Colorectal cancer (CRC) remains a major cause of cancer-related mortality globally. Histone deacetylase (HDAC) inhibitors such as vorinostat (VOR) produce antitumor effects by inducing cell cycle arrest and apoptosis through suppression of HDAC activity. However, clinical application of vorinostat in solid tumors has been constrained by pharmacokinetic and delivery challenges — notably rapid circulatory clearance, limited tumor accumulation, and off-target distribution to non-malignant tissues. The authors of the present study sought to address these barriers by developing a targeted nanoparticle delivery system for vorinostat intended to improve tumor delivery and therapeutic index in CRC.
The investigational carrier is a polymeric nanoparticle composed of poly(lactic-co-glycolic acid) (PLGA) decorated with poly(ethylene glycol) (PEG) and functionalized with aminoethyl anisamide (AEAA). The platform is referred to as PLGA-PEG-AEAA, and when loaded with vorinostat is designated T-NP.VOR. AEAA is incorporated to provide active targeting capability, leveraging receptor-mediated uptake pathways expressed by CRC cells. The abstract identifies this targeted PLGA-PEG-AEAA construct as the core delivery platform used to overcome rapid clearance and poor tumor distribution of free vorinostat.
In vitro experiments reported in the abstract demonstrate that T-NP.VOR significantly enhanced cellular uptake in colorectal cancer cells compared with non-targeted controls and free drug. The increased internalization was attributed to Sigma‑1 receptor-mediated uptake, consistent with the intended targeting mechanism of the AEAA ligand. Enhanced cellular delivery of vorinostat via the targeted nanoparticle is presented as the proximal mechanism by which downstream pharmacodynamic effects were amplified in CRC cells.
Following improved cellular uptake, T-NP.VOR produced functional inhibition of HDAC activity in CRC cells. The formulation induced cell cycle arrest and promoted apoptosis in vitro. These pharmacodynamic outcomes align with the known mechanism of vorinostat and suggest that targeted delivery increased intracellular exposure sufficiently to potentiate canonical effects of HDAC inhibition. The abstract does not report detailed quantitative metrics (for example, percent uptake increase, cell cycle phase distribution, caspase activation levels, or apoptosis rates); such experimental specifics require review of the full article.
In an orthotopic colorectal cancer mouse model, T-NP.VOR markedly prolonged systemic circulation relative to free vorinostat and improved tumor distribution compared with free drug and a non-targeted nanoparticle formulation. These changes in pharmacokinetics and biodistribution are described as key contributors to the formulation’s enhanced in vivo efficacy. The abstract indicates prolonged blood residence and enhanced tumor accumulation but does not provide numerical pharmacokinetic parameters, area-under-curve values, or tissue concentration data in the abstract itself.
Improved tumor delivery of T-NP.VOR translated into significant antitumor activity in the orthotopic CRC model. The targeted nanoformulation produced marked tumor growth suppression and extended survival of treated animals when compared to both free vorinostat and a non-targeted nanoformulation. The abstract presents these efficacy outcomes qualitatively; specific measures of tumor volume reduction, survival statistics, or comparative effect sizes are not included in the abstract text and would be available in the full publication.
The study concludes that the PLGA-PEG-AEAA nanocarrier is a promising delivery platform for vorinostat in colorectal cancer therapy. By enabling Sigma‑1 receptor-mediated uptake, prolonging systemic circulation, and improving tumor distribution, T-NP.VOR enhanced HDAC inhibition, drove cell cycle blockade and apoptosis in vitro, and produced superior antitumor efficacy and survival benefit in an orthotopic CRC model compared with free drug or non-targeted nanoparticles. These findings support further investigation of targeted polymeric nanoparticles to overcome delivery limitations of HDAC inhibitors in solid tumors.
The PubMed abstract summarizes the main findings but omits many experimental details necessary for full appraisal and replication. The abstract does not report specific dosing regimens, quantitative pharmacokinetic parameters, exact uptake percentages, statistical analyses, safety or toxicity data, or mechanistic biomarkers beyond HDAC inhibition and apoptosis. For full methodological details, quantitative results, and any reported adverse effects or translational considerations, readers should consult the full text (Int J Pharm; DOI: 10.1016/j.ijpharm.2026.127274).