m-dPEG₂₅-amido-dPEG₂₄-DSPE - ≥95% , CAS No.M487892

CAS: M487892 Cat. No.: M487892 Molecular Weight: 3019.76

GRADE & PURITY ≥95%

Storage

Store at -20°C,Argon charged

Shipped In

Ice chest + Ice pads

Specifications

Specifications & Purity

≥95%

Legal Information

Products Protected under U.S. Patents # 7,888,536 B2dPEG is a registered trademark of Quanta BioDesign

Storage

Store at -20°C,Argon charged

Shipped In

Ice chest + Ice pads

This product requires cold chain shipping. Ground and other economy services are not available.

Purity

≥95%

Names and Identifiers

Molecular Weight

3019.76

Application Protocols

General, literature-based protocols for PEG–lipid use. Adjust to your system and consult primary references.

1. PEGylated liposome via thin-film hydration

• Dissolve DSPC or DSPE, cholesterol, and m-dPEG₂₅-amido-dPEG₂₄-DSPE in CHCl3:MeOH (2:1) at desired mol% (e.g., 55:40:5).
• Form a thin film (rotavap), then high-vacuum dry ≥2 h.
• Hydrate with buffer preheated to 75 °C, vortex, and perform 5–10 freeze–thaw cycles.
• Extrude through 200 nm then 100 nm membranes at 70–75 °C. Characterize by DLS and phosphate assay.

2. Ethanol injection (halogen-free)

• Prepare a 10 mg/mL ethanolic lipid solution containing 1–5 mol% PEG–lipid, warmed to 60–70 °C.
• Rapidly inject into 10× volume of prewarmed buffer with vigorous stirring; maintain final EtOH ≤10%.
• Remove ethanol by dialysis or TFF; sterile-filter (0.22 μm) if required for cell-free assays.

3. Post-insertion into preformed vesicles

• Warm vesicle suspension to ≥70 °C. Add a minimal volume of ethanolic PEG–lipid stock dropwise (target 1–2 mol%).
• Incubate 30–60 min with gentle mixing; cool, then purify by SEC to remove free PEG–lipid.

Note: Parameters are general guidance, not product specifications. Optimize mol%, temperature, and times for your system.

Biological Roles

This reagent is designed for research on biomembranes and nanomaterials; it is not a biological metabolite.

• General/literature roles of PEG–lipids in biological research:

  • Create sterically stabilized model membranes and vesicles for studying membrane biophysics, protein–membrane interactions, and colloidal stability under physiological ionic strength.
  • Reduce nonspecific protein adsorption (“stealth” behavior) in in vitro assays, aiding interpretation of binding and transport phenomena without confounding corona effects.
  • Provide hydration layer and entropic repulsion that can modulate vesicle aggregation and fusion kinetics in model systems.

• DSPE anchor significance (literature):

  • High Tm saturated tails promote rigid bilayers suitable for high-temperature handling and for assembling with other high-Tm lipids (DSPC) in controlled studies.

• PEG brush properties (literature):

  • Hydrophilic, flexible coils with low protein affinity; methoxy-capped termini are neutral and reduce potential for unintended interactions.

• Note: No endogenous biological pathway participation is implied. Use is limited to research applications as stated (For research use only).

Buffer Applications

Not a buffering agent. This product does not establish or control solution pH.

• Practical note: Select buffers based on your biological assay (e.g., PBS, HEPES, citrate). Ensure compatibility with lipid assembly:
  • Hydrate lipid films above DSPE Tm in the intended buffer to avoid buffer exchange later.
  • Physiological salt (e.g., 150 mM NaCl) can influence vesicle size and PEG–brush conformation; optimize empirically.
  • Avoid buffers containing strong oxidants. Filter (0.22 μm) buffers before hydration to minimize particulates.

Green Alternatives

While chloroform and DCM are common for PEG–lipid film formation, greener workflows can be adopted without sacrificing quality.

