Single-File Diffusion of Protein Drugs through Cylindrical Nanochannels

A new drug delivery device using cylindrical block copolymer nanochannels was successfully developed for controlled protein drug delivery applications. Depending on the hydrodynamic diameter of the protein drugs, the pore size in cylindrical nanochannels could be controlled precisely down to 6 nm by Au deposition. Zero-order release of bovine serum albumin (BSA) and human growth hormone (hGH) by single-file diffusion, which has been observed for gas diffusion through zeolite pores, was realized up to 2 months without protein denaturation. Furthermore, a nearly constant in vivo release of hGH from the drug delivery nanodevice implanted to Sprague−Dawley (SD) rats was continued up to 3 weeks, demonstrating the feasibility for long-term controlled delivery of therapeutic protein drugs

Bioimaging of Hyaluronate–Interferon α Conjugates Using a Non-Interfering Zwitterionic Fluorophore

We conducted real-time bioimaging of the hyaluronate–interferon α (HA–IFNα) conjugate using a biologically inert zwitterionic fluorophore of ZW800-1 for the treatment of hepatitis C virus (HCV) infection. ZW800-1 was labeled on the IFNα molecule of the HA–IFNα conjugate to investigate its biodistribution and clearance without altering its physicochemical and targeting characteristics. Confocal microscopy clearly visualized the effective <i>in vitro</i> cellular uptake of the HA–IFNα conjugate to HepG2 cells. After verifying the biological activity in Daudi cells, we conducted the pharmacokinetic analysis of the HA–IFNα conjugate, which confirmed its target-specific delivery to the liver with a prolonged residence time longer than that of PEGylated IFNα. <i>In vivo</i> and <i>ex vivo</i> bioimaging of the ZW800-1-labeled HA–IFNα conjugate directly showed real-time biodistribution and clearance of the conjugate that are consistent with the biological behaviors analyzed by an enzyme-linked immunosorbent assay. Furthermore, the elevated level of OAS1 mRNA in the liver confirmed <i>in vivo</i> antiviral activity of HA–IFNα conjugates. With the data taken together, we could confirm the feasibility of ZW800-1 as a biologically inert fluorophore and target-specific HA–IFNα conjugate for the treatment of HCV infection

<i>In Situ</i> Supramolecular Assembly and Modular Modification of Hyaluronic Acid Hydrogels for 3D Cellular Engineering

A facile <i>in situ</i> supramolecular assembly and modular modification of biocompatible hydrogels were demonstrated using cucurbit[6]uril-conjugated hyaluronic acid (CB[6]-HA), diaminohexane-conjugated HA (DAH-HA), and tags-CB[6] for cellular engineering applications. The strong and selective host–guest interaction between CB[6] and DAH made possible the supramolecular assembly of CB[6]/DAH-HA hydrogels in the presence of cells. Then, the 3D environment of CB[6]/DAH-HA hydrogels was modularly modified by the simple treatment with various multifunctional tags-CB[6]. Furthermore, we could confirm <i>in situ</i> formation of CB[6]/DAH-HA hydrogels under the skin of nude mice by sequential subcutaneous injections of CB[6]-HA and DAH-HA solutions. The fluorescence of modularly modified fluorescein isothiocyanate (FITC)-CB[6] in the hydrogels was maintained for up to 11 days, reflecting the feasibility to deliver the proper cues for cellular proliferation and differentiation in the body. Taken together, CB[6]/DAH-HA hydrogels might be successfully exploited as a 3D artificial extracellular matrix for various tissue engineering applications

Hyaluronic Acid–Gold Nanoparticle/Interferon α Complex for Targeted Treatment of Hepatitis C Virus Infection

Gold nanoparticles (AuNPs) have been extensively investigated as an emerging delivery carrier of various biopharmaceuticals. Instead of nonspecific polyethylene glycol (PEG) conjugated interferon α (IFNα) for the clinical treatment of hepatitis C virus (HCV) infection, in this work, a target-specific long-acting delivery system of IFNα was successfully developed using the hybrid materials of AuNP and hyaluronic acid (HA). The HA–AuNP/IFNα complex was prepared by chemical binding of thiolated HA and physical binding of IFNα to AuNP. According to antiproliferation tests in Daudi cells, the HA–AuNP/IFNα complex showed a comparable biological activity to PEG-Intron with a highly enhanced stability in human serum. Even 7 days postinjection, HA–AuNP/IFNα complex was target-specifically delivered and remained in the murine liver tissue, whereas IFNα and PEG-Intron were not detected in the liver. Accordingly, HA–AuNP/IFNα complex significantly enhanced the expression of 2′,5′-oligoadenylate synthetase 1 (OAS1) for innate immune responses to viral infection in the liver tissue, which was much higher than those by IFNα, PEG-Intron, and AuNP/IFNα complex. Taken together, the target-specific HA–AuNP/IFNα complex was thought to be successfully applied to the systemic treatment of HCV infection

<i>In Situ</i> Supramolecular Assembly and Modular Modification of Hyaluronic Acid Hydrogels for 3D Cellular Engineering

A facile <i>in situ</i> supramolecular assembly and modular modification of biocompatible hydrogels were demonstrated using cucurbit[6]uril-conjugated hyaluronic acid (CB[6]-HA), diaminohexane-conjugated HA (DAH-HA), and tags-CB[6] for cellular engineering applications. The strong and selective host–guest interaction between CB[6] and DAH made possible the supramolecular assembly of CB[6]/DAH-HA hydrogels in the presence of cells. Then, the 3D environment of CB[6]/DAH-HA hydrogels was modularly modified by the simple treatment with various multifunctional tags-CB[6]. Furthermore, we could confirm <i>in situ</i> formation of CB[6]/DAH-HA hydrogels under the skin of nude mice by sequential subcutaneous injections of CB[6]-HA and DAH-HA solutions. The fluorescence of modularly modified fluorescein isothiocyanate (FITC)-CB[6] in the hydrogels was maintained for up to 11 days, reflecting the feasibility to deliver the proper cues for cellular proliferation and differentiation in the body. Taken together, CB[6]/DAH-HA hydrogels might be successfully exploited as a 3D artificial extracellular matrix for various tissue engineering applications

3D Tissue Engineered Supramolecular Hydrogels for Controlled Chondrogenesis of Human Mesenchymal Stem Cells

Despite a wide investigation of hydrogels as an artificial extracellular matrix, there are few scaffold systems for the facile spatiotemporal control of mesenchymal stem cells (MSCs). Here, we report 3D tissue engineered supramolecular hydrogels prepared with highly water-soluble monofunctionalized cucurbit[6]­uril–hyaluronic acid (CB[6]-HA), diaminohexane conjugated HA (DAH-HA), and drug conjugated CB[6] (drug-CB[6]) for the controlled chondrogenesis of human mesenchymal stem cells (hMSCs). The mechanical property of supramolecular HA hydrogels was modulated by changing the cross-linking density for the spatial control of hMSCs. In addition, the differentiation of hMSCs was temporally controlled by changing the release profiles of transforming growth factor-β3 (TGF-β3) and/or dexamethasone (Dexa) from the hydrolyzable Dexa-CB[6]. The effective chondrogenic differentiation of hMSCs encapsulated in the monoCB[6]/DAH-HA hydrogel with TGF-β3 and Dexa-CB[6] was confirmed by biochemical glycosaminoglycan content analysis, real-time quantitative PCR, histological, and immunohistochemical analyses. Taken together, we could confirm the feasibility of cytocompatible monoCB[6]/DAH-HA hydrogels as a platform scaffold with controlled drug delivery for cartilage regeneration and other various tissue engineering applications