Stearic acid PEG thiol - MW 3400 Da

Cat. No.: S164311

GRAU & PUREZA MW 3400 Da

Storage

Room temperature

Shipped In

Normal

Visão geral

Stearic acid is an 18 carbon saturated fatty acid lipid with excellent hydrophobicity. PEG modified stearic acid is an excellent amphilphilic polymer with both hydrophilicity and hydrophobility. Pegylated lipids are excellent liposome formation materials that can be used for drug delivery, gene transfection and vaccine delivery as well. These materials can also be used for targeted drug delivery by modifying their surfaces with targeting ligands such as antibodies, peptides.

Especificações

Especificações e pureza

MW 3400 Da

Condições de armazenamento de armazenamento

Room temperature

Enviado em

Normal

Propriedades químicas e físicas

• Solubilidade: Solid powder;Soluble in regular aqeous solution as well as most organic solvents

Application Protocols

Item-specific tested applications, recommended concentrations, or protocols: Not specified for this item; refer to CoA/Spec Sheet and SDS.

Note: For technique-specific procedures (e.g., gold SAM formation, liposome film hydration, thiol–maleimide coupling), consult peer-reviewed literature and internal SOPs appropriate to your system. Validate parameters such as solvent, concentration, atmosphere, and time at small scale before scale-up.

Biological Roles

Item-specific biological data: Not specified for this item; refer to CoA/Spec Sheet.

General context (literature/general):

• Stearic acid is a saturated C18 fatty acid commonly found in biological membranes as stearoyl chains within phospholipids. It contributes to membrane rigidity and phase behavior.
• Polyethylene glycol (PEG) is a hydrophilic, flexible, and biocompatible polymer often used to impart steric stabilization and reduce nonspecific biomolecular adsorption at interfaces.
• A stearoyl–PEG–thiol conjugate merges these features: the hydrophobic tail can insert into lipid-like environments or hydrophobic surfaces, while PEG provides a hydrated corona. The terminal thiol allows covalent or coordinative attachment (e.g., to gold) to create biointerface-modifying layers.
• In model systems, such conjugates are used to tailor colloidal stability, reduce protein fouling, and modulate interfacial interactions in assays, biosensors, and nanoparticle dispersions.

Note: The above describes typical biochemical roles in research contexts. No clinical/medical claims are made.

Buffer Applications

This product is not a classical buffering agent and does not define a buffer pH range. Therefore, standard buffer recipes are not typically applicable.

Practical guidance (general):

• When used in aqueous systems (e.g., for surface functionalization or micelle/liposome preparation), select buffers that are compatible with thiols:
  • Avoid buffers containing heavy metal ions (which can catalyze thiol oxidation) or oxidants.
  • If preserving free –SH is critical, include a compatible reductant such as TCEP (non-thiol reducing agent) at low millimolar concentrations; avoid DTT if it will interfere with downstream thiol chemistry.
  • Common choices: phosphate-buffered saline (PBS) or HEPES, degassed and filtered; pH 6.5–7.4 for maleimide couplings (literature general).

For precise conditions and compatibility with your application, consult the literature and validate empirically.

Green Alternatives

Green chemistry considerations focus mainly on solvent choice and process conditions for handling PEG–lipid thiols.

Greener solvent options (literature/general):

• Replace chlorinated solvents (DCM/CHCl3) for film casting with:
  • 2-Methyltetrahydrofuran (2-MeTHF): bio-based, higher boiling than THF; good for many amphiphiles.
  • Cyclopentyl methyl ether (CPME): low peroxide formation tendency; good for hydrophobic components.
  • Ethyl acetate or isopropanol: viable for certain dissolution/blending steps, though may require warming.
• Aqueous or aqueous/ethanol systems: where PEG length is sufficient to confer water compatibility, use buffered aqueous ethanol for SAM deposition or formulation to reduce VOC emissions.

Comparison (general, trade-offs):

• 2-MeTHF vs CHCl3: safer profile and renewable sourcing, but lower solubility for very high-MW PEG–lipids; may need mild heat.
• Ethanol vs DCM: greener and miscible with water, but slower evaporation and potential for thiol oxidation if aerated; degas before use.

Process improvements:

• Minimize oxygen exposure (degassing) to prevent thiol oxidation instead of adding excess chemical reductants.
• Use solvent recycling and low-temperature vacuum evaporation to reduce energy use.

