A peptide is a short chain of amino acids bonded together by peptide bond. Peptides differ from proteins as there are shorter in length than a protein that contains more than 50 amino acids. Peptides are generally considered to be a chain of two or more amino acids. A chain that includes up to fifteen amino acids is called an oligopeptide, these include dipeptides, tripeptides, hexapeptides, pentapeptides and tetrapeptides.
In cells, peptides such as growth factors and hormones can perform biological functions and provide instructions for the cell. To produce products such as keratin, a keratin cell will synthesise a peptide from a DNA template and this will serve as the instruction to produce keratin from the protein manufacturing machinery in the cell, the ribosome, then go on to be further modified by the Golgi apparatus. This instruction will only be given in response to insulin-like growth factor and other growth factors.
Insulin-like growth factor is the major growth stimulator of the hair follicle. Insulin-like growth factor is production in the liver is stimulated by growth hormone and inhibited by stress (cortisol), inflammation or nutritional deficiencies.
Liposomal peptides in the same sequence as peptides will have the same functional effect as the biological protein. Thus, liposomal proteins identical to peptides that act as signals to instruct cell growth, can directly stimulate the increased synthesis of keratin within keratin cells without the requirement of biological growth factors.