The present invention provides a tissue expander (10) comprising a self-inflating core (12or 2e) having a non-inflated state and an inflated state and a coating (14) surrounding said core (12or 12e), in which said core (12or 12e) comprises a compacted self-inflating material and said coating comprises a fluid impermeable material having a plurality of apertures therethrough for allowing the passage of fluid to the core (12or12e) and in which the coating (14) is separable or separated from the core (12or 12e) such as to allow the coating to provide a support function during use. The invention also provides a method of manufacturing the product.
