DSPE-PEG-NHS - ≥95%, MW 1000 Da

Cat. No.: D163639

GRADE & PURITY ≥95%, MW 1000 Da

Storage

Protected from light,Store at -20°C,Argon charged

Shipped In

Ice chest + Ice pads

Übersicht

1,2-Distearoyl-sn-Glycero-3-Phosphoethanolamine (DSPE) conjugated Polyethylene Glycol, DSPE PEG is a phospholipid PEG conjugate which has both hydrophilicity and hydrophobility. Pegylated phospholipids are excellent liposome formation materials that can be used for drug delivery, gene transfection and vaccine delivery as well. Pegylation of phospholipids significantly improves the blood circulation time and stability for encapsulated drugs. These materials can also be used for targeted drug delivery by modifying their surfaces with targeting ligands such as antibodies, peptides.

Specifications

Spezifikationen & Reinheit

≥95%, MW 1000 Da

Storage

Protected from light,Store at -20°C,Argon charged

Verschickt in

Ice chest + Ice pads

Dieses Produkt erfordert Kühlkettenversand. Grundversand und andere Economy-Optionen sind nicht verfügbar.

Reinheit

≥95%

Chemische und physikalische Eigenschaften

• Löslichkeit: Off-white/white solid or viscous liquid depends on molecule weight;Soluble in regular aqeous solution as well as most organic solvents
• Empfindlichkeit: Moisture sensitive；light sensitive

Application Protocols

The following are general, literature-based protocols to guide use; adapt to your system. No item-specific validated protocols are provided.

A. Protein conjugation to DSPE-PEG-NHS (in solution):

• Dissolve DSPE-PEG-NHS at 10–50 mg/mL in anhydrous DMSO.
• Prepare protein in amine-free buffer (e.g., 50 mM HEPES, 150 mM NaCl, pH 7.4–8.0). Optional: include 5–10% DMSO for solubility.
• Add DSPE-PEG-NHS slowly to protein (typical 2–10 eq per lysine target). Incubate 1–2 h at room temp.
• Quench with 20–50 mM ethanolamine for 15 min.
• Purify by SEC or dialysis to remove NHS, DMSO, and unconjugated lipid–PEG.

B. Post-insertion into preformed liposomes and surface coupling:

• Warm liposome dispersion to just above the lipid transition temperature.
• Add DSPE-PEG-NHS (from dry DMSO stock) to achieve desired mol%. Incubate 10–30 min with gentle mixing.
• Exchange into pH 7.4–8.0 amine-free buffer containing your amine-bearing ligand; react 0.5–2 h.
• Quench residual NHS; polish by SEC to remove free ligand.

C. Surface modification of amine-rich nanoparticles:

• Disperse particles in carbonate buffer (pH 8.3) with 10% DMSO.
• Add DSPE-PEG-NHS (1.5–5 eq per surface amine). Mix 1–3 h.
• Wash extensively to remove by-products.

Tips:

• Avoid Tris and high primary amine backgrounds.
• Verify conjugation by TNBS assay, zeta potential/size shift, or XPS on surfaces.

Biological Roles

This product is intended for research use only. The following describes general, non-clinical behavior of DSPE-PEG-NHS components (literature):

• Membrane anchoring: The DSPE moiety (two C18 chains) embeds robustly into lipid bilayers, favoring ordered phases due to high chain melting temperature. This provides a stable bilayer anchor for the PEG chain.
• PEG corona formation: Surface-grafted PEG forms a hydration layer that resists non-specific protein adsorption and colloidal aggregation, aiding the creation of stealth-like model systems in vitro.
• Reactive display: The NHS terminus enables covalent attachment of amine-containing ligands (peptides, proteins, sugars with amino linkers), facilitating construction of ligand-presenting vesicles or nanoparticles for biochemical assays and receptor-binding studies.
• Colloidal stabilization: DSPE-PEG conjugates reduce vesicle fusion and opsonization in experimental setups, improving dispersion stability of liposomes and lipid–polymer hybrid particles.
• Biocompatibility context: PEGylated phospholipids are widely used in biophysical and biochemical research due to generally favorable tolerance in model systems; nonetheless, specific cell or protein interactions depend on ligand density, PEG length, and membrane composition.

Note: No medical or clinical claims are made. Biological performance varies with PEG MW, molar ratio in membranes, ligand identity, and environmental conditions (pH, ionic strength, temperature). Confirm suitability empirically for your assay or model system.