• Greener solvent/process choices (literature/general):

  • Ethanol injection or rapid micro-mixing into aqueous buffer, followed by diafiltration, avoids halogenated solvents.
  • Isopropanol or ethanol for stock solutions when solubility permits; gently warm (≤60–70 °C) to aid dissolution.
  • tert-Butanol:water co-lyophilization enables solvent removal with lower toxicity and easier handling than chlorinated solvents.

• Comparison summary (literature; illustrative):

  Greener option | Pros | Cons --- | --- | --- Ethanol injection | Halogen-free, scalable, GMP-friendly processes (in general) | May require higher temperature; solubility limits for some PEG–lipids Isopropanol | Lower toxicity than DCM/CHCl3; good solvency for many lipids | Higher bp, longer drying; sometimes poorer DSPE solvation tert-Butanol lyophilization | Forms elegant cakes; easy reconstitution | Requires freeze-drying infrastructure; residual t-BuOH monitoring

• Additional green practices:

  • Use closed systems to minimize solvent losses; recover solvents where possible.
  • Optimize PEG–lipid mol% to the minimum effective level to reduce material use.

Pharmaceutical Uses

No clinical or therapeutic claims are made. Research-only reagent.

• Formulation research roles (literature/general):

  • Excipient component in model liposomes/LNPs to study how PEG brush length and density affect particle size, stability, and protein adsorption in vitro.
  • Tool for screening process parameters (ethanol injection vs thin-film hydration, temperature ramps) using a high-Tm anchor lipid.

• Considerations for translational workflows (guidance only):

  • Discrete PEG length can simplify characterization and facilitate tighter CQA windows in development studies, compared with polydisperse PEG–lipids.
  • When comparing to pharmacopeial materials, match lipid identity (e.g., DSPE) and document PEG dispersity. Confirm material specifications with your quality unit; this SKU’s pharmacopeial status is Not specified for this item; refer to CoA/Spec Sheet.

• Regulatory notes: If pursuing regulated applications, sourcing, residual solvents, and trace impurities must be controlled and justified. This listing is for research use only.

Physical Properties

Item-specific physicochemical specifications (this lot):

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

General/literature guidance for components and class (not item specifications):

• Aggregation/assembly: Amphiphile that self-assembles into bilayers, liposomes, or mixed micelles depending on composition and concentration. The PEG corona thickness scales with PEG length; discrete PEGs yield narrower size distributions than polydisperse mPEG analogs.
• DSPE main-chain melting (Tm): typically high, ~74 °C for DSPE bilayers without PEGylation (literature). PEGylation and co-lipids can depress Tm and broaden transitions.
• Solubility (formulation practice):
  • Good solubility in chloroform, dichloromethane, and mixtures with methanol/ethanol (literature, common for PEGylated lipids).
  • Dispersible in aqueous buffers upon hydration above the lipid Tm with sonication/extrusion; forms stable liposomes when blended with helper lipids (e.g., cholesterol) (literature).
• Hydrophilicity/lipophilicity: Amphiphilic; PEG block is highly hydrophilic and protein-repellent, DSPE is strongly hydrophobic.
• Critical micelle behavior: PEG–lipid micellization occurs above a formulation-dependent CMC; absolute values vary with chain length and salt (literature; not specified for this item).
• pKa: The phosphate/ethanolamine zwitterion renders the headgroup neutral overall near physiological pH (literature).

Quality & Grades

• Item-specific quality information from Product Data:

  • Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
  • Stabilizers: Not specified for this item; refer to CoA/Spec Sheet.

• What “discrete PEG (dPEG)” implies (general/literature):

  • Discrete (monodisperse) PEGs are single-length oligomers rather than the broad molecular-weight distributions of conventional mPEG. This narrows variability in hydrodynamic size, surface density, and pharmacokinetic surrogates in research models.
  • dPEG–lipids support better batch-to-batch reproducibility in nanoparticle assembly and analytical characterization (DLS/NTA), compared with polydisperse PEG–lipids.

