The earliest reports of tissue augmentation using subcutaneous implantation of small adipose grafts appeared over a century ago, with German surgeon Neuber. Later, with the discovery of the syringe, Brunning first injected fat in 1911, but significant resorption and fat necrosis depopularized this technique. It was not until liposuction and the concept of micro fat grafting that the use of lipoaspirate for soft-tissue augmentation successfully resurfaced. Concurrent with the initial efforts to graft fat came attempts to inject other synthetic materials to volumize soft tissue. In 1899, Robert Gersuny first injected Vaseline, while later, Eckstein used paraffin to correct fistulas and hernias and to attain aesthetic soft-tissue augmentation. However, serious complications such as granulomatous inflammatory reactions and nodule formation, embolization, and migration were reported early on, yet paraffin kept being used for over two decades before it was abandoned. The first reports of the use of silicone date from the end of World War II in Japan when numerous women had their breasts injected with non-medical grade silicone. Shortly after, in 1947, Dr. James Barrett Brown first used silicone for the correction of soft-tissue deficits in the US. Concurrently, hard and rubber silicone found use in creating alloplastic implants. However, early flawed animal experiments suggested that injectable silicone was safe, and physicians relied heavily on this improper information. The popularity of the technique led to numerous complications such as lump formation, migration, ulceration, and extrusion. In 1981, bovine collagen was the first filler approved by the FDA for soft-tissue augmentation, and it soon became the gold standard against which all fillers were compared. Its rapid resorption and allergenic nature led to a series of efforts to develop a compound that would not cause allergic reactions and that would last longer. It was not until two decades later that HA became available for clinical use. HA found multiple medical uses before it was approved in the USA as a soft-tissue filler. The high demand and success of HA products led to an intense search for products that are similar to HA, did not cause hypersensitivity reactions, but are longer lasting.