Buffer Applications

DSPE-PEG-NHS is not a buffering agent; it does not define a pH range or buffering capacity. However, buffer choice is critical for its NHS–amine coupling chemistry (general guidance):

• Use amine-free buffers: Avoid Tris, glycine, ammonium salts, or other primary/secondary amine-containing buffers which will quench the NHS ester.
• Recommended systems (literature):
  • PBS or HEPES at pH 7.2–7.6 for gentler conditions (slower hydrolysis, lower protein perturbation).
  • Sodium bicarbonate/carbonate or phosphate at pH 8.0–8.5 to increase coupling rate (with higher hydrolysis risk; shorten reaction times).
• Ionic strength: 50–150 mM salts commonly used to maintain protein stability and colloidal behavior.
• Co-solvent: 5–20% dry DMSO or DMF can aid solubility without excessively accelerating hydrolysis; add immediately before use.
• Temperature: 0–25 °C; cooler temperatures prolong NHS lifetime at the cost of slower kinetics.
• Quenching/capping: After coupling, add ethanolamine or glycine to cap unreacted NHS groups, then dialyze or desalt.

Recipe hints:

• Filter buffers (0.22 µm), degas if working with liposomes, and verify pH at working temperature. Prepare fresh to minimize dissolved CO2 shifts. Always validate conditions for your protein or ligand stability.

Green Alternatives

Greener process choices focus on solvent selection and energy minimization (literature guidance):

Solvent pathway comparison for lipid film formation and conjugation:

• Traditional: Chloroform/CH2Cl2 dissolution → rotary evaporation → hydration. Excellent solubility but higher environmental and safety burdens.
• Greener: Ethanol injection or tert-butanol lyophilization → hydration. Avoids chlorinated solvents; facilitates scale-up with lower EHS impact.

Coupling media:

• Traditional: Anhydrous DMF throughout reaction.
• Greener option: Anhydrous DMSO or aqueous carbonate buffer with minimal DMSO cosolvent (≤10–20%) to maintain solubility, reducing organic load while preserving NHS integrity.

Small comparison (pros/cons):

• Ethanol: renewable, lower toxicity; may reduce NHS half-life vs DMF; requires careful water content control.
• DMSO: low volatility, good EHS profile relative to DMF; hygroscopic—use dry grade to protect NHS.
• CPME/EtOAc: limited solubility for DSPE-PEG conjugates; may work for intermediate processing but less universal.

Operational greening:

• Use room-temperature conjugations where feasible to avoid heating.
• Microscale, high-concentration stocks minimize solvent volumes and exposure times.
• Apply in-line solvent exchange (diafiltration) to cut batch water/solvent usage.

Trade-offs: The NHS ester’s water-lability constrains fully aqueous, solvent-free approaches. Balance greenness with reaction efficiency, validating recovery and residual solvent levels suitable for your research use.

Pharmaceutical Uses

No clinical or therapeutic claims are made for this product. The following describes general formulation roles in research and development contexts:

• Excipient role (research): DSPE-PEG conjugates serve as surface-active amphiphiles that stabilize lipid-based nanoparticles, liposomes, and lipid–polymer hybrids. The PEG domain reduces non-specific interactions; the NHS terminus enables installation of targeting ligands for mechanistic studies.
• Process utilities:
  • Post-insertion into preformed vesicles to tailor surface functionality without reformulating the entire bilayer.
  • Conjugation platform to attach peptides, proteins, or small molecules via amide bonds to the PEG terminus.
• Parameter control: PEG molecular weight and grafting density modulate particle size, zeta potential, and serum interaction in in vitro systems.
• Reference standards: Some grades of DSPE-PEGs are used as reference materials during development to assess the impact of PEGylation or ligand density; pharmacopeial status, if any, is product-specific and not provided here.

Regulatory note:

• For research use only. Suitability for any regulated application requires independent qualification of identity, purity, residual solvents, and bioburden. Consult the CoA/Spec Sheet for batch-level data and perform additional testing aligned with your quality system.

