scholarly journals Investigating PEGDA and GelMA Microgel Models for Sustained 3D Heterotypic Dermal Papilla and Keratinocyte Co-Cultures

2021 ◽  
Vol 22 (4) ◽  
pp. 2143 ◽  
Author(s):  
Justin J.Y. Tan ◽  
Duc-Viet Nguyen ◽  
John E. Common ◽  
Chunyong Wu ◽  
Paul C.L. Ho ◽  
...  

Hair follicle morphogenesis is heavily dependent on reciprocal, sequential, and epithelial-mesenchymal interaction (EMI) between epidermal stem cells and the specialized cells of the underlying mesenchyme, which aggregate to form the dermal condensate (DC) and will later become the dermal papilla (DP). Similar models were developed with a co-culture of keratinocytes and DP cells. Previous studies have demonstrated that co-culture with keratinocytes maintains the in vivo characteristics of the DP. However, it is often challenging to develop three-dimensional (3D) DP and keratinocyte co-culture models for long term in vitro studies, due to the poor intercellular adherence between keratinocytes. Keratinocytes exhibit exfoliative behavior, and the integrity of the DP and keratinocyte co-cultured spheroids cannot be maintained over prolonged culture. Short durations of culture are unable to sufficiently allow the differentiation and re-programming of the keratinocytes into hair follicular fate by the DP. In this study, we explored a microgel array approach fabricated with two different hydrogel systems. Using poly (ethylene glycol) diacrylate (PEGDA) and gelatin methacrylate (GelMA), we compare their effects on maintaining the integrity of the cultures and their expression of important genes responsible for hair follicle morphogenesis, namely Wnt10A, Wnt10B, and Shh, over prolonged duration. We discovered that low attachment surfaces such as PEGDA result in the exfoliation of keratinocytes and were not suitable for long-term culture. GelMA, on the hand, was able to sustain the integrity of co-cultures and showed higher expression of the morphogens overtime.

2017 ◽  
Vol 85 (3) ◽  
Author(s):  
Maria A DeCicco RePass ◽  
Ying Chen ◽  
Yinan Lin ◽  
Wenda Zhou ◽  
David L. Kaplan ◽  
...  

ABSTRACT Cryptosporidium spp. are apicomplexan parasites of global importance that cause human diarrheal disease. In vitro culture models that may be used to study this parasite and that have physiological relevance to in vivo infection remain suboptimal. Thus, the pathogenesis of cryptosporidiosis remains poorly characterized, and interventions for the disease are limited. In this study, we evaluated the potential of a novel bioengineered three-dimensional (3D) human intestinal tissue model (which we developed previously) to support long-term infection by Cryptosporidium parvum. Infection was assessed by immunofluorescence assays and confocal and scanning electron microscopy and quantified by quantitative reverse transcription-PCR. We found that C. parvum infected and developed in this tissue model for at least 17 days, the extent of the study time used in the present study. Contents from infected scaffolds could be transferred to fresh scaffolds to establish new infections for at least three rounds. Asexual and sexual stages and the formation of new oocysts were observed during the course of infection. Additionally, we observed ablation, blunting, or distortion of microvilli in infected epithelial cells. Ultimately, a 3D model system capable of supporting continuous Cryptosporidium infection will be a useful tool for the study of host-parasite interactions, identification of putative drug targets, screening of potential interventions, and propagation of genetically modified parasites.


2020 ◽  
Vol 8 (11) ◽  
pp. 324-332 ◽  
Author(s):  
Abraham A. Embi

One mechanism of action of antibiotics such as tetracyclines involves the disruption of pathogens cell membranes. This author had previously demonstrated in vitro and in vivo the utility of a human miniorgan, a.k.a. hair follicle as sentinel in demonstrating the deleterious effect of alcohol by showing a disruption in metabolism. In this manuscript, the hair follicle was again used in vitro as sentinel in direct contact with another exogenous substance in two forms, namely liquid and powder tetracycline. The results demonstrate the adhesion property of tetracycline as a mechanism causing deleterious effect on the biological active cells of the follicle’s dermal papilla, and the consequent disruption in metabolism. Notably, it was documented a strong affinity of the antibiotic to the keratin skeleton of the hair follicle. In a recent published report, the adverse effect of tetracycline induction on experimentally deficient mitochondrial DNA (mtDNA) mouse was reversed and documented 30 days after discontinuation of the tetracycline diet. The experiments herein presented correlate and confirm previous findings of long term exposure to tetracycline causing not only damage the pathogen; but also healthy human cells. Since mtDNA may play a role in aging and age-associated diseases: Beware of tetracycline therapy on the elderly.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 791 ◽  
Author(s):  
Ming-Hsiang Chang ◽  
Yu-Ping Hsiao ◽  
Chia-Yen Hsu ◽  
Ping-Shan Lai

Wound infection extends the duration of wound healing and also causes systemic infections such as sepsis, and, in severe cases, may lead to death. Early prevention of wound infection and its appropriate treatment are important. A photoreactive modified gelatin (GE-BTHE) was synthesized by gelatin and a conjugate formed from the 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and the 2-hydroxyethyl methacrylate (HEMA). Herein, we investigated the photocurable polymer solution (GE-BTHE mixture) containing GE-BTHE, poly(ethylene glycol) diacrylate (PEGDA), chitosan, and methylene blue (MB), with antimicrobial functions and photodynamic antimicrobial chemotherapy for wound dressing. This photocurable polymer solution was found to have fast film-forming property attributed to the photochemical reaction between GE-BTHE and PEGDA, as well as the antibacterial activity in vitro attributed to the ingredients of chitosan and MB. Our in vivo results also demonstrated that untreated wounds after 3 days had the same scab level as the GE-BTHE mixture-treated wounds after 20 s of irradiation, which indicates that the irradiated GE-BTHE mixture can be quickly transferred into artificial scabs to protect wounds from an infection that can serve as a convenient excisional wound dressing with antibacterial efficacy. Therefore, it has the potential to treat nonhealing wounds, deep burns, diabetic ulcers and a variety of mucosal wounds.


