# Triblock Polyampholyte‐Based Nanovesicles for Targeted Spleen Delivery

## TL;DR

Researchers developed nanovesicles from a special polymer that can deliver drugs specifically to the spleen in mice.

## Contribution

The study introduces a new type of nanovesicle using triblock polyampholytes for targeted spleen delivery.

## Key findings

- Nanovesicles with a 140 nm diameter and 15 nm membrane thickness were successfully assembled.
- Cross-linking the membrane improved stability in physiological conditions.
- The nanovesicles accumulated selectively in the spleen after intravenous injection in mice.

## Abstract

Polymeric vesicles are a promising platform for targeted drug delivery. In this study, nanovesicles are developed using triblock polyampholytes composed of neutral poly(ethylene glycol), cationic poly(L‐lysine), and anionic poly(α,β‐aspartic acid) segments (PEG‐PLys‐PAsp) poly(aspartate) segments. By controlling the polymerization degree of these cationic and anionic segments, narrowly distributed nanovesicles are successfully assembled with a hydrodynamic diameter of ≈140 nm. The membrane thickness of the nanovesicles is around 15 nm, corresponding to a uniform polyion complex layer. Cross‐linking the membrane of the nanovesicles via amide bonds enhance their stability in physiological salt and temperature conditions. In vivo, the cross‐linked nanovesicles exhibit prolonged blood circulation and selective accumulation in the spleen after intravenous injection in mice. This approach demonstrates the potential of polyampholyte‐based nanovesicles (TPBV) for targeted drug delivery applications to the spleen.

Polymeric nanovesicles, assembled from triblock polyampholytes, exhibit unilamellar structure and enhanced stability through membrane cross‐linking. These nanovesicles demonstrate prolonged blood circulation and selective accumulation in the spleen after intravenous injection in mice, highlighting their potential for targeted drug delivery applications.