Physical Properties

Item-specific values:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Other specifications (mp/bp/density/UV cutoff, water, metals, peroxides): Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for DSPE-PEG-NHS:

• Physical state: Typically a white to off-white waxy solid or powder, becoming fluid above the DSPE chain melting transition (literature Tm for DSPE lipids ~55–74 °C depending on PEG length and hydration).
• Solubility:
  • Good in chlorinated and aromatic organics (e.g., CHCl3, CH2Cl2, toluene) and polar aprotics (dry DMF, DMSO).
  • Dispersible/soluble in aqueous buffers when formulated into micelles or liposomes; free NHS ester hydrolyzes in water, especially at pH >7.
• Amphiphilicity: Forms micelles or integrates into lipid bilayers; critical micelle concentration is low and depends on PEG MW and temperature (literature: sub-µM to µM range; verify for specific grade).
• Stability:
  • NHS ester is moisture-sensitive and gradually hydrolyzes to the non-reactive acid; rate increases with pH and temperature.
  • PEG chain is stable; DSPE tails crystallize at low T and melt at elevated T.
• Refractive index/logP/pKa: Not meaningful as single values for this polymer–lipid conjugate; consult literature or analytical data for the specific grade.

Practical implications:

• Prepare anhydrous stock solutions (DMSO/DMF) and use promptly.
• Warm gently (40–60 °C) to aid dissolution; avoid prolonged heating in aqueous media to limit NHS loss.

Quality and Grades

Item-specific grade/purity statements:

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

What to look for in DSPE-PEG-NHS quality (general guidance):

• PEG molecular weight and polydispersity (Đ): Determines hydrodynamic size, micellization, and steric stabilization. High-purity materials report number-average (Mn) and weight-average (Mw) values.
• Substitution level/identity: Confirmation that the PEG terminus is NHS-activated (vs. acid or other end groups) by NMR and MS.
• Residual solvents and volatiles: Important for sensitive formulations; high-grade materials list GC headspace limits.
• Moisture content: NHS esters are moisture-sensitive; Karl Fischer values may be provided for tight specifications.
• Acyl chain profile: Verification of C18:0/C18:0 DSPE (stearoyl) distribution and low lyso-lipid content.
• Peroxide value: PEGs can contain trace peroxides; premium grades control and report this. Not specified for this item; refer to CoA/Spec Sheet.
• Bioburden/endotoxin: For certain research applications, low endotoxin levels are desirable; check the CoA if relevant to your workflow.

Interpreting common grades (context):

• Research grade: Suitable for general laboratory use; typical structural confirmation and purity.
• Premium/low-bioreactive grades: Tighter control of PEG Đ, solvents, peroxides, and endotoxin; improved batch-to-batch consistency.

Recommendation: Review the CoA/Spec Sheet for this SKU for exact PEG MW, assay method (e.g., 1H NMR integration, MALDI), and any stabilizers or antioxidants if used.

Reaction and Applications

Core chemistry (literature):

• Activated ester coupling: The NHS ester reacts selectively with primary amines to form stable amide bonds. This underpins conjugation of peptides, proteins (lysine residues, N-termini), amine-functional polymers, and nanoparticles.
• Mechanistic notes: Nucleophilic attack by R–NH2 on the activated ester yields a tetrahedral intermediate, expelling N-hydroxysuccinimide; reaction rate increases with pH (7.5–8.5) and with appropriate co-solvent to maintain solubility.

Nanomaterials/formulation uses:

• PEGylated liposomes: DSPE anchors in bilayers; PEG provides steric stabilization; terminal NHS enables ligand decoration (antibodies, peptides, small molecules) for targeted delivery studies.
• Post-insertion: Incorporate DSPE-PEG-NHS into preformed liposomes/micelles, then perform surface conjugation in mild buffer.
• Surface modification: Immobilize onto amine-rich substrates (e.g., chitosan, PEI-coated particles) to create antifouling layers with covalent linkage.

Practical tips:

• Maintain anhydrous stocks; prepare fresh working solutions right before coupling.
• Control stoichiometry: Use slight excess of NHS ester to drive completion; quench with ethanolamine after coupling to cap unreacted NHS.
• Avoid competing nucleophiles (Tris, glycine) and strong bases; keep temperature moderate (room temperature) to balance rate and hydrolysis.
• Verify coupling by TNBS assay (amine consumption), Ellman’s test (if thiols are involved in orthogonal schemes), or by SDS-PAGE/SEC for protein conjugates.

Note: Specific reaction parameters (time, equivalents) depend on the PEG MW, target, and formulation; optimize empirically.

