Ms Alicia Fernández San Millán's, an agricultural engineer has developed a technique which uses plastidial transformation which results in the production of Human serum albumin (HSA) from tobacco plants. HSA is an intravenous protein most commonly used in the world for therapeutic needs.
It is mainly used to stabilize blood volume and to avoid risk of heart attacks. It is used for haemorrhages, burns, surgical operations or when the patient shows symptoms of malnutrition or dehydration, chronic infections and renal or liver illnesses. The annual consumption of HSA in Spain is about 10 tons and across the world it is exceeds 500 tons. She said that this technique is an economically viable alternative.
By using this technique one can produce HSA in large quantities than those obtained by nuclear transformation. This technique has been patented at a world level and there is already a company interested in marketing it. Usually commercial albumin is extracted from blood but it is not sufficient to meet the world demand. The other methods are obtaining HSA from yeasts and mammal cells.
The price at the pharmacy of albumin produced using plasma is 4 euros per gram whereas the production cost is between 300 and 4,000 euros per gram. Another alternative is the production of albumin from vegetables using nuclear transformation. On the other hand the plastidial system enables the extraction of great quantities of albumin.
With nuclear transformation, the maximum level obtained is 0.5% and from plastidial transfer it is increased to 14-7%. With the nuclear transformation method, gene integrates into the DNA of the cell nucleus of the leaf and, thus, can only manage a small number of copies. With the plastidial system the gene is introduced into the chloroplast, where photosynthesis takes place and where the genomes can multiply up to 10,000 times. Care should be taken that the genes do not escape through pollen transmission.
The tobacco plant is very easy to handle genetically and also it is great generator of biomass. The protein is produced in the chloroplasts, the more the leaf biomass the more the albumin. But the trails are all conducted in the tobacco plants have been with laboratory varieties. The aim is to do tests with commercial varieties.
The commercial varieties of tobacco are some 30 times more productive in terms of biomass. But further experiments have to be done as this protein has to be injected intravenously into patients, it has to be thoroughly purified to eliminate any kind of contaminant. Moreover, it is necessary to assure that the protein obtained has an identical structure to the human one to guarantee that its functioning will be 100%.