ABSTRACT
OBJECTIVE： To prepare Paclitaxel（PTX）nanostructured lipid carriers （NLC） modified by small peptide alanine-glutamic acid-tyrosine-leucine-arginine （AEYLR）， and to evaluate its anti-tumor effect in vitro and in vivo. METHODS： NLC， PTX-NLC （P-NLC） and AEYLR modified P-NLC （A-P-NLC） were prepared by emulsion evaporation-low temperature solidification curing method. Its appearance， particle size， multi-dispersion index（PDI） and Zeta potential were characterized，encapsulation rate，drug loading and in vitro drug release were detected respectively. Using NCI-H1299 and S180 cells as objects， CCK-8 method was adopted to investigate inhibitory effects of free PTX， P-NLC and A-P-NLC （0.44-44.00 μg/mL， by PTX） to those cells. The half inhibition concentration （IC50） was calculated. Using S180 tumor-bearing mice as model animal， anti-tumor effects of free PTX， P-NLC and A-P-NLC （5 mg/kg， by PTX） were evaluated. RESULTS： P-NLC and A-P-NLC were round-like and dispersed evenly. The particle size， PDI and Zeta potential of A-P-NLC were （43.92±0.76） nm， 0.203±0.034 and （－19.77±1.16） mV， which were all increased to certain extent， compared with P-NLC. The encapsulation efficiency and drug loading of A-P-NLC were （95.71±0.68）％ and（1.97±0.25）％， which were both decreased to certain extent， compared with P-NLC. The cumulative release rate of A-P-NLC was（35.17±2.08）％ within 48 h， showing significant sustained-release effect compared with free PTX； the release of A-P-NLC was slower than P-NLC. Compared with free PTX and P-NLC， inhibitory rates of same concentration of A-P-NLC to NCI-H1299 cells and S180 cells were almost increased significantly， while IC50 values were all decreased significantly. There was no death in S180 tumor-bearing mice treated with A-P-NLC and the general condition was good； the volume of tumors was significantly reduced， the mass of tumors was significantly reduced， and the inhibition rate of tumors was significantly increased （P＜0.05 or P＜0.01）. CONCLUSIONS： A-P-NLC has significantly sustained-release effects； its inhibitory rate to NCI-H1299 cells and S180 cells in vitro， and its inhibitory effects on S180 solid tumor in mice are all better than free PTX and P-NLC， while the toxicity is decreased to certain extent.
ABSTRACT
Small peptides is one of the main components in the final product of protein digestion in the gastrointestinal tract,which plays an important role in protein nutrition.Present studies show that small peptides in the intestine can be absorbed directly into the circulation,which is also the main form of protein absorption in vivo.However,the transporter system of small peptides is independent from that of amino acids.This paper elaborates on the absorption and transport system of small peptides,their advantages in enteral nutrition,and some small peptides with critical physiological functions.
ABSTRACT
Objective To investigate the effects of tg19320,a small peptide,interfering with IgG-FcγR interaction on the adhesion of neutrophils to endothelium and the expression of intercellular adhesion molecule 1 (ICAM-1)in endothelial cells and its possible mechanism.Methods Tg19320 was prepared by solid-phase peptide synthesis.ANCA IgG was isolated from the serum of active ANCA-associated systemic vasculitis(AASV)patients.When primary human umbilical vein endothelial cells(HUVEC)grew into connuence in cytokine-free eonditions,the cells were stimulated with TNF-α,human normal IgG,ANCA IgG and ANCA IgG+tg19320 respectively.HUVEC were pretreated with tg19320 for 45 minutes before being stimulated by ANCA IgG.Non-activated neutrophils was added to treat HUVEC and adhesion was measured by cell count.The expression of ICAM-1 mRNA and protein was assessed by real-time PCR and Western blot respectively.Soluble ICAM-1(sICAM-1)was determined using ELISA technique.Phosphorylation of IκB-α was assessed by Western blot. Results ANCA IgG significantly up-regulated the expression of ICAM-1 in HUVEC and promoted sICAM-1 release(P＜0.05),and TNF-α enhanced the effect of ANCA.These effects were almost completely abolished by tgl9320 both at protein and mRNA level.Furthermore,ANCA IgG increased the IκB-α phosporylation in HUVEC and tg19320could inhibit the effect. Conclusions ANCA IgG can modulate the expression of ICAM-1 and sICAM-1 release in endothelial cells.FcγR probably play a critical role in the ICAM-1 expression up-regulated by ANCA,which is mediated in part through NF-κB signaling pathway.Tg19320 has protective effect on endothelium in AASV in vitro.
ABSTRACT
Objective Despite regular treatment,antineutrophil eytoplasmie antibodies(ANCA)asso- ciated systemic vasculitis(AASV),in which the role of Fc?Rs has been established,are still associated with significant long-term mortality and remain an important cause of end-stage renal failure.ANCA plays an im- portant role in the pathogenisis of primary systemic small vessel vasculitis(PSV)by their potential to activate neutrophils.Because the interaction between ANCA and its receptors on the Fc portion of immunoglobulins (Fc?R)on neutrophils is essential in the activation process,we investigate the inhibitory,effect of tg19320 on ANCA induced activation of neutrophils,which is a tetrameric tripeptide that interferes with IgG/Fe?Rs in- teraction.Methods We prepared tg19320 by solid-phase peptide syntbesis.The binding between tg19320 and human IgG was assessed by enzyme-linked immunosorbent assay.The biological activity of tg19320 to intefere with FcF?receptor recognition was identified by rosette formation assay.ANCA IgG was prepared from the sera of active Wegener's granulomatosis(WG)and microscopic polyangiitis(MPA)patients.Neu- trophils isolated from the blood of healthy volunteers were primed with TNF-?(2 ng/ml)and then incubated with ANCA IgG(200?g/ml),or pretreated with tg19320(2.5 mg/ml)and then added with ANCA IgG.Su- peroxide burst of neutrophils was determined by Ferri-cytochrome reduction assay.Results We found that tg19320 bound tightly to human IgG in a dose dependent manner and the inhibition of the rosette formation between SRBC-IgG and U937 cells was statistically significant(20.3% vs 53.2%,P