Growth and growth factor production by human nasal septal chondrocytes in serum-free media.

BACKGROUND: Tissue-engineered human cartilage offers vast possibilities as a source of graft implant material for reconstructive surgery. Serum-supplemented growth media is successful in supporting chondrocyte proliferation in vitro. Serum, however, contains exogenous growth factors that hamper the identification and quantification of growth factors autogenously produced by chondrocytes. We explore the possibility of using a commercially available serum-free medium UltraCULTURE as an alternative to modified Webber's medium (MWM), the standard media used in chondrocyte cell culture. METHODS: Human nasal septal chondrocytes were grown in UltraCULTURE containing various concentrations of basic fibroblast growth factor (bFGF; 0, 1, 10, and 100 ng/mL) with or without insulin-like growth factor and compared with chondrocytes grown in MWM. Growth curves and transforming growth factor (TGF) beta 1 production were analyzed. RESULTS: We found no differences in the ability to sustain cell viability in culture between the two base media types. We also found no statistically significant differences in TGF-beta 1 production by chondrocytes grown in either system. Finally, there were no statistically significant differences in chondrocyte proliferation between cultures supplemented with bFGF at 10 and 100 ng/mL. CONCLUSION: UltraCULTURE media is a cost-effective, serum-free alternative to standard media with compatible growth characteristics. It offers specific advantages over standard serum-containing media for the precise measurement of autogenous growth factor production by cultured chondrocytes. Furthermore, UltraCULTURE's serum-free environment would be ideal for safely producing tissue-engineered cartilage grafts.

Effects of tamoxifen on normal human dermal fibroblasts.

OBJECTIVE: To evaluate the effects of tamoxifen on the growth and autocrine growth factor production of human dermal fibroblasts from the face. METHODS: In vitro study of normal adult dermal fibroblast cells developed from surgical specimens in a serum-free model. Cell cultures were exposed to 5-, 8-, 12-, 16-, and 50-microg/mL concentrations of tamoxifen solution. Cell counts were performed, and the cell-free supernatants were collected at 0, 1, 3, 5, and 7 days after the initial exposure. Population doubling times were calculated, and supernatants were quantitatively assayed for basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF) beta1. RESULTS: Tamoxifen appears to delay cellular proliferation rates in a dose-dependent manner up to a concentration of 12 microg/mL. Higher concentrations, approaching 50 microg/mL, appear to have a toxic effect on cell growth. The analysis of growth factor production revealed decreased levels of bFGF and VEGF but no change in the levels of TGF-beta1. CONCLUSIONS: The in vitro findings of delayed cell proliferation and decreased production of VEGF and bFGF in cells exposed to tamoxifen are consistent with previous in vivo reports of delayed wound healing but improved scar formation. The in vitro findings of growth factor modulation by tamoxifen provide cellular and molecular evidence supporting the clinical use of tamoxifen to ultimately improve scar formation.

Facial resurfacing for nonmelanoma skin cancer prophylaxis.

OBJECTIVE: To determine the effect of facial skin resurfacing for treatment of actinic keratoses (AKs) and prophylaxis against new primary basal and squamous cell carcinomas in individuals with previous nonmelanoma skin cancer (NMSC) or severe photodamage. DESIGN: Randomized, prospective 5-year trial. SETTING: Dermatology and otolaryngology clinics of a Veterans Affairs hospital. PATIENTS: Thirty-four patients with a history of facial or scalp AKs or basal or squamous cell carcinoma were enrolled. Five of 7 eligible patients who declined study-related treatment were used as controls. Twenty-seven patients were randomized to 3 treatment arms; 3 patients were discontinued from the study. INTERVENTIONS: Carbon dioxide laser resurfacing, 30% trichloroacetic acid peel, or 5% fluorouracil cream applied twice daily for 3 weeks. MAIN OUTCOME MEASURES: Reduction in the number of AKs was measured 3 months after treatment. The incidence of new NMSC in treated areas was assessed between January 1, 2001, and June 30, 2005. Times from baseline to diagnosis of first skin cancer were compared between the treatment and control groups. RESULTS: Treatment with fluorouracil, trichloroacetic acid, or carbon dioxide laser resulted in an 83% to 92% reduction in AKs (P< or =.03), a lower incidence of NMSC compared with the control group (P<.001), and a trend toward longer time to development of new skin cancer compared with the control group (P=.07). However, no significant differences were noted among the treatment groups. CONCLUSION: All 3 modalities demonstrated benefit for AK reduction and skin cancer prophylaxis compared with controls and warrant further study in a larger trial.

Effects of mitomycin-C on normal dermal fibroblasts.

