Encapsulation of anticancer drug by hydrogen-bonded multilayers of tannic acid

Abstract

Tannic acid (TA)-based multilayer assemblies have attracted increasing interest for biomedical applications. Here we explore properties of TA-poly(N-vinylpyrrolidone) (TA-PVPON) hydrogen-bonded multilayers for drug encapsulation and long-term storage. We demonstrate that the small molecular weight anticancer drug, doxorubicin (DOX), can be successfully loaded into (TA-PVPON) capsules with high encapsulation efficiency. We have also found that the encapsulated DOX can be efficiently stored inside the capsules for the pH range from pH = 7.4 to pH = 5. We show that the chemical and functional stability of TA at neutral and basic pH values is achieved through complexation with PVPON. The UV-vis spectrophotometry and in situ ellipsometry analyses of the hydrogen bonding interactions between TA and PVPON at different pH values reveal pH-dependent behavior of TA-PVPON capsules for the pH range from pH = 7.4 to pH = 5. Increasing deposition pH value from pH = 5 to pH = 7.4 leads to a 2-fold decrease in capsule thickness. However, this trend is reversed when salt concentration of the deposition solutions is increased from 0.01 M to 0.1 M NaCl. We have also demonstrated that the permeability of (TA-PVPON) capsules prepared using low salt deposition conditions and pH = 7.4 can be increased 2-fold by exposure of the capsules to 0.1 M NaCl salt solutions at the same pH. Our work opens new perspectives for design of novel polymer carriers for controlled drug delivery in cancer therapy.

Pickering Emulsion Gels Prepared by Hydrogen-Bonded Zein/Tannic Acid Complex Colloidal Particles

“…This complexation further suppressed the ionization of TA, resulting in the improvement of their drug encapsulation and long-term storage. 11,24 In a similar way, hydrogen-bonding interaction between protonated TA and zein might dominate in the ZTP formed at pH 5.0. At pH 3.0 and 7.0, TA was in partial ionization of hydroxyl groups, leading to the formation of electrostatic complexes with low surface charge and unstable colloidal dispersions.…”

“…As a weak acid, TA completely protonates and ionizes at pH 3.0 and 7.0, respectively. 11 Therefore, the increase of α-helix content at pH 3.0 and 7.0 might contribute to the formation of electrostatic complexes between zein and protonated or ionized TA. Figure 3B clearly shows evidence for a conformational change of zein in aqueous ethanol solution that was induced by TA binding.…”

Islet encapsulation with polyphenol coatings decreases pro-inflammatory chemokine synthesis and T cell trafficking

“…(PVPON/TA) multilayer hollow capsules were synthesized as previously described [6, 35] by incubating 1.5 mL of 10%-aqueous suspension of silica microspheres to PVPON (1 mg mL −1 ) solution (0.01 M sodium phosphate, pH=3.5) for 10 min. The silica particle suspension was subsequently pelleted and rinsed two times with 0.01 M sodium phosphate (pH=3.5) to remove unbound excess of polymer.…”

Nanosized Camptothecin Conjugates for Single and Combined Drug Delivery

“…By carefully adjusting the surface property and biocompatibility, polymers can be decorated with different active drugs and self-assemble into nanoparticles for targeted drug delivery (43)(44)(45)(46).…”