Reaction Conditions

General literature guidance for NHS–amine coupling with DSPE-PEG-NHS (optimize per system):

• Solvent system: Start from anhydrous DMSO or DMF stock; dilute into amine-free buffer (PBS, HEPES, or carbonate). Final organic content 5–20% v/v balances solubility and NHS stability.
• pH: 7.2–7.6 for sensitive proteins; 8.0–8.5 for faster kinetics on small-molecule amines or robust substrates.
• Temperature: 0–25 °C. Lower temperatures extend NHS half-life; room temperature is common for 0.5–4 h reactions.
• Stoichiometry: 1.2–5.0 molar equivalents of NHS ester per available primary amine for completion; adjust for steric hindrance and surface crowding.
• Time: 30 min–4 h typical; monitor progress by amine consumption assays (e.g., TNBS), SEC shift for proteins, or HPLC for small ligands.
• Additives: 0.1–0.5 M NaCl may improve colloidal stability. Avoid amine-containing buffers (Tris) and strong nucleophiles.
• Quench: Ethanolamine (10–50 mM) or excess glycine after coupling to cap unreacted NHS; then purify by dialysis, spin filtration, or SEC.
• Workup: Remove DMSO/DMF by diafiltration; maintain temperature below lipid transition during purification to preserve vesicle integrity when applicable.

Expected outcomes (context):

• High conversion to amide under optimized conditions; hydrolysis is the main side reaction. Degree of labeling and surface ligand density depend on PEG MW, sterics, and accessibility.

Note: No item-specific specifications are provided here; verify conditions empirically and consult the SDS/CoA for constraints.

Safety and Handling

Item-specific hazard data:

• Signal word / GHS classification / H-statements / Pictograms: Not specified for this item; refer to SDS.

Known handling considerations (general, literature):

• Moisture sensitivity: The NHS ester hydrolyzes to the carboxylic acid, reducing reactivity. Handle under dry, inert gas (argon or nitrogen) and avoid aqueous exposure until use.
• Thermal sensitivity: Prolonged heating in aqueous or basic media accelerates NHS hydrolysis; minimize exposure time at elevated temperatures.
• Dust/particulate: As a fine solid, may form nuisance dust. Avoid inhalation; use appropriate containment.
• PPE: Laboratory coat, safety glasses, and chemical-resistant gloves (e.g., nitrile). For weighing, consider a balance enclosure or local exhaust.
• Incompatibilities:
  • Primary/secondary amines (including Tris buffer) will consume NHS.
  • Strong bases accelerate hydrolysis; strong oxidants are generally incompatible with organic materials.
• First aid overview (refer to SDS for authoritative guidance):
  • Inhalation: Move to fresh air; seek medical advice if symptoms persist.
  • Skin/eye contact: Rinse with water for at least 15 minutes; remove contaminated clothing; seek medical attention if irritation develops.
  • Ingestion: Rinse mouth; seek medical advice.
• Waste: Collect solutions and rinses as organic chemical waste. Quench residual NHS reactivity by controlled hydrolysis before disposal if required by local regulations.

Storage from Product Data:

• Protected from light; Store at −20 °C; Argon charged. Shipments are sent in an ice chest with ice pads. Keep tightly sealed with desiccant; minimize freeze–thaw by aliquoting.

Solvent Selection

Role and polarity (general):

• Amphiphilic polymer–lipid. The hydrophobic DSPE anchors in lipophilic phases; PEG imparts hydrophilicity. The NHS end is reactive and water-labile.

Preferred solvents by task:

• Stock preparation (anhydrous): Dry DMSO or DMF are favored for dissolving and dispensing with minimal NHS loss. Also soluble in CHCl3/CH2Cl2 for thin-film hydration methods.
• Aqueous conjugation: Dilute an anhydrous stock into amine-free buffer at pH 7.2–8.5 immediately before use. Avoid Tris, glycine, and other primary amine buffers.
• Liposome work: Use ethanol (injection method) or tert-butanol (lyophilization) as greener alternatives to chlorinated solvents when feasible.

Miscibility/handling tips (literature):

• DMSO/DMF are fully miscible with water, easing transfer into buffer for coupling.
• Chloroform provides excellent solubility for thin-film formation but is less green and requires rigorous removal.
• Ethanol can dissolve many lipid mixtures warm (40–60 °C) and is compatible with rapid solvent exchange protocols.

Comparison snapshot:

• DMSO (ε ≈ 47): maximizes NHS lifetime; easy buffer blending; remove by dialysis after coupling.
• DMF (ε ≈ 37): similar benefits; ensure low water content.
• Ethanol (ε ≈ 25): greener; good for bilayer assembly; not ideal for extended NHS storage.

Rule of thumb: Dissolve in anhydrous polar aprotic, perform rapid conjugation after dilution into buffer, and avoid prolonged exposure to aqueous basic media.

