Pop superstar Madonna has urged fans to make donations to her charity to mark her 55th birthday on Friday (16Aug13).

The singer is celebrating the milestone by boosting funds for her Raising Malawi foundation, asking devotees to hand over their cash to help her surgeon friend Dr. Eric Borgstein continue working with sick children in the country.

She has posted a picture of her pal on her Instagram.com page with a caption which reads, "Thank u (sic) all for your birthday love! Help me celebrate my birthday, by donating to Raising Malawi to support the work of one of my heroes, pediatric surgeon Dr. Eric Borgstein... Revolution of love!"