Fig. 1: In vivo host cell recruitment and transfection efficiency of LiNx.

a Schematic of the LiNx vaccination platform, providing an immunostimulatory niche by recruiting host immune cells to the microgel matrix (1). LiNx-delivered LNPs can transfect non-APCs (2) and recruited macrophage-like cells, followed by antigen expression, processing, and epitope presentation on MHC-I (3) or MHC-II (4) in different pathways. b, c Kinetics of host cell recruitment following injection of three different LiNx in C57BL/6 mice (30 μg mOVA per mouse, s.c.). The number of living cells was counted within composites on both day 3 and day 7 post-injection (b). Flow cytometry was employed to determine the count of macrophage-like cells (CD3^–CD11b⁺Ly6g^–CD11c^–) and DC-like cells (CD3^–CD11b⁺ Ly6g^–CD11c⁺) on day 3 (c). d, f Ai9 mice were administered the three LiNx loaded with mCre via s.c. injections (30 μg mCre per mouse). Transfection of cells in the composite was analysed by flow cytometry. The number of cells positive for tdTomato (d), as well as DC-like cells (CD11b⁺CD11c⁺) cells (e) and macrophage-like cells (CD11b⁺CD11c^–) (f) positive for tdTomato on day 5 and day 10 post-injection were shown. g–i C57BL/6 mice received s.c. injections of D6 LiNx loaded with either mLuc or Cy5-labelled mRNA (30 μg per mouse). g The transfection efficiency of D6 LiNx at the injection site and in major organs was assessed using IVIS imaging. The relative percentage of transfection and biodistribution for D6 LiNx is shown in (h). IVIS images of luciferase transfection for D6 LiNx are presented in (i). Data represent the mean  ±  s.e.m. (n =  8 mice for (b, c), n = 4 mice for (d–f) and n = 5 mice for (g–i)). Box plots in (g) represent the median (centre line), the 25th and 75th percentiles (bounds of the box), and the minimum and maximum values (whiskers); individual data points represent values from independent biological replicates. Data were analysed using one-way ANOVA and Tukey’s multiple comparisons test. *P < 0.05, **P < 0.01, ****P < 0.0001. NS, not significant. Source data are provided as a Source Data file. Figure 1a was created in BioRender.