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pH-Responsive "Supra-Amphiphilic" Nanoparticles Based on Homoarginine Polypeptides
Korra Praveen1,2, Soumen Das1,2, Vinita Dhaware1,2
1Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
ACS Applied Bio Materials
|January 13, 2022
Summary
Researchers developed pH-sensitive supra-amphiphilic nanoparticles using poly(homoarginine) and carboxylic acids. These nanoparticles encapsulate dyes and disassemble at low pH, showing potential for drug delivery applications.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Polymer Chemistry
Background:
- Stimuli-responsive nanomaterials are crucial for targeted drug delivery.
- Poly(l-lysine) based supra-amphiphiles are well-studied, but poly(l-arginine) systems are less explored.
- Arginine's guanidine group exhibits stronger binding to carboxylates than lysine's amine.
Purpose of the Study:
- To fabricate pH-sensitive supra-amphiphilic nanoparticles using poly(homoarginine) and carboxylic acids.
- To investigate the self-assembly, pH-responsiveness, and encapsulation capabilities of these novel nanoparticles.
- To evaluate the cytotoxicity and cellular uptake of the fabricated nanoparticles.
Main Methods:
- Synthesis of PEG-b-poly(homoarginine) (PEG2k-b-PHR30) block copolymer via controlled polymerization.
- Fabrication of nanoparticles by mixing PEG2k-b-PHR30 with various carboxylic acids (including dexamethasone).
- Characterization of nanoparticle size, dye encapsulation (Nile red), pH-dependent disassembly, cytotoxicity, and cellular uptake via microscopy.
Main Results:
- PEG2k-b-PHR30 was synthesized with controlled molecular weights and low polydispersity indices.
- Supra-amphiphilic nanoparticles (<200 nm) were formed through strong guanidine-carboxylate interactions.
- Nanoparticles encapsulated Nile red and disassembled at pH 4-5 due to carboxylic acid protonation.
- Cytotoxicity varied with the carboxylic acid used; dexamethasone-based nanoparticles showed lower cell viability.
Conclusions:
- pH-sensitive supra-amphiphilic nanoparticles can be successfully fabricated using PEG-b-poly(homoarginine) and carboxylic acids.
- These nanoparticles demonstrate controlled disassembly in response to pH changes, indicating potential for drug release.
- The strong arginine-carboxylate interaction facilitates nanoparticle formation and cellular uptake, suggesting promise for nanomedicine applications.
