pinecone/core-2020-05-10-deduplication huggingface dataset:
Interactive endothelial phenotype maintenance and osteogenic differentiation of adipose tissue stromal vascular fraction SSEA-4+ -derived cells

"Version of Record online: 29 OCT 2015"Bone formation relies on complex processes that require well-orchestrated interactions between several cell types, such as bone-forming cells (osteoblasts, OBs) and endothelial cells (ECs). Their co-culture has been proved relevant to mimicking specific features of the bone niche. Here we propose the co-culture of microvascular-like ECs and pre-OBs, both derived from the SSEA-4+ cell subpopulation from the stromal vascular fraction of human adipose tissue (SSEA-4+ hASCs), to define the conditions in which cells synergistically communicate to support the full differentiation of pre-OBs and maintenance of the EC phenotype. Co-cultures of different ratios of the two cell types were established and maintained for up to 21 days in standard endothelial maintenance (ENDO) and osteogenic differentiation (OST) media, as well as in a mixture of these (MIX). The osteogenic maturation of pre-OBs (ALP activity, OPN and OCN expression, calcium deposition), the evolution of EC numbers (CD31+ cells) and maintenance of the endothelial phenotype (CD31 and vWF expression, LDL uptake) were assessed throughout the culture time as a function of cell ratio and culture media. The results obtained demonstrate that EC number has a significant effect on the osteogenic differentiation of pre-OBs, depending on the medium used. While in ENDO medium the osteogenic differentiation was not observed, in the OST and MIX media it was attained at similar levels, except for the co-culture with a higher number of ECs in MIX medium. These findings demonstrate that the use of SSEA-4+ hASCs as a single-cell source is promising to attain 3D bone-like models with the potential to promote vascularized bone tissue regeneration.The authors are grateful to the Portuguese Foundation for
Science and Technology (FCT) for personal grants SFRH/BD/
42968/2008 through the MIT–Portugal Programme (SMM).
The research leading to these results has received funding from
the MIT/ECE/0047/2009 project, the European Union Seventh
Framework Programme (Grant No. FP7/2007-2013, under Grant
Agreement No. REGPOT-CT2012-316331-POLARIS) and the
European Research Council (Advanced Grant No. ERC-2012-
AdG_20120216-321266 for the project ComplexiTE)
Bio-inspired design of a magnetically active trilayered scaffold for cartilage tissue engineering

An important topic in cartilage tissue engineering is the development of biomimetic scaffolds which mimic the depth/dependent material properties of the native tissue. We describe an advanced trilayered nanocomposite hydrogel (ferrogel) with a gradient in compressive modulus from the top to the bottom layers (p<0.05) of the construct. Further, the scaffold was able to respond to remote external stimulation, exhibiting an elastic, depth/dependent strain gradient. When bovine chondrocytes were seeded into the ferrogels and cultured for up to 14 days, there was good cell viability and a biochemical gradient was measured with sulfated glycosaminoglycan increasing with depth from the surface. This novel construct provides tremendous scope for tailoring location/specific cartilage replacement tissue; by varying the density of magnetic nanoparticles, concentration of base hydrogel and number of cells, physiologically relevant depth/dependent gradients may be attained
Conditioned media from hypoxic-cultured human dental pulp cells promotes bone healing during distraction osteogenesis

