Triple stimulus-responsive polypeptide nanoparticles that enhance intratumoral spatial distribution

Area of Science:

• Biomaterials Science
• Nanotechnology
• Drug Delivery

Background:

• Nanoparticle drug delivery faces challenges with limited tumor penetration.
• Tumor microenvironments often exhibit lower extracellular pH compared to normal tissues.

Purpose of the Study:

• To develop the first pH-responsive polypeptide micelle for enhanced tumor drug delivery.
• To investigate micelle dissociation at the acidic pH characteristic of solid tumors.

Main Methods:

• Self-assembly of histidine-rich elastin-like polypeptide block copolymer into micelles at 37 °C.
• Stabilization of micelles using Zn(2+).
• Assessment of micelle disruption at pH 6.4 compared to pH 7.4.

Main Results:

• Spherical micelles were formed and stabilized by Zn(2+).
• Micelles demonstrated pH-dependent dissociation, disrupting as pH decreased from 7.4 to 6.4.
• In vivo studies showed superior tumor penetration and distribution for pH-sensitive micelles over controls.

Conclusions:

• pH-responsive polypeptide micelles offer a promising strategy to overcome nanoparticle tumor penetration limitations.
• Targeted micelle dissociation at tumor-specific pH enhances drug delivery efficacy.
• This approach represents a significant advancement in targeted cancer nanotherapeutics.