ABSTRACT
A hyaluronic acid-based anionic nanogel formed by self-assembly of cholesteryl-group-bearing HA is designed for protein delivery. The HA nanogel spontaneously binds various types of proteins without denaturation, such as recombinant human growth hormone, erythropoietin, exendin-4, and lysozyme. The HA nanogel shows unique colloidal properties, in particular that an injectable hydrogel is formed by salt-induced association of the HA nanogel. A pharmacokinetic study in rats shows that an in situ gel formulation, prepared by simply mixing rhGH and HA nanogel in phosphate buffer, maintains plasma rhGH levels within a narrow range over one week. Therefore, HA nanogels offer a simple method for easy formulation of therapeutic proteins and are effective for sustained protein release systems.
Subject(s)
Growth Hormone/pharmacokinetics , Hyaluronic Acid/analogs & derivatives , Hyaluronic Acid/chemistry , Animals , Buffers , Cholesterol Esters/chemistry , Delayed-Action Preparations , Drug Carriers , Erythropoietin/chemistry , Exenatide , Growth Hormone/administration & dosage , Humans , Hydrogels , Injections , Male , Muramidase/chemistry , Peptides/chemistry , Protein Stability , Rats , Rats, Sprague-Dawley , Sodium Chloride/chemistry , Venoms/chemistryABSTRACT
Novel hybrid hyaluronan (HA) hydrogel encapsulating nanogels was designed for sustained delivery of protein. HA modified with 2-aminoethyl methacrylate was cross-linked via Michael addition in the presence of cholesteryl group-bearing pullulan (CHP) nanogels. The nanogels were physically entrapped and well dispersed in a three-dimensional network of chemically cross-linked HA (HA gel). Therapeutic peptides and proteins, such as glucagon-like peptide-1, insulin and erythropoietin, were spontaneously trapped in the CHP nanogels in the HA gel just by immersing hybrid hydrogels into the drug solutions. CHP/protein complex nanogels were released from the hybrid hydrogels in a sustained manner both in vitro and in vivo. The release was controlled by the cross-linking density and the degradability of the HA gel, modulated by the initial gelation condition. The synergy between the CHP nanogel as a drug reservoir and the HA gel as a nanogel-releasing matrix of the hybrid hydrogel system simultaneously achieved both simple drug loading and controlled release with no denaturation of the protein drugs. This is a new method of fabricating biodegradable controlled release matrix with molecular chaperone-like activity for therapeutic proteins.
Subject(s)
Drug Carriers/chemistry , Hyaluronic Acid/chemistry , Hydrogels/chemistry , Molecular Chaperones/administration & dosage , Nanostructures/chemistry , Peptide Fragments/administration & dosage , Recombinant Proteins/administration & dosage , Animals , Cross-Linking Reagents/chemistry , Delayed-Action Preparations , Injections, Intravenous , Male , Microscopy, Electron, Transmission , Molecular Chaperones/blood , Molecular Chaperones/pharmacokinetics , Peptide Fragments/blood , Peptide Fragments/pharmacokinetics , Rats , Rats, Sprague-Dawley , Recombinant Proteins/blood , Recombinant Proteins/pharmacokinetics , Solubility , Surface PropertiesABSTRACT
Novel photoresponsive nanogels were prepared by the self-assembly of spiropyrane-bearing pullulan (SpP). The solution properties of the nanogels could be controlled by photostimulation via isomerization between hydrophobic spiropyrane and hydrophilic merocyanine. The molecular chaperone-like activity of the nanogels in protein refolding was investigated. The activity of citrate synthase significantly increased when the amphiphilicity of SpP nanogels was switched by photostimulation.
