Azficel-T

The mechanism of action of azficel-T, or autologous human fibroblasts, is not fully elucidated. Autologous fibroblasts correct dermal defects such as acne or other dermal conditions associated with aging, such as reduced elasticity. The importance of collagen matrix production by fibroblasts in maintaining skin integrity and reducing the appearance of scars has been highlighted. The appearance of acne scars is also associated with the loss of collagen at the site of inflammation following resolution of localized intense inflammation and wound healing associated with inflammatory acne. Fragmentation of the dermal collagen matrix occurs in the natural aging process; due to UV-induced photodamage and the actions of collagen-degrading enzymes (matrix metalloproteinases, MMPs) overtime, the structural integrity of the dermis and function of fibroblasts may be impaired. While fibroblasts are responsible in the synthesis, organization, regulation and the maintenance of collagen network, the function of fibroblasts are strongly dependent on the physical properties of collagen fibres, and vice versa. The aging process is associated with a reduced rate of collagen turnover and formation of modified crosslinks that normally give structural support for collagen fibres. These crosslinks prevent the removal of degraded collagen, leading to accumulation of collagen fragments within the extracellular matrix, and compromised structural and mechanical integrity of the dermis. Integrins that are expressed by the fibroblasts allow the cell to bind to collagen matrix and allow mechanical tension within fibroblasts and the collagenous matrix. In the presence of fragmented collagen, the fibroblasts lose attachment to the collagen matrix and collapse within the dermis and subsequently leads to reduced collagen production and increased production of MMPs. Autologous human fibroblasts have the ability to increase the formation of human collagen in vivo and promote remodelling of pre-existing extracellular matrix in the scarred tissue. They may also decrease the degradation of collagen.