Selenium NanoParticles
| Category | Role in cancer |
| -------------------------------- | ----------------------------------------------------------------------------------------------- |
| Sodium Selenium (selenite) | Direct cytotoxic redox poison |
| Selenium (organic / nutritional) | **Redox buffer & immune modulator** (generally *anti-therapy* when oxidative stress is desired) |
| SeNPs | Tunable redox-signaling anticancer platform |
The introduction of borneol led to a significant reduction in the size of selenium nanoparticles (SeNPs), as documented in the study (Prabhakaret et al., 2013).
In the chemical synthesis of selenium nanoparticles, a precursor such as sodium selenite (Na₂SeO₃) is dissolved in water to form a homogenous solution. A reducing agent, like ascorbic acid or sodium borohydride (NaBH₄), is then added to the solution. The reducing agent donates electrons to the selenium ions (SeO32−SeO32), reducing them to elemental selenium (Se0Se^0). This reduction process leads to the nucleation of selenium atoms, which subsequently grow into nanoparticles through controlled aggregation.
Se NPs might be hepatoprotective.
(chemoprotective)
(radioprotective)
(radiosensitizer)
Selenium nanoparticles (SeNPs) are a biocompatible, less-toxic,
and more controllable form of selenium compared to inorganic salts (like sodium selenite).
Major SeNPs hepatoprotective mechanisms
Mechanism Description Key markers affected
1. Antioxidant activity SeNPs boost antioxidant enzyme ↓ ROS, ↓ MDA, ↑ GSH, ↑ GPx
systems (GPx, SOD, CAT) and scavenge
ROS directly.
2. Anti-inflammatory effect Downregulate NF-κB, TNF-α, ↓ TNF-α, ↓ IL-1β, ↓ IL-6
IL-6, and COX-2 pathways.
3. Anti-apoptotic action Balance between Bcl-2/Bax and reduce ↑ Bcl-2, ↓ Bax, ↓ Caspase-3
caspase-3 activation in hepatocytes.
4. Metal/toxin chelation SeNPs can bind or transform toxic ↓ liver metal accumulation
metals (Cd²⁺, Hg²⁺, As³⁺)
into less harmful complexes.
5. Mitochondrial protection Maintain membrane potential, Preserved ΔΨm, ↑ ATP
prevent mitochondrial ROS burst,
and ATP loss.
6. Regeneration support Stimulate hepatocyte proliferation ↑ PCNA, improved histology
and repair via redox signaling
and selenoproteins.
Comparison: SeNPs vs. Sodium Selenite
Property SeNPs Sodium Selenite
Toxicity Low Moderate–high
Bioavailability Controlled, often slow- Rapid, less controllable
release
ROS balance Adaptive, mild antioxidant Can flip to pro-oxidant easily
Safety margin Wide Narrow
Hepatoprotection Strong, sustained Protective at low dose,
toxic at high dose
Form of SeNPs matter:
1. Core composition / capping agent: SeNPs can be stabilized with polysaccharides, proteins, or small molecules. Some stabilizers may interact with cellular redox systems differently—e.g., a protein-capped SeNP may have slower release and less ROS generation, whereas a bare SeNP might induce stronger ROS in cancer cells.
2. Particle size: Smaller SeNPs (<50 nm) tend to generate more ROS and may enhance anticancer activity, but could theoretically interfere with ROS-dependent chemo if administered simultaneously. Larger SeNPs are slower-acting and may be safer alongside chemo.
3. Surface charge / coating: Positively charged or functionalized SeNPs can preferentially enter tumor cells, whereas neutral or negatively charged forms may distribute more evenly. This affects both selective cytotoxicity and interaction with normal cells.
"30 mg of Na2SeO3.5H2O was added to 90 mL of Milli-Q water.
Ascorbic acid (10 mL, 56.7 mM) was added dropwise to sodium selenite solution with vigorous stirring.
10 µL of polysorbate were added after each 2 ml of ascorbic acid.
Selenium nanoparticles were formed after the addition of ascorbic acid.
This can be visualized by a color change of the reactant solution from clear white to clear red.
All solutions were made in a sterile environment by using a sterile cabinet and double distilled water."
SeNPs Cancer relevant pathways
| Rank |
Pathway (direction) |
Notes (key mechanistic readout) |
Ref |
| 1 |
Redox stress / ROS ↑ |
SeNPs commonly elevate intracellular ROS in cancer cells (often upstream of downstream apoptosis/autophagy signaling). |
(ref) |
| 2 |
DNA damage / DDR ↑ |
ROS-linked DNA damage response reported in anti-angiogenic/cancer models (e.g., DNA damage as part of the cytotoxic cascade). |
(ref) |
| 3 |
PI3K → Akt → mTOR ↓ |
Frequently reported as inhibited (or functionally downshifted), aligning with reduced survival signaling and increased stress-death programs. |
(ref) |
| 4 |
Mitochondrial integrity (ΔΨm) ↓ |
Mitochondrial membrane potential loss is a recurring early event (mitochondria-centered cytotoxicity). |
(ref) |
| 5 |
Intrinsic apoptosis (caspase cascade) ↑ |
Activation of caspase-mediated apoptosis (e.g., caspase-3 activation) commonly follows mitochondrial disruption. |
(ref) |
| 6 |
Stress MAPK (p38) ↑ |
p38 signaling is reported as engaged in ROS-associated SeNP cytotoxicity programs (context: apoptosis signaling). |
(ref) |
| 7 |
p53 program ↑ |
p53 pathway activation/“reactivation” can be amplified in SeNP-based constructs (p53 target genes up; apoptosis up). |
(ref) |
| 8 |
Autophagy regulation ↑ (often pro-death or dysregulated) |
Functionalized SeNPs can drive autophagy as a major action mode in colorectal cancer models (often intertwined with cytotoxicity). |
(ref) |
| 9 |
Angiogenesis (VEGF → VEGFR2 → ERK/Akt) ↓ |
Anti-angiogenic SeNP designs suppress VEGF-driven signaling and tube formation in endothelial/tumor angiogenesis models. |
(ref) |
| 10 |
NF-κB signaling ↓ |
NF-κB activation markers (e.g., p-p65 / p-IκBα) can be reduced by decorated SeNPs in inflammatory signaling models relevant to tumor-promoting inflammation. |
(ref) |
| 11 |
Androgen receptor axis (AR transcriptional activity) ↓ |
Reported in prostate cancer context: AR downregulation/disruption via Akt/Mdm2/AR-linked apoptosis framework. |
(ref) |
| 12 |
Ferroptosis ↑ (Nrf2/HO-1/SLC7A11/GCLC/GPX4 ↓) |
Some decorated SeNPs are explicitly reported to induce ferroptosis, including downregulation of System Xc−/GSH/GPX4-axis proteins and iron-homeostasis shifts. |
(ref) |
|