Biomedical subjects

Susan Y Quan

Publications and source records attributed to Susan Y Quan.

3 recordsLinked to original sources

PubMed2005

Combined effect of hyberbaric oxygen and N-acetylcysteine on fibroblast proliferation.

OBJECTIVE: To examine the combined effect of hyperbaric oxygen and N-acetylcysteine, a well-studied antioxidant, on fibroblast proliferation and production of 3 specific growth factors: basic fibroblast growth factor, vascular endothelial growth factor, and transforming growth factor beta1. DESIGN: In vitro study. SUBJECTS: None. INTERVENTIONS: Human dermal fibroblasts were propagated in serum-free medium and subjected to daily 90-minute 2-atm hyperbaric oxygen treatments with varying concentrations of N-acetylcysteine for 7 consecutive days. Cell proliferation and growth factor assays were performed on days 0, 1, 3, 5, and 7. RESULTS: Population doubling time decreased significantly with 40 micromol/L of N-acetylcysteine supplementation of 2-atm hyperbaric oxygen treatment. Higher levels of N-acetylcysteine increased population doubling time. CONCLUSIONS: Supplementation of hyperbaric oxygen therapy with 40 mumol/L of N-acetylcysteine appears to increase fibroblast proliferation without producing an unfavorable growth factor profile for normal healing. This suggests that this level of N-acetylcysteine may foster an ideal redox environment for fibroblast proliferation in a hyperbaric oxygen environment.

Acetylcysteine↗

PubMed2003

Cartilage tissue engineering using cryogenic chondrocytes.

OBJECTIVE: To generate in vitro hyaline cartilage from cryogenically preserved human septal chondrocytes in a simulated microgravity environment on a 3-dimensional biodegradable scaffolding material. METHODS: In this experiment, cryogenically frozen chondrocytes were thawed and cultured in a monolayer in serum-based chondrocyte media. They were seeded onto 3-dimensional biopolymer scaffolds in a spinner flask. The seeded constructs were then transferred to a bioreactor (an environment of solid-body rotation) for 6 weeks. Chondrocyte growth and extracellular matrix production in the constructs were confirmed by cell count, cell viability, and histologic analysis and by electron microscopy. RESULTS: Histologic sections stained with hematoxylin-eosin and Alcian blue (for acidic proteoglycans) confirmed the presence of hyaline cartilage in the cartilage constructs. Ultrastructural examination using transmission electron microscopy demonstrated matrix formation and chondrocyte viability. CONCLUSIONS: This study proves that chondrocytes that are cryogenically stored for extended periods can be used to grow cartilage in vitro. Cryogenically preserved chondrocytes retain their ability to grow in tissue culture, redifferentiate, and produce extracellular matrix.

Bioreactors↗

PubMedDate not supplied

Effect of hyperbaric oxygen on the growth factor profile of fibroblasts.

OBJECTIVES: Hyperbaric oxygen (HBO) has been used in the clinical setting to heal problem wounds, yet its direct effects on fibroblasts are not clear. The present study evaluates the effects of HBO on the growth and autocrine production of growth factors by fibroblasts grown in an in vitro, serum-free environment. METHODS: Human dermal fibroblasts were propagated in serum-free media and subjected to daily 90-minute HBO treatments at 1.0, 1.5, 2.0, 2.5, and 3.0 atm of pressure for 7 consecutive days. Cell proliferation and growth-factor assays for basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and transforming growth factor beta1 (TGF-beta1) were performed on days 1, 3, 5, and 7. RESULTS: On day 1, HBO inhibited growth of fibroblasts at all atmospheric pressures compared with control. By day 7, cell proliferation was significantly enhanced only in cells treated with 2.0-atm HBO compared with controls. Secretion of bFGF was significantly increased by HBO-treated fibroblasts on day 1; VEGF levels slightly increased with HBO treatment on day 1, but this effect was not statistically significant; TGF-beta1 levels were detectable on day 1 only for control and HBO-treated cells at 1.0 atm, and not detectable for any cell groups after day 1. CONCLUSIONS: These results suggest that daily HBO treatment enhances the growth of fibroblasts when administered to a critical degree. Also, HBO appears to directly effect fibroblast production of autocrine growth factors on initial exposure. We postulate that fibroblasts possess the ability to respond to hyperoxia directly, which causes changes in cell signaling pathways involved in cellular proliferation and growth factor production.

Cell Communication↗