Electrospun triple‐layered PLLA/gelatin. PRGF/PLLA scaffold induces fibroblast migration

2019 ◽  
Vol 120 (7) ◽  
pp. 11441-11453 ◽  
Author(s):  
Mehrdad Piran ◽  
Mahdi Shiri ◽  
Mahsa Soufi Zomorrod ◽  
Elaheh Esmaeili ◽  
Mina Soufi Zomorrod ◽  
...  
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.


2021 ◽  
pp. 039139882110255
Author(s):  
Sara Anajafi ◽  
Azam Ranjbar ◽  
Monireh Torabi-Rahvar ◽  
Naser Ahmadbeigi

Background: Sufficient blood vessel formation in bioengineered tissues is essential in order to keep the viability of the organs. Impaired development of blood vasculatures results in failure of the implanted tissue. The cellular source which is seeded in the scaffold is one of the crucial factors involved in tissue engineering methods. Materials and methods: Considering the notable competence of Bone Marrow derived Mesenchymal Stem Cell aggregates for tissue engineering purposes, in this study BM-aggregates and expanded BM-MSCs were applied without any inductive agent or co-cultured cells, in order to investigate their own angiogenesis potency in vivo. BM-aggregates and BM-MSC were seeded in Poly-L Lactic acid (PLLA) scaffold and implanted in the peritoneal cavity of mice. Result: Immunohistochemistry results indicated that there was a significant difference ( p < 0.050) in CD31+ cells between PLLA scaffolds contained cultured BM-MSC; PLLA scaffolds contained BM-aggregates and empty PLLA. According to morphological evidence, obvious connections with recipient vasculature and acceptable integration with surroundings were established in MSC and aggregate-seeded scaffolds. Conclusion: Our findings revealed cultured BM-MSC and BM-aggregates, capacity in order to develop numerous connections between PLLA scaffold and recipient’s vasculature which is crucial to the survival of tissues, and considerable tendency to develop constructs containing CD31+ endothelial cells which can contribute in vessel’s tube formation.


2021 ◽  
pp. 1-13
Author(s):  
Eduardo Anitua ◽  
Victoria Muñoz ◽  
Libe Aspe ◽  
Roberto Tierno ◽  
Adrian García-Salvador ◽  
...  

<b><i>Introduction:</i></b> Skin injury and wound healing is an inevitable event during lifetime. However, several complications may hamper the regeneration of the cutaneous tissue and lead to a chronic profile that prolongs patient recovery. Platelet-rich plasma is rising as an effective and safe alternative to the management of wounds. However, this technology presents some limitations such as the need for repeated blood extractions and health-care interventions. <b><i>Objective:</i></b> The aim of this study was to assess the use of an endogenous and storable topical serum (ES) derived from plasma rich in growth factors promoting wound healing, and to obtain preliminary data regarding its clinical and experimental effect over ulcerated skin models and patient care. <b><i>Methods:</i></b> Human dermal fibroblast and 3D organotypic ulcerated skin models were used to assess ES over the main mechanisms of wound healing including cell migration, edge contraction, collagen synthesis, tissue damage, extracellular matrix remodeling, cell death, metabolic activity, and histomorphometry analysis. Additionally, 4 patients suffering from skin wounds were treated and clinically assessed. <b><i>Results:</i></b> ES promoted dermal fibroblast migration, wound edge contraction, and collagen synthesis. When topically applied, ES increased collagen and elastin deposition and reduced tissue damage. The interstitial edema, structural integrity, and cell activity were also maintained, and apoptotic levels were reduced. Patients suffering from hard-to-heal wounds of different etiologies were treated with ES, and the ulcers healed completely within few weeks with no reported adverse events. <b><i>Conclusion:</i></b> This preliminary study suggests that ES might promote cutaneous wound healing and may be useful for accelerating the re-epithelization of skin ulcers.


2009 ◽  
Vol 297 (1) ◽  
pp. C133-C139 ◽  
Author(s):  
Shirley C. Chen ◽  
Ranvikram S. Khanna ◽  
Darrell C. Bessette ◽  
Lionel A. Samayawardhena ◽  
Catherine J. Pallen

Protein tyrosine phosphatase-α (PTPα) is a widely expressed receptor-type phosphatase that functions in multiple signaling systems. The actions of PTPα can be regulated by its phosphorylation on serine and tyrosine residues, although little is known about the conditions that promote PTPα phosphorylation. In this study, we tested the ability of several extracellular factors to stimulate PTPα tyrosine phosphorylation. The growth factors IGF-I and acidic FGF induced the highest increase in PTPα phosphorylation at tyrosine 789, followed by PMA and lysophosphatidic acid, while EGF had little effect. Further investigation of IGF-I-induced PTPα tyrosine phosphorylation demonstrated that this occurs through a novel Src family kinase-independent mechanism that does not require focal adhesion kinase, phosphatidylinositol 3-kinase, or MEK. We also show that PTPα physically interacts with the IGF-I receptor. In contrast to IGF-I-induced PTPα phosphorylation, this association does not require IGF-I. The interaction of PTPα and the IGF-I receptor is independent of PTPα catalytic activity, and expression of exogenous PTPα does not promote IGF-I receptor tyrosine dephosphorylation, indicating that PTPα does not act as an IGF-I receptor phosphatase. However, PTPα mediates IGF-I signaling, because IGF-I-stimulated fibroblast migration was reduced by ∼50% in cells lacking PTPα or in cells with mutant PTPα lacking the tyrosine 789 phosphorylation site. Our results suggest that PTPα tyrosine phosphorylation can occur in response to diverse stimuli and can be mediated by various tyrosine kinases. In the case of IGF-I, we propose that IGF-I-induced tyrosine 789 phosphorylation of PTPα, possibly catalyzed by the PTPα-associated IGF-I receptor tyrosine kinase, is required for efficient cell migration in response to this growth factor.


2001 ◽  
Vol 270 (2) ◽  
pp. 214-222 ◽  
Author(s):  
Matthew L. Edin ◽  
Alan K. Howe ◽  
Rudy L. Juliano

2016 ◽  
Vol 23 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Weizhong Yang ◽  
Yong Yi ◽  
Yuan Ma ◽  
Li Zhang ◽  
Jianwen Gu ◽  
...  

AbstractNano biphasic calcium phosphate (BCP) particles were synthesized using the sol-gel method. As-prepared BCP particles were combined with poly-L-lactide (PLLA) to fabricate nano-BCP/PLLA composite scaffold through a series of processing steps containing solvent self-diffusion, hot-pressing, and particulate leaching. The composite had a suitable porous structure for bone tissue engineering scaffold. In comparison, micro-BCP/PLLA scaffold was studied as well. Nano-BCP particles were distributed homogeneously in the PLLA matrix, and much more tiny crystallites exposed on the surface of the pore wall. Due to the finer inorganic particle distribution in the PLLA phase and the larger area of the bioactive phase exposed in the pore wall surface, nano-BCP/PLLA scaffold had enhanced compressive strength, good bioactivity, and superior cell viability. A nonstoichiometric apatite layer could be rapidly formed on the surface of nano- BCP/PLLA when soaked in simulated body fluid. The MG-63 cell viability of nano-BCP/PLLA scaffold is significantly higher than that of micro-BCP/PLLA scaffold. Therefore, nano-BCP/PLLA composite may be a suitable alternative for bone tissue engineering scaffold.


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