedures. In the present case series, we document the outcomes of sinus augmentation surgery using tissue-engineered bone grafts.Three patients requiring bilateral sinus augmentation received tissue-engineered bone grafts combined with xenograft prior to implant placement. Implants were placed and loaded 6 and 12 months postaugmentation, respectively. Radiographs were taken and clinical examinations were performed preoperatively and at 4, 6, 12, and 18 months postaugmentation. Biopsies were o…
Degradable poly(amidoamine) hydrogels as scaffolds for in vitro culturing of peripheral nervous system cells.
2012
This paper reports on the synthesis and physico-chemical, mechanical, and biological characterization of two sets of poly(amidoamine) (PAA) hydrogels with potential as scaffolds for in vivo peripheral nerve regeneration. They are obtained by polyaddition of piperazine with N,N′-methylenebis(acrylamide) or 1,4-bis(acryloyl)piperazine with 1,2-diaminoethane as cross-linking agent and exhibit a combination of relevant properties, such as mechanical strength, biocompatibility, biodegradability, ability to induce adhesion and proliferation of Schwann cells (SCs) preserving their viability. Moreover, the most promising hydrogels, that is those deriving from 1,4-bis(acryloyl)piperazine, allow the …