Tumor‐Triggered Controlled Drug Release from Electrospun Fibers Using Inorganic Caps for Inhibiting Cancer Relapse

Abstract

A smart, tumor-trigged, controlled drug release using inorganic "caps" with CO3 (2-) functional groups in electrospun fibers is presented for inhibiting cancer relapse. When the drug-loaded intelligent electrospun fibers encounter pathological acidic environments, the inorganic gates react with the acids and produce CO2 gas, which enables water penetration into the core of the fibers to induce rapid drug release.

Tumor-triggered drug release from calcium carbonate-encapsulated gold nanostars for near-infrared photodynamic/photothermal combination antitumor therapy

“…The surfactant-free GNSs were initially synthesized according to the seed-mediated template-assisted protocol with some modifications 30. The acquired GNSs were subsequently covered by a layer of CaCO 3 , into which ICG were simultaneously entrapped 25. Transmission electron microscopy (TEM) images showed that the GNSs exhibited outstanding size uniformity with a diameter of 96 ± 7.5 nm, and dozens of branches extended from their surfaces (Figure 1A, Figure S1).…”

“…The reaction solution was kept under moderate stirring for 2 hours and GNS were acquired then. Next, calcium carbonate coating on GNSs was carried out according to Zhao's method with some modifications 25. Briefly, 1 mL of CaCl 2 (10 mg/mL) and 20 μL of ICG (500 μg/mL) were added to 50 mL as-prepared GNSs followed by moderate stirring for 24 hours.…”

“…Different stimulus including pH, light and temperature have been used in drug release to prevent its inactivity and minimize the side-effects to healthy tissues 1, 24-25. Of those, the most appealing way in anti-cancer therapy is the use of the acidic environment of the tumor region to trigger the release of the drug due to pH variation.…”

“…As a well-known building material for natural hard tissues such as bones and teeth with biocompatibility and nontoxicity, CaCO 3 is extensively utilized as drug carrier and biomedicine 26-27. More importantly, CaCO 3 is stable at physiological pH of 7.4, while readily dissolved into bio-components of Ca 2+ and CO 2 gas in response to an acidic environment 25. Due to hypoxia and imperfect blood vessels system in the tumor tissue, the tumor cells form and maintain the extracellular acidic microenvironment by abnormal energy metabolism and the regulation of specific proteins.…”

“…Due to hypoxia and imperfect blood vessels system in the tumor tissue, the tumor cells form and maintain the extracellular acidic microenvironment by abnormal energy metabolism and the regulation of specific proteins. Take this as an opportunity, CaCO 3 was previously used as a cap to seal the encapsulated drug in the delivery device 25.…”