Stimulation of wound healing by positively charged dextran beads depends upon clustering of beads and cells in close proximity to the wound

Tawil, Nabil J; Connors, David; Gies, David R.; Bennett, Steven; Gruskin, Elliott; Mustoe, Thomas A.

doi:10.1046/j.1524-475x.1999.00389.x

Cited by 6 publications

(8 citation statements)

References 33 publications

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“…By using the related curve in Figure 8, the specific growth rate and the doubling time were determined as 0.028 h −1 and 24.7 h, respectively for culturing of L929 cells on poly(PEGMA‐DMAPM‐EDM) microcarriers. NIH 3T3 fibroblasts were cultured on positively charged DEAE Sephadex 25 microcarriers in DMEM and the cell counts up to 4 × 10 5 cells/mL were obtained with the microcarrier concentration of 1 mg/mL 43. On the other hand, the cell concentration of about 2 × 10 6 cells/mL reached in the cultivation of CHO cells on Cytodex and Cytopore microcarriers 44…”

Section: Resultsmentioning

confidence: 99%

“…NIH 3T3 fibroblasts were cultured on positively charged DEAE Sephadex 25 microcarriers in DMEM and the cell counts up to 4 ϫ 10 5 cells/mL were obtained with the microcarrier concentration of 1 mg/ mL. 43 On the other hand, the cell concentration of about 2 ϫ 10 6 cells/mL reached in the cultivation of CHO cells on Cytodex and Cytopore microcarriers. 44 The cell densities between 1 ϫ 10 5 and 2.5 ϫ 10 5 cells/ cm 2 were reported for the cultivation of rat hepatoma cells on polyamidoamine dendrimer immobilized polystyrene culture plates.…”

Section: Cell Morphology and Proliferationmentioning

confidence: 98%

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Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

et al. 2006

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A new polyethylene glycol (PEG) based microcarrier was designed and examined by the attachment and growth of mouse fibroblast cells. In the design of microcarrier, a PEG-based macromonomer, polyethyleneglycol methacrylate (PEGMA), was selected as the main component of hydrogel beads since PEG is known as a nontoxic and biocompatible material. A relatively new cationic comonomer, N-[3-(dimethylamino)propyl]methacrylamide (DMAPM), with higher ionization ability with respect to the similar comonomers was used for providing cationic charge to the hydrogel structure. In the first part, a suspension copolymerization method was developed for the production of cationically charged hydrogel beads as a potential microcarrier for cell culturing. The suspension copolymerization by using ethylene dimethacrylate (EDM) as cross-linking agent and cyclohexanol as the diluent provided spherical, polydisperse poly(PEGMA-DMAPM-EDM) hydrogel beads with an average size of 121 microm. The hydrogel beads exhibited a pH-dependent swelling behavior. The L929 mouse fibroblast cells were cultured on poly(PEGMA-DMAPM-EDM) hydrogel beads with an initial concentration of 200,000 cells/mL. The cells were incubated in Dulbecco's modified Eagle's medium during 5 days and the cell proliferation was investigated at every 24 h. An effective cell attachment and growth up to 3.5 x 10(6) cells/mL were observed with the poly(PEGMA-DMAPM-EDM) hydrogel beads. The results indicated that the proposed microcarrier was a significant alternative to the hydrogel beads obtained by the copolymerization of 2-hydroxyethyl methacrylate and 2-dimethylaminoethylmethacrylate commonly used in microcarrier-facilitated cell culturing studies.

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Section: Resultsmentioning

confidence: 99%

Section: Cell Morphology and Proliferationmentioning

confidence: 98%

Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

et al. 2006

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“…Wound breaking strength significantly increases in rat and nonhuman primate linear incisions through the first few weeks of wound healing as a result of a single dose of DEAE A25 at the time of wound closure. 13,14,17–20 Our unpublished data show that cells adhere, proliferate, and form cell‐bead aggregates with DEAE A25 and that macrophages clustered around the beads for up to 10 days post‐wounding. In the current studies, we attempt to correlate the increases in wound breaking strength with changes in the expression of TGF‐β1 and its receptor.…”

Section: Discussionmentioning

confidence: 95%

“…Beads were then processed for indirect immunofluorescence as previously described. 20 Briefly, cell‐bead aggregates were transferred to microcentrifuge tubes. Primary antibody was added to the aggregates in PBS at room temperature for 30–45 minutes and cells were then fixed with 3% paraformaldehyde (Aldrich Chemical Company, Inc., Milwaukee, WI).…”