Distraction osteogenesis (DO) is a surgical procedure used to correct various skeletal disorders. Improving the technique by reducing the healing time would be of clinical relevance. The aim of this study was to determine the angiogenic and regenerative potential of conditioned media (CMs) collected from human dental pulp cells (hDPCs) grown under different culture conditions. CM collected from cells under hypoxia was used to improve bone healing and the DO procedure in vivo. The angiogenic potentials of CMs collected from hDPCs grown under normoxic (−Nor) and hypoxic (−Hyp) conditions were evaluated by quantitative PCR (VEGF-A, angiopoietin-1, angiopoietin-2, interleukin-6 (IL-6) and CXCL12), ELISA assays (VEGF-A, Ang-2), tube-formation and wound-healing assays, using human umbilical vein endothelial cells. The results demonstrated that hypoxic CM had significantly higher angiogenic potential than normoxic CM. Human fetal osteoblasts (hFOBs) were exposed to CM, followed by alizarin red staining, to assess the osteogenic potential. It was found that CM did not enhance the mineralization capacity of hFOBs. DO was performed in the tibiae of 30 mice, followed by a local injection of 20 µl CM (CM–Nor and CM–Hyp groups) or serum-free DMEM (control group) into the distraction zone every second day. The mice were sacrificed at days 13 and 27. The CM–Hyp treatment revealed a higher X-ray density than the control group (p < 0.05). Our study suggests that the angiogenic effect promoted by hypoxic culture conditions is dependent on VEGF-A and Ang-2 released from hDPCs. Furthermore, CM–Hyp treatment may thus improve the DO procedure, accelerating bone healing. © 2015 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons, Ltd
Can host reaction animal models be used to predict and modulate skin regeneration?

The study of host reactions in the biomedical and tissue engineering (TE) fields is a key issue but
somehow set aside where TE constructs are concerned. Every day new biomaterials and TE constructs
are being developed and presented to the scientific community. The combination of cells and biomolecules
with scaffolding materials, as TE constructs, make the isolation and the understanding of the
effect of each one those elements over the overall host reaction difficult. Eventually, all variables influence
the host reaction and the performance of the constructs. For this reason, current assessment
of the in vivo performance of TE constructs follows individual approaches, using specific animal
models to independently provide insights regarding the contribution of the biomaterials/scaffolds
towards the host reaction, and of all the constructs regarding their functionality. Skin wound healing
progress into tissue regeneration or repair is highly dependent on the specificities of the inflammatory
stage, as demonstrated by comparison between fetal and adult mechanisms. Thus, it would be
expected that insights acquired from host tissue reaction evaluation to biomaterials/scaffolds would
be explored to predict healing progression and improve the functionality of skin TE constructs. The
rational of this review is to make a comprehensive analysis of to what extent the knowledge obtained
from the evaluation of in vivo host reactions to implantable biomaterials/scaffolds has been used in
the design of skin TE strategies, by promoting tissue regeneration rather than repair.T.C.S. acknowledges Grant No. RL3-TECT-NORTE-01-0124-FEDER-000020, co-financed by the North Portugal Regional Operational Programme (ON.2-O Novo Norte), under the National Strategic Reference Framework, through the European Regional Development Fund
Human cell culture process capability: a comparison of manual and automated production

This is the pre-peer reviewed version of the article which has been published at: http://dx.doi.org/10.1002/term.217Cell culture is one of the critical bioprocessing steps required to generate sufficient human-derived cellular material for most cell-based therapeutic applications in regenerative medicine. Automated cell expansion is fundamental to the development of scaled, robust and cost effective commercial production processes for cell-based therapeutic products. This paper describes the first application of process capability analysis to establish and compare the short-term process capability of manual and automated processes for the in vitro expansion of a selected anchorage-dependent cell line. Estimates of the process capability indices (Cp, Cpk) have been used to assess the ability of both processes to consistently meet the requirements for a selected productivity output and to direct process improvement activities. Point estimates of Cp and Cpk show that the manual process has poor capability (Cp = 0.55, Cpk = 0.26) compared to the automated process (Cp = 1.32, Cpk = 0.25), resulting from excess variability. Comparison of point estimates, which shows that Cpk < Cp, indicates that the automated process mean was off-centre and that intervention is required to adjust the location of the process mean. A process improvement strategy involving an adjustment to the automated process settings has demonstrated in principle that the process mean can be shifted closer to the centre of the specification to achieve an estimated seven-fold improvement in process performance. In practice, the 90% confidence bound estimate of Cp (Cp = 0.90) indicates that that once the process is centred within the specification, a further reduction of process variation is required to attain an automated process with the desired minimum capability requirement
Modulating cell adhesion to polybutylene succinate biotextile constructs for tissue engineering applications

