does not absorb any fluids. transparent film dressings are used primarily on dry wounds. hydrogel dressings: this type of dressing is more directed towards infected areas and those in need of a moist environment to heal properly. it helps promote the body's own natural functions of removing necrotic tissue. it is advised not to be used on dry wounds. hydrocolloid dressings: unlike transparent film dressings, hydrocolloid dressings do not allow oxygen to reach the wound. it is a wet-to-dry technique but is not recommended for infected areas. this type of dressing can last up to 7 days with a close eye and must be removed with care. biologically based dressings: integra lifesciences’ artificial skin is placed on a wound where burned or scarred skin has been removed. the two-layer membrane provides scaffolding to regrow a new layer of dermis. alternative treatments for wounds: leeches and maggots medical leeches were cleared as a medical device in 2004 after being an indispensable tool in the 19th century and even in use in the middle ages. this unique use of creatures is utilized in many surgeries today. leeches have the ability to assist with compromised tissue with the components of their saliva. their saliva contains a local anesthetic, thrombin inhibitor, antibiotic properties and a histamine-like vasodilator. these capabilities help in surgeries such as transplants, skin grafts, and even reconstructive surgeries. the leeches help localize the wound and help produce blood flow. this is helpful in operations where blood clots occur and they help dilate the blood vessels. baron dominique jean larrey, surgeon-in-chief of napoleon's grande armée pioneered the use of maggots to prevent infection in wounds. they were also used by military medical aids during world war 2. they worked as biomedical debriding agents by ingesting bacteria and breaking them down within their intestines. maggots give off an enzyme that disinfects wounds and promotes healing and this is why they became the first organism in the united states that were used as a medical device in january 2004.