Fig. 5: In vivo biosafety of wf-UMP and metabolic distribution of mKNN PNPs.

a Representative images of skin condition at the treated site (blue dotted box) in healthy Balb/c mice at days 0, 3, 6, 10, 14, and 28 after treatment with blank MN patch (MN), mKNN MN patch (mKNN MN), and wf-UMP (n = 4 mice). Scale bars, 1 cm. b, c H&E staining (b) and epidermal thickness of the skin (c) in healthy Balb/c mice following various treatments on day 28 (n = 4 independent samples), while ns denotes no significance. Scale bar, 200 μm. d, H&E staining of major organs (heart, liver, spleen, lung, and kidney) from mice treated with control and wf-UMP at the experimental endpoint. Scale bars, 100 μm. e–g Blood routine test results for WBC (e), RBC (f), and HGB (g) in mice after treatments on day 28 (n = 4 biologically independent mice). h-j, Liver aminotransferase levels for ALF (h), AST (i), and creatinine (j) levels in the blood after different treatments detected on day 28 (n = 4 biologically independent mice). k Quantification of Nb concentration in tumors over time following wf-UMP treatment, measured by ICP-OES, showing the retention of mKNN PNPs at the tumor site (n = 3 independent samples). l Representative biological TEM images showing distribution of mKNN PNPs within tumors post-treatment with wf-UMP. Red arrows indicate clusters of nanoparticles. Scale bars, 2 μm (top) and 500 nm (bottom). All data are represented as mean ± .e.m. Statistical difference was calculated using a two-tailed unpaired student’s t-test. Source data are provided as a Source Data file.