The proinflammatory
cytokine,
tumor necrosis factor-α (TNF-α), is elevated in several diseases such as
uveitis,
rheumatoid arthritis and non-healing chronic
wounds. Adding
Infliximab, a chimeric
IgG1 monoclonal antibody raised against TNF-α, to chronic
wound fluid can neutralise human TNF-α, thereby providing a potential therapeutic option for chronic wound healing. However, to avoid the need for repeated application in a clinical setting, and to protect the therapeutic antibody from the hostile environment of the
wound, suitable delivery vehicles are required. Porous
silicon (pSi) is a biodegradable high surface area material commonly employed for
drug delivery applications. In this study, the use of pSi microparticles (pSi MPs) for the controlled release of
Infliximab to disease environments, such as chronic
wounds, is demonstrated. Surface chemistry and pore parameters for
Infliximab loading are first optimised in pSi films and loading conditions are transferred to pSi MPs. Loading regimens exceeding 60 μg of
Infliximab per mg of pSi are achieved.
Infliximab is released with zero-order release kinetics over the course of 8 days. Critically, the released antibody remains functional and is able to sequester TNF-α over a weeklong timeframe; suitable for a clinical application in chronic
wound therapy.