Versatile Layer-By-Layer Highly Stable Multilayer Films: Study of the Loading and Release of FITC-Labeled Short Peptide in the Drug Delivery Field

Surface Self-Assembly Construction of Therapeutic Contact Lens with Bacterial "Kill-Releasing" and Drug-Reloading Capabilities for Efficient Bacterial Keratitis Treatment

Bacterial keratitis, an ophthalmic emergency, can cause corneal perforation and even endophthalmitis, thus leading to severe visual impairment. To achieve effective treatment of bacterial keratitis, good bioavailability of antimicrobial drugs on the ocular surface is desired. In this investigation, a layer-by-layer (LBL) self-assembly combined with the host-guest recognition was used to construct an antibacterial coating on the surface of corneal contact lens (CLs) to improve drug bioavailability and achieve successful treatment of bacterial keratitis. First, a radical copolymerization of acrylic acid (AA) and 1-adamantan-1-ylmethyl acrylate (AdA) was carried out to synthesize a polyanionic copolymer P(AA-co-AdA) (defined as PAcA). Then, PAcA copolymer combined with poly(ethyleneimine) (PEI) was used for a layer-by-layer (LBL) self-assembly to fabricate multilayer films on the surface of CLs. An antibacterial conjugate, β-cyclodextrin-levofloxacin (β-CD-LEV), was successfully synthesized and utilized to generate antibacterial coating through a host-guest interaction between AdA and β-CD-LEV. The antibacterial ability and treatment effect of bacterial keratitis was evaluated by in vitro assay and in vivo test in an animal model of staphylococcal keratitis, demonstrating that the antibacterial coating had good antibacterial and germicidal efficacy both in vivo and in vitro. We believe that this work will provide a promising strategy for the treatment of bacterial keratitis.

Hyaluronic-Acid-Based Organic-Inorganic Composites for Biomedical Applications

Applications of natural hyaluronic acid (HYH) for the fabrication of organic-inorganic composites for biomedical applications are described. Such composites combine unique functional properties of HYH with functional properties of hydroxyapatite, various bioceramics, bioglass, biocements, metal nanoparticles, and quantum dots. Functional properties of advanced composite gels, scaffold materials, cements, particles, films, and coatings are described. Benefiting from the synergy of properties of HYH and inorganic components, advanced composites provide a platform for the development of new drug delivery materials. Many advanced properties of composites are attributed to the ability of HYH to promote biomineralization. Properties of HYH are a key factor for the development of colloidal and electrochemical methods for the fabrication of films and protective coatings for surface modification of biomedical implants and the development of advanced biosensors. Overcoming limitations of traditional materials, HYH is used as a biocompatible capping, dispersing, and structure-directing agent for the synthesis of functional inorganic materials and composites. Gel-forming properties of HYH enable a facile and straightforward approach to the fabrication of antimicrobial materials in different forms. Of particular interest are applications of HYH for the fabrication of biosensors. This review summarizes manufacturing strategies and mechanisms and outlines future trends in the development of functional biocomposites.

Special Issue: Advanced Materials in Drug Release and Drug Delivery Systems

Development of new drug molecules is costly and requires longitudinal, wide-ranging studies; therefore, designing advanced pharmaceutical formulations for existing and well-known drugs seems to be an attractive device for the pharmaceutical industry [...].

LC-MS/MS analysis of partial structure of Panax ginseng protein and its distribution in vivo

Protein from Panax ginseng can improve learning, memory, and analgesia. Here, we investigated a fluorescence labeling method that can be used to determine the in vivo distribution of P. ginseng protein (PGP). High-performance liquid chromatography (HPLC) was used to define the amino acid composition and molecular weight of PGP; LC-MS/MS was used to identify the PGP structure, which was fluorescently-labeled using a fluorescein isothiocyanate (FITC) probe. The connection form of the PGP fluorescent marker (PGP-FITC) was identified by ultraviolet and infrared spectrophotometry. The in vivo distribution of PGP was observed by fluorescence imaging, and tissue content was determined. Results showed that PGP was enriched in the brain and that vascular epithelial cells showed specific uptake. We provide an experimental method to label and identify the in vivo distribution of PGP, which forms the basis for future studies to determine whether PGP can penetrate the blood-brain barrier (BBB) and elucidate the transport mechanism.