Table 2.
Summary of the different strategies implemented into MSNs for achieving dual or hierarchical targeting.
| Targeting Agents | Approach | Cell line | Reference |
|---|---|---|---|
| Dual Targeting | |||
| Hyaluronic acid + RGD | Two different membrane targeting agents | SKOV-3 | [181,182] |
| Biotin + Folic acid | HeLa | [183] | |
| Bevacizumab + EpCAM aptamer | SW480 | [184] | |
| Benzylguanidine derivatives | Y-shaped scaffold using the same membrane targeting agent | NB-1691 | [185] |
| RGD + TAT | Sequential vascular-membrane-organelle targeting | HeLa | [186] |
| Folic acid + Dexamethasone | Sequential membrane-organelle targeting | HeLa | [187] |
| Hyaluronic acid + Triphenylphosphonium | MGC-803 | [188] | |
| Hyaluronic acid + Positive charge | Janus dual membrane targeting | A549 | [189] |
| Folic acid + TPP | Janus membrane-organelle targeting | LnCAP | [190] |
| Hierarchical Targeting | |||
| Positive charge | pH-responsive benzoic imine bond | HepG2, HeLa | [193,194,195] |
| RGD | U87 | [196] | |
| Positive charge | Thermally-cleavable bond | HOS | [197] |
| Hyaluronic acid | MMP-2-degradable gelatin | MDA-MB-231 | [198] |
| Folic acid | HT-29 | [199] | |
| RGD | RGD masked with MMP-2-clevable peptide sequence | 4T1, HT-29 | [200,201] |
Cell lines. Breast. MDA-MB-231 (adenocarcinoma); 4T1 (mouse breast cancer that simulates stage IV human breast cancer); MMT (mouse breast cancer). Lung. A549 (adenocarcinoma). Colon. SW480 (adenocarcinoma); HT-29 (adenocarcinoma). Liver. HepG2 (hepatoblastoma). Ovary. SKOV-3 (ovarian serous cystadenocarcinoma). Prostate. LnCAP (carcinoma). Endocervix. HeLa (papillomavirus-related endocervical adenocarcinoma); Bone. HOS (osteosarcoma). Brain. NB-1691 (neuroblastoma); U87 (glioblastoma). Stomach. MGC-803 (adenocarcinoma).