Extended Data Fig. 8: Microneedle dissolution.
From: A microneedle vaccine printer for thermostable COVID-19 mRNA vaccines
(a) Dimensions of an individual microneedle used in pyramid or conical microneedle patches. Spacing between two adjacent needles (pitch) is 1000 µm. (b) Representative optical imaging of needle dissolution upon application ex vivo on pig skin as a function of time for MNPs of pyramid and conical shape. (c–e) Comparison between conical and pyramid microneedles made from PVP:PVA 2:1 and 1:1, in terms of dissolved volume in ex vivo pig skin. Unpaired, two-tailed t-tests (n = 23–59 needles per group). Data represent mean ± s.d. P values are represented by: *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001. NS, not significant.
