Targeting the resolution pathway of inflammation using Ac2–26 peptide-loaded PEGylated lipid nanoparticles for the remission of rheumatoid arthritis

Rheumatoid arthritis(RA)is a common autoimmune disease characterized by joint inflammation and immune dysfunction.Although various therapeutic approaches have been utilized for the treatment of RA in clinical applications,the low responsiveness of RA patients and undesired systemic toxicity are still unresolved problems.Targeting the resolution pathway of inflammation with pro-resolving mediators would evoke the protective actions of patient for combating the inflammation.Ac2–26,a 25-amino acid peptide derived from Annexin A(a pro-resolving mediator),has shown good efficacy in the treatment of inflammatory disorders.However,the low bioavailability of Ac2–26 peptides hinders their efficacy in vivo.In this paper,we formed PEGylated lipid nanoparticles(LDNPs)by the co-assembly of l-ascorbyl palmitate(L-AP)and N-(carbonyl methoxypolyethylene glycol-2000)-1,2-distearoyl-sn–glycero-3-phosphoethanolamine(DSPE-PEG 2 k)to encapsulate and deliver Ac2–26 peptides to the arthritic rats.They showed good stability and biocompatibility.After being intravenously administrated,Ac2–26 peptide-loaded PEGylated lipid nanoparticles(ADNPs)showed the prolonged in vivo circulation time and enhanced accumulation in inflamed sites.In vivo therapeutic evaluations revealed that ADNPs could attenuate synovial inflammation and improve joint pathology.Therefore,the pro-resolving therapeutic strategy using ADNPs is effective in RA treatment.

Protein-spatiotemporal partition releasing gradient porous scaffolds and anti-inflammatory and antioxidant regulation remodel tissue engineered anisotropic meniscus

Meniscus is a wedge-shaped fibrocartilaginous tissue,playing important roles in maintaining joint stability and function.Meniscus injuries are difficult to heal and frequently progress into structural breakdown,which then leads to osteoarthritis.Regeneration of heterogeneous tissue engineering meniscus(TEM)continues to be a scientific and translational challenge.The morphology,tissue architecture,mechanical strength,and functional applications of the cultivated TEMs have not been able to meet clinical needs,which may due to the negligent attention on the importance of microenvironment in vitro and in vivo.Herein,we combined the 3D(three-dimensional)-printed gradient porous scaffolds,spatiotemporal partition release of growth factors,and anti-inflammatory and anti-oxidant microenvironment regulation of Ac2-26 peptide to prepare a versatile meniscus composite scaffold with heterogeneous bionic structures,excellent biomechanical properties and anti-inflammatory and anti-oxidant effects.By observing the results of cell activity and differentiation,and biomechanics under anti-inflammatory and anti-oxidant microenvironments in vitro,we explored the effects of anti-inflammatory and anti-oxidant microenvironments on construction of regional and functional heterogeneous TEM via the growth process regulation,with a view to cultivating a high-quality of TEM from bench to bedside.