Porous silicon advances in drug delivery and immunotherapy

• Porous silicon particles can be fabricated in diverse geometrical configurations and sizes.
• Multistage delivery of therapeutics for cancer is superior to single particle therapy.
• pSi microparticles presenting pathogen-associated molecular patterns activate immune cells.

Biomedical applications of porous silicon include drug delivery, imaging, diagnostics and immunotherapy. This review summarizes new silicon particle fabrication techniques, dynamics of cellular transport, advances in the multistage vector approach to drug delivery, and the use of porous silicon as immune adjuvants. Recent findings support superior therapeutic efficacy of the multistage vector approach over single particle drug delivery systems in mouse models of ovarian and breast cancer. With respect to vaccine development, multivalent presentation of pathogen-associated molecular patterns on the particle surface creates powerful platforms for immunotherapy, with the porous matrix able to carry both antigens and immune modulators.