Photorenewable Azobenzene Polymer Brush-Modified Nanoadsorbent for Selective Adsorption of LDL in Serum

Abstract

The elevated concentration of low-density lipoprotein (LDL) is recognized as a leading factor of hyperlipidemia (HLP), and selective adsorption of serum LDL is regarded as a practical therapy. Based on the superior structure–function characteristics of stimuli-responsive materials, a photorenewable nanoadsorbent (SiO2@Azo@Gly) with high selectivity and reusability was developed using azobenzene as the functional ligand. Its principle was certified by the preparation of silicon nanoparticles with atom transfer radical polymerization (ATRP)-initiating groups via a sol–gel reaction and their subsequent grafting of azobenzene polymer brushes by surface-initiated ATRP, followed by modification with glycine. Immobilization of carboxylated azobenzene polymer brushes onto the nanoparticles endowed SiO2@Azo@Gly with high adsorption selectivity and reusability. The advanced nanoadsorbent exhibited excellent LDL adsorption capacity at about 27 mg/g and could be regenerated by illumination with high efficiency (circulations ≥ 5); this was further verified by transmission electron microscopy (TEM) and Fourier-transform infrared (FTIR) analysis. SiO2@Azo@Gly also demonstrated superior adsorption efficiency and selectivity in serum from HLP patients, the respective adsorption capacities of LDL, triglyceride, and total cholesterol were about 15.65, 24.48, and 28.36 mg/g, and the adsorption to high-density lipoprotein (cardioprotective effect) was only about 3.66 mg/g. Green regeneration of the nanoadsorbent could be achieved completely through a simple photoregeneration process, and the recovery rate was still 97.9% after five regeneration experiments.

Preparation of UV-responsive hydrogels based on nanocellulose and their utilization in fungicide delivery

“…17,18 The photosensitive groups of AZO can absorb energy at specific UV wavelengths, leading to structural changes from the stretched trans to the compact form, thereby achieving non-contact remote-controlled drug release. 19 Considering their large surface area, small size, strong adsorption capacity, and good biocompatibility, cellulose nanocrystals (CNC) can help develop a smart delivery system for fungicides, and are ideal materials for improving leaf deposition, enhancing stability, prolonging fungicide release, and decreasing fungicide loss. 20,21 They can enhance the adhesion of fungicides to plant surfaces and exhibit excellent drug-loading performance.…”

“…17,18 The photosensitive groups of AZO can absorb energy at specific UV wavelengths, leading to structural changes from the stretched trans to the compact form, thereby achieving non-contact remote-controlled drug release. 19…”

Simultaneous Rosiglitazone Release and Low-Density Lipoprotein Removal by Chondroitin Sodium Sulfate/Cyclodextrin/Poly(acrylic acid) Composite Adsorbents for Atherosclerosis Therapy

“…The main strategies for reducing LDL concentration levels include dietary adjustments, lipid-lowering medications (mostly statins), and low-density lipoprotein apheresis (LDL-a) . The first two methods exhibit limited therapeutic efficacy for patients with familial hyperlipidemia and may develop resistance to lipid-lowering drugs with prolonged use. − LDL-a, a blood purification technique, efficiently and selectively removes excess LDL through the LDL adsorbents. , The LDL adsorbents include immunoadsorbents, hydrophobic adsorbents, , and ion exchange adsorbents. − Present reported adsorbents utilize hydrophobic sites for binding cholesterol on LDL and negatively charged sites for binding positively charged Apo B-100 of LDL …”

Acoustic Delivery of Plasma Low-Density Lipoprotein into Liver via ApoB100-Targeted Microbubbles Inhibits Atherosclerotic Plaque Growth

“…16 Moreover, their shells can be functionalized with a ligand, creating targeted MBs that can specially bind to biomarkers overexpressed during disease development. 17 For instance, Hughes et al utilized targeted MBs to capture circulating tumor cells in the bloodstream of mice for early cancer diagnosis. 18 Beyond their diagnostic role, MBs can also produce stable and inertial cavitation effects when exposed to high-power US irradiation, resulting in structural changes to the alignment of the phospholipid membranes.…”

“…These MBs, which are approximately 1–5 μm in size, have the ability to accumulate in the liver and be phagocytized by Kupffer cells (KCs) . Moreover, their shells can be functionalized with a ligand, creating targeted MBs that can specially bind to biomarkers overexpressed during disease development . For instance, Hughes et al utilized targeted MBs to capture circulating tumor cells in the bloodstream of mice for early cancer diagnosis .…”