Note: Selection must be validated for your specific PEG length and application; solubility and film quality can vary.

Pharmaceutical Uses

Item-specific pharmacopeial status or excipient grade: Not specified for this item; refer to CoA/Spec Sheet.

General formulation roles (literature/general; research context only):

• PEG–lipid amphiphiles are widely explored in formulation science as surface modifiers and steric stabilizers for colloids, liposomes, and nanoparticles in research settings.
• The stearoyl moiety serves as a hydrophobic anchor for insertion into lipid bilayers or hydrophobic cores, while PEG imparts hydration and reduces aggregation or nonspecific adsorption.
• Terminal thiol functionality enables further conjugation (e.g., to maleimide-bearing ligands) or strong binding to gold surfaces for sensor interfaces and diagnostic device components.
• Process considerations: control of free-thiol content is important to ensure consistent conjugation efficiency; careful solvent removal and hydration methods affect particle size and dispersity.

No therapeutic claims are made. This product is supplied for research use only.

Physical Properties

Item-specific specifications: Not specified for this item; refer to CoA/Spec Sheet.

General/qualitative properties (literature/general):

• Physical state/appearance: PEG–lipid conjugates are often waxy solids or viscous oils at ambient temperature; exact form depends on PEG chain length and overall MW.
• Solubility profile: amphiphilic. Readily soluble in polar aprotic organic solvents (e.g., DMSO, DMF, dichloromethane, chloroform), alcohols (MeOH/EtOH), and many glycol ethers. Aqueous solubility depends on PEG length; short PEGs may require co-solvent or surfactant; longer PEG chains can impart water dispersibility and self-assembly into micelles.
• Partitioning: exhibits strong hydrophobic interactions from the C18 chain and hydrophilicity from PEG, promoting interfacial activity.
• Aggregation: above certain concentrations, can form micelles or insert into lipid bilayers; critical aggregation behavior depends on PEG length and medium ionic strength.
• Thermal behavior: PEG segments soften with increasing temperature; fatty acyl crystallinity can cause melting transitions; exact melting point is formulation-dependent.
• Stability: thiol groups can oxidize to disulfides upon air/light exposure; ester linkages (if present) are susceptible to hydrolysis under strong acidic/basic conditions.

Note: For numerical values such as melting point, density, or exact refractive index, consult the specific CoA/SDS for this SKU.

Quality and Grades

Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

Context for this class of materials (general):

• PEG–lipid conjugates are often offered in research or synthetic grades with emphasis on identity, functional group integrity (free –SH content), and low residual solvents. Where applicable, vendors may report parameters such as:
  • Functional group content: thiol titer or percent free thiol versus disulfide.
  • Residual solvent levels (GC) and water content (Karl Fischer).
  • Metal content (ICP) if intended for nanomaterials interfacing.
  • Polydispersity/PEG chain distribution (MALDI/ESI-MS, GPC).
• Stabilizers: Some thiol-terminated materials are shipped under inert gas or with trace antioxidant to limit oxidation; the presence/absence of any stabilizer is item-specific. For S164311, stabilizers are not specified; refer to CoA.

How to interpret grades (general):

• Research grade: suitable for most R&D tasks, surface modification, micelle/liposome work.
• Higher-purity or low-UV grades: prioritized for analytical or photophysical studies where background absorbance is critical.

Recommendation: Verify free-thiol content and moisture level upon receipt if your application is sensitive (e.g., gold-thiol self-assembly or maleimide coupling).

Reaction and Applications

Manufacturer applications: Not provided in Product Data for this SKU.

General applications for stearoyl–PEG–thiol (literature/general):

• Surface modification: terminal thiol forms strong Au–S bonds for self-assembled monolayers (SAMs) on gold nanoparticles, films, and electrodes; the stearoyl–PEG backbone imparts colloidal stability and antifouling character.
• Nanomaterials dispersion: amphiphilic coating to transfer hydrophobic nanoparticles into aqueous media; PEG reduces aggregation and protein adsorption.
• Supramolecular assemblies: incorporation into micelles, polymersomes, and liposomes to tune corona properties, steric stabilization, and stealth behavior in model systems.
• Crosslinking/disulfide chemistry: thiol enables reversible disulfide formation for redox-responsive materials; can be used to graft onto electrophilic handles (e.g., maleimides, vinyl sulfones, activated esters—via thiol–Michael or through intermediate linkers).
• Immobilization strategies: anchor hydrophobic moieties into polymer matrices or onto hydrophobic surfaces via the stearoyl tail while presenting a reactive thiol at the interface.