• Analytical expectations for high-end PEG–lipids (guidance, not item specs):

  • Identity and dispersity typically supported by HRMS and/or MALDI; purity assessed by HPLC/UPLC and NMR. Residual solvents/moisture reported on CoA.
  • Low levels of peroxides are desirable to avoid oxidative byproducts; confirm on CoA when available.

• Practical implications:

  • Monodispersity simplifies mol% calculations in lipid blends (e.g., 0.5–10 mol% PEG–lipid in liposomes, literature guidance) because the PEG brush length is defined.
  • If UV transparency or trace-metal content are critical for your application (e.g., spectroscopic studies), consult the CoA/Spec Sheet for this specific SKU.

Reaction & Applications

Primary utility is in self-assembly and surface engineering rather than stoichiometric synthesis.

• Liposomes and lipid nanoparticles (LNPs) (literature/general):

  • Incorporation of defined-length PEG coronas to modulate colloidal stability, reduce protein adsorption, and tune interparticle interactions in model systems. Typical loading 0.5–10 mol% relative to total lipid; optimize empirically for size and stability.
  • Especially useful with high-Tm backbones (DSPE, DSPC) for robust bilayers in elevated-temperature processing.

• Mixed micelles and nanodiscs:

  • Formation of PEG–lipid micelles for solubilization of hydrophobes or as precursors for ligand display when co-formulated with reactive lipids.

• Surface passivation and immobilization:

  • Insertion of the DSPE anchor into preformed bilayers or supported lipid membranes to create protein-resistant surfaces.
  • PEG brush can reduce nonspecific adsorption on nanoparticles or sensor surfaces; the methoxy-capped terminus is inert and non-reactive, providing a neutral corona.

• Bioconjugation context:

  • The “amido” linkage is pre-formed; this SKU is not a reactive linker. For ligand attachment, blend with complementary functionalized PEG–lipids (e.g., maleimide-PEG–DSPE, NHS-PEG–DSPE) in the same formulation.

• Practical tips (literature):

  • Hydrate above DSPE Tm (~74 °C) for efficient dispersion; use repeated freeze–thaw cycles and membrane extrusion to control size.
  • Remove organic solvents thoroughly (vacuum ≥2 h; residual-solvent analysis as needed) to ensure reproducibility and biocompatibility in research assays.

Reaction Conditions

Assembly and processing conditions (literature/general guidance for PEG–DSPE formulations; adjust empirically):

• Thin-film hydration:

  • Dissolve lipids (including this PEG–lipid) in chloroform or CHCl3:MeOH (2:1). Evaporate under rotary vacuum to a thin film; follow with ≥2 h high vacuum to remove residuals.
  • Hydrate with prewarmed buffer above DSPE Tm (typically ~74 °C for DSPE-rich systems). Vortex and apply 5–10 freeze–thaw cycles to enhance lamellarity control.
  • Size by extrusion (0.1–0.2 μm membranes) at ≥70–75 °C; monitor size/PDI by DLS.

• Ethanol injection/rapid mixing:

  • Prepare a warm ethanolic lipid solution (e.g., 5–20 mg/mL). Inject rapidly into stirred, prewarmed buffer (≥65–70 °C), maintaining final ethanol ≤10% v/v; remove solvent by dialysis or TFF.

• Post-insertion (for PEG–lipid enrichment):

  • Incubate preformed vesicles above Tm with a small ethanolic solution of the PEG–lipid; allow insertion (30–60 min), then purify.

• Typical composition notes:

  • PEG–lipid at 0.5–10 mol% with helper lipids (DSPC/DSPE + cholesterol) balances stealth and membrane integrity; exact levels are system-dependent.

• Analytical checks:

  • Quantify total lipid by phosphate assay or HPLC-ELSD; assess residual solvent by GC; evaluate stability by DLS over time.

