Journal: Tissue Engineering. Part A

Article Title: * Hyaluronic Acid/Collagen Hydrogel as an Alternative to Alginate for Long-Term Immunoprotected Islet Transplantation

doi: 10.1089/ten.tea.2016.0477

Figure Lengend Snippet: Glucose-stimulated insulin secretion of encapsulated islets. (A) Stimulation indices (ratio of high glucose insulin secretion to low glucose secretion) were measured at days 3, 7, 14, 21, and 28 in vitro for encapsulated islets in HA-COL and alginate-RGD hydrogels and for unencapsulated controls. The stimulation index for control cells in media did not change significantly over time, which was also true for islets encapsulated in HA-COL and alginate (n = 3 donor animals). (B) Actual secreted insulin concentrations in response to low and high glucose incubations normalized to IEQ are summarized. Data shown are the mean values from three separate donors measured in triplicate for each group at 3, 7, 14, 21, and 28 days. Significant differences were denoted with an asterisk (p < 0.05). Incubation periods were 90 min for both low and high glucose conditions. IEQ, islet equivalents.

Article Snippet: Ultrapure, sterile “RGD” conjugated sodium alginate (Novatech MVG GRGDSP peptide-coupled alginate; FMC Biopolymer) was reconstituted in sterile deionized water containing 300 mM mannitol (to maintain isotonicity) at a concentration of 1% by weight to match that of the HA-COL gels.

Techniques: In Vitro, Incubation

Journal: PLoS ONE

Article Title: QHREDGS Enhances Tube Formation, Metabolism and Survival of Endothelial Cells in Collagen-Chitosan Hydrogels

doi: 10.1371/journal.pone.0072956

Figure Lengend Snippet: (A) HMVEC-D were cultured on collagen I and permeability was assessed using a Transwell assay (N = 3/group). Endothelial cells were serum starved (1 hr) and FITC labeled albumin was added to the top well and cells were incubated. QHREDGS or scrambled (DQSHER) peptides at 400 µM or control (PBS) were added (1 hr). Thrombin was added to induce permeability and the amount of FITC-linked albumin in the bottom well was quantified (Pa/hr) (3 hr). Peptide QHREDGS reduced HMVEC-D permeability (*P = 0.004) compared to control and scrambled peptide (**P = 0.001) groups. (B) Transendothelial electrical resistance was measured in HMVEC-D cultured on collagen I. HMVEC-D were serum starved and QHREDGS or scrambled (DQSHER) peptides at 400 µM or control (PBS) were added (1 hr). Thrombin was added to reduce resistance and resistance was measured as a function of time (N = 2/group). Peptide QHREDGS increased QHREDGS resistance compared to control and scrambled peptides. Red coloured triangles indicate normalized resistance values for the QHREDGS treated group.

Article Snippet: Linear QHREDGS peptide, scrambled QHREDGS peptide (DQSHGER), GRGDSP peptide (SynBioSci), angiopoietin-2 (ang2), or ang1 (R&D Systems) or matched vehicles (PBS) were added (N = 6/group with studies done in duplicate) in phenol red-free DMEM/0.5% BSA and incubated (0.5 hr, 37°C, 10% CO 2 ).

Techniques: Cell Culture, Permeability, Transwell Assay, Labeling, Incubation, Control

Journal: PLoS ONE

Article Title: QHREDGS Enhances Tube Formation, Metabolism and Survival of Endothelial Cells in Collagen-Chitosan Hydrogels

doi: 10.1371/journal.pone.0072956

Figure Lengend Snippet: (A) Mouse MS1 endothelial cells were incubated with linear QHREDGS peptide, scrambled QHREDGS peptide (DQSHGER), GRGDSP peptide, control (PBS), or 200 nM angiopoietin-2 (ang2) or angiopoietin-1 (ang1) (0.5 hr). Then, 100 µM L-arginine was added and cells incubated (1.5 hr). Extracellular nitric oxide (NO) levels were measured (N = 6/group). In graphs, the mean value is indicated with a bar. Linear QHREDGS peptide increased NO levels at 500 and 100 µM (*P≤0.00001) and ang1 also increased NO levels (**P = 0.0002). Ang2, GRGDSP, and scrambled QHREDGS peptides had no effect on NO levels compared to controls. (B) MS1 endothelial cells were incubated with peptides and proteins as above, except SNAP (NO donor) was added to the 1.5 hr incubation with L-arginine. In graphs, the mean value is indicated with a bar. Linear QHREDGS peptide at 500 µM and ang1 increased NO levels (*P<0.002). Scrambled QHREDGS peptide and 100 µM QHREDGS did not affect NO levels. Triangle color code: control (black), scrambled peptide (gray), QHREDGS peptide (red), GRGDSP peptide (burgundy), ang2 (green) and ang1 (blue).

Article Snippet: Linear QHREDGS peptide, scrambled QHREDGS peptide (DQSHGER), GRGDSP peptide (SynBioSci), angiopoietin-2 (ang2), or ang1 (R&D Systems) or matched vehicles (PBS) were added (N = 6/group with studies done in duplicate) in phenol red-free DMEM/0.5% BSA and incubated (0.5 hr, 37°C, 10% CO 2 ).

Techniques: Incubation, Control

Journal: PLoS ONE

Article Title: QHREDGS Enhances Tube Formation, Metabolism and Survival of Endothelial Cells in Collagen-Chitosan Hydrogels

doi: 10.1371/journal.pone.0072956

Figure Lengend Snippet: (A-B) MS1 endothelial cells were incubated with 500 µM QHREDGS or scrambled QHREDGS peptide (DQSHER) or control (PBS) overnight. (A) Cells were incubated for 4 hr with MTT, absorbances measured at 570 nm, and values normalized to cell number (N = 5/group). Peptide QHREDGS increased MS1 endothelial cell viability (*P = 0.001) as indicated by the increased processing of MTT by mitochondria. (B) QHREDGS peptide increased endothelial cell ATP levels, whereas scrambled QHREDGS had no such effect (*P = 0.03). (C) MS1 endothelial cells were incubated with 500 µM QHREDGS or scrambled QHREDGS peptide or control (PBS) for 3 hr. QHREDGS peptide increased endothelial cell NADH/NADPH levels (*P = 0.05) suggesting increased cellular energetics. Optical density (OD).

Article Snippet: Linear QHREDGS peptide, scrambled QHREDGS peptide (DQSHGER), GRGDSP peptide (SynBioSci), angiopoietin-2 (ang2), or ang1 (R&D Systems) or matched vehicles (PBS) were added (N = 6/group with studies done in duplicate) in phenol red-free DMEM/0.5% BSA and incubated (0.5 hr, 37°C, 10% CO 2 ).

Techniques: Incubation, Control

Journal: Frontiers in Bioengineering and Biotechnology

Article Title: Autologous Fibrin Glue as an Encapsulating Scaffold for Delivery of Retinal Progenitor Cells

doi: 10.3389/fbioe.2014.00085

Figure Lengend Snippet: Line chart showing the effect of different RGD peptides (GRGDSP and RGDS) on the attachment of RPCs to fibrin-coated plates as compared to a control peptide (GRGESP) . Data were expressed as mean ± SE ( n = 6). Results were considered significant when ANOVA was confirmed by Bonferroni post hoc test at p < 0.05.

Article Snippet: The peptides, GRGDSP and GRGESP (sterile-filtered HPLC grade), were purchased from Bachem Bioscience, Inc. (Torrance, CA, USA) while RGDS (sterile-filtered HPLC grade) was purchased from Tocris Bioscience, Inc. (Bristol, UK).

Techniques: Control