biostudies-literatureWelling MMDutch Research Council (NWO)607-614https://www.ebi.ac.uk/biostudies/studies/S-EPMC8028042biostudies-literatureUnknown32(3)Cyclodextrin (CD)-based host-guest interactions with adamantane (Ad) have demonstrated use for functionalizing living cells <i>in vitro</i>. The next step in this supramolecular functionalization approach is to explore the concept to deliver chemical cargo to living cells <i>in vivo</i>, e.g., inoculated bacteria, in order to study their dissemination. We validated this concept in two rodent <i>Staphylococcus aureus</i> models. Bacteria (1 × 10⁸ viable <i>S. aureus</i>) were inoculated by (1) intramuscular injection or (2) intrasplenic injection followed by dissemination throughout the liver. The bacteria were prefunctionalized with ^99mTc-UBI_29-41-Ad₂ (primary vector), which allowed us to both determine the bacterial load and create an <i>in vivo</i> target for the secondary host-vector (24 h post-inoculation). The secondary vector, i.e., chemical cargo delivery system, made use of a ¹¹¹In-Cy5_0.5CD₉PIBMA₃₉ polymer that was administered intravenously. Bacteria-specific cargo delivery as a result of vector complexation was evaluated by dual-isotope SPECT imaging and biodistribution studies (¹¹¹In), and by fluorescence (Cy5); these evaluations were performed 4 h post-injection of the secondary vector. Mice inoculated with nonfunctionalized <i>S. aureus</i> and mice without an infection served as controls. Dual-isotope SPECT imaging demonstrated that ¹¹¹In-Cy5_0.5CD₉PIBMA₃₉ colocalized with ^99mTc-UBI_29-41-Ad₂-labeled bacteria in both muscle and liver. In inoculated muscle, a 2-fold higher uptake level (3.2 ± 1.0%ID/g) was noted compared to inoculation with nonfunctionalized bacteria (1.9 ± 0.4%ID/g), and a 16-fold higher uptake level compared to noninfected muscle (0.2 ± 0.1%ID/g). The hepatic accumulation of the host-vector was nearly 10-fold higher (27.1 ± 11.1%ID/g) compared to the noninfected control (2.7 ± 0.3%ID/g; <i>p</i> < 0.05). Fluorescence imaging of the secondary vector corroborated SPECT-imaging and biodistribution findings. We have demonstrated that supramolecular host-guest complexation can be harnessed to achieve an <i>in vivo</i> cargo delivery strategy, using two different bacterial models in soft tissue and liver. This proof-of-principle study paves a path toward developing innovative drug delivery concepts via cell functionalization techniques.Bioconjugate chemistryCyclodextrin/Adamantane-Mediated Targeting of Inoculated Bacteria in Mice.PMC8028042864.13.00316141Vici-fellowship - NWO 16141Vidi fellowship - 864.13.003Duszenko NWelling MMBuckle Tvan Willigen DMvan Leeuwen FWBRoestenberg MSmits WKfalseCyclodextrin/Adamantane-Mediated Targeting of Inoculated Bacteria in Mice.Cyclodextrin (CD)-based host-guest interactions with adamantane (Ad) have demonstrated use for functionalizing living cells <i>in vitro</i>. The next step in this supramolecular functionalization approach is to explore the concept to deliver chemical cargo to living cells <i>in vivo</i>, e.g., inoculated bacteria, in order to study their dissemination. We validated this concept in two rodent <i>Staphylococcus aureus</i> models. Bacteria (1 × 10⁸ viable <i>S. aureus</i>) were inoculated by (1) intramuscular injection or (2) intrasplenic injection followed by dissemination throughout the liver. The bacteria were prefunctionalized with ^99mTc-UBI_29-41-Ad₂ (primary vector), which allowed us to both determine the bacterial load and create an <i>in vivo</i> target for the secondary host-vector (24 h post-inoculation). The secondary vector, i.e., chemical cargo delivery system, made use of a ¹¹¹In-Cy5_0.5CD₉PIBMA₃₉ polymer that was administered intravenously. Bacteria-specific cargo delivery as a result of vector complexation was evaluated by dual-isotope SPECT imaging and biodistribution studies (¹¹¹In), and by fluorescence (Cy5); these evaluations were performed 4 h post-injection of the secondary vector. Mice inoculated with nonfunctionalized <i>S. aureus</i> and mice without an infection served as controls. Dual-isotope SPECT imaging demonstrated that ¹¹¹In-Cy5_0.5CD₉PIBMA₃₉ colocalized with ^99mTc-UBI_29-41-Ad₂-labeled bacteria in both muscle and liver. In inoculated muscle, a 2-fold higher uptake level (3.2 ± 1.0%ID/g) was noted compared to inoculation with nonfunctionalized bacteria (1.9 ± 0.4%ID/g), and a 16-fold higher uptake level compared to noninfected muscle (0.2 ± 0.1%ID/g). The hepatic accumulation of the host-vector was nearly 10-fold higher (27.1 ± 11.1%ID/g) compared to the noninfected control (2.7 ± 0.3%ID/g; <i>p</i> < 0.05). Fluorescence imaging of the secondary vector corroborated SPECT-imaging and biodistribution findings. We have demonstrated that supramolecular host-guest complexation can be harnessed to achieve an <i>in vivo</i> cargo delivery strategy, using two different bacterial models in soft tissue and liver. This proof-of-principle study paves a path toward developing innovative drug delivery concepts via cell functionalization techniques.2021-01-01T00:00:00Z2021 Mar2025-04-18T15:42:33.641Z2022-02-09T14:18:04.773ZS-EPMC80280423362105210.1021/acs.bioconjchem.1c00061