Table 2.
Summary of notable examples of integrin-targeting AuNPs.
| Peptide | Type of AuNPs | Observed Effects | Ref. |
|---|---|---|---|
| cycloRGD | AuNCs (1.7–2.7 nm size range) |
Higher affinity towards αvβ3 was observed for targeting AuNCs. A PEG spacer between the peptide and the AuNC surface was crucial for enhanced tumor accumulation. However, no significant therapeutic effect was described, possibly due to the flawed NP design. | [125,130,159] |
| RGD | AuNPs (29, 51, and 80 nm in diameter) |
The 29 nm AuNPs showed higher tumor accumulation, longer plasma half-life than larger AuNPs. | [160] |
| RGD | AuNPs (10 nm in diameter) |
These smaller AuNPs showed similar tumor accumulation as the 29 nm AuNPs from [149]. | [161] |
| (RGD)4 | AuNPs (30 nm in diameter) |
In in vitro PPTT cell death mechanisms depended on the laser type and dosage. Lower energy continuous wave (cw) laser treatment led to apoptosis, while higher energy cw laser treatment led to necrosis. | [162] |
| (RGD)4 | AuNRs (25 by 6 nm) | This targeted PPTT mainly induced inhibition of Rho GTPases, actin, microtubule, and kinase-related signaling pathways. | [131,163] |
| cycloRGD | AuNRs (50 by 15 nm in [164]; 55 by 15 nm in [165]) | These AuNRs were used for DOX or paclitaxel co-delivery. This strategy combined effects of chemo-phototherapy, active targeting of tumors, and multiple stimuli-responsive drug release. | [164,165] |
| cycloRGD | AuNSs | These AuNSs showed high photothermal conversion efficiency producing a 24.2 °C increase in the tumor area temperature. A single treatment was sufficient to completely inhibit the tumor progression for at least two weeks. | [166] |
| RGD | AuNSs | This treatment caused caspase-dependent apoptosis in HepG2 cells, signs of mitochondria-mediated apoptosis, loss of lysosomal membrane integrity, and enhanced autophagy. Tumor temperature increased by ~20 °C during the PPTT treatment, comparably set up as in the above-mentioned study. | [30] |
| (RGD)4 | AuNPs (20 nm in diameter) | Combined radiotherapy with these AuNPs resulted in significant downregulation of fibronectin signaling by 50%. This phenomenon was accompanied by serious suppression of invasive activity by 67% compared to radiotherapy alone. | [167] |
| isoDGR | AuNPs (25 nm in diameter) |
This multicomponent system comprised a gold core, cytokines IL-12 and/or TNF, and DOX. The synergistic effect was explained by affected endothelial permeability due to the isoDRG-peptide integrin-mediated uptake, and consequential reduction in drug penetration barriers. Presence of the cytokines was to trigger a reaction from immunocompetent cells directed towards the tumor. The results suggest that the displayed TNF played a more important role in the studied tumor inhibition than the displayed IL-12. | [128,142] |