Factors involved in the success of Castanea henryi stem cuttings in different cutting mediums and cutting selection periods

Chinquapin(Castanea henryi) is a dual-purpose tree species in China valued for as a source of timber and starch.We investigated the effect of four cutting mediums(pure vermiculite;peat:river sand at 3:1 v/v;peat:krasnozem at 1:1 v/v;and pure krasnozem) and three stem cutting periods(March,May,and July) on rooting performance of C.henryi cuttings.Different cutting periods and cutting mediums greatly influenced the rooting rate of C.henryi,ranging from 3.35 to 77.31%.Principal component analysis indicated that the best combination of cutting period and cutting medium was semi-hardwood cuttings(May cuttings)+krasnozem.Histological evidence indicated that adventitious root initials were present by week 5-6,and that the site of root primordia initiation was observed in the vascular cambium.Stem anatomical structures observed at different periods indicated that a xylem/radius ratio of29.90-37.42% and a fractured phloem fiber ring are indicative of rooting success.The relational model between rooting index and medium properties indicated that nutrient content and porosity significantly influenced callus production.However,pH strongly affected C.henryi root formation,with the Pearson correlation coefficients for May and July cuttings of-0.856 and-0.947,respectively.Our protocol is helpful to achieve mass clone propagation of improved C.henryi genotypes,thus overcoming a common hurdle in chinquapin breeding programs.

Impact of particle size and pH on protein corona formation of solid lipid nanoparticles:A proof-of-concept study

When nanoparticles were introduced into the biological media,the protein corona would be formed,which endowed the nanoparticles with new bio-identities.Thus,controlling protein corona formation is critical to in vivo therapeutic effect.Controlling the particle size is the most feasible method during design,and the infuence of media pH which varies with disease condition is quite important.The impact of particle size and pH on bovine serum albumin(BSA)corona formation of solid lipid nanoparticles(SLNs)was studied here.The BSA corona formation of SLNs with increasing particle size(120-480 nm)in pH 6.0 and 7.4 was investigated.Multiple techniques were employed for visualization study,conformational structure study and mechanism study,etc."BSA corona-caused aggregation"of SLN2-3 was revealed in pH 6.0 while the dispersed state of SLNs was maintained in pH 7.4,which signifcantly affected the secondary structure of BSA and cell uptake of SLNs.The main interaction was driven by van der Waals force plus hydrogen bonding in p H 7.4,while by electrostatic attraction in pH 6.0,and size-dependent adsorption was confrmed.This study provides a systematic insight to the understanding of protein corona formation of SLNs.