Poly(acrylamide co-acrylic acid) for use as an in situ gelling vitreous substitute

2017 ◽  
Vol 32 (5) ◽  
pp. 528-541 ◽  
Author(s):  
Joshua T Davis ◽  
Paul D Hamilton ◽  
Nathan Ravi
Keyword(s):  
Acrylic Acid ◽  
Retinal Pigment ◽  
Water Soluble ◽  
Retinal Pigment Epithelial Cells ◽  
Feed Ratio ◽  
Impedance Sensing ◽  
In Vitro Biocompatibility ◽  
Vitreous Substitutes

Our objective is to improve on our previous work developing thiol-containing water-soluble copolyacrylamides that form hydrogels in situ for use as vitreous substitutes. In this study, we evaluate the incorporation of acrylic acid by varying the feed ratio of acrylic acid monomer from 0 to 40 mol% in combination with acrylamide, and bis-acryloylcystamine as the reversible cross-linker. After polymerization, the formed copolymer hydrogels were reduced with dithiothreitol to cleave the disulfide cross-linkers. Purified, lyophilized copolymers were made in a concentration range of 12.5–17.5 mg/mL (polymer in deionized water) and were gelled by oxidation. Chemical, physical, optical, and rheological characterizations along with in vitro biocompatibility studies were performed using thiazolyl blue and Electric Cell–substrate Impedance Sensing. Increasing the percentage of acrylic acid caused the polymer to gel at 12.5 mg/mL as opposed to 20 mg/mL without acrylic acid. Storage modulus values covered the range of natural vitreous (1–108 Pa). Biocompatibility testing in tissue culture with retinal pigment epithelial cells (ARPE-19) showed no toxicity at 10 mg/mL or less when compared to controls, higher concentrations. In contrast to our previously reported copolyacrylamide hydrogels, these hydrogels remain optically clear and gel at lower concentrations and have the potential for use as vitreous substitutes.

Cyanidin-3-glucoside attenuates 4-hydroxynonenal- and visible light-induced retinal damage in vitro and in vivo

2019 ◽  
Vol 10 (5) ◽  
pp. 2871-2880 ◽  
Author(s):  
Yong Wang ◽  
Wentao Qi ◽  
Yazhen Huo ◽  
Ge Song ◽  
Hui Sun ◽  
...  
Keyword(s):  
Retinal Pigment Epithelial ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Retinal Damage ◽  
Protective Effects ◽  
Pigment Epithelial ◽  
Induced Apoptosis ◽  
Pigment Epithelial Cells

Cyanidin-3-glucoside has efficient protective effects on 4-hydroxynonenal-induced apoptosis, senescence, and angiogenesis in retinal pigment epithelial cells.

Effect of hrWnt7a on Human Retinal Pigment Epithelial Cells In Vitro

2015 ◽  
Vol 159 (4) ◽  
pp. 534-540 ◽  
Author(s):  
A. V. Kuznetsova ◽  
A. M. Kurinov ◽  
E. V. Chentsova ◽  
P. V. Makarov ◽  
M. A. Aleksandrova
Keyword(s):  
Epithelial Cells ◽  
Retinal Pigment Epithelial ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelial Cells ◽  
Pigment Epithelial ◽  
Pigment Epithelial Cells

The cytoskeletal elements of human retinal pigment epithelium: in vitro and in vivo

1988 ◽  
Vol 91 (2) ◽  
pp. 303-312
Author(s):  
N.M. McKechnie ◽  
M. Boulton ◽  
H.L. Robey ◽  
F.J. Savage ◽  
I. Grierson
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cytokeratin 18 ◽  
Rpe Cells ◽  
Human Retinal Pigment Epithelium ◽  
Cytoskeletal Elements

The cytoskeletal elements of normal (in situ) and cultured human retinal pigment epithelium (RPE) were studied by a variety of immunocytochemical techniques. Primary antibodies to vimentin and cytokeratins were used. Positive immunoreactivity for vimentin was obtained with in situ and cultured material. The pattern of reactivity obtained with antisera and monoclonals to cytokeratins was more complex. Cytokeratin immunoreactivity could be demonstrated in situ and in cultured cells. The pattern of cytokeratin expression was similar to that of simple or glandular epithelia. A monoclonal antibody that specifically recognizes cytokeratin 18 identified a population of cultured RPE cells that had particularly well-defined filamentous networks within their cytoplasm. Freshly isolated RPE was cytokeratin 18 negative by immunofluorescence, but upon culture cytokeratin 18 positive cells were identifiable. Cytokeratin 18 positive cells were identified in all RPE cultures (other than early primaries), regardless of passage number, age or sex of the donor. In post-confluent cultures cytokeratin 18 cells were identified growing over cytokeratin 18 negative cells, suggesting an association of cytokeratin 18 immunoreactivity with cell proliferation. Immunofluorescence studies of retinal scar tissue from two individuals revealed the presence of numerous cytokeratin 18 positive cells. These findings indicate that RPE cells can be identified by their cytokeratin immunoreactivity and that the overt expression of cytokeratin 18 may be associated with proliferation of human RPE both in vitro and in vivo.

scholarly journals In Vitro Biocompatibility and Osteoblast Differentiation of an Injectable Chitosan/Nano-Hydroxyapatite/Collagen Scaffold

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Chen ◽  
Zhi Huang ◽  
Xiaoming Li ◽  
Songjian Li ◽  
Zhilai Zhou ◽  
...  
Keyword(s):  
Collagen Scaffold ◽  
Reaction Cell ◽  
In Vitro Biocompatibility ◽  
In Situ Forming ◽  
Osteogenic Markers ◽  
Polymerase Chain ◽  
Cell Expression

The purpose of this study was to evaluate the in vitro cell biocompatibility of an in situ forming composite consisting of chitosan (CS), nano-hydroxyapatite and collagen (nHAC), which has a complex hierarchical structure similar to natural bone. MC3T3-E1 mouse calvarial preosteoblasts were cultured on the surface of the injectable CS/nHAC and CS scaffold. The proliferations of seeded MC3T3-E1 were investigated for 10 days. Cytotoxicity, cell proliferation, and cell expression of osteogenic markers such as alkaline phosphatase (ALP), type 1 collagen (COL-1), RUNX-2, and osteocalcin (OCN) were examined by biochemical assay and reverse transcription polymerase chain reaction. Cell viability and total cellularity (measured by dsDNA) were similar between the two scaffold groups. However, ALP, COL-1, OCN, and RUNX-2 production were significantly greater when osteoblasts were cultured on CS/nHAC scaffolds. The increase in osteogenic markers production on CS/nHAC scaffolds indicated that these scaffolds were superior to chitosan-only scaffolds in facilitating osteoblast mineralization. These results demonstrate the potential of the CS/nHAC scaffolds to be used in bone tissue engineering.

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