Drug-Embedded Nanovesicles Assembled from Peptide-Decorated Hyaluronic Acid for Rheumatoid Arthritis Synergistic Therapy.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes endless pain and poor quality of life in patients. Usage of a lubricant combined with anti-inflammatory therapy is considered a reasonable and effective approach for the treatment of RA. Herein, inspired by glycopeptides, a peptide-decorated hyaluronic acid was synthesized, and the grafted Fmoc-phenylalanine-phenylalanine-COOH (FmocFF) peptide self-assembled with ß-sheet conformations could induce the folding of polymer molecular chains to form a vesicle structure in aqueous solution. The hydrophobic anti-inflammatory drug curcumin (Cur) could be embedded in the vesicle walls through π-π interactions with the FmocFF peptide. Furthermore, the inflammation suppression function of the Cur-loaded vesicles both in vitro and in vivo was demonstrated to be an effective treatment for RA therapy. This work proposes new insights into the folding and hierarchical assembly of glycopeptide mimics, providing an efficient approach for constructing intelligent platforms for drug delivery, disease therapy, and diagnostic applications.

Green Tea Polyphenol Induced Mg2+-rich Multilayer Conversion Coating: Toward Enhanced Corrosion Resistance and Promoted in Situ Endothelialization of AZ31 for Potential Cardiovascular Applications.

As a promising biodegradable metallic material, magnesium (Mg) and its alloys have attracted special attention in the recent decade. However, challenges still remain due to its high corrosion rate and insufficient biocompatibility after implantation. In this work, we prepare a simple and versatile green tea phenol-metal induced multilayer conversion coating (Mg2+ incorporated epigallocatechin gallate (EGCG) coating) on magnesium alloys' (AZ31) substrate by layer-by-layer (LBL) method. The surface morphology results revealed that, with the incorporation of Mg2+, the as-formed EGCG/Mg coating was rich in phenol-Mg complex and presented more homogeneous and dense morphology, with far less cracks than the pure EGCG coating. The in vitro degradation rate and corrosion resistance were studied by electrochemical corrosion tests and monitoring of the changed pH value and hydrogen evolution, respectively, which revealed that the corrosion rate was effectively decreased compared to that of bare AZ31 after it was protected by EGCG/Mg coating. In vitro and ex vivo thrombogenicity test demonstrated the EGCG/Mg coatings presented an impressive improvement in decreasing the adhesion and activation of platelets and erythrocytes, in activated partial thromboplastin time (APTT), and in antithrombogenicity compared to those of bare AZ31. Owing to the mild degradation rate, in combination with the biological function of EGCG, enhanced endothelial cells' (ECs') adhesion and proliferation, suppressed smooth muscle cells' (SMCs') adhesion/proliferation, and inhibited cytokine release were observed on EGCG/Mg coated AZ31 alloy. Besides, the in vivo subcutaneous embedding experiment suggested that the EGCG/Mg coating performed more mild tissue response due to the improved corrosion resistance to the surrounding microenvironment. Moreover, for in vivo abdominal aorta assay, the EGCG/Mg coated AZ31 wire presented better corrosion resistance and enhanced re-endothelialization compared to bare AZ31 wire. These results suggested the potential of using green tea polyphenol induced Mg2+-rich multilayer conversion coating for enhanced corrosion protection and desired biocompatibility of biodegradable cardiovascular implants.