Reference paper
Lipid nanoparticle platforms for p53-targeted cancer therapy
https://doi.org/10.1186/s12645-026-00431-9 ↗
LNPs are the most clinically validated nanocarrier platform in oncology. This review reframes LNP development around p53 — inactivated in over 50% of human cancers — and unifies four nucleic-acid strategies (p53 mRNA, mutant-p53 siRNA, miR-34a mimics, CRISPR-Cas9) under one biological framework, with liver-dominant biodistribution, anti-PEG immunogenicity, manufacturing scalability and regulatory complexity as the persistent barriers.
- Ionizable lipids with optimised pKa (6.0–7.0) enable efficient endosomal escape.
- p53 mRNA-LNPs restore wild-type p53 in TP53-deficient tumours and sensitise to mTOR and checkpoint inhibition.
- KEYNOTE-942 Phase IIb: mRNA-4157 + pembrolizumab, 44% reduction in recurrence risk (neoantigen vaccine, not p53).
- AI-driven lipid discovery screened 1.6 million virtual lipids.
- Stimuli-responsive LNPs (pH, redox, enzyme) achieve tumour-selective release.
- Passive EPR delivers a median of only 0.7% of the injected dose to tumours.
How the paper maps onto the Designer
map- Four p53 strategies + dual cargoCargo selector with paper-recommended class per TP53 variant
- Table 1 — LNP platformsArchitecture selector, range checks, 3D architecture view
- Table 2 — active targetingLigand + density vs passive 0.7% EPR
- Fig. 3 — triggered releasepH / redox / enzyme / thermo / ultrasound release curves
- SORT trade-offsCharged-lipid fraction: biodistribution and escape penalty
- Anti-PEG immunogenicityCorona choice, repeat-dose ABC risk
- Immunotherapy combinationAnti-PD-1 toggle and KEYNOTE-942 context
- Table 3 — clinical pipelinePlatform benchmarks in the Designer
Fig. 1 · LNP architectures for p53-directed therapy
figureA · Conventional liposome
bilayer · aqueous core · p53 mRNA
B · Solid lipid NP
solid lipid matrix · siRNA + hydrophobic drug
C · Ionizable LNP
pH-responsive lipid layer · PEG corona · pKa 6.0–7.0
D · Lipid-polymer hybrid
PLGA core · lipid shell · PEG corona · pDNA / CRISPR
Schematic representation only; does not represent experimental imaging data (as stated in the paper).
Table 1 · Comparison of LNP platforms for p53-directed cancer drug delivery
table| Feature | Liposome | Solid lipid NP | NLC | Ionizable LNP | Lipid-polymer hybrid |
|---|---|---|---|---|---|
| Size (nm) | 80–120 | 100–300 | 100–250 | 50–150 | 100–300 |
| Drug loading (%) | 5–10 | 2–8 | 5–15 | 10–20 | 8–20 |
| Encapsulation efficiency (%) | 80–95 | 60–80 | 70–90 | 85–95 | 80–90 |
| p53 cargo compatibility | mRNA, miRNA | siRNA, hydrophobic | mRNA, siRNA | mRNA, siRNA, sa-mRNA | pDNA, CRISPR |
| Clinical status | Approved | Phase I/II | Preclinical | Approved | Preclinical |
| Key limitations | Low endosomal escape; rapid clearance if non-PEGylated | Low drug-loading capacity; burst release | Less stable than SLNs during long-term storage | Liver-dominant biodistribution; anti-PEG immunogenicity | Complex manufacturing; scalability challenges |
SLN = solid lipid nanoparticle; NLC = nanostructured lipid carrier; LPHN = lipid-polymer hybrid nanoparticle; pDNA = plasmid DNA; sa-mRNA = self-amplifying mRNA. Values are typical literature ranges and vary with formulation parameters and cargo.
Fig. 2A · DLS size distribution
figure- p53 mRNA-LNP · ~95 nm
- p53 siRNA-LNP · ~120 nm
- empty LNP · ~150 nm
Mean ≈95 nm (p53 mRNA-LNP), ≈120 nm (siRNA-LNP), ≈150 nm (empty LNP). Representative simulated profile, as in the paper.
