# Design and Characterization of Functionalized Polyelectrolyte–Dicephalic Surfactant Complexes as Multipurpose Colloidal Systems

## TL;DR

This paper explores new polyelectrolyte-surfactant complexes that combine antimicrobial properties with drug delivery capabilities for biomedical use.

## Contribution

The study introduces novel antimicrobial-functionalized PESCs with a cationic dicephalic surfactant for controlled drug delivery.

## Key findings

- The PESCs effectively encapsulate and release curcumin, a model hydrophobic drug.
- The complexes show colloidal stability and surface activity suitable for biomedical applications.
- Combining antibacterial PAA derivatives with dicephalic surfactants creates tunable, multifunctional carriers.

## Abstract

Polyelectrolyte–surfactant complexes (PESCs) have
emerged
as versatile soft-matter systems, offering unique opportunities for
the design of multifunctional delivery platforms. Therefore, this
study investigates the design, formation, and characterization of
novel PESCs based on antimicrobial-functionalized poly­(acrylic acid)
(PAA) derivatives and a newly synthesized cationic dicephalic surfactant,
2-dodecyl-N,N,N,N’,N’,N’-hexamethyl-propan-1,3-ammonium
dibromide (C12-DCNMe3Br). Building
on our previous work on antimicrobial-decorated PAAs grafted with
thymol (PAA-THY-15), menthol (PAA-MEN-15), and carvacrol (PAA-CAR-15),
these polyanions were combined with the oppositely charged surfactant
to construct multipurpose carrier systems. The designed PESCs were
loaded with curcumin (CUR), a model hydrophobic drug with therapeutic
properties, to evaluate their potential applicability as drug delivery
systems (DDSs). A variety of physicochemical techniques were applied
to gain insight into the complexation processes, self-assembly behavior,
and functional properties of the resulting PESCs. Surface activity
of new complexes was assessed by goniometric measurements, while their
colloidal stability over time was studied using the turbidimetric
method. Dynamic light scattering (DLS) provided information on particle
size, polydispersity, and surface charge. Encapsulation efficiency
(EE) and release kinetics were assessed by UV–vis spectrophotometry
to evaluate the ability of the complexes to effectively entrap CUR
and provide sustained release. The integration of antibacterial PAA
derivatives with dicephalic surfactants highlights the versatility
of PESCs as tunable, multifunctional carriers that combine antimicrobial
protection with controlled drug delivery. These findings demonstrate
that the designed complexes are promising candidates for advanced
DDSs and pave the way for further development of functional colloidal
materials tailored for biomedical applications.