Pentacosadiynoic acid-mPEG (MW 1000) , CAS No.P1440273

CAS: P1440273 Cat. No.: P1440273 Peso molecolare: 1000 (Average)

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Panoramica

Pentacosadiynoic acid-mPEG (MW 1000) is a PEG lipid that can improve the delivery efficiency and tissue specificity of poorly soluble drugs. Pentacosadiynoic acid-mPEG (MW 1000) can be used in drug delivery research.

Specifiche

Condizioni di conservazione di stoccaggio

Store at -20°C

Spedito in

Ice chest + Ice pads

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Nomi e identificatori

Peso molecolare

1000 (Average)

Application Protocols

Illustrative, literature‑based protocols for PDA