Development of porous silicon nanocarriers for parenteral peptide delivery.

Porous silicon (PSi) is receiving growing attention in biomedical research, for example, in drug and peptide delivery. Inspired by several advantages of PSi, herein, thermally oxidized (TOPSi, hydrophilic), undecylenic acid-treated thermally hydrocarbonized (UnTHCPSi, moderately hydrophilic), and thermally hydrocarbonized (THCPSi, hydrophobic) PSi nanocarriers are investigated for sustained subcutaneous (sc) and intravenous (iv) peptide delivery. The route of administration is shown to affect drastically peptide YY3-36 (PYY3-36) release from the PSi nanocarriers in mice. Subcutaneous nanocarriers are demonstrated to be capable to sustain PYY3-36 delivery over 4 days, with the high absolute bioavailability values of PYY3-36. The pharmacokinetic parameters of PYY3-36 are presented to be similar between the sc PSi nanocarriers despite surface chemistry. In contrast, iv-delivered PSi nanocarriers display significant differences between the surface types. Overall, these results demonstrate the feasibility of PSi nanocarriers for the sustained sc delivery of peptides.