A Biodegradable Nano-Drug Delivery Platform for Co-Delivery of Minocycline and Chitosan to Achieve Efficient and Safe Non-Surgical Periodontitis Therapy.

INTRODUCTION: Mesoporous silica nanoparticles (MSN) are widely used as ideal nanovehicles for the delivery of chemotherapeutic drugs. However, the balance between high anti-periodontitis activity and low biotoxicity has been challenging to maintain in most relevant studies owing to the slow degradation of silica in living organisms. METHOD: In this study, -responsive hydroxyapatite (HAP) was doped into the MSN skeleton, and the chemotherapeutic drug minocycline hydrochloride (MH) was loaded into the pores of MSN, forming a negatively charged drug delivery system. Cationic chitosan (COS) is a biodegradable material with high antibacterial performance and good biosafety. In this study, COS was immobilized on the surface of the drug-loaded particles through stable charge interaction to construct a composite drug delivery system (MH@MSNion@COS). RESULTS: In vitro and cellular experiments demonstrated effective degradation of the nanocarrier system and synchronized controlled release of the drug. Notably, compared with single MH administration, this system, in which MH and COS jointly regulated the expression levels of periodontitis- associated inflammatory factors (TNF-α, IL-6, IL-1ß, and iNOS), better inhibited the progress of periodontitis and induced tissue regeneration without showing significant toxic side effects in cells. CONCLUSION: This system provides a promising strategy for the design of intelligent, efficient, and safe anti-periodontitis drug delivery systems.

Rational design, synthesis and biological evaluation of novel HIV-1 protease inhibitors containing 2-phenylacetamide derivatives as P2 ligands with potent activity against DRV-Resistant HIV-1 variants.

A novel kind of potent HIV-1 protease inhibitors, containing diverse hydroxyphenylacetic acids as the P2-ligands and 4-substituted phenyl sulfonamides as the P2' ligands, were designed, synthesized and evaluated in this work. Majority of the target compounds exhibited good to excellent activity against HIV-1 protease with IC50 values below 200 nM. In particular, compound 18d with a 2-(3,4-dihydroxyphenyl) acetamide as the P2 ligand and a 4- methoxybenzene sulfonamide P2' ligand exhibited inhibitory activity IC50 value of 0.54 nM, which was better than that of the positive control darunavir (DRV). More importantly, no significant decline of the potency against HIV-1DRVRS (DRV-resistant mutation) and HIV-1NL4_3 variant (wild type) for 18d was detected. The molecular docking study of 18d with HIV-1 protease (PDB-ID: 1T3R, www.rcsb.org) revealed possible binding mode with the HIV-1 protease. These results suggested the validity of introducing phenol-derived moieties into the P2 ligand and deserve further optimization which was of great value for future discovery of novel HIV-1 protease.