ABSTRACT
Vitamin C or L-ascorbic acid has diverse functions in the body, especially healing promotion in tissue injury via participating in the hydroxylation reactions required for collagen formation. Systemic administration of vitamin C plays an important role on gingival fibroblast proliferation and functions. Whether local or rinsing administration of vitamin C alters gingival fibroblast wound healing behavior remains unclear. The aim of this study was to investigate the rinsing effect of vitamin C on gingival fibroblast behavior utilizing an in vitro wound healing model. Primary human gingival fibroblasts isolated from gingival tissue were rinsed with medium containing various concentrations of vitamin C. The rinsing effect of vitamin C on in vitro wound healing was assessed using a scratch test assay. Cell migration, cell viability, and extracellular matrix gene expression were analyzed by transwell migration assay, MTT assay, and real-time RT-PCR, respectively. We found that rinsing with 10 or 20 µg/ml vitamin C significantly increased fibroblast migration (p ≤ 0.05). However, no significant effect was found in the cell viability or in vitro wound healing assays. In contrast, rinsing with 50 µg/ml vitamin C significantly delayed wound closure (p ≤ 0.05). Real-time PCR demonstrated that 50 µg/ml vitamin C significantly increased fibroblast expression of COL1, FN, IL-6, and bFGF. The data demonstrate that rinsing with vitamin C (10/20 µg/ml) accelerates fibroblast migration. However, 50 µg/ml of vitamin C increases the expression of COL1, FN, IL-6, and bFGF, which are related to fibroblast wound healing activity. Prescribing vitamin C with the appropriate duration and drug administration method should be determined to maximize its benefit.
ABSTRACT
STATEMENT OF PROBLEM: Candida adherence to the denture base is an important cause of denture stomatitis. In addition, infections with drug-resistant Candida have become more prevalent, especially among elderly and immunocompromised patients. Thus, alternative safe antifungal agents for oral applications are needed. PURPOSE: The purpose of this in vitro study was to investigate the activity of chitosan, a natural biopolymer, against common oral Candida species and its efficacy in inhibiting C albicans adherence to denture-base acrylic resin. MATERIAL AND METHODS: The minimum fungicidal concentrations (MFCs) of 5 types of chitosan against 6 species of Candida and 10 C albicans clinical isolates were determined by broth and agar dilution, respectively. N-succinyl chitosan (NSC), low- and high-molecular-weight water-soluble chitosan (LMWC and HMWC), and oligomer and polymer shrimp-chitosan were examined. NSC and HMWC, as pure gel and as a mixture with carboxymethylcellulose (CMC), were applied to acrylic resin disks, incubated with C albicans for 24 hours, and washed, and adherent cells were collected for colony count. The effects of HMWC on human gingival fibroblasts after 1 and 24 hours of treatment were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The retention force of HMWC gel was measured by using a universal testing machine. The Kruskal-Wallis and Mann-Whitney U tests were used to compare the antiadherence activity (α=.05). RESULTS: HMWC had the highest antifungal activity against most Candida species tested and C albicans clinical isolates. HMWC gel completely inhibited C albicans adherence to denture base acrylic resin (P<.001). CMC denture adhesive significantly increased C albicans adherence (P<.001), but adding 2×MFC HMWC into CMC reduced the adherence, although this was not statistically significant (P=.06). HMWC at 1×MFC and 2×MFC showed no toxic effect on gingival fibroblast viability and proliferation. Moreover, the retention force provided by HMWC gel was sufficient for use as a denture adhesive (>5000 Pa). CONCLUSIONS: High-molecular-weight, water-soluble chitosan is a biocompatible biopolymer that could inhibit C albicans adherence and that showed properties suitable for development into an antifungal denture adhesive.
