scholarly journals A Liquid Hydrogel to Restore Long Term Corneal Integrity After Perforating and Non-Perforating Trauma in Feline Eyes

Author(s):  
Alejandro Juarez ◽  
Mohamed Djallali ◽  
Marilyse Piché ◽  
Mathieu Thériault ◽  
Marc Groleau ◽  
...  

Purpose: To evaluate long-term in vivo functionality of corneas regenerated using a cell-free, liquid hydrogel filler (LiQD Cornea) after deep corneal trauma in the feline model.Methods: Two healthy cats underwent 4 mm diameter stepwise 250/450 µm deep surgical corneal ablation with and without needle perforation. The filler comprising 10% (w/w) collagen-like peptide conjugated to polyethylene glycol (CLP-PEG) and 1% fibrinogen and crosslinked with 2% (w/w) 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), was applied to the wound bed previously coated with thrombin (250 U/ml). In situ gelation occurred within 5 min, and a temporary tarsorrhaphy was performed. Eyes were examined weekly for 1 month, then monthly over 12 months. Outcome parameters included slit-lamp, Scheimpflug tomography, optical coherence tomography, confocal and specular microscopy, and immunohistochemistry studies.Results: The gelled filler was seamlessly incorporated, supporting smooth corneal re-epithelialization. Progressive in-growth of keratocytes and nerves into the filler corresponding to the mild haze observed faded with time. The regenerated neo-cornea remained stably integrated throughout the 12 months, without swelling, inflammation, infection, neovascularization, or rejection. The surrounding host stroma and endothelium remained normal at all times. Tomography confirmed restoration of a smooth surface curvature.Conclusion: Biointegration of this hydrogel filler allowed stable restoration of corneal shape and transparency in the feline model, with less inflammation and no neovascularization compared to previous reports in the minipig and rabbit models. It offers a promising alternative to cyanoacrylate glue and corneal transplantation for ulcerated and traumatized corneas in human patients.

Blood ◽  
1985 ◽  
Vol 66 (6) ◽  
pp. 1460-1462 ◽  
Author(s):  
ME Pietrzyk ◽  
GV Priestley ◽  
NS Wolf

It was found in a long-term bromodeoxyuridine (BrdU) infusion study that two or more different subpopulations of bone marrow stem cells exist in mice. One of these subpopulations appears to be noncycling and forms approximately 10% of eight-day CFU-S. Another one, a subpopulation of slowly cycling bone marrow cells, is represented as 14- day CFU-S. The 14-day CFU-S have a regular increment in the percentage of the subpopulation entering the cycle over time, with a cell generation half-time of 21 days. The cycling status in these experiments was ascertained by in vivo continuous long-term BrdU infusion. An improved method is presented for long-term BrdU infusion with UV killing of cycled cells.


RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 13029-13036 ◽  
Author(s):  
Ning Zhao ◽  
Jing-Min Liu ◽  
Shuang Liu ◽  
Xue-Meng Ji ◽  
Huan Lv ◽  
...  

Schematic illustration of the preparation of bioluminescent bacteria and the experimental design of tracing of the foodborne bacteria in vivo.


2020 ◽  
Vol 6 (25) ◽  
pp. eaba2187 ◽  
Author(s):  
Christopher D. McTiernan ◽  
Fiona C. Simpson ◽  
Michel Haagdorens ◽  
Chameen Samarawickrama ◽  
Damien Hunter ◽  
...  

Transplantation with donor corneas is the mainstay for treating corneal blindness, but a severe worldwide shortage necessitates the development of other treatment options. Corneal perforation from infection or inflammation is sealed with cyanoacrylate glue. However, the resulting cytotoxicity requires transplantation. LiQD Cornea is an alternative to conventional corneal transplantation and sealants. It is a cell-free, liquid hydrogel matrix for corneal regeneration, comprising short collagen-like peptides conjugated with polyethylene glycol and mixed with fibrinogen to promote adhesion within tissue defects. Gelation occurs spontaneously at body temperature within 5 min. Light exposure is not required—particularly advantageous because patients with corneal inflammation are typically photophobic. The self-assembling, fully defined, synthetic collagen analog is much less costly than human recombinant collagen and reduces the risk of immune rejection associated with xenogeneic materials. In situ gelation potentially allows for clinical application in outpatient clinics instead of operating theaters, maximizing practicality, and minimizing health care costs.


