a substance that is an important part of skin and connective tissue (= material that supports and connects organs and joints in the body), and that is used in some products and treatments intended to make the skin healthy and attractive

The treatment involves injecting a form of hyaluronic acid into the dermis that underlies the wrinkles. 该疗法涉及将一种透明质酸注射到皱纹所在的真皮层。