# Modular Design of Mesoporous Silica Nanoparticles Enables Bioimaging, Dual Chemotherapy, and Combinatorial Gene Silencing in Triple-Negative Breast Cancer

## TL;DR

A new modular nanoparticle system combines chemotherapy and gene silencing to treat aggressive breast cancer more effectively.

## Contribution

A modular nanoparticle platform that enables simultaneous delivery of chemotherapy and RNAi agents targeting multiple survival pathways in TNBC.

## Key findings

- The formulation achieved strong gene silencing and enhanced cytotoxicity in TNBC cells.
- Combining therapies minimized immune activation and outperformed single treatments.
- The platform can be adapted to target new survival pathways in cancer cells.

## Abstract

Triple-negative breast
cancer (TNBC) accounts for 10–15%
of all breast cancers and remains the most aggressive subtype due
to its resistance to standard chemotherapy. A key factor behind its
resistance is the activation of antiapoptotic pathways, which help
tumor cells evade drug-induced death. We present a modular platform
for combinatorial therapy, simultaneously delivering different clinically
approved chemotherapeutics and RNAi agents targeting multiple survival
pathways in vitro. To ensure that therapeutic activation occurs only
after cellular uptake, mesoporous silica nanoparticles were functionalized
with cisplatin and gemcitabine via reduction-sensitive linkers, while
surface modification with polyethylenimine enabled pH-responsive release
of programmable RNA nanoparticles that, upon intracellular dicing,
produce DS RNAs targeting the expression of Survivin and BCL-2. This
optimized formulation achieved strong gene silencing, minimized immune
activation, and enhanced cytotoxicity in TNBC cells compared to either
treatment alone. The results highlight the potential of this combinatorial
strategy to overcome chemoresistance by delivering multiple therapeutics
that simultaneously target distinct survival pathways in cancer cells
and can be readily modified and adapted to new targets.