The biological logic is straightforward. Cancer cells rewire lipid metabolism to fuel membranes, signaling pathways and energy production, and cholesterol sits at the center of that rewiring. It stabilizes lipid rafts, the membrane microdomains that organize receptor tyrosine kinases and survival signaling through PI3K-AKT-mTOR pathways. It is stored as cholesteryl esters in lipid droplets that buffer stress during rapid proliferation. Altered cholesterol handling also contributes to chemotherapy resistance, because cholesterol-enriched membranes support ABC transporter activity that pumps drugs out of cells, and to immune escape, since cholesterol accumulation can impair CD8+ T cell function and skew macrophage polarization.

Yet the authors stress that cholesterol dependency is highly context-dependent. Distinct cholesterol pools, including accessible plasma-membrane cholesterol, lysosomal free cholesterol, endoplasmic reticulum-associated sterols and esterified stores in lipid droplets, serve different biological functions. A drop in total cholesterol is therefore neither a universal therapeutic goal nor sufficient evidence of mechanism. Uptake restriction may help against a lipoprotein-dependent tumor, whereas blocking esterification can actually increase membrane cholesterol availability in CD8+ T cells and strengthen their tumor-killing capacity. The same intervention that starves a malignant cell could exhaust an immune effector.

To bring order to a crowded literature, the review introduces a four-level evidence grading scheme. Grade I requires direct measurement of a specified sterol pool or metabolite together with mechanism-specific rescue or an independent selective perturbation. Grade II covers direct quantitative sterol measurements without such causal validation. Grade III denotes indirect support such as staining, target-protein expression or pathway signatures. Grade IV describes studies where perturbation of a relevant sterol pool was never established at all, including receptor-mediated nanoparticle uptake alone. Strikingly, most platforms surveyed earned Grade II or III, and only a handful reached Grade I.

The first strategy targets cholesterol supply. Cholesterol-poor HDL-mimetic nanoparticles, built with an apoA-I and phospholipid surface that engages the SR-B1 receptor but lacking the cholesteryl-ester cargo of native HDL, reduced cholesterol uptake in platinum-resistant ovarian cancer models and drove lipid peroxidation with decreased GPX4 expression, a ferroptosis-like death mode rescued by ferrostatin-1. In lymphoma, related HDL nanoparticles induced compensatory biosynthetic programs, and the review notes that germinal-center diffuse large B-cell lymphoma is sensitive to this approach while activated B-cell-like lymphoma resists it by maintaining cholesterol through BCR-associated synthesis. Combining the nanoparticles with BCR/SYK inhibitors overcame that resistance, illustrating how material choice must match metabolic phenotype.

A second strategy disrupts intracellular homeostasis. Core-shell nanoparticles co-delivering atorvastatin and doxorubicin coordinate mevalonate-pathway inhibition with chemotherapy in drug-resistant breast cancer, lowering measured cholesterol and membrane P-glycoprotein levels to improve drug retention. Amphiphilic cyclodextrin nanoparticles directly extract plasma-membrane cholesterol, triggering lipid peroxidation and mitochondrial apoptosis in cancer cells with limited toxicity toward tested nonmalignant controls. Avasimibe-loaded polymers inhibit the SOAT1 enzyme that esterifies cholesterol, raising intracellular free cholesterol to provoke endoplasmic reticulum stress and apoptosis. In pancreatic cancer, liposomes co-delivering an ISG15-silencing plasmid with atorvastatin produced synthetic lethality in cancer stem-like cells, with sterol profiling showing cholesterol rising while biosynthetic intermediates fell.

The third and most chemically inventive strategy turns cholesterol itself into a reaction substrate. Cholesterol oxidase catalyzes conversion of accessible free cholesterol into cholest-4-en-3-one while generating hydrogen peroxide as a coproduct. Nanoparticles built around iron metal-organic frameworks, copper-doped Prussian blue, platinum-zinc oxide and manganese nanozymes all protect the enzyme, deliver it to tumors and couple cholesterol consumption with additional redox chemistry, from Fenton-like reactions to sonodynamic and photodynamic therapy. In bladder cancer, a zinc-cobalt framework co-delivering the enzyme with doxorubicin reported cholesterol reduction and altered membrane rigidity that improved drug retention while activating cGAS-STING immune signaling.

But the authors flag a critical blind spot in these catalytic platforms: the identity and fate of the sterol products are largely uncharacterized. Cholesterol oxidase chemistry differs fundamentally from the hydroxylation and epoxidation pathways that generate signaling oxysterols such as 27-hydroxycholesterol and 5,6-epoxycholesterol, whose downstream metabolites can either promote tumor growth through the glucocorticoid receptor or suppress it through the differentiation agent dendrogenin A. Neither a drop in total cholesterol nor a rise in reactive oxygen species reveals which products formed or what they do. The review calls for chromatographic identification with authentic standards and isotope-labeled controls before any product-level claims are accepted.

The fourth strategy modulates immune cell cholesterol. In CD8+ T cells, inhibiting SOAT1-mediated esterification increases membrane cholesterol, enhancing T cell receptor clustering, immunological synapse formation and cytotoxic activity. In B16-F10 melanoma models, liposomes co-delivering paclitaxel and alpha-galactosylceramide were combined with avasimibe to counteract the esterification that accompanies T cell activation. Macrophages offer a different target: a sprayable hydrogel delivering DHCR7-targeting nanoregulators to glioma-supportive macrophages reduced macrophage-derived cholesterol supply and improved control of orthotopic glioblastoma, earning a Grade I rating alongside a lipid nanoparticle study showing that replacing formulation cholesterol with defined oxysterols produced formulation- and model-dependent, sometimes opposing, effects on tumor growth.

The review closes with a development framework connecting target cell, sterol pool, metabolic dependency, material function and evidence grade. Metabolic compensation remains the central barrier: suppressing uptake can activate SREBP2-driven biosynthesis, while blocking synthesis can increase reliance on exogenous supply, and stromal cells and circulating lipoproteins may sustain cholesterol delivery despite intervention. Safety questions are equally unresolved, since tissues such as the adrenal gland and regenerating neurons depend on cholesterol handling in ways that short-term toxicity studies cannot capture. The authors propose phenotype-guided stratification using tumor SR-B1 and SQLE expression, macrophage profiling and lipoprotein uptake assays to match patients with candidate platforms, while insisting that evidence grades should advance only when defined sterol target engagement is causally linked to therapeutic benefit. Until then, they conclude, cholesterol-targeted biomaterials remain a compelling hypothesis awaiting rigorous proof.

Subject of Research: Biomaterial strategies targeting cholesterol metabolism as a therapeutic vulnerability in cancer

Article Title: Rewiring cholesterol vulnerabilities with biomaterials: Mechanisms and opportunities for cancer therapy

Article References: Chen, X., Zou, M., Chen, Z., Wu, J., Wu, G., Zhou, Z., Xu, R., Li, N., Feng, W., Guo, Z., Zhao, X., & Cui, L. (2026). Rewiring cholesterol vulnerabilities with biomaterials: Mechanisms and opportunities for cancer therapy. Materials Today Bio, 41, Article 103762. https://doi.org/10.1016/j.mtbio.2026.103762

Image Credits: AI Generated

DOI: 10.1016/j.mtbio.2026.103762

Keywords: cholesterol metabolism, cancer therapy, biomaterials, nanoparticles, ferroptosis, cholesterol oxidase, CD8 T cells, macrophages, lipid rafts, tumor microenvironment, preclinical research, evidence grading