Task: Synthesis of DSPE-PEG-CONHNH2
Task: Dialysis of DSPE-PEG-CONHNH2
Task: Synthesis of DSPE-PEG-CONHNH2 (trial 2)
Ligands can also be covalently bound to the hydrazide groups grafted onto PEG-DSPE to form a hydrazide bond. Oxidized ligands have been reported to react with the hydrazide groups of the anchor to form Hz-PEG-DSPE.,
Microemulsions contain lipophilic agents without any inner water phase, which may be a more suitable carrier for the delivery of lipophilic drugs. The microemulsions prepared with PEG-DSPE have many advantages, such as enhancing the capacity of loading the hydrophobic drugs, increasing the blood-circulation time, and improving the bioavailability, in delivering drugs to tumors.,
DSPE-PEG-SH to DSPE-PEG-CONHNH2
DSPE-PEG2000-RGD was synthesized by conjugating thecysteine residue of the three RGD peptides to DSPE, PEG2000 andMal, respectively. Briefly, DSPE-PEG2000-Mal and Cys-RGD (molarratio, 1:1.5) were mixed in 8 ml chloroform/4 ml methanol (2:1,v/v), and 0.3 ml triethylamine was added as a catalyst. The mixturewas gently stirred for 24 h in the dark at room temperature. Oncethin layer chromatography (DCM/MeOH/HO; 3:0.5:0.001)demonstrated that no DSPE-PEG2000-Mal remained, indicating thesynthesis of DSPE-PEG2000-RGD was completed, the mixture wasevaporated by a Yamato RE200B rotary evaporator (Yarong Biolab Co.,Ltd., Shanghai, China) in a vacuum. The residue was redissolved inchloroform and the solution was filtered to purify the product. Thefiltrate was then evaporated again by rotary evaporation to obtainthe final product (DSPE-PEG2000-RGD), which was stored at
For the purposes of obtaining a hepatocyte-selective drug delivery system, a novel tetravalent galactosylated diethylenetriaminepentaacetic acid-distearoyl phosphatidylethanolamine (4Gal-DTPA-DSPE) was synthesized. The chemical structure of 4Gal-DTPA-DSPE was confirmed by proton nuclear magnetic resonance and mass spectrometry. The four galactose-modified liposomes (4Gal-liposomes) were prepared by thin-film hydration method, then doxorubicin (DOX) was encapsulated into liposomes using an ammonium sulfate gradient loading method. The liposomal formulations with 4Gal-DTPA-DSPE were characterized by laser confocal scanning microscopy and flow cytometry analysis, and the results demonstrated that the 4Gal-liposomes facilitated the intracellular uptake of DOX into HepG2 cells via asialoglycoprotein receptor-mediated endocytosis. Cytotoxicity assay showed that the cell proliferation inhibition effect of 4Gal-liposomes was higher than that of the conventional liposomes without the galactose. Additionally, pharmacokinetic experiments in rats revealed that the 4Gal-liposomes displayed slower clearance from the systemic circulation compared with conventional liposomes. The organ distributions in mice and the study on frozen sections of liver implied that the 4Gal-liposomes enhanced the intracellular uptake of DOX into hepatocytes and prolonged the circulation. Taken together, these results indicate that liposomes containing 4Gal-DTPA-DSPE have great potential as drug delivery carriers for hepatocyte-selective targeting.
Lipid Products | DSPE-PEG(2000) Amine | 880128
The liposomes are composed of 1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol, TopFluor cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethylene glycol)-2000] (DSPE-PEG-maleimide). These liposomes were manufactured from Avanti Polar Lipids, based on a specified composition and certain requirements. Specifically, the liposome formulation consists of 65.8 mol% DSPC, 31.9 mol% cholesterol, 1 mol% TopFluor cholesterol, and 1.3 mol% DSPE-PEG2000-maleimide in a 1x PBS pH 7.4 solution at a concentration of 30 mg of liposomes per mL. The liposomal solution was prepared using the extrusion method through a 0.1 um pore-size membrane yielding a final liposome diameter of 157.3 nm based on dynamic light scattering (DLS). The liposome forms the basis of the drug delivery vesicle, with the DSPE-PEG-maleimide ligand available for conjugation reactions with a highly reactive maleimide group at the distal end. For the formulation of our dual-ligand liposome approach, the DSPE-PEG-maleimide embedded within the liposome forms the basis of the shorter ligand in the system that is exposed after binding and cleavage of the pH-sensitive longer ligand.
