Background: Multiple oral complications were reported in patients who receive radiotherapy for head and neck cancers.
Objectives: Investigating the healing power of bone marrow derived mesenchymal stem cells compared to microvesicles on dorsal lingual mucosa in irradiated albino rats.
Methods: 30 adult male albino rats were used. Rats were then divided randomly into three groups, 10 rats each. Group A: Irradiated rats received no treatment. Group B: Irradiated rats received a single dose of 1×106  bone marrow derived mesenchymal stem cells (BM-MSCs) injected intravenously, immediately after irradiation. Group C: Irradiated rats received a single dose of 30 μg microvesicles (derived from bone marrow stem cells) injected intravenously, immediately after irradiation. Each animal group was further divided into two subgroups (5 rats each) according to their date of scarification as follows: Subgroup I: The animals were sacrificed at day 3 following irradiation. Subgroup II: The animals were sacrificed at day 7 following irradiation. After scarification the tongue was dissected and examined histologically, histochemically and by real time-polymerase chain reaction (RT-PCR) for keratin 10 expression.
Results: Histologically, irradiated groups received no treatment (groups AI&AII) showed marked epithelial and connective tissue degeneration. On the other hand both treated irradiated groups showed marked improved histological features (group B & C) during both experimental periods (3 and 7 days). However the microvesicles treated group demonstrated normal histology especially at 7 days. Histochemical examination using masson´s trichrome stain revealed an increased collagen density in groups (B & C) as compared to group A during both experimental periods. This increase was statistically significant. RT-PCR results showed statistically significant increase in keratin 10 expression in groups (B & C) as compared to group A during experimental periods I & II.
Conclusions: Both BM-MSCs and microvesicles showed healing power in atrophied epithelium and connective tissue of dorsal lingual mucosa after radiotherapy, however treatment with microvesicles revealed more positive effect than BM-MSCs.