OBJECTIVES: To evaluate the effects of mitomycin-C on the growth and autocrine growth factor production of human dermal fibroblasts from the face. STUDY DESIGN: In vitro study using normal adult dermal fibroblast cell lines in a serum-free model. METHODS: Cell cultures were exposed to 4 mg/mL, 0.4 mg/mL, 0.04 mg/mL, 0.004 mg/mL, and 0.0004 mg/mL concentrations of mitomycin-C solution. Cell counts were performed, and the cell-free supernatants were collected at 0, 1, 3, and 5 days after the initial exposure. Population doubling times were calculated and supernatants were quantitatively assayed for basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta1. RESULTS: Continuous exposure to mitomycin-C caused fibroblast cell death by day 7 at all tested concentrations. A 4 minute exposure to mitomycin-C at 4 mg/mL caused rapid fibroblast cell death. A 4-minute exposure to mitomycin-C at either 0.4 mg/mL or 0.04 mg/mL resulted in decreased fibroblast proliferation. A 4 minute exposure to mitomycin-C at 0.4 mg/mL resulted in a marked increase in the production of both bFGF and TGF-beta1. CONCLUSIONS: A clinically ideal concentration of mitomycin-C would slow fibroblast proliferation yet not cause cell death to allow for a wound healing response. Mitomycin-C 0.4 mg/mL for 4 minutes satisfies the above criteria in vitro.

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.

Effects of copper tripeptide on the growth and expression of growth factors by normal and irradiated fibroblasts.

OBJECTIVE: To evaluate the effects of copper tripeptide (GHK-Cu) on the growth and autocrine production of basic fibroblast growth factor, transforming growth factor beta1, and vascular endothelial growth factor by normal and irradiated fibroblasts in a serum-free in vitro environment. METHODS: Primary human dermal fibroblast cell lines were established after explantation from intraoperative specimens obtained from patients who had undergone radiation therapy for head and neck cancer. Normal and irradiated fibroblasts were propagated in serum- and growth factor-free media. Treatment groups were exposed to GHK-Cu (1 x 10(-9) mol/L). We measured cell counts and production of basic fibroblast growth factor, transforming growth factor beta1, and vascular endothelial growth factor. RESULTS: Irradiated fibroblasts survived and replicated in serum-free media. The population-doubling times of normal and irradiated fibroblasts exposed to GHK-Cu were faster than those of nontreated controls. Irradiated fibroblasts treated with GHK-Cu doubled at a rate that approximated that of untreated controls, and produced significantly more basic fibroblast growth factor and vascular endothelial growth factor than untreated controls early after GHK-Cu exposure. CONCLUSIONS: Irradiated fibroblasts survive and replicate in serum-free media, establishing this model as ideal for evaluating growth factor production in vitro. Copper tripeptide accelerates the growth of normal and irradiated fibroblasts to the point where treated irradiated fibroblasts approximate the population-doubling time of normal controls. An early increase in basic fibroblast growth factor and vascular endothelial growth factor production by GHK-Cu-treated irradiated fibroblasts may improve wound healing.

Radiofrequency nonablative tissue tightening.

Minimally invasive procedures have become an extremely important component of a facial cosmetic surgery practice. This article describes a new radiofrequency device that tightens soft tissue without ablating the skin. The net result of this is a noninvasive brow lift, facelift, or neck lift. This modality does not replace current surgical procedures but is an excellent complement to them and a treatment option for patients to consider. The author's experience with this device is discussed.

The effect of silicone gel on basic fibroblast growth factor levels in fibroblast cell culture.

BACKGROUND: Topical silicone gel has shown promise in the treatment of hypertrophic and keloid scars. However, its mechanism of action remains undetermined. OBJECTIVE: To investigate whether the presence of silicone alters the secretion of basic fibroblast growth factor (bFGF), a key cytokine involved in the scar formation process. DESIGN: Serum-free fibroblast cell cultures were established from normal, keloid, and fetal skin, which heals without scarring, and exposed to silicone gel. Serial cell counts were performed, and supernatants were collected for bFGF quantification by enzyme-linked immunosorbent assay at 4, 24, 72, and 120 hours. RESULTS: Growth curves were similar and no statistically significant differences in population doubling times were observed between treated and untreated specimens. Statistically significant differences in bFGF levels between treated and untreated normal fibroblasts were observed at 24, 72, and 120 hours after cell culture initiation. Differences in bFGF levels between treated and untreated fetal fibroblasts that approached statistical significance were observed at 72 and 120 hours. CONCLUSIONS: These results suggest that silicone gel is responsible for increased bFGF levels in normal and fetal dermal fibroblasts. We postulate that silicone gel treats and prevents hypertrophic scar tissue, which contains histologically normal fibroblasts, by modulating expression of growth factors such as bFGF. Our data support the hypothesis that substances that favorably influence wound healing do so by correcting a deficiency or overabundance of the growth factors that orchestrate the tissue repair process.

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.

Prevention and correction of nasal tip bossae in rhinoplasty.