1998 ◽  
Vol 188 (8) ◽  
pp. 1485-1492 ◽  
Author(s):  
Damo Xu ◽  
Woon Ling Chan ◽  
Bernard P. Leung ◽  
David Hunter ◽  
Kerstin Schulz ◽  
...  
Keyword(s):  
T Helper ◽  
Th2 Cell ◽  
A Cell ◽  

Interleukin (IL)-18 induces interferon (IFN)-γ synthesis and synergizes with IL-12 in T helper type 1 (Th1) but not Th2 cell development. We report here that IL-18 receptor (IL-18R) is selectively expressed on murine Th1 but not Th2 cells. IL-18R mRNA was expressed constitutively and consistently in long-term cultured clones, as well as on newly polarized Th1 but not Th2 cells. IL-18 sustained the expression of IL-12Rβ2 mRNA, indicating that IL-18R transmits signals that maintain Th1 development through the IL-12R complex. In turn, IL-12 upregulated IL-18R mRNA. Antibody against an IL-18R–derived peptide bound Th1 but not Th2 clones. It also labeled polarized Th1 but not Th2 cells derived from naive ovalbumin–T cell antigen receptor-αβ transgenic mice (D011.10). Anti–IL-18R antibody inhibited IL-18– induced IFN-γ production by Th1 clones in vitro. In vivo, anti–IL-18R antibody reduced local inflammation and lipopolysaccharide-induced mortality in mice. This was accompanied by shifting the balance from Th1 to Th2 responses, manifest as decreased IFN-γ and proinflammatory cytokine production and increased IL-4 and IL-5 synthesis. Therefore, these data provide a direct mechanism for the selective effect of IL-18 on Th1 but not Th2 cells. They also show that the synergistic effect of IL-12 and IL-18 on Th1 development may be due to the reciprocal upregulation of their receptors. Furthermore, IL-18R is a cell surface marker distinguishing Th1 from Th2 cells and may be a therapeutic target.


1973 ◽  
Vol 138 (2) ◽  
pp. 364-372 ◽  
Author(s):  
M. Hatanaka ◽  
R. Klein ◽  
C. W. Long ◽  
R. Gilden

Tumorigenic and nontumorigenic mutants induced by a single 5'-bromodeoxyuridine (BrdU) treatment of a nonproducer (NP) tumorigenic cell line were isolated and characterized. Among the cloned derivatives were examples of virus-free and sarcoma virus-producing cell lines. Oncogenicity did not correlate with production of virus or ease of rescue of the sarcoma genome. All lines, including nononcogenic derivatives, retained the sarcoma genome. Phenotypic reversion of some cell mutants was observed after in vivo inoculation or long term in vitro cultivation. The M-50T cell line, obtained from a tumor induced by M-50 cells, had a sarcoma genome rescuable by direct superinfection; this was only achieved with parental M-50 cells by a cell fusion rescue technique. The M-43-2T cell, obtained from a single small static tumor induced by otherwise nononcogenic M-43-2 cells, shed sarcoma virus and became tumorigenic. M-58-4-48 became tumorigenic after passage 48 of the M-58-4 line, which was originally nontumorigenic. These observations of phenotypic reversion demonstrate that the presence of the sarcoma gene in cells is an essential but not sufficient condition of tumorigenesis.


2013 ◽  
Vol 750-752 ◽  
pp. 1651-1655
Author(s):  
Bai Yan Sui ◽  
Cheng Tie Wu ◽  
Jiao Sun

Mesoporous bioactive glass (MBG) has superior bioactivity and degradation than non-mesoporous bioactive glass (BG) in vitro. But the biological effect of MBG in vivo is still unknown. In this study, MBG powders with 20μm were implanted into the femoral condyles in SD rats. BG powders with 20μm were used as a control. The local degradation and osteogenesis were observed at 1 week and 4 weeks after implantation, and the systemic toxicity of the degradation products were also evaluated simultaneously. The results revealed MBG powders had the faster rate of degradation and better osteogenesis effect than BG powders at 4 weeks, although the most of material still remained in situ. Histopathological analyses indicated the degradation products did not have any damage to major organs such as liver and kidney. In conclusion, this preliminary study demonstrated that MBG powders have more excellent biological effect at 4 weeks than that of BG in vivo. However the long-term effect needs to be confirmed.


Author(s):  
Marshal Shahu Maskarenj ◽  
Ravi Chavali ◽  
Ankita Mathur ◽  
Prakash Chandra Ghosh ◽  
Sushanta Kumar Mitra

Membrane Bio Reactor (MBR) technology is a promising alternative to municipal and industrial wastewater treatment owing to low sludge production and wide range of acceptable influents. Biofouling in MBRs hampers long term functionality of the system through reduction in permeate flux over time. Membrane biofouling could necessitate periodic membrane backwashing or even require membrane replacement, thus increasing operational cost for the systems. Microbe-secreted extracellular polymeric substance (EPS) forms a complex matrix on the surface; is persistent against physical removal and tends to resist high concentrations of antimicrobial agents, thus playing a major role in membrane biofouling. There is a need for developing methods towards efficient removal of biofoulants from surfaces. In tandem with low DC current, the synergistic effect of antimicrobial agents has been reported successful towards reducing biofilm formation leading to biofouling. This paper discusses the application of in-plane bioelectric effect as a solution to biofouling in MBRs; especially Microbial Fuel Cells and Microbial Desalination Cells towards harnessing in-situ current for tackling biofouling, thus facilitating longer system functionality.


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.


2016 ◽  
Vol 4 (7) ◽  
pp. 1343-1353 ◽  
Author(s):  
Jia Liu ◽  
Ke Wang ◽  
Jie Luan ◽  
Zhi Wen ◽  
Lei Wang ◽  
...  

Chitosan and PEG-based self-healable in situ hydrogel developed as a long-term MRI reporter.


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