Practical notes:

• Maintain reducing conditions (e.g., include TCEP in aqueous buffers or use argon-degassed, anhydrous solvents) to preserve free –SH prior to coupling.
• If forming SAMs, freshly prepare solutions (1–2 mM typical in ethanol) and allow sufficient incubation time (2–24 h) depending on surface and desired packing density.
• For film hydration methods, co-dissolve with other lipids in CHCl3, evaporate to a thin film, desiccate, then hydrate and cycle through freeze–thaw/sonication as needed.

Reaction Conditions

Item-specific conditions: Not specified for this item; refer to CoA/Spec Sheet and SDS.

General literature guidance for thiol-functional conjugates:

• Thiol–maleimide Michael addition:
  • Solvent: PBS or HEPES buffer (pH 6.5–7.0) often optimal to minimize maleimide hydrolysis; co-solvent DMSO (10–30%) can aid solubilization.
  • Temperature: 20–25°C; typical reaction times 0.5–4 h.
  • Stoichiometry: 1.1–1.5 equiv thiol to maleimide; exclude oxygen; optional TCEP (0.5–2 mM) to maintain reduced thiols.
• Gold–thiol self-assembly (SAM formation):
  • Solvent: ethanol or isopropanol (anhydrous), 1–2 mM ligand.
  • Temperature: ambient; immersion 2–24 h, followed by solvent rinsing.
  • Environment: protect from light/oxygen to limit oxidation; freshly cleaned gold surfaces improve order.
• Disulfide formation:
  • Mild air oxidation in buffered aqueous solution or controlled oxidants (e.g., dilute H2O2) to couple thiols; monitor to avoid over-oxidation to sulfinic/sulfonic acids.
• Thin-film hydration for assemblies:
  • Co-dissolve components in CHCl3 or greener alternatives (2-MeTHF/EtOAc if soluble), rotary evaporate to a film, desiccate, hydrate with buffer at above transition temperature, then apply sonication or extrusion.

These are general conditions; optimize for your specific PEG length and application.

Safety and Handling

Item-specific hazard data: Not specified for this item; refer to SDS for authoritative information.

General guidance (literature/general):

• Likely GHS: Many PEGylated lipids are not classified as acutely hazardous; however, absence of classification does not eliminate risk. Handle as a laboratory chemical.
• Potential hazards: thiols may have strong odor; thiols can oxidize to disulfides—minimize exposure to air/oxidants. Dusts or films can be slippery.
• Incompatibilities: strong oxidizing agents (risk of thiol oxidation), strong bases/acids (risk of ester hydrolysis if ester-linked), and materials generating peroxides are generally not problematic but avoid unnecessary exposure.
• PPE: safety glasses, lab coat, and appropriate gloves (e.g., nitrile). Use in a fume hood when weighing or dissolving to manage odors and solvent vapors.
• First aid (overview, not a substitute for SDS):
  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Skin contact: wash with soap and water; remove contaminated clothing.
  • Eye contact: rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; seek medical attention if irritation persists.
  • Ingestion: rinse mouth; do not induce vomiting; seek medical attention.
• Fire safety: treat as an organic combustible solid; use CO2, dry chemical, or foam extinguishers.

Always consult the current SDS for S164311 before use. Research use only.

Solvent Selection

Item-specific solubility specs: Not specified for this item; refer to CoA/Spec Sheet.

General solvent behavior (literature/general for stearoyl–PEG–thiol amphiphiles):

• Polarity class: amphiphilic. Dissolves well in polar aprotic organic solvents (DMSO, DMF, NMP), chlorinated solvents (CHCl3, DCM), and alcohols. Solubility in water depends strongly on PEG chain length; longer PEG enhances aqueous dispersibility.
• Recommended solvents by task:
  • Stock solutions for bioconjugation: anhydrous DMSO or DMF (helps maintain free –SH; easy miscibility with aqueous buffers upon dilution).
  • Thin film/hydration for liposomes or micelles: chloroform or chloroform:methanol for film casting, then evaporate and hydrate with buffer.
  • Surface assembly on gold: ethanol or isopropanol commonly used for forming self-assembled monolayers (SAMs); ensure low water/oxygen to preserve thiol.
• Dielectric/miscibility (general): DMSO (ε ~47), DMF (ε ~37), ethanol (ε ~24), chloroform (ε ~4.8). Choose higher dielectric to favor dissolution of PEG-rich variants; use lower dielectric to aid film casting.

