Local Drug Delivery Strategy for Cancer Treatment: Use of Biocompatible Sol-Gel-Derived Porous Materials

Porous silica xerogel materials have been developed to use as drug-release agents to be implanted directly in or near cancerous tissues. In order to test the capacity of the materials to absorb and then to release medicinal substances, a battery of examinations (UV and visible micro-Raman, porosity measurements, UV-visible absorption spectra) have been made using test drug molecules (clotrimazole, primaquine diphosphate and the anti-cancer agent vinblastine sulphate). Results show that the molecules can be post-doped into the gels and the Raman data provide indications of the best conditions for detecting the substances absorbed in the gels. Spectroscopic results show that the drug molecules are released by the xerogel over a period of 10 days. These results are promising for the development of these materials as drug-release agents.

Antibacterial and pH-responsive Quaternized Hydroxypropyl Cellulose-g-Poly(THF-co-epichlorohydrin)Graft Copolymer:Synthesis,Characterization and Properties

The novel quaternized hydroxypropyl cellulose-g-poly(THF-co-epichlorohydrin)graft copolymers,HPC-g-QCP(THF-co-ECH),have been successfully synthesized to combine the properties from hydrophilic hard HPC biomacromolecular backbone and hydrophobic flexible polyether branches.Firstly,the P(THF-co-ECH)living chains were synthesized by cationic ring-opening copolymerization of THF with ECH.Secondly,P(THF-co-ECH)living chains were grafted onto HPC backbone by reaction with-OH groups along HPC to produce HPC-g-P(THF-co-ECH)graft copolymers.Thirdly,the mentioned graft copolymers were quaternized by reaction with ternanyamine to generate functionalized HPC-g-QCP(THF-co-ECH).The HPC-g-QCP(THF-co-ECH)graft copolymers exhibited good antibacterial ability against S.aureus or E.coli bacteria.The ibuprofen(IBU)-loaded microparticles of HPC-g-(QC)P(THF-co-ECH)graft copolymers were prepared by electrospraying.The in vitro pH-responsive drug-release behavior of IBU reached up to 75%of drug-loaded at pH=7A.This quaternized graft copolymer was beneficial to solving the problems of a burst effect and fast release of HPC as drug carriers.

Photocaged prodrug under NIR light-triggering with dual-channel fluorescence: in vivo real-time tracking for precise drug delivery

Light-triggered drug delivery system is an effective strategy for precise diagnosis and therapy in cancer treatment. However, it suffers from difficultly balancing the dosimetry of drug with light dose and a lack of in vivo models for validating their clinical benefits. Here we report an unprecedented near-infrared(NIR) light photocaged cyanine-based prodrug Cy-CPT-Biotin with dual-channel fluorescence mode, enabling NIR light to precisely regulate where, when and how the intact and active prodrugs are delivered. The synergy of photochemical reaction and modulation in π-conjugated polyene backbone of cyanine can fully perform distinct dual-channel fluorescence changes in a NIR light-mediated manner. The prodrug has striking characteristics of excellent tumor-targeting ability, real-time monitoring of the in vivo behaviors by dual-channel mode and NIR-light triggering,especially for achieving fine regulation and on-demand drug release in the precise dosimetry of drug with light dose in living animals. This optical orthogonality strategy that conjuncts with NIR light-triggered and dual-channel fluorescence in vivo imaging provides a powerful tool for in vivo real-time tracking and finely tuning the prodrug release for precise drug delivery.