In vitro assessment of bioadhesion for periodontal and buccal drug delivery

Bioadhesion could significantly improve oral therapeutics for periodontal diseases and mucosal lesions. This project was designed to examine the factors important to prolonged adhesion (adhesion time) in organ culture under standardized conditions. A wide variety of bioadhesives were tested in the model and the effect of mucin was also examined. Whilst many gels adhered for 1–5 h, others (chitosan and Eudispert) showed no retention loss over 4 d. Histologically, chitosan also showed excellent tissue wetting properties. For most materials, however, mucin significantly reduced adhesion times (P < 0.05). In conclusion, the absence of mucin, the control of gel hydration and swelling, and wetting characteristics were identified as key factors for prolonged adhesion.