Textile-based technologies are powerful routes for the production of three-dimensional porous architectures for tissue engineer- ing applications because of their feasibility and possibility for scaling-up. Herein, the use of knitting technology to produce polybutylene succinate fibre-based porous architectures is described. Furthermore, different treatments have been applied to functionalize the surface of the scaffolds developed: sodium hydroxide etching, ultraviolet radiation exposure in an ozone atmosphere and grafting (acrylic acid, vinyl phosphonic acid and vinyl sulphonic acid) after oxygen plasma activation as a way to tailor cell adhesion. A possible effect of the applied treatments on the bulk properties of the textile scaffolds has been considered and thus tensile tests in dry and hydrated states were also carried out. The microscopy results indicated that the surface morphol- ogy and roughness were affected by the applied treatments. The X-ray photoelectron spectroscopy and contact angle measure- ments showed the incorporation of oxygen-containing groups and higher surface free energy as result of the surface treatments applied. The DNA quantification and scanning electron microscopy analysis revealed that these modifications enhanced cell adhesion and altered cell morphology. Generally, sodium hydroxide treatment altered most significantly the surface properties, which in turn resulted in a high number of cells adherent to these surfaces. Based on the results obtained, the proposed surface treatments are appropriate to modify polybutylene succinate knitting scaffolds, influencing cell adhesion and its potential for use in tissue engineering applications.Â Portuguese Foundation for Science
and Technology (FCT) under POCTI and/or FEDERprogrammes under
the scope of the project TISSUE2TISSUE (PTDC/CTM/105703/
2008). The FCT distinction attributed to ALO under the Investigator
FCT programme (IF/00411/2013
Core-shell silk hydrogels with spatially tuned conformations as drug delivery system

Hydrogels of spatially controlled physicochemical properties are appealing platforms for tissue engineering and drug delivery. In this study, core-shell silk fibroin (SF) hydrogels of spatially controlled conformation were developed. The core-shell structure in the hydrogels was formed by means of soaking the preformed (enzymatically crosslinked) random coil SF hydrogels in methanol. When increasing the methanol treatment time from 1 to 10 minutes, the thickness of the shell layer can be tuned from about 200 to around 850 Âµm as measured in wet status. After lyophilization of the rehydrated core-shell hydrogels, the shell layer displayed compact morphology and the core layer presented porous structure, when observed by scanning electron microscopy. The conformation of the hydrogels was evaluated by Fourier transform infrared spectroscopy in wet status. The results revealed that the shell layer possessed dominant Î²-sheet conformation and the core layer maintained mainly random coil conformation. Enzymatic degradation data showed that the shell layers presented superior stability to the core layer. The mechanical analysis displayed that the compressive modulus of the core-shell hydrogels ranged from around 25 kPa to about 1.1 MPa by increasing the immersion time in methanol. When incorporated with albumin, the core-shell SF hydrogels demonstrated slower and more controllable release profiles compared with the non-treated hydrogel. These core-shell SF hydrogels of highly tuned properties are useful systems as drug delivery system and may be applied as cartilage substitute.This study was funded by the Portuguese Foundation for Science and Technology (FCT) projects Tissue2Tissue (PTDC/CTM/105703/2008) and OsteoCart (PTDC/CTM-BPC/115977/2009), as well as the European Union’s FP7 Programme under grant agreement no. REGPOT-CT2012-316331-POLARIS. Le-Ping Yan was awarded a FCT PhD scholarship (SFRH/BD/ 64717/2009). The FCT distinctions attributed to J.M. Oliveira and A.L. Oliveira under the Investigador FCT program (IF/ 00423/2012) and (IF/00411/2013) are also greatly acknowledged, respectively
PDGF is a potent initiator of bone formation in a tissue engineered model of pathological ossification

This is an open access article published by Wiley and distributed under the terms of the Creative Commons Attribution 4.0 Licence (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/Heterotopic ossification (HO) is a debilitating condition defined by the rapid formation of bone in soft tissues. What makes HO fascinating is firstly the rate at which bone is deposited, and secondly the fact that this bone is structurally and compositionally similar to that of a healthy adult. If the mechanisms governing HO are understood, they have the potential to be exploited for the development of potent osteoinductive therapies. With this aim, we utilised a tissue engineered skeletal muscle model to better understand the role of inflammation on this debilitating phenomenon. We showed myoblasts could be divided into two distinct populations, myogenic cells and undifferentiated "reserve" cells. Gene expression analysis of myogenic and osteo-regulatory markers confirmed that "reserve" cells were primed for osteogenic differentiation, but had a reduced capacity for myogenesis. Osteogenic differentiation was significantly enhanced in the presence of PDGF-BB and BMP2, and correlated with conversion to a Sca-1(+) /CD73(+) phenotype. Alizarin red staining showed that PDGF-BB promoted significantly more mineral deposition than BMP2. Finally, we showed that PDGF-induced mineralisation was blocked in the presence of the pro-inflammatory cytokines TNFα and IL1. In conclusion, the present study identified that PDGF-BB is a potent osteoinductive factor in a model of tissue engineered skeletal muscle, and that the osteogenic capacity of this protein was modulated in the presence of pro-inflammatory cytokines. These findings reveal a possible mechanism by which HO develops following trauma. Importantly, these findings have implications for the induction and control of bone formation for regenerative medicine
Synthesis and characterization of divinyl-fumarate Poly-ε-caprolactone for scaffolds with controlled architectures

This is the peer reviewed version of the following article: RONCA, A. ... et al, 2016. Synthesis and characterization of divinyl-fumarate Poly-ε-caprolactone for scaffolds with controlled architectures. Journal of Tissue Engineering and Regenerative Medicine, doi:10.1002/term.2322., which has been published in final form at http://dx.doi.org/10.1002/term.2322. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.A vinyl-terminated Polycaprolactone has been developed for tissue engineering applications using a one-step synthesis and functionalization method based on Ring Opening Polymerization (ROP) of ԑ-caprolactone, with Hydroxyl Ethyl Vinyl Ether (HEVE) acting both as the initiator of ROP and as photo-curable functional group. The proposed method employs a catalyst based on Al, instead of the most popular Tin(II) 2-ethylhexanoate, to reduce the cytotoxicity. Following the synthesis of the vinyl-terminated polycaprolactone, its reaction with Fumaryl Chloride (FuCl) results in a divinyl-fumarate polycaprolactone (VPCLF). The obtained polymers were thoroughly characterized using Fourier Transform Infrared Spectroscopy (FTIR) and gel permeation chromatography (GPC) techniques. The polymer has been successfully employed, in combination with N-vinyl Pyrrolidone (NVP), to fabricate films and computer-designed porous scaffolds by micro-stereolithography (μ-SL) with Gyroid and Diamond architectures. Characterization of the networks indicated the influence of NVP content on the network properties. Human Mesenchymal Stem Cells (hMSCs) adhered and spread onto VPCLF/NVP networks showing good biological properties and no cytotoxic effect
The productivity limit of manufacturing blood cell therapy in scalable stirred bioreactors

This is an open access article published by Wiley and distributed under the terms of the Creative Commons Attribution 4.0 Licence (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/Manufacture of red blood cells (RBCs) from progenitors has been proposed as a method to reduce reliance on donors. Such a process would need to be extremely efficient for economic viability given a relatively low value product and high 2E12 cell dose. Therefore, the aim of these studies was to define the productivity of an industry standard stirred-tank bioreactor and determine engineering limitations of commercial RBC production. Cord blood derived CD34+ cells were cultured under erythroid differentiation conditions in a stirred micro-bioreactor (ambr™). Enucleated cells of 80% purity could be created under optimal physical conditions: pH 7.5, 50% oxygen, without gas-sparging (which damaged cells) and with mechanical agitation (which directly increased enucleation). O2 consumption was low (~5x10(-8) µg/cell.hr) theoretically enabling erythroblast densities in excess of 5x10(8) /ml in commercial bioreactors and sub-10 L/unit production volumes. The bioreactor process achieved a 24% and 42% reduction in media volume and culture time respectively relative to unoptimized flask processing. However, media exchange limited productivity to 1 unit of erythroblasts per 500 L of media. Systematic replacement of media constituents, as well as screening for inhibitory levels of ammonia, lactate and key cytokines did not identify a reason for this limitation. We conclude that the properties of erythroblasts are such that the conventional constraints on cell manufacturing efficiency, such as mass transfer and metabolic demand, should not prevent high intensity production; furthermore this could be achieved in industry standard equipment. However, identification and removal of an inhibitory mediator is required to enable these economies to be realized
Anti-angiogenic potential of VEGF blocker dendron-laden gellan gum hydrogels for tissue engineering applications

Damage of non-vascularised tissues such as cartilage and cornea can result in healing processes accompanied by a non-physiological angiogenesis. Peptidic aptamers have recently been reported to block the vascular endothelial growth factor (VEGF). However, the therapeutic applications of these aptamers is limited due to their short half-life in vivo. In this work, an enhanced stability and bioavailability of a known VEGF blocker aptamer sequence (WHLPFKC) was pursued through its tethering of molecular scaffolds based on hyperbranched peptides, the poly(É -lysine) dendrons, bearing three branching generations. The proposed design allowed simultaneous and orderly-spaced exposure of sixteen aptamers per dendrimer to the surrounding biological microenvironent, as well as a relatively hydrophobic core based on di-phenylalanine aiming to promote an hydrophobic interaction with the hydrophobic moieties of ionically-crosslinked metacrylated gellan gum (iGG-MA) hydrogels. The VEGF blocker dendrons were entrapped in iGG-MA hydrogels and their capacity to prevent endothelial cell sprouting was assessed qualitatively and quantitatively using 3D in vitro models and the in vivo chick chorioallantoic membrane (CAM) assay. The data demonstrate that at nanoscale concentrations, the dendronised structures were able to enhance control of the biological actvity of WHLPFKC at the material/tissue interface and hence the anti-angiogenic capacity of iGG-MA hydrogels not only preventing blood vessel invasion, but also inducing their regression at the tissue/iGG-MA interface. The in ovo study confirmed that iGG-MA functionalised with the dendron VEGF blockers do inhibit angiogenesis by controlling both size and ramifications of blood vessels in proximity of the implanted gel surface.This work was mainly supported by the EC FP7 project Disc Regeneration (Contract No 
NMP3-LA-2008-213904). This study was also funded by the EC FP7 Programme contract 
agreement no REGPOT-CT2012-316331-POLARIS
Human corneal fibroblast migration and ECM synthesis during stromal repair: Role played by PDGF-BB, bFGF, and TGFβ1 (HCFs migration and ECM synthesis during stromal repair: GFs effects)

Producción CientíficaThe development of treatments that modulate corneal wound healing to avoid fibrosis during tissue repair is important for the restoration of corneal transparency after an injury. To date, few studies have studied the influence of growth factors (GFs) on human corneal fibroblast (HCF) expression of extracellular matrix (ECM) proteins such as collagen types I and III, proteoglycans such as perlecan, or proteins implicated in cellular migration such as α5β1-integrin and syndecan-4. Using in vitro HCFs, we developed a mechanical wound model to study the influence of the GFs basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF-BB), and transforming growth factor beta 1 (TGFβ1) on ECM protein production and cellular migration. Our results show that mechanical wounding provokes the autocrine release of bFGF and TGFβ1 at different time points during the wound closure. The HCF response to PDGF-BB was a rapid closure due to fast cellular migration associated with a high focal adhesion replacement and a high expression of collagen and proteoglycans, producing a non-fibrotic healing. bFGF stimulated non-fibrotic ECM production and limited the migration process. Finally, TGFβ1 induced expression of the fibrotic markers collagen type III and α5β1 integrin, and it inhibited cellular migration due to the formation of focal adhesions with a low turnover rate. The novel in vitro HCF mechanical wound model can be used to understand the role played by GFs in human corneal repair. The model can also be used to test the effects of different treatments aimed at improving the healing process