Comparison to alternatives:

• Versus purely hydrophobic thiols (e.g., octadecanethiol): PEG spacer confers water compatibility and reduces nonspecific adsorption.
• Versus PEG-maleimide lipids: thiol end enables direct gold binding and disulfide chemistry; maleimides favor Michael addition with thiols.

Practical tips:

• Use dry, oxygen-reduced solvents to minimize thiol oxidation. Filter solutions (0.22 µm) for formulation work.

Storage and Reconstitution

Item-specific storage and shipping (from Product Data):

• Storage conditions: Room temperature.
• Shipped in: Normal.
• Research use only.

Reconstitution and handling:

• Item-specific reconstitution instructions: Not specified for this item; refer to CoA/Spec Sheet.

General handling guidance (literature/general):

• To prepare stock solutions, use dry, oxygen-reduced solvents (e.g., anhydrous DMSO, DMF, or ethanol) to maintain the thiol in the reduced state. Prepare fresh or store aliquots under inert gas.
• Protect from light and air to limit thiol oxidation; if prolonged storage of solutions is needed, consider inert-atmosphere vials and low temperatures consistent with solvent choice.
• Avoid strong acids/bases if an ester linkage is present; neutral pH buffers are typically gentler on PEG–lipid conjugates.

Always consult the SDS and CoA for S164311 for authoritative storage and handling details.

Structure and Identity

Item-specific facts (from Product Data):

• Product name: Stearic acid PEG thiol (SKU: S164311)
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: 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.

General structural description (literature/general):

• Stearic acid PEG thiol typically denotes an amphiphilic conjugate comprising a hydrophobic stearoyl segment (C18 saturated fatty acyl chain) linked via a polyethylene glycol (PEG) spacer to a terminal thiol group (–SH).
• Likely features: a long aliphatic chain (stearoyl), a polyether backbone [–(CH2–CH2–O)n–], and a terminal thiol. The stearic acid moiety is commonly attached to PEG through an ester or amide linkage, depending on synthesis.
• Functional groups present: long-chain alkyl, ether oxygens (PEG), thiol (nucleophilic; oxidizable to disulfide). If ester-linked, an ester carbonyl is present; if amide-linked, an amide carbonyl and –NH– may be present.
• 2D description in words: a C18 linear alkyl chain connected at one end to a carbonyl, then to a flexible PEG chain of variable length terminating in a free sulfhydryl group.

Synthetic Utility

General synthetic features (literature/general):

• Functional handles: a terminal thiol (–SH) provides a versatile nucleophile for:
  • Thiol–Michael additions to activated alkenes (maleimides, acrylates, vinyl sulfones).
  • Formation of thioethers via SN2 displacement on suitable electrophiles (e.g., alkyl halides with good leaving groups).
  • Coordination to soft metals (Au, Ag) enabling self-assembled monolayers and nanoparticle capping.
  • Reversible disulfide formation under oxidative conditions for redox-responsive linkages.
• Amphiphilic design utility: the stearoyl segment anchors the conjugate within hydrophobic domains, allowing spatial presentation of the PEG–thiol at interfaces for selective modification of surfaces or assemblies.
• Linkage considerations: If the stearoyl group is connected via an ester, it may be hydrolytically labile under strong basic or acidic conditions; amide linkages offer greater stability but require different coupling chemistry.
• Orthogonality: Thiol chemistry can proceed under mild, aqueous-compatible conditions, often orthogonal to amine/NHS ester reactions occurring on other components.

Use cases:

• Post-functionalization of liposomes, polymeric nanoparticles, or hydrogels via thiol–ene/Michael routes.
• Immobilization of biomolecules bearing maleimide tags onto hydrophobic substrates through the stearoyl anchor.

Item-specific reactivity parameters are not specified for S164311; verify with small-scale trials.

Target Specificity

Not applicable. This product is a small-molecule amphiphile, not an antibody, enzyme, or biological ligand with defined antigen/epitope specificity.

If used to present ligands at surfaces or particles via thiol chemistry, specificity will derive from the attached ligand, not from the stearoyl–PEG–thiol itself.

Perguntas frequentes

How should this product be stored?

Store at room temperature.

How is this product shipped?

This product ships under standard ambient conditions. No temperature-controlled packaging is required.

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.