Pyridoxine regulates hair follicle development via the PI3K/Akt, Wnt and Notch signalling pathways in rex rabbits

This study was conducted to evaluate the effect of pyridoxine on the development of hair follicles in Rex rabbits and the underlying molecular mechanism.Two hundred 3-month-old Rex rabbits were randomly divided into 5 groups and fed diets supplemented with 0,5,10,20,or 40 mg/kg pyridoxine.The hair follicle density on the dorsal skin and the gene and protein expression levels of components of the phosphoinositide 3-kinase(PI3 K)/protein kinase B(PKB or Akt),Wnt,Notch and bone morphogenetic protein(BMP)signalling pathways were measured.In addition,free hair follicles were isolated from Rex rabbits and cultured with pyridoxine in vitro to measure hair shaft growth.Furthermore,dermal papilla cells(DPC)were isolated from the skin of Rex rabbits and cultured with pyridoxine in vitro to measure the gene and protein expression levels of components of the PI3 K/Akt,Wnt,Notch and BMP signalling pathways.The results showed that the addition of dietary pyridoxine significantly increased the total follicle density,secondary follicle density,and secondary-to-primary ratio(S/P,P<0.05),that the growth ratio of hair stems was promoted by pyridoxine in basic culture medium,and that the growth length of tentacle hair follicles cultured in the pyridoxine group was longer than that in the control group(P<0.05).In addition,pyridoxine changed the DPC cycle progression and promoted cell proliferation,and appropriate concentrations of pyridoxine(10 and 20μmol/L)significantly inhibited cell apoptosis(P<0.05).Pyridoxine significantly affected the gene expression of components of the PI3 K/Akt,Wnt and Notch signalling pathways in the skin and DPC of Rex rabbits(P<0.05),increased the levels of phosphorylated catenin beta 1(CTNNB1)and Akt,and decreased the level of phosphorylated glycogen synthase kinase 3 beta(GSK-3β)(P<0.05).Therefore,the molecular mechanism by which pyridoxine promotes hair follicle density in Rex rabbits probably occurs through activation of the PI3 K/Akt,Wnt and Notch signalling pathways,prolonging hair follicle growth and delaying the onset of telogen.

A fully absorbable biomimetic polymeric micelle loaded with cisplatin as drug carrier for cancer therapy

cis-dichlorodiammineplatinum(II)(CDDP)-loaded polymeric micelles for cancer therapy have been developed to reduce the serious side effects of cisplatin CDDP.Herein,polymeric micelles incorporated with cisplatin are prepared based on the complexation between CDDP and hydrophilic poly(L-glutamic acid)-b-poly(2-methacryloyloxyethyl phosphorylcholine)(PLG-b-PMPC)diblock copolymers.These CDDP-loaded micelles possess an average size of 91nm with narrow distribution,providing remarkable stability in media containing proteins.The release of CDDP from the micelles is faster at pH 5.0 and pH 6.0 than that at pH 7.4 and in a sustained manner without initial burst release.In addition,there is almost no difference in cellular uptake between these CDDP-loaded micelles and free CDDP.Moreover,in vitro cytotoxicity test shows they possess high efficacy to kill 4T1 cells as compared with free drug.Thus,PLG-b-PMPC copolymer might be a promising carrier for CDDP incorporating in cancer therapy.

A biomimetic and pH-sensitive polymeric micelle as carrier for paclitaxel delivery

As nano-scale drug delivery systems,smart micelles that are sensitive to specific biological environment and allowed for target site-triggered drug release by reversible stabilization of micelle structure are attractive.In this work,a biocompatible and pH-sensitive copolymer is synthesized through bridging poly(2-methacryloyloxyethyl phosphorylcholine)(PMPC)block and poly(D,L-lactide)(PLA)block by a benzoyl imine linkage(Blink).Biomimetic micelles with excellent biocompatibility based on such PLA-Blink-PMPC copolymer are prepared as carriers for paclitaxel(PTX)delivery.Due to the rapid breakage of the benzoyl imine linkage under acidic condition,the micelle structure is disrupted with accelerated PTX release.Such pH-sensitive triggered drug release behavior in synchronization with acidic conditions at tumor site is helpful for improving the utilization of drug and facilitating antitumor efficacy.These micelles can be used as promising drug delivery systems due to their biocompatible and smart properties.

