Designing Polymeric Multifunctional Nanogels for Photothermal Inactivation: Exploiting Conjugate Polymers and Thermoresponsive Platforms

<b>Background/Objectives</b>: Photothermal therapy (PTT) is an emerging minimally invasive strategy in biomedicine that converts near-infrared (NIR) light into localized heat for the targeted inactivation of pathogens and tumor cells. <b>Methods and Results</b>: In this study...

Full description

Saved in:
Bibliographic Details
Main Authors: Ignacio Velzi, Edith Ines Yslas, Maria Molina
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Pharmaceutics
Subjects:
Online Access:https://www.mdpi.com/1999-4923/17/7/827
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:<b>Background/Objectives</b>: Photothermal therapy (PTT) is an emerging minimally invasive strategy in biomedicine that converts near-infrared (NIR) light into localized heat for the targeted inactivation of pathogens and tumor cells. <b>Methods and Results</b>: In this study, we report the synthesis and characterization of thermoresponsive nanogels composed of poly (<i>N</i>-isopropylacrylamide-<i>co</i>-<i>N</i>-isopropylmethylacrylamide) (PNIPAM-<i>co</i>-PNIPMAM) semi-interpenetrated with polypyrrole (PPy), yielding monodisperse particles of 377 nm diameter. Spectroscopic analyses—including <sup>1</sup>H-NMR, FTIR, and UV-Vis—confirmed successful copolymer formation and PPy incorporation, while TEM images revealed uniform spherical morphology. Differential scanning calorimetry established a volumetric phase transition temperature of 38.4 °C, and photothermal assays demonstrated a ΔT ≈ 10 °C upon 10 min of 850 nm NIR irradiation. In vitro antimicrobial activity tests against <i>Pseudomonas aeruginosa</i> (ATCC 15692) showed a dose-time-dependent reduction in bacterial viability, with up to 4 log CFU/mL. Additionally, gentamicin-loaded nanogels achieved 38.7% encapsulation efficiency and exhibited stimulus-responsive drug release exceeding 75% under NIR irradiation. <b>Conclusions</b>: Combined photothermal and antibiotic therapy yielded augmented bacterial killing, underscoring the potential of PPy-interpenetrated nanogels as smart, dual-mode antimicrobials.
ISSN:1999-4923