Chitosan Nanocapsules for pH‐Triggered Dual Release Based on Corrosion Inhibitors as Model Study

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/ppsc.201800086. Chitosan (CS) is known for its uniqueness in terms of containing reactive functional groups, i.e., amino and hydroxyl groups, along the chain which offer the noncovalent bonds and chemical modifications. At pH 3 in emulsion system, the CS chains are under charge-charge repulsive force, leading the polysaccharide chains to align as the hollow nanospheres and at that time, the crosslink leads to the nanocapsules. The CS nanocapsules allow the model cargos, i.e., corrosion inhibitors, entrapment not only via the noncovalent bond based on the weak interaction in the core for 2-mercaptobenzothiazole (MBT) cargo but also via the chemical bonds based on the amino group remaining on CS structure to result in either amide or Schiff base linkage in case of 3-nitrosalicylic acid (3NiSA) cargo. The release studies indicate that CS nanocapsules can release two cargoes upon pH change due to the acidic/basic-triggered cleavage of bonds between cargoes and nanocapsules. Once corrosion occurs, resulting in variation of the local pH value, the CS nanocapsules release MBT in fast and 3NiSA in a slow, sustained manner. The efficiency of the approach is demonstrated using the nanocapsules for hindering the corrosion of copper as measured by electrochemical quartz crystal microbalance. Nanocapsule Delivery SystemsRecently, the development of nanocarriers for material appli cations has required not only high efficient encapsulation but also the capability to control the release of cargoes such as drugs, proteins, corrosion inhibitors, and catalysts. [1][2][3] Encapsulation

Influence of Association on Binding of Disaccharides to YKL-39 and hHyal-1 Enzymes

“…The subscript resp describes orbital-relaxation effects, while the 𝛿𝛿 𝐻𝐻𝐻𝐻 (2) term corresponds to the higher-order induction effects obtained from the Hartree-Fock (HF) interaction energy. The electrostatic ( 𝐸𝐸 (10) ) is a Coulombic charge-clouds-interactions term, The anionic HA and HP ligands and the cationic CHI ligand exhibit the same binding affinity (−6.3 kcal•mol −1 ).…”

“…As a smart material, such capsules are equipped with stimuli-responsive controlled-release functions for targeted and/or controlled release. These capsules are frequently constructed on saccharide motifs [ 2 ]. In this regard, efforts have been directed toward studying polysaccharides with repeating units that bear an electrolyte group (polyelectrolytes), such as chitosan (CHI) or furcellaran (FUR), or glycosaminoglycans such as hyaluronic acid (HA), cellobiose (CB), or heparine (HP).…”

Encapsulation of Doxorubicin in Furcellaran/Chitosan Nanocapsules by Layer-by-Layer Technique for Selectively Controlled Drug Delivery

“…The drug delivery system used in targeted therapies is often designed to protect cargo from environmental impact, to have good biodegradation, excellent bioavailability, adequate tissue distribution, low toxicity, and to ensure that the drug is released under required conditions . An encapsulation of the drug into the nanocapsule (CAPS) carrier usually provides required dual role properties as environment drug protection and controlled release . Polysaccharides based CAPS derived from natural materials represent a promising candidate for the safe and controlled drug administration.…”

“…2 An encapsulation of the drug into the nanocapsule (CAPS) carrier usually provides required dual role properties as environment drug protection and controlled release. 3 Polysaccharides based CAPS derived from natural materials represent a promising candidate for the safe and controlled drug administration. Different types of the polysaccharides can be used for the CAPS formation such us furcellaran (FUR), alginate, cellulose, carrageenan, or potato starch.…”

Chitosan Microspheres as Carriers for pH‐Indicating Species in Corrosion Sensing

“…The chemical structure of chitosan contains amino and hydroxyl groups, therefore providing functional groups for further chemical modifications. In particular, chitosan is biocompatible, biodegradable, nontoxic, and pH responsive, making it a suitable functional natural polymer for tailoring systems or matrices for different active compounds in different applications. Chitosan is a weak base with a pKa value for the d ‐glucosamine residue of about 6.2–7.9 and, therefore, insoluble at neutral and alkaline pH .…”