Effects of Platelet-Rich Plasma and Concentrated Growth Factor on Viability of Ultra-Diced Cartilage Grafts in a Rabbit Model.

BACKGROUND: Although rhinoplastic surgery has progressed considerably in recent years, nasal dorsal irregularities still cause postoperative distress for both surgeons and patients. PURPOSE: The aim of this study was to measure the association between two biologic graft adjuncts, platelet-rich plasma (PRP) and concentrated growth factor (CGF), and ultra-diced cartilage viability in an animal model. STUDY DESIGN, SETTING, AND SAMPLE: This study was designed as a randomized in-vivo study using a rabbit model. Fourteen rabbits were utilized in this investigation. The ultra-diced cartilage was obtained from auricular cartilage. PREDICTOR VARIABLE: The graft biologic adjunct is the predictor variable. There were three treatment groups: graft mixed with PRP or CGF or untreated (control). The grafts were placed in three separate pockets opened on the same rabbit. Grafts were harvested 3 months after insertion for analysis. MAIN OUTCOME VARIABLE(S): The primary outcome variable was histopathological and regenerative scores obtained from multiple histopathological parameters indicating the viability of the cartilage. Histopathological score parameters were chondrocyte loss, inflammation, fibrosis, cartilage fragmentation, and calcified area formations in the lacunae. Regenerative score parameters were peripheral cell proliferation in the cartilage tissue, vascularization in the connective tissue, proteoglycan increase in the matrix, and the amount of connective tissue. COVARIATES: The variables were age, sex, and weight. ANALYSES: Statistical analysis employed the analysis of variance test, with a significance level of P < .05. RESULTS: The sample was composed of 14 rabbits and 42 samples. The histopathologic scores were 11.93 (±2.49), 8.78 (±2.19), and 6.85 (±1.46) for the control, PRP, and CGF groups, respectively. A statistically significant difference was found in the PRP (P < .0275) and CGF (P < .0001) groups compared to the control group. The regenerative scores were 6.21 (±0.97), 8.85 (±1.70), and 12.07 (±1.26) for the control, PRP and CGF groups, respectively. A statistically significant difference was found in the PRP (P < .0159) and CGF (P < .0001) groups compared to the control group. CONCLUSION AND RELEVANCE: This is the first study investigating the ultra-diced cartilage graft in an experimental animal model. Histopathological examination has shown that mixing ultra-diced cartilage with CGF or PRP increases viability by reducing the histopathological score and increasing the regenerative score.

Effects of a Thermosensitive In Situ Gel Containing Mometasone Furoate on a Rat Allergic Rhinitis Model.

Background Mometasone furoate, one of the second generation intranasal corticosteroids, is currently used in suspension form due to its poor solubility. However, this is not favorable for nasal application because of the rapid elimination of the instilled drug from the nasal cavity by mucociliary clearance and delayed onset of action due to the slow dissolution of drug in suspension. Objective The aim of this study was to determine the antiallergic effects of mucoadhesive thermosensitive in situ gel containing mometasone furoate that we developed previously to prolong the contact between the drug and nasal mucosa and to prevent drainage of the formulation in an ovalbumin-induced rat model of allergic rhinitis. Methods An experimental allergic rhinitis model was developed in female Wistar albino rats by intraperitoneal injection of ovalbumin every 2 days for 14 days followed by its repeated intranasal instillation for 7 consecutive days. Intranasal instillation of ovalbumin was continued every other day for 14 days. Mometasone furoate in situ gel (5 µg/10 µl), mometasone furoate suspension (5 µg/10 µl), and physiological saline (10 µl) were administered into the bilateral nasal cavities from day 22 to day 35. Antiallergic effects were evaluated through histopathological evaluation, analysis of ovalbumin-specific serum immunoglobulin E, and a symptom score. Results Mometasone furoate in situ gel significantly decreased the nasal symptoms and ovalbumin-specific serum immunoglobulin E level as compared with mometasone furoate suspension and physiological saline. Additionally, inflammatory histological symptoms such as mucosal edema, vascular dilatation, eosinophil infiltration, and loss of cilia within the nasal mucosa of allergic rhinitis model rats were remarkably improved with the treatment of mometasone furoate in situ gel. Conclusion These results suggest that mometasone furoate in situ gel has a better therapeutic potential for the treatment of allergic rhinitis compared to mometasone furoate suspension.