These are general literature conditions and not product specifications.

Safety & Handling

• Classification from Product Data:
  • Signal Word: Not specified for this item; refer to SDS.
  • H-Statements: Not specified for this item; refer to SDS.
  • GHS Classification/Pictograms: Not specified for this item; refer to SDS.
• General laboratory safety (guidance; defer to SDS for authoritative instructions):
  • Handle as a research chemical in a fume hood or clean area to avoid contamination of high-purity lipids.
  • Wear appropriate PPE: lab coat, safety glasses, and nitrile gloves. Avoid dust/aerosol generation when handling dry material.
  • Avoid inhalation/ingestion; prevent contact with skin and eyes. Wash thoroughly after handling.
• Incompatibilities (general for lipids/PEGylated lipids):
  • Strong oxidizers may degrade unsaturated lipids; DSPE is saturated but the PEG chain can undergo oxidative scission under harsh conditions. Minimize exposure to oxidants and UV.
  • Prolonged exposure to moisture and elevated temperature can promote hydrolysis of ester linkages in phospholipids; maintain dry, inert atmosphere as specified.
• First aid (general):
  • Eye/skin contact: Rinse with water for several minutes; remove contaminated clothing.
  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Ingestion: Rinse mouth; seek medical attention if unwell.
• Waste: Dispose according to institutional and local regulations for organic chemical waste.
• Always consult the product-specific SDS for definitive hazard and response information.

Solvent Selection

This amphiphilic PEG–lipid dissolves well in selected organic solvents and is hydrated into aqueous media for assembly.

• Item-specific constraints: Storage under argon at −20 °C is specified; formulate promptly after thaw to minimize moisture uptake.

• Solubility/miscibility profile (literature/general for PEG–DSPE analogs):

  • Good: chloroform, dichloromethane, chloroform:methanol (2:1), ethanol, isopropanol, and tert-butanol (often used for co-lyophilization).
  • Limited: acetonitrile and DMF may dissolve PEG but not always efficiently solvate the DSPE tails without gentle heat.
  • Aqueous: disperses upon hydration above the DSPE Tm with agitation/sonication; forms liposomal or micellar assemblies in buffered saline.

• Selection guidance by task:

  • Thin-film hydration: chloroform or chloroform:methanol blends enable homogeneous films with other lipids (cholesterol, DSPC, ionizable lipids).
  • Solvent injection (ethanol injection/rapid mixing): absolute ethanol with buffered aqueous phase, followed by solvent removal/diafiltration.
  • Freeze–thaw/lyophilization methods: tert-butanol:water co-solvent facilitates crystalline-free cakes and rapid reconstitution.

• Comparison (literature):

  • Chloroform provides excellent solubility and uniform films but is less green; ethanol is greener and compatible with solvent-injection methods, though solubility of high-PEG lipids may require warming.
  • IPA can be a compromise for process safety vs solubility.

Storage & Reconstitution

• Item-specific storage from Product Data:

  • Store at −20 °C, Argon charged.
  • Shipped in ice chest with ice pads.
  • Research Use Note: For research use only.

• Storage best practices (guidance):

  • Keep tightly sealed under inert gas (argon or nitrogen) to minimize moisture and oxidative exposure. Protect from light.
  • Allow vial to warm to room temperature in a desiccator before opening to prevent condensation.
  • Aliquot upon first opening to minimize freeze–thaw and headspace oxygen; re-purge with argon before re-freezing.

• Reconstitution (general recommendations for PEG–DSPE):

  • For organic stock: dissolve at 5–20 mg/mL in chloroform or ethanol. For halogen-free workflows, use warm ethanol or isopropanol; confirm complete dissolution.
  • For direct aqueous use: hydrate thin films above DSPE Tm (~74 °C, literature) with prewarmed buffer and sonicate or extrude to achieve desired size.
  • For lyophilized cakes: co-dissolve in tert-butanol:water, freeze, and lyophilize; reconstitute with warm buffer.