Fig. 2B · Zeta potential vs pH
figure- ionizable LNP · pKa 6.5
Ionizable LNP with pKa 6.5: charge transition for endosomal escape while remaining near-neutral in circulation (pH 7.4).
Fig. 2C · Encapsulation efficiency by platform
figure- Ionizable LNP85–95%
- Liposome80–95%
- Solid lipid NP60–80%
- NLC70–90%
- Lipid-polymer hybrid80–90%
Drawn from Table 1 ranges (typical literature values). Ionizable LNPs exceed 90% encapsulation.
Fig. 2D · PDI distributions
figure- Ionizable LNP
- Liposome
- NLC
- Hybrid
All formulations below the 0.3 acceptance threshold. Representative simulated plots.
p53 as a master therapeutic target · four LNP strategies
text| Strategy | Indicated when | Caveat |
|---|---|---|
| p53 mRNA | TP53-null or loss-of-function (LOF) mutations where no dominant-negative protein is expressed. | Therapeutic window is limited by the duration of p53 expression; transient transfection may be insufficient. |
| Mutant-p53 siRNA | Gain-of-function (GOF) missense mutants with oncogenic dominant-negative or neomorphic activity. | Release follows a burst (0–2 h), sustained (2–12 h) and plateau (>12 h) profile. |
| siRNA + mRNA (single LNP) | Intra-tumoural heterogeneity where wild-type, null and GOF clones coexist; silences mutant and restores wild-type. | Explored for refractory liver cancer; two cargo classes in one particle complicate formulation. |
| miR-34a mimic | Engages the p53 downstream axis regardless of mutational status, though less directly. | MRX34 (liposomal miR-34a) was discontinued for immune-related adverse events. |
| CRISPR-Cas9 / RNA editing | Permanent TP53 correction (e.g. circular ADAR-recruiting RNAs for nonsense mutations). | Delivery across tumour vasculature, editing efficiency and off-target mutagenesis remain barriers. |
Restoring p53 reactivates p21/CDKN1A cell-cycle arrest, Bax/Bcl-2 apoptosis and caspase-3 activation, senescence and ferroptosis, and the miR-34 positive-feedback loop.
Table 2 · Active targeting strategies for p53-directed LNP delivery
table| Strategy | Ligand | Target | Cancer types | Status | Key limitations |
|---|---|---|---|---|---|
| Folate | Folic acid | FR-α | Ovarian, Breast | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Off-target accumulation in kidneys; requires high FR-α expression |
| Transferrin | Transferrin | TfR | Glioma / GBM, Leukemia | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Competition with endogenous transferrin; receptor saturation |
| RGD peptide | cRGDfK | αvβ3 integrin | Melanoma, Glioma / GBM | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Lower affinity for human vs. murine integrins; off-target in bone |
| Anti-HER2 | Trastuzumab Fab | HER2 | Breast, Gastric | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Potential cardiotoxicity; internalization variability |
| Anti-EGFR | Cetuximab Fab | EGFR | Colorectal, HNSCC | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Skin toxicity; mutations affecting binding |
| Aptamer | AS1411 | Nucleolin | Leukemia, Breast | Preclinical | Nuclease degradation in vivo; rapid clearance |
| Hyaluronic acid | HA oligos | CD44 | Breast, Colorectal, Ovarian | Platform (preclinical; clinical phases refer to general ligand use, not p53-specific products) | Rapid clearance; CD44 isoform specificity |
Phases indicate clinical exploration of the ligand/platform generally, not specifically for p53 cargo. No dedicated p53-directed ligand-targeted LNP product has yet entered clinical trials.
Fig. 3A · pH-responsive p53 mRNA release
figure- pH 5.5 · endosome
- pH 6.5 · tumour microenvironment
- pH 7.4 · blood
Accelerated release at pH 5.5 (endosomal) vs pH 6.5 (tumour microenvironment) and pH 7.4 (blood).
Fig. 3B · Three-phase siRNA release
figure- siRNA · ionizable LNP
Burst (0–2 h), sustained (2–12 h) and plateau (>12 h) phases from ionizable LNPs.
Fig. 3C · Thermosensitive release (NLC)
figure- 37 °C
- 40 °C
- 42 °C
- 45 °C
Release at 37–45 °C with a trigger zone at 40–42 °C (DPPC gel-to-liquid-crystalline transition ≈41 °C).