OBJECTIVE: To describe our experiences with nasal tip bossae, suggest a standard nomenclature, discuss causative factors, and provide a comprehensive, analytic approach to the prevention and correction of bossae. BACKGROUND: Nasal tip bossae are knoblike protuberances of the alar cartilages that can arise after rhinoplasty. Early bossae are due to uncorrected or inadvertently created asymmetries, while late bossae are due to fibrosis and scar contracture acting on a weakened or unreconstituted cartilaginous framework. Numerous techniques may be used to prevent and treat bossae; however, we found no article in the existing literature that presents an in-depth, analytic description of management techniques. METHODS: We analyzed the predisposing factors and techniques leading to bossa formation and studied principles of prevention and correction. All rhinoplasty cases that presented for revision from 1985 through 2000 were reviewed for bossae formation via internal computer search. Previous operative records for rhinoplasty cases were examined when available. Intraoperative notes and photgraphs of the revision surgery were examined. RESULTS: Etiologies for bossae were consistently found, and successful treatment modalities were noted. CONCLUSIONS: Nasal tip bossae are most often due to dynamic forces acting on iatrogenic changes and/or weakness in the alar cartilages. By minimizing cartilage excision, reinforcing areas of weakness, avoiding asymmetry and irregularity, and maintaining alar integrity, formation of bossae may be prevented. The treatment of bossae must be individualized and can range from simple suture stabilization techniques to complex domal cartilage replacement grafts, depending on the observed defect.

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.

Growth factor profile of irradiated human dermal fibroblasts using a serum-free method.

Radiation therapy for cancer permanently damages tissue in the line of treatment. This study sought to establish a serum-free protocol to evaluate the growth of irradiated fibroblasts and to analyze the levels of basic fibroblast growth factor (bFGF) and transforming growth factor-beta (TGF-beta) compared with normal fibroblasts. One irradiated cell line of human dermal fibroblasts was established from an intraoperative specimen obtained from a patient who had undergone radiation therapy for head and neck cancer. Irradiated and normal fibroblasts were then plated in UltraCULTURE (serum and growth factor free), modified Webber's medium (bFGF 50 ng/ml, insulin-like growth factor 100 ng/ml), and Dulbecco's Modified Eagle Medium with 10% fetal bovine serum (serum with undefined basal growth factors). Irradiated cells were also seeded in UltraCULTURE with 50 and 100 ng/ml of bFGF. Cell counts were performed at 0, 1, 3, 5, and 7 days, and cell supernatants were assayed for bFGF and TGF-beta. Irradiated and normal fibroblasts exhibited stronger growth in modified Webber's medium than in Dulbecco's Modified Eagle Medium with 10% fetal bovine serum. Growth of irradiated fibroblasts under bFGF modulation was similar to their growth in Webber's medium. Furthermore, irradiated fibroblasts remained viable in a serum-free and growth factor-free environment for at least 7 days; however, their growth and autocrine growth factor production was less than that of normal cells. This confirms the results of previous studies suggesting that cells from irradiated tissue undergo cellular changes. This study provides an effective model for the first-line evaluation of agents to improve wound healing, and it helps to establish standard levels of bFGF and TGF-beta production for irradiated fibroblasts.

Heparin stimulates production of bFGF and TGF-beta 1 by human normal, keloid, and fetal dermal fibroblasts.

BACKGROUND: Heparin decreases dermal fibroblast proliferation and collagen production according to several studies. Heparin may mediate these effects by altering the levels of growth factors such as basic fibroblast growth factor (bFGF) and transforming growth factor-beta 1 (TGF-b1). This study sought to delineate the effect of heparin on proliferation and bFGF and TGF-b1 production by human normal, keloid, and fetal dermal fibroblasts. MATERIAL/METHODS: Human normal, keloid, and fetal dermal fibroblasts were propagated in a serum-free in vitro model, with exposure to 0 microg/ml, 50 microg/ml, 300 microg/ml, or 600 microg/ml heparin for 0, 24, 72, or 96 hours. Cell counts were determined by phase contrast microscopy. Levels of bFGF and TGF-b1 in the supernatants were determined by enzyme-linked immunosorbant assay (ELISA). RESULTS: Heparin inhibited keloid and fetal fibroblast proliferation. All doses of heparin significantly stimulated production of bFGF by normal (341% to 1137% increase), keloid (237% to 1955% increase), and fetal fibroblasts (292% to 1866% increase) at all time points (p<0.05). Heparin (300 microg/ml and 600 microg/ml) also stimulated production of TGF-b1 by normal (56% to 75%), keloid (105% to 269%), and fetal fibroblasts (25% to 57%), with statistical significance (p<0.05) at various time points. 600 microg/ml heparin generally caused the greatest increase in growth factor levels. CONCLUSIONS: Heparin inhibits proliferation by keloid and fetal fibroblasts and significantly stimulates production of bFGF and TGF-b1 by normal, keloid, and fetal dermal fibroblasts. These effects of heparin on dermal fibroblasts may have implications for wound healing in vivo.