Supramolecular Micelles and Reverse Micelles Based on Cyclodextrin Polyrotaxanes

A new supramolecular self-assembly approach to construct micelles and reverse micelles was reported.Double-hydrophilic block copolymers poly(ethylene oxide)-b-poly(N-isopropylacrylamide) (PEO-b-PNIPAAm) was synthesized via atom transfer radical polymerization (ATRP) using PEO macroinitiator.Because of the lower critical solution temperature (LCST) phase behavior of PNIPAAm,PEO-b-PNIPAAm block copolymers self-assembled to form PNIPAAm-core micelles at 40 ℃.The PNIPAAm-core micelles were disassembled to unimers when the temperature was decreased to 25 ℃.But the addition of α-cyclodextrins (α-CDs) could induce the formation of PNIPAAm-shell micelles because of the 'channel-type' crystallities induced by PEO/α-CDs polyrotaxanes.The assembly and disassembly procedure of micelles and reverse micelles were investigated by dynamic light scattering (DLS),X-ray diffraction (XRD),1H NMR and transmission electron microscopy (TEM).

Polyphenol based hybrid nano-aggregates modified collagen fibers of biological valve leaflets to achieve enhanced mechanical,anticoagulation and anti-calcification properties

Glutaraldehyde(Glut)-crosslinked porcine pericardium and bovine pericardium are mainly consisted of collagen and widely used for the preparation of heterogenous bioprosthetic heart valves(BHV),which play an important role in the replacement therapy of severe valvular heart disease,while their durability is limited by degeneration due to calcification,thrombus,endothelialization difficulty and prosthetic valve endocarditis.Herein,we develop a novel BHV,namely,TPly-BP,based on natural tannic acid and polylysine to improve the durability of Glut crosslinked bovine pericardium(Glut-BP).Impressively,tannic acid and polylysine could form nanoaggregates via multiple hydrogen bonds and covalent bonds,and the introduction of nanoaggregates not only improved the mechanical properties and collagen stability but also endowed TPly-BP with good biocompatibility and hemocompatibility.Compared to Glut-BP,TPly-BP showed significantly reduced cytotoxicity,improved endothelial cell adhesion,a low hemolysis ratio and obviously reduced platelet adhesion.Importantly,TPly-BP exhibited great antibacterial and in vivo anti-calcification ability,which was expected to improve the in vivo durability of BHVs.These results suggested that TPly-BP would be a potential candidate for BHV.

Facile fabrication of functional cellulose paper with high-capacity immobilization of Ag nanoparticles for catalytic applications for tannery wastewater

It has been a research goal to develop macroscopic materials with an optimized surface structure to affix silver nanoparticles which could contaminate water and maximize their practical functions.Cellulose paper is a versatile biomass material valued for its abundance,low cost,biocompatibility,and natural composition.Until now,its potential application in water purification has not been adequately explored.In this study,gallic acid-modified silver nanoparticles(GA@AgNPs)were loaded onto commercial cellulose filter paper using a simple lipoic acid modification process(GA@AgNPs-LA-CP).Scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),and X-ray diffraction(XRD)were used to characterize the GA@AgNPs-LA-CP.The catalytic activity of the GA@AgNPs-LA-CP was evaluated by the reduction reaction of methylene blue(MB),Rhodamine B(RhB),and 4-nitrophenol(4-NP)with sodium borohydride(NaBH4).The GA@AgNPs-LA-CP exhibited excellent catalytic activity toward MB,RhB,and 4-NP,taking advantage of its high specific surface area generated by the cellulose fiber network structure.Interestingly,due to the electrostatic interactions between the cationic dyes and the GA@AgNPs,the as-prepared catalytic composite material serves as a better catalyst for MB and RhB,suggesting dual applications of the composite materials for organic wastewater treatment and the removal of harmful dyes.This implies that the immobilization of AgNPs on cellulose papers is an effective method and can be applied to efficient wastewater treatment applications.