• Stability notes (guidance):

  • Avoid prolonged exposure to temperatures >−20 °C when stored. Short-term handling at ambient is acceptable during weighing and formulation.
  • Monitor for signs of degradation (odor, discoloration, unexpected DLS behavior). Consult CoA/SDS for any item-specific stability data.

Structure & Identity

A discrete-PEG (dPEG)–modified phospholipid combining a high–phase-transition zwitterionic phosphatidylethanolamine (DSPE) anchor with two covalently linked, monodisperse PEG segments.

• Item-specific identifiers from Product Data:

  • SKU: M487892
  • Product Name: m-dPEG₂₅-amido-dPEG₂₄-DSPE
  • CAS: M487892 (catalog identifier)
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

• Structural features (general/literature description):

  • Hydrophobic anchor: 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) with two C18:0 chains; zwitterionic headgroup at physiological pH.
  • Hydrophilic corona: two discrete-length PEG segments: one terminates in methoxy (m-dPEG25), the other is an amide-linked dPEG24 segment connecting to DSPE. The “amido” denotes a stable amide linkage between PEG and the PE headgroup.
  • Overall architecture: amphiphile with a bulky, well-defined PEG brush extending from the membrane anchor, designed to confer steric stabilization and reduced nonspecific interactions.
  • Topology (2D verbal): glycerol backbone esterified at sn-1/sn-2 by stearates; phosphate linking to ethanolamine; ethanolamine nitrogen substituted via amide to a discrete PEG24 chain, further extended and capped on one branch with methoxy (discrete PEG25). No stereocenters are introduced beyond the native sn-configuration of glycerol (not resolved here).

• Stereochemistry/tautomerism: DSPE bears the natural sn-glycerol stereochemistry (literature); PEG segment is achiral. No expected tautomers.

Synthetic Utility

Although not a classical small-molecule reagent, m-dPEG₂₅-amido-dPEG₂₄-DSPE is a valuable building block for constructing soft-matter assemblies and hybrid materials.

• Functional groups and reactivity (item context):

  • DSPE contains ester linkages (hydrolyzable under strong base/acid) and a phosphate diester; the PEG chain is capped with methoxy and is non-reactive. The “amido” linkage to PEG is robust to most formulation conditions.

• Transformations/uses (literature/general):

  • Incorporation into liposomes, supported bilayers, and polymer–lipid hybrids to impart protein resistance and steric stabilization.
  • Co-assembly with functionalized lipids (maleimide-, azide-, or NHS–PEG–lipids) enables spatial separation between reactive and inert PEG coronas, aiding ligand display while maintaining stealth background.
  • Surface transfer/insertion into existing bilayers or vesicles to tune corona density post-assembly (thermal incubation above Tm).

• Retrosynthetic value:

  • Provides a pre-constructed amphiphile eliminating the need for on-bench PEGylation of lipids, improving reproducibility and reducing side reactions.

• Compatibility:

  • Stable in neutral aqueous buffers; avoid strong bases/acids and prolonged high-temperature exposure to limit ester hydrolysis. Organic solvent exposure should be brief and followed by thorough removal.

Target Specificity

Not an antibody, enzyme, or ligand-targeting molecule. No target specificity data apply to this SKU.

• If targetable functionality is required, co-formulate with functional PEG–lipids (e.g., maleimide-PEG–DSPE for thiol coupling) or incorporate ligand-bearing lipids to impart specificity in your research system.

Frequently Asked Questions

What is the purity of this product?

This product is supplied at ≥95% purity (chemical assay). Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at ?20 °C under argon. It is supplied under an argon blanket; reseal under inert gas after each use.

How is this product shipped?

This product ships in an insulated container with ice pads. Unpack on arrival and transfer it to the storage condition stated above.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is M487892, and the molecular weight is 3019.76 g/mol.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.