Fig. 3D · Redox-responsive release vs GSH
figure- disulfide-lipid LNP
Intracellular GSH (2–10 mM) triggers near-complete release; extracellular GSH (~10 µM) does not.
Fig. 4A · Dose response in p53-null HCT116
figure- p53 mRNA-LNP
- free doxorubicin
- empty LNP
Conceptual: p53 mRNA-LNP vs free doxorubicin vs empty LNP. Generated artificially for visualisation in the paper; not a single experimental dataset.
Fig. 4B · Selectivity at 1 µM
figure- p53-null cancer34%
- p53-WT cancer46%
- HDF fibroblasts91%
- BEAS-2B epithelium88%
Preferential cytotoxicity in p53-null and wild-type cancer cells vs normal HDF fibroblasts and BEAS-2B bronchial epithelium. Conceptual values.
Fig. 4C · Xenograft growth inhibition
figure- control
- anti-PD-1
- p53 mRNA-LNP
- p53-LNP + anti-PD-1
p53 mRNA-LNP and the combination with anti-PD-1 show superior efficacy in HCT116 xenografts. Conceptual.
Fig. 4D · Temporal p53 restoration
figure- p53 protein
- p21 (CDKN1A)
- cleaved caspase-3
p53 protein peaks at 24 h, followed by p21 (CDKN1A) and cleaved caspase-3. Transient expression limits the therapeutic window.
Table 3 · Selected LNP-based cancer therapeutics in clinical development (2020–2026)
table| Product | Platform | Cargo | Indication | Phase | Company |
|---|---|---|---|---|---|
| Doxil | PEG-liposome | Doxorubicin | Ovarian, Kaposi | Approved | Multiple |
| Onivyde | Liposome | Irinotecan | Pancreatic | Approved | Ipsen |
| Vyxeos | Liposome | Cyt/Daun | AML | Approved | Jazz |
| mRNA-4157 | Ionizable LNP | mRNA neoantigens | Melanoma, NSCLC | Phase III | Moderna/Merck |
| BNT122 | Ionizable LNP | mRNA neoantigens | Colorectal | Phase II | BioNTech |
| BNT111 | Ionizable LNP | mRNA (fixed) | Melanoma | Phase II | BioNTech |
| mRNA-2752 | Ionizable LNP | OX40L/IL-23/36 | Solid tumours | Phase I | Moderna |
| p53 mRNA-LNP | Ionizable LNP | p53 mRNA | HCC, NSCLC, pancreatic | Preclinical / Exploratory Phase I (no published results) | Academic/Industry |
* mRNA-4157 and BNT122 are personalized neoantigen vaccines and do not encode p53; they are included to illustrate clinical validation of the ionizable LNP-mRNA platform in oncology, not as p53-directed therapies. AML = acute myeloid leukaemia; NSCLC = non-small cell lung cancer; HCC = hepatocellular carcinoma.
Clinical translation: challenges and solutions
text- Manufacturing: microfluidic mixing is the industry standard; flow rates and mixing ratios set size, PDI and encapsulation, and scale-up must preserve critical quality attributes.
- Immunogenicity: anti-PEG antibodies can cause accelerated blood clearance on repeat dosing; mitigations are alternative polymer coronas, PEG dose optimisation and biomimetic coatings.
- Regulatory: LNP products may be combination products; EMA nanomedicine reflection paper and FDA liposome guidance apply.
- Barriers: p53 expression duration, TP53 heterogeneity within tumours, and liver-dominant biodistribution (SORT or active targeting, each with trade-offs).
Future perspectives
text- AI-driven LNP design: virtual lipid screening and models trained on LNP activity datasets (Witten et al. 2025).
- SORT nanoparticles: extrahepatic delivery via charged lipids, with endosomal-escape and scale-up trade-offs.
- Biomimetic approaches: cell-membrane-coated NPs and exosome-mimetic LNPs; personalised p53 mRNA-LNPs from TP53 sequencing.
- Self-amplifying mRNA for lower doses; CRISPR-Cas9 and circular ADAR-recruiting RNAs for TP53 correction.
Figures 2–4 in the paper are conceptual plots simulated for visualisation; the curves here reproduce those trends and are not experimental data. Reference: https://doi.org/10.1186/s12645-026-00431-9 ↗