Autocrine growth factor production by fetal, keloid, and normal dermal fibroblasts.

OBJECTIVE: To evaluate differences in fibroblast autocrine growth factor production by human fetal, keloid, and normal adult dermal fibroblasts. DESIGN: Serum-free cell lines of fetal, keloid, and normal adult dermal fibroblasts were established. Cell counts were performed and supernatants collected at 4, 24, and 72 hours. Cell-free supernatants were quantitatively assayed for transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF). RESULTS: Population doubling times for fetal, keloid, and normal adult fibroblasts were 120.0, 88.1, and 128.4 hours, respectively. Differences in population doubling times did not reach statistical significance. Statistically significant differences between TGF-beta1 levels from fetal and normal adult fibroblasts were seen at 24 and 72 hours. Significant differences between TGF-beta1 levels from keloid and normal adult fibroblasts were also seen at 24 and 72 hours. Fetal fibroblasts demonstrated higher levels of bFGF than normal adult fibroblasts at each time point, but these differences were not statistically significant. No significant differences were observed between keloid and normal adult bFGF levels. CONCLUSIONS: Both fetal and keloid fibroblasts produce significantly more TGF-beta1 than normal adult fibroblasts. Our data and the data of others suggest that fetal fibroblasts produce more bFGF than adult fibroblasts. The serum-free model we describe can be used to quantitatively measure autocrine growth factor production by cells that underlie clinically different types of wound healing. This model provides information that may allow us to better treat and prevent undesirable scarring.

Effect of blended CO2 and erbium:YAG laser irradiation on normal and keloid fibroblasts: a serum-free study.

OBJECTIVE: The purpose of this study was to determine the effect of combined CO2 and Er:YAG laser irradiation on normal (NF) and keloid (KF) facial dermal fibroblast production of TGF-beta1 and bFGF. BACKGROUND DATA: Keloids produce excess collagen. TGF-beta1 is integral to the growth and stimulation of fibroblasts and collagen; bFGF inhibits collagen synthesis. TGF-beta1 and bFGF production influence wound healing and may be manipulated by laser irradiation. MATERIALS AND METHODS: Human normal fibroblasts (NF) and keloid fibroblasts (KF) (2 x 10(4) cells/mL in serum-free media) were exposed to 1.7 J/pulse Er:YAG laser energy and CO2 delivered at either 3 or 5 W and at a duty cycle of 25%, 50%, or 100%. TGF-beta1 and bFGF were assayed using a quantitative ELISA. RESULTS: KF demonstrated a statistically significant mean population doubling time (PDT) when compared with NF (p=0.01). Irradiated KF and NF had longer PDTs than controls. All NF, excluding one irradiated group, and the three KF treated with 3 W secreted more bFGF than controls. Irradiated KF secreted less TGF-beta1 than controls. Significance was reached with the two groups exposed to 3 W at a duty cycle of 25% and 50% (p=0.04 and 0.05, respectively). All irradiated NF secreted less TGF-beta1 than controls. CONCLUSION: The combined CO2 and Er:YAG laser increased the release of bFGF, which has been shown to promote tightly organized collagen bundles, and decreased the concentration of TGF-beta1, which has also been shown to promote fibrosis formation. This laser may have a future role in keloid treatment, as well as normal facial scar prevention.

Triamcinolone stimulates bFGF production and inhibits TGF-beta1 production by human dermal fibroblasts.

BACKGROUND: Triamcinolone acetonide has been shown to decrease both cellular proliferation and collagen production by dermal fibroblasts. An alteration of cytokine levels may mediate these effects. OBJECTIVE: To delineate the effect of triamcinolone acetonide on both cellular proliferation and the production of basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGF-beta1) by human fibroblasts grown in a serum-free in vitro model. METHODS: Human normal and keloid dermal fibroblasts were propagated in a serum-free in vitro model with exposure to 0, 5, 10, or 20 microm triamcinolone acetonide for 0, 24, 72, or 96 hours. Cell counts were determined by phase contrast microscopy. Levels of bFGF and TGF-beta1 in the supernatants were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: In our study, 20 microm triamcinolone acetonide caused statistically significant increases in the peak levels of bFGF for normal and keloid fibroblast cell lines (P < 0.05). It also caused statistically significant decreases in the level of TGF-beta1 for normal and keloid fibroblast cell lines. For the keloid fibroblasts, 10 microm triamcinolone acetonide also caused a statistically significant decrease in the level of TGF-beta1. CONCLUSION: We conclude from these results that triamcinolone acetonide increases the production of bFGF and decreases production of TGF-beta1 by human dermal fibroblasts.