Section: Methodsmentioning

confidence: 99%

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Increase in wound breaking strength in rats in the presence of positively charged dextran beads correlates with an increase in endogenous transforming growth factor‐β1 and its receptor TGF‐βRI in close proximity to the wound

Connors¹,

Gies²,

Lin

et al. 2000

Wound Repair Regeneration

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We have previously shown that positively charged beads (DEAE A25) increase wound breaking strength in linear incisions in rats and nonhuman primates at days 10-14 post-wounding. The increased wound strength may result in part from a stimulation of cells adjacent to the DEAE A25 beads to produce growth factors important for wound healing. In this report, we investigate this hypothesis by comparing the relative expression levels of transforming growth factor-beta1 and its receptor transforming growth factor-beta receptor type I in DEAE A25-treated and contralateral untreated rat linear incisions. DEAE A25-treated incisions were stronger than untreated control wounds at 3 days post-wounding, and the difference in breaking strength reached statistical significance at days 5, 7 and 10. Immunohistochemical analysis revealed a significant increase in transforming growth factor-beta1 and transforming growth factor-beta receptor type I expression in DEAE A25-treated incisions, up to 7 days post-wounding, as compared to untreated control wounds. FACS analysis revealed that macrophage cell lines exposed to DEAE A25 in vitro upregulate transforming growth factor-beta1 and transforming growth factor-beta receptor type I expression by 2-3 fold. Therefore, the increase in expression of transforming growth factor-beta1 and transforming growth factor-beta receptor type I in DEAE A25-treated incisions may be due to an increase in the concentration of macrophages adjacent to DEAE A25 beads, as well as the stimulation of individual macrophages to produce greater amounts of transforming growth factor-beta1 and transforming growth factor-beta receptor type I. This study also supports the significance of transforming growth factor-beta1 in wound healing.

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Effect of Topically Applied Charged Particles on Healing of Colonic Anastomoses

Güler¹

2002

Arch Surg

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Hypothesis: Various forms of electrical stimulation can improve wound healing in different tissues, but their application to gastrointestinal tract healing has not been investigated. We assumed that positively charged diethylaminoethyl cross-linked dextran bead (diethylaminoethyl Sephadex [DEAE-S]) particles would have a beneficial effect on the healing of colonic anastomoses. Design: Experimental animal study. Setting: Animal research laboratory of a university hospital. Animals: Forty female Wistar albino rats. Interventions: Right colonic transection and anastomosis was performed in 5 animal groups. The control group received no treatment; the placebo group, methylcellulose gel; and the DEAE-S group, DEAE-S in methyl cellulose gel applied topically around the anastomoses. The fecal peritonitis (FP) group underwent cecal ligation and perforation simultaneously with the anastomosis to cause FP; the FP + DEAE-S group also received DEAE-S applied around the anastomoses. Main Outcome Measures: After the completion of postoperative day 4, all rats were killed. Anastomotic bursting pressures and hydroxyproline concentrations in perianastomotic tissue were measured and compared. Results: Mean bursting pressures were 115.1 mm Hg in the control group, 113.6 mm Hg in the placebo group, 159.4 mm Hg in the DEAE-S group, 62.8 mm Hg in the FP group, and 121.1 mm Hg in the FP+DEAE-S group (P=.001, 1-way analysis of variance [ANOVA]). The differences between the control vs DEAE-S groups, placebo vs DEAE-S groups, and FP vs FP+DEAE-S groups were significant (PϽ.05, t test). Mean hydroxyproline concentrations were 5.2 µg/mg in the control group, 4.9 µg/mg in the placebo group, 5.6 µg/mg in the DEAE-S group, 4.5 µg/mg in the FP group, and 5.4 µg/mg in the FP+DEAE-S group (P=.09, 1-way ANOVA). The difference between the FP and FP+DEAE-S groups was significant (P=.04, t test). Conclusions: A positively charged particle, DEAE-S, improves healing of colonic anastomoses in healthy rats and in rats with FP. This inexpensive, nontoxic material is easily applied and deserves further evaluation in gastrointestinal tract healing.

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Stimulation of wound healing by positively charged dextran beads depends upon clustering of beads and cells in close proximity to the wound

Cited by 6 publications

References 33 publications

Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture

Increase in wound breaking strength in rats in the presence of positively charged dextran beads correlates with an increase in endogenous transforming growth factor‐β1 and its receptor TGF‐βRI in close proximity to the wound

Effect of Topically Applied Charged Particles on Healing of Colonic Anastomoses

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