PEG or polyglycerin attached phospholipid (PEG phospholipid) are available for long circulating liposome formulation.
Activated functional group attached phospholipid either PEG end or non PEG end are also available for immunoliposome or targeting use liposome.
For non injectable use, DPPC, POPC and POPG are recommended for pulmonary delivery while DOPC, POPC and DDPC are recommended for nasal delivery.
We also offer custom-made synthesis of phospholipid and provide unique liposome research kit (Empty liposome) for drug delivery systems (DDS).
Custom Synthesis; Print; DSPE-PEG(2000) Amine | 880128
DSPE PEG Maleimide - JenKem Technology USA
Task: Synthesis of DSPE-PEG-SH
Lipid Products | DSPE-PEG(2000) Azide | 880228
DSPE-PEG-Amine to DSPE-PEG-SH
Refer also to DSPE-PEG DBCO Avanti Number 880229
DSPE PEG Derivatives
Custom Synthesis; Print; DSPE-PEG ..
Taken together, these results indicate that the liposomes that contained 4Gal-DTPA-DSPE could effectively target the HepG2 cells via the ASGP-R.
DSPE-PEG-RGD peptide conjugates (A), Schematic …
Li . designed folate receptor-targeted hollow gold nanospheres carrying siRNA recognizing NF-B, a transcription factor related to the expression of genes involved in tumor development [,]. In this case, the photothermal effects of gold nanospheres were utilized to regulate drug release and as a therapeutic tool. Core/shell-structured hollow gold nanospheres (HAuNS, 40 nm) were initially synthesized, consisting of a thin gold wall with a hollow interior, and the structures displayed strong surface plasmon resonance (SPR) tunability in the near-IR region [-]. Thiol-modified siRNA duplexes directed toward the NF-B p65 subunit were then introduced to the surface of HAuNS. Folates were coupled to the nanoparticles through a thioctic acid-terminated PEG linker to produce F-PEG-HAuNS-siRNA (Figure A and B). Irradiation with a pulsed near-IR laser (800 nm) altered the absorption spectra of the HAuNS-siRNA solutions significantly, indicating a loss in the structural integrity and triggering the dissociation of siRNA from HAuNS, when demonstrated by TEM and fluorescence microscopy images. This mode of action is termed 'photothermal transfection'. Intravenous injection of the nanospheres into HeLa xenografts resulted in the distinct downregulation of the NF-B p65 subunit only for the folate-conjugated nanosphere treatment combined with near-IR laser irradiation, suggesting that selective targeting and endolysosomal escape of the nanoparticles was activated by near-IR irradiation at the tumor site. tests, in which therapy was combined with administration of irinotecan, a chemotherapeutic agent that increases sensitivity to NF-B inhibition, yielded a substantially enhanced apoptotic response (Figure C). micro-positron emission tomography (PET))/computed tomography (CT) imaging also confirmed the folate-mediated tumor-targeted theranostic properties of the nanostructures (Figure D). Although significant uptake of the nanoparticles was observed in the liver, spleen, kidney, and lung, no significant downregulation of p65 in these organs was observed as a result of the tumor-selective near-IR irradiation.
Biotins (BIO) Polymers, PEGs, PLGA, PLA, DSPE
Graphite-coated magnetic FeCo core-shell nanocrystals for few-cells enrichment and detection were reported . FeCo nanocrystals were synthesized by a chemical vapor deposition method and became water soluble via coating the graphite shell with DSPE-PEG-NH2 and C18-PMH-mPEG polymers, while preventing the magnetic core from oxidation and degradation. These functionalized MNPs were stable and suitable for significant biological applications, such as cell staining, manipulation, cancer cell separation, enrichment and detection. The MNPs -stained cells showed directed motions under external magnetic manipulation.
mPEG-DSPE - Advanced BioChemicals
(A) Schematic diagram showing bioconjugation of HAuNS-siRNA and photothermal-induced siRNA release. (B) Schematic diagram showing the synthesis of F-PEG-HAuNS-siRNA and the proposed intracellular events following near-IR irradiation. (C) Effect of p65 siRNA photothermal transfection combined with irinotecan delivered to nude mice bearing HeLa cancer xenografts. (D) Micro-PET/CT imaging of nude mice bearing HeLa cervical cancer xenografts in right rear leg 6 h after intravenous injection of F-PEG-HAuNS-siRNA(DOTA-64Cu) or PEG-HAuNS-siRNA(DOTA-64Cu). Arrowheads indicate the tumors. Reproduced with permission from ref. .
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."