Storage and Reconstitution

Item-specific storage (from Product Data):

• Protected from light
• Store at −20 °C
• Argon charged
• Shipped in: Ice chest + ice pads

General best practices for DSPE-PEG-NHS:

• Moisture/oxygen control: Keep tightly sealed with desiccant. Maintain inert headspace (Ar/N2). Minimize vial openings; work quickly.
• Aliquoting: Prepare single-use aliquots to avoid repeated freeze–thaw and moisture ingress. Warm sealed vials to room temperature before opening to prevent condensation.
• Shelf life: NHS esters slowly hydrolyze even under ideal storage; check the CoA/Spec Sheet for retest or expiry dates and perform a quick activity check (e.g., TNBS consumption) if materials are aged.

Reconstitution guidance (literature):

• Dissolve in anhydrous DMSO or DMF to prepare concentrated stocks (e.g., 10–100 mg/mL). Mix gently at 25–40 °C to aid dissolution; avoid prolonged heating.
• For lipid film methods, dissolve in chloroform or ethanol, then evaporate and hydrate under your chosen protocol.
• For aqueous coupling, dilute freshly into amine-free buffer at the desired pH and proceed immediately to minimize hydrolysis.

Compatibility notes:

• Avoid amine-containing buffers (Tris, glycine) before quenching.
• After use, purge headspace with argon and re-seal promptly. Dispose of partially hydrolyzed solutions according to institutional chemical waste procedures.

Structure and Identity

Item-specific identifiers (for this SKU):

• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• 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 / InChI / InChIKey: Not specified for this item; refer to CoA/Spec Sheet.

General structural description (literature):

• Name/Type: DSPE-PEG-NHS = 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) bearing a poly(ethylene glycol) chain (PEG) terminated with an N-hydroxysuccinimide (NHS) ester.
• Architecture: Amphiphile with a zwitterionic phosphoethanolamine headgroup, two C18 saturated acyl chains (stearoyl) on glycerol (sn-1, sn-2), and a PEG spacer linked to the ethanolamine nitrogen; the PEG terminus is activated as NHS ester for amide coupling.
• Key functional groups: Ester linkages (glycerol fatty esters), phosphate diester, secondary amine (amidated to PEG), terminal activated ester (NHS).
• PEG length: Varies by grade (commonly 1–5 kDa in literature); exact PEG MW for this item is not specified here.
• 2D description: A glycerophospholipid backbone (phosphatidylethanolamine) with two parallel long alkyl chains, phosphate linking to ethanolamine; the ethanolamine nitrogen is substituted by a flexible –(CH2)–(OCH2CH2)n– chain ending in a succinimidyl carbonate-like ring (NHS) forming an activated ester.

Notes:

• DSPE confers bilayer anchoring via hydrophobic C18 chains; PEG imparts stealth/antifouling; NHS enables conjugation to primary amines. Exact substitution and polydispersity should be confirmed on the CoA.

Synthetic Utility

While not a classic small-molecule building block, DSPE-PEG-NHS is highly valuable in bioconjugation and materials synthesis (literature):

• Functional groups: Terminal NHS ester (activated carboxyl) for amide bond formation with primary amines; internal phosphate diester and lipid esters are inert under mild coupling conditions.
• Orthogonal assembly: Combine with other PEG–lipid handles (e.g., maleimide, azide, alkyne) to achieve multi-functional surfaces via sequential orthogonal reactions.
• Retrosynthetic viewpoint: Think of DSPE as a hydrophobic anchoring module and PEG–NHS as a reactive hydrophilic spacer; their union enables targeted presentation of ligands on soft matter interfaces (liposomes, polymersomes, supported bilayers).
• Material fabrication:
  • Ligand-decorated vesicles for receptor-binding assays.
  • Brush-like coatings on amine-rich substrates to reduce fouling and provide capture chemistries.
  • Hydrogel modification where amine-bearing networks are post-functionalized to introduce lipid–PEG motifs.
• Analytical confirmation: After coupling, verify amide formation by FTIR (amide I/II), 1H/13C NMR (PEG region changes), MALDI/ESI-MS for small ligands, and XPS or QCM-D for surfaces.

Caveats:

• NHS reacts with water; design workflows to minimize aqueous exposure prior to conjugation.
• For protein conjugation, control degree of labeling (DOL) to avoid over-modification; use competing lysine protection or site-selective strategies if needed.

Target Specificity

Not applicable. This product is a reactive lipid–PEG reagent and does not possess inherent biological target specificity. Any specificity arises from ligands covalently attached via the NHS–amine coupling. No antibody, epitope, or clone information is associated with this SKU.

Häufig gestellte Fragen

How should this product be stored?

Store at ?20 °C, protected from light, 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.