Development of a novel electrospun nanofibrous delivery system for poorly water-soluble β-sitosterol

Electrospinning was used as a novel technique for fabricating polymeric nanofibers of a serum cholesterol lowering and poorly water-soluble plant sterol, β-sitosterol. Chitosan was used as a stabilizer/carrier polymer. The mean diameters of nanofibers ranged from 150 nm to218 nm. β-sitosterol was in an amorphous form and homogeneously dispersed in the nanofibers. The β-sitosterol-loaded nanofibers were freely water-soluble and exhibited very short lag-time in releasing the plant sterol. The dissolution was associated with an immediate recrystallization of β-sitosterol in submicron level. In conclusion, electrospinning is a promising future technology for the formulation of poorly water-soluble plant sterols.

Mussel-Inspired and Bioclickable Peptide Engineered Surface to Combat Thrombosis and Infection

Thrombosis and infections are the two major complications associated with extracorporeal circuits and indwelling medical devices,leading to significant mortality in clinic.To address this issue,here,we report a biomimetic surface engineering strategy by the integration of mussel-inspired adhesive peptide,with bio-orthogonal click chemistry,to tailor the surface functionalities of tubing and catheters.Inspired by mussel adhesive foot protein,a bioclickable peptide mimic(DOPA)4-azidebased structure is designed and grafted on an aminated tubing robustly based on catechol-amine chemistry.Then,the dibenzylcyclooctyne(DBCO)modified nitric oxide generating species of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid(DOTA)chelated copper ions and the DBCO-modified antimicrobial peptide(DBCO-AMP)are clicked onto the grafted surfaces via bio-orthogonal reaction.The combination of the robustly grafted AMP and Cu-DOTA endows the modified tubing with durable antimicrobial properties and ability in long-term catalytically generating NO from endogenous snitrosothiols to resist adhesion/activation of platelets,thus preventing the formation of thrombosis.Overall,this biomimetic surface engineering technology provides a promising solution for multicomponent surface functionalization and the surface bioengineering of biomedical devices with enhanced clinical performance.

Programmable immune activating electrospun fibers for skin regeneration

Immune cells play a crucial regulatory role in inflammatory phase and proliferative phase during skin healing.How to programmatically activate sequential immune responses is the key for scarless skin regeneration.In this study,an“Inner-Outer”IL-10-loaded electrospun fiber with cascade release behavior was constructed.During the inflammatory phase,the electrospun fiber released a lower concentration of IL-10 within the wound,inhibiting excessive recruitment of inflammatory cells and polarizing macrophages into anti-inflammatory phenotype“M2c”to suppress excessive inflammation response.During the proliferative phase,a higher concentration of IL-10 released by the fiber and the anti-fibrotic cytokines secreted by polarized“M2c”directly acted on dermal fibroblasts to simultaneously inhibit extracellular matrix overdeposition and promote fibroblast migration.The“Inner-Outer”IL-10-loaded electrospun fiber programmatically activated the sequential immune responses during wound healing and led to scarless skin regeneration,which is a promising immunomodulatory biomaterial with great potential for promoting complete tissue regeneration.