1999 ◽  
Vol 8 (3) ◽  
pp. 293-306 ◽  
Author(s):  
Gregory M. Cruise ◽  
Orion D. Hegre ◽  
Francis V. Lamberti ◽  
Steven R. Hager ◽  
Ron Hill ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charmainne Cruje ◽  
P. Joy Dunmore-Buyze ◽  
Eric Grolman ◽  
David W. Holdsworth ◽  
Elizabeth R. Gillies ◽  
...  

AbstractVascular research is largely performed in rodents with the goal of developing treatments for human disease. Micro-computed tomography (micro-CT) provides non-destructive three-dimensional imaging that can be used to study the vasculature of rodents. However, to distinguish vasculature from other soft tissues, long-circulating contrast agents are required. In this study, we demonstrated that poly(ethylene glycol) (PEG)-coated gadolinium nanoparticles can be used as a vascular contrast agent in micro-CT. The coated particles could be lyophilized and then redispersed in an aqueous solution to achieve 100 mg/mL of gadolinium. After an intravenous injection of the contrast agent into mice, micro-CT scans showed blood pool contrast enhancements of at least 200 HU for 30 min. Imaging and quantitative analysis of gadolinium in tissues showed the presence of contrast agent in clearance organs including the liver and spleen and very low amounts in other organs. In vitro cell culture experiments, subcutaneous injections, and analysis of mouse body weight suggested that the agents exhibited low toxicity. Histological analysis of tissues 5 days after injection of the contrast agent showed cytotoxicity in the spleen, but no abnormalities were observed in the liver, lungs, kidneys, and bladder.


2018 ◽  
Vol 11 (1) ◽  
pp. 26-38 ◽  
Author(s):  
Yixin Tao ◽  
Qingchun Yang ◽  
Lei Wang ◽  
Jie Zhang ◽  
Xuming Zhu ◽  
...  

Abstract Hair follicle dermal sheath (DS) harbors hair follicle dermal stem cells (hfDSCs), which can be recruited to replenish DS and dermal papilla (DP). Cultured DS cells can differentiate into various cell lineages in vitro. However, it is unclear how its plasticity is modulated in vivo. Wnt/β-catenin signaling plays an important role in maintaining stem cells of various lineages and is required for HF development and regeneration. Here we report that activation of β-catenin in DS generates ectopic HF outgrowth (EF) by reprogramming HF epidermal cells and DS cells themselves, and endows DS cells with hair inducing ability. Epidermal homeostasis of pre-existing HFs is disrupted. Additionally, cell-autonomous progressive skin fibrosis is prominent in dermis, where the excessive fibroblasts largely originate from DS. Gene expression analysis of purified DS cells with activated β-catenin revealed significantly increased expression of Bmp, Fgf, and Notch ligands and administration of Bmp, Fgf, or Notch signaling inhibitor attenuates EF formation. In summary, our findings advance the current knowledge of high plasticity of DS cells and provide an insight into understanding how Wnt/β-catenin signaling controls DS cell behaviors.


2016 ◽  
Vol 89 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Meda Sandra Orasan ◽  
Iulia Ioana Roman ◽  
Andrei Coneac ◽  
Adriana Muresan ◽  
Remus Ioan Orasan

 Research in the field of reversal hair loss remains a challenging subject.As Minoxidil 2% or 5% and Finasteride are so far the only FDA approved topical treatments for inducing hair regrowth, research is necessary in order to improve therapeutical approach in alopecia. In vitro studies have focused on cultures of a cell type - dermal papilla or organ culture of isolated cell follicles . In vivo research on this topic was performed on mice, rats, hamsters, rabbits, sheep and monkeys, taking into consideration the advantages and disadvantages of each animal model and the depilation options. Further studies are required not only to compare the efficiency of different therapies but more importantly to establish their long term safety.


2019 ◽  
Vol 5 (11) ◽  
pp. eaax4520 ◽  
Author(s):  
Yesl Jun ◽  
JaeSeo Lee ◽  
Seongkyun Choi ◽  
Ji Hun Yang ◽  
Maike Sander ◽  
...  

Native pancreatic islets interact with neighboring cells by establishing three-dimensional (3D) structures, and are surrounded by perfusion at an interstitial flow level. However, flow effects are generally ignored in islet culture models, although cell perfusion is known to improve the cell microenvironment and to mimic in vivo physiology better than static culture systems. Here, we have developed functional islet spheroids using a microfluidic chip that mimics interstitial flow conditions with reduced shear cell damage. Dynamic culture, compared to static culture, enhanced islet health and maintenance of islet endothelial cells, reconstituting the main component of islet extracellular matrix within spheroids. Optimized flow condition allowed localization of secreted soluble factors near spheroids, facilitating diffusion-mediated paracrine interactions within islets, and enabled long-term maintenance of islet morphology and function for a month. The proposed model can aid islet preconditioning before transplantation and has potential applications as an in vitro model for diabetic drug testing.


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