scholarly journals Microfluidic 3D printing polyhydroxyalkanoates-based bionic skin for wound healing

2021 ◽  
Author(s):  
Wentai Guo ◽  
Xiaocheng Wang ◽  
Chaoyu Yang ◽  
Rongkang Huang ◽  
Hui Wang ◽  
...  

Abstract Biomimetic scaffolds with extracellular matrix (ECM)-mimicking structure have been widely investigated in wound healing applications, while insufficient mechanical strength and limited biological activity remain major challenges. Here, we present a microfluidic 3D printing biomimetic polyhydroxyalkanoates-based scaffold with excellent mechanical properties and hierarchical porous structures for enhanced wound healing. This scaffold is composed of poly(3-hydroxybutyrate-4-hydroxybutyrate) (P34HB) and polycaprolactone (PCL), endowing it with excellent tensile strength (2.99 MPa) and degradability (80% of weight loss within 7 days). The ECM-mimicking hierarchical porous structure allows bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cells (HUVECs) to proliferate and adhere on the scaffolds. Besides, anisotropic composite scaffolds loaded with BMSCs and HUVECs can significantly promote re-epithelization, collagen deposition and capillary formation in rat wound defects, indicating their satisfactory in vivo tissue regenerative activity. These results indicate the feasibility of polyhydroxyalkanoates-based biomimetic scaffolds for skin repair and regeneration, which also provide a promising therapeutic strategy in diverse tissue engineering applications.

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yuhua Sun ◽  
Bingjun Zhang ◽  
Dong Zhai ◽  
Chengtie Wu

AbstractExosomes have attracted increasing attention in tissue regeneration and repair due to their roles in intercellular communication. Developing a customized delivery system is key to exosome-based regenerative therapeutics. Bioceramics play an important role in the immunomodulation of macrophages. Here, three-dimensional (3D) printing was applied to construct porous scaffolds with β-tricalcium phosphate (β-TCP) bioceramic-induced macrophage exosomes (BC-Exos). The three-dimensional-printed BC-Exo scaffolds, exhibiting a predefined structure and persistent release of exosomes, displayed distinct immunomodulatory effects and improved osteogenesis/angiogenesis. The BC-Exos in the printed scaffolds modulated macrophage polarization and the expression of chemokines for the recruitment of bone marrow mesenchymal stem cells (BMSCs) and endothelial cells. Scaffolds with BC-Exos from macrophages with a mixed phenotype significantly enhanced the osteogenic differentiation and immunosuppression of BMSCs and improved the angiogenic activity of human umbilical vein endothelial cells in vitro. For the potential mechanism, β-TCP bioceramics have an important effect on the immunomodulation of macrophages by regulating gene expression, increasing exosome production, and altering exosomal miRNA cargos, thereby affecting the paracrine effects of BC-Exos on immunomodulation and osteogenesis/angiogenesis. This study suggests that 3D printing of bioceramic-induced macrophage exosomes may be a useful strategy for tissue engineering and regenerative medicine.


Author(s):  
D.J.P. Ferguson ◽  
A.R. Berendt ◽  
J. Tansey ◽  
K. Marsh ◽  
C.I. Newbold

In human malaria, the most serious clinical manifestation is cerebral malaria (CM) due to infection with Plasmodium falciparum. The pathology of CM is thought to relate to the fact that red blood cells containing mature forms of the parasite (PRBC) cytoadhere or sequester to post capillary venules of various tissues including the brain. This in vivo phenomenon has been studied in vitro by examining the cytoadherence of PRBCs to various cell types and purified proteins. To date, three Ijiost receptor molecules have been identified; CD36, ICAM-1 and thrombospondin. The specific changes in the PRBC membrane which mediate cytoadherence are less well understood, but they include the sub-membranous deposition of electron-dense material resulting in surface deformations called knobs. Knobs were thought to be essential for cytoadherence, lput recent work has shown that certain knob-negative (K-) lines can cytoadhere. In the present study, we have used electron microscopy to re-examine the interactions between K+ PRBCs and both C32 amelanotic melanoma cells and human umbilical vein endothelial cells (HUVEC).We confirm previous data demonstrating that C32 cells possess numerous microvilli which adhere to the PRBC, mainly via the knobs (Fig. 1). In contrast, the HUVEC were relatively smooth and the PRBCs appeared partially flattened onto the cell surface (Fig. 2). Furthermore, many of the PRBCs exhibited an invagination of the limiting membrane in the attachment zone, often containing a cytoplasmic process from the endothelial cell (Fig. 2).


Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.


2005 ◽  
Vol 289 (4) ◽  
pp. H1669-H1675 ◽  
Author(s):  
John P. Cullen ◽  
Shariq Sayeed ◽  
Ying Jin ◽  
Nicholas G. Theodorakis ◽  
James V. Sitzmann ◽  
...  

The aim of this study was to determine the effect of ethanol (EtOH) on endothelial monocyte chemotactic protein-1 (MCP-1) expression. IL-1β increased the production of MCP-1 by human umbilical vein endothelial cells from undetectable levels to ∼900 pg/ml at 24 h. EtOH dose-dependently inhibited IL-1β-stimulated MCP-1 secretion as determined by ELISA: 25 ± 1%, 35 ± 7%, and 65 ± 5% inhibition for 1, 10, and 100 mM EtOH, respectively, concomitant with inhibition of monocyte adhesion to activated endothelial cells. Similarly, EtOH dose-dependently inhibited IL-1β-stimulated MCP-1 mRNA expression. Experiments with actinomycin D demonstrated that EtOH decreased the stability of MCP-1 mRNA. In addition, EtOH significantly reduced NF-κB and AP-1 binding activity induced by IL-1β and inhibited MCP-1 gene transcription. Binding of 125I-labeled MCP-1 to its receptor (CCR2) on THP-1 human monocytic cells was not affected by EtOH treatment. Modulation of the expression of MCP-1 represents a mechanism whereby EtOH could inhibit atherogenesis by blocking the crucial early step of monocyte adhesion and subsequent recruitment to the subendothelial space. These actions of EtOH may underlie, in part, its cardiovascular protective effects in vivo.


2015 ◽  
Vol 35 (3) ◽  
pp. 875-884 ◽  
Author(s):  
Hongyuan Song ◽  
Dongyan Pan ◽  
Weifeng Sun ◽  
Cao Gu ◽  
Yuelu Zhang ◽  
...  

Background/Aims: Annexin II receptor (AXIIR) is able to mediate Annexin II signal and induce apoptosis, but its role in angiogenesis remains unclear. This study tries to investigate the role of AXIIR in angiogenesis and the plausible molecular mechanism. Methods/Results: RNA interference technology was used to silence AXIIR, and the subsequent effects in vitro and in vivo were evaluated thereafter. Our data indicated that human umbilical vein endothelial cells (HUVECs) expressed AXIIR and knockdown of AXIIR significantly inhibited HUVECs proliferation, adhesion, migration, and tube formation in vitro and suppressed angiogenesis in vivo. Furthermore, AXIIR siRNA induced cell arrest in the S/G2 phase while had no effect on cell apoptosis. We found that these subsequent effects might be via suppressing the expression of matrix metalloproteinase 2and matrix metalloproteinase 9. Conclusion: AXIIR participates in angiogenesis, and may be a potential therapeutic target for angiogenesis related diseases.


2004 ◽  
Vol 382 (3) ◽  
pp. 933-943 ◽  
Author(s):  
Hironobu YAMASHITA ◽  
Akira GOTO ◽  
Tatsuhiko KADOWAKI ◽  
Yasuo KITAGAWA

We have previously shown that the LG4 (laminin G-like) domain of the laminin α4 chain is responsible for the significantly higher affinity of the α4 chain to heparin than found for other α chains [Yamaguchi, Yamashita, Mori, Okazaki, Nomizu, Beck and Kitagawa (2000) J. Biol. Chem. 275, 29458–29465]; four basic residues were identified to be essential for this activity [Yamashita, Beck and Kitagawa (2004) J. Mol. Biol. 335, 1145–1149]. By creating GST (glutathione S-transferase)-fused LG1, LG2, LG4 and LG5 proteins, we found that only LG4 is active for the adhesion of human HT1080 cells, human umbilical vein endothelial cells and Drosophila haemocytes Kc167 with a half-saturating concentration of 20 μg/ml. Adhesion was counteracted by treatment of the cells with heparin, heparan sulphate and heparitinase I. Upon mutating the four basic residues essential for heparin binding within LG4, the adhesion activity was abolished. Pull-down experiments using glutathione beads/GST-fusion proteins indicate a direct interaction of LG4 with syndecan-4, which might be the major receptor for cell adhesion. Neither the release of glypican-1 by treating human cells with phosphatidylinositol-specific phospholipase C nor targeted knockdown of dally or dally-like protein impaired the cell-adhesion activity. As the LG4–LG5 domain of the α4 chain is cleaved in vivo from the main body of laminin-8 (α4β1γ1), we suggest that the heparan sulphate proteoglycan-binding activity of LG4 is significant in modulating the signalling of Wnt, Decapentaplegic and fibroblast growth factors.


Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 383
Author(s):  
Jianlin Zhu ◽  
Lu Wang ◽  
Fan Liu ◽  
Jinghua Pan ◽  
Zhimeng Yao ◽  
...  

Abnormal angiogenesis is one of the important hallmarks of colorectal cancer as well as other solid tumors. Optimally, anti-angiogenesis therapy could restrain malignant angiogenesis to control tumor expansion. PELP1 is as a scaffolding oncogenic protein in a variety of cancer types, but its involvement in angiogenesis is unknown. In this study, PELP1 was found to be abnormally upregulated and highly coincidental with increased MVD in CRC. Further, treatment with conditioned medium (CM) from PELP1 knockdown CRC cells remarkably arrested the function of human umbilical vein endothelial cells (HUVECs) compared to those treated with CM from wildtype cells. Mechanistically, the STAT3/VEGFA axis was found to mediate PELP1-induced angiogenetic phenotypes of HUVECs. Moreover, suppression of PELP1 reduced tumor growth and angiogenesis in vivo accompanied by inactivation of STAT3/VEGFA pathway. Notably, in vivo, PELP1 suppression could enhance the efficacy of chemotherapy, which is caused by the normalization of vessels. Collectively, our findings provide a preclinical proof of concept that targeting PELP1 to decrease STAT3/VEGFA-mediated angiogenesis and improve responses to chemotherapy due to normalization of vessels. Given the newly defined contribution to angiogenesis of PELP1, targeting PELP1 may be a potentially ideal therapeutic strategy for CRC as well as other solid tumors.


Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2660-2669 ◽  
Author(s):  
Guoxin Wu ◽  
David W. Essex ◽  
Frank J. Meloni ◽  
Toshiro Takafuta ◽  
Kingo Fujimura ◽  
...  

The platelet glycoprotein Ib (GpIb) complex is composed of four polypeptides: the disulfide-linked GpIbα and GpIbβ and the noncovalently associated GpIX and GpV. GpIbα contains binding sites for von Willebrand factor and for thrombin and mediates platelet adhesion to the subendothelium under conditions of high shear stress. We have previously shown the presence of GpIbα and GpIbβ mRNA and protein in cultured human umbilical vein endothelial cells (HUVECs) as well as the presence of GpIbα mRNA and protein in tonsillar endothelium. We, therefore, probed ECs for the presence of the other components of the GpIb/IX/V complex. We have identified the presence of GpIX and GpV mRNA in cultured HUVEC monolayers. The sequence of HUVEC GpIX cDNA was identical to the previously published human erythroleukemia (HEL) cell GpIX cDNA sequence. Two species of GpV mRNA, one of 3 kb and one of 4.4 kb, were found in HUVECs, whereas HEL cells displayed only the 4.4-kb species and the megakaryocytic cell line CHRF-288 contained only the 3-kb species. We previously showed that EC GpIbα protein is identical in molecular weight to platelet GpIbα. HUVEC GpIbβ, in contrast to its platelet counterpart, has a molecular weight of 50 kD and forms a correspondingly larger disulfide-bonded complex with EC GpIbα. The molecular weights of GpIX and GpV were 22 and 88 kD, respectively, identical to the corresponding platelet polypeptides. Furthermore, we have identified all four components of the complex in tonsillar vessels. Using flow cytometry, we have established that all four polypeptides of the GpIb/IX/V complex are expressed on the surface membranes of cultured HUVECs and adult aortic ECs. Furthermore, using two-color fluorescence, we have shown that all ECs expressing GpIbα also express GpIX and GpV on their surface. The ratio of GpIbα:GpIX:GpV is 1:1:0.5, which is identical to the ratio present in platelets. None of the polypeptides of the GpIb complex could be identified on the surface of human smooth muscle cells or lymphocytes. The presence of all members of the GpIb complex in the EC membrane suggests that this complex may play a role in endothelial function in vivo.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Jonathan Brown ◽  
Qiong Duan ◽  
Gabriel Griffin ◽  
Ronald Paranal ◽  
Steven Bair ◽  
...  

Introduction The BET bromodomain-containing family of proteins (BRD2, BRD3, BRD4) are epigenetic readers that coactivate transcription. Recent evidence indicates that BETs promote carcinogenesis and inflammation in sepsis, while BET bromodomain inhibitors are promising anti-cancer therapies. However, the role of chromatin remodeling in atherosclerosis in general and through BETs in particular remains unknown. Hypothesis We hypothesized that BET bromodomain-containing proteins coactivate proinflammatory responses in the vasculature with functional effects that promote atherogenesis. Methods and Results BET bromodomain inhibition, achieved with the highly selective, small-molecule inhibitor JQ1 significantly reduced early atherosclerosis (12 weeks) in cholesterol-fed, LDL receptor-null mice. In pursuing mechanisms for this effect, we identified BET protein expression in mouse and human endothelial cells (ECs) as well as endothelium from human atherosclerotic plaque. Treating human umbilical vein endothelial cells (HUVECs) with either JQ1 or siRNA to BRD2 or BRD4 potently suppresses TNFα-induced expression of adhesion molecules (SELE, VCAM1) and chemokines (CCL2, CXCL8). In chromatin immunoprecipation studies, TNFα stimulation of ECs recruited BETs to adhesion molecule and chemokine promoters coincident with RNA polymerase II and cyclin T1 localization, without altering NF-κB recruitment. In functional studies, JQ1 suppressed 1) monocyte adhesion to TNFα-activated HUVECs, 2) leukocyte rolling on cremaster post-capillary venules (intravital microscopy); 3) leukocyte transmigration (parallel-plate flow chamber); and 4) monocyte recruitment in thioglycolate-induced peritonitis in vivo . Conclusions BET bromodomain-containing proteins are novel determinants of pro-inflammatory transcription in the endothelium. Targeting chromatin by BET bromodomain inhibition may be a therapeutic strategy to limit atherosclerosis and other disorders involving endothelial inflammation.


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