Precise Controlled Target Molecule Release through Light-Triggered Charge Reversal Bridged Polysilsesquioxane Nanoparticles

Abstract

Precise control of target molecule release time, site, and dosage remains a challenge in controlled release systems. We employed a photoresponsive molecule release system via light-triggered charge reversal nanoparticles to achieve a triggered, stepwise, and precise controlled release platform. This release system was based on photocleavage-bridged polysilsesquioxane nanoparticles which acted as nanocarriers of doxorubicin loaded on the surface via electrostatic interaction. The nanoparticles could reverse into positive charges triggered by 254 nm light irradiation due to the photocleavage of the o-nitrobenzyl bridged segment. The charge reversal property of the nanoparticles could release loaded molecules. Doxorubicin was selected as a positively charged model molecule. The as-prepared nanoparticles with an average size of 124 nm had an acceptable doxorubicin loading content up to 12.8%. The surface charge of the nanoparticles could rapidly reverse from negative (−28.20 mV) to positive (+18.9 mV) upon light irradiation for only 10 min. In vitro release experiments showed a cumulative release up to 96% with continuously enhancing irradiation intensity. By regulating irradiation parameters, precisely controlled drug release was carried out. The typical “stepped” profile could be accurately controlled in an on/off irradiation mode. This approach provides an ideal light-triggered molecule release system for location, timing, and dosage. This updated controlled release system, triggered by near-infrared or infrared light, will have greater potential applications in biomedical technology.

Self-targeting of zwitterion-based platforms for nano-antimicrobials and nanocarriers

“…Also here, zwitterion-based platforms might offer possibilities as light-responsive zwitterions have been described. [49][50][51] Precise light-assisted or magnetic-targeting to micrometersized infectious biofilms (estimated dimensions 4-200 mm 52 ) and distribution of nano-antimicrobials over the entire depth of a biofilm is impossible with current clinical technologies that are better suited for external targeting of chemotherapeutic nanocarriers to centimeter-sized tumors. 53 As a general drawback, external triggering requires additional instrumentation and implies another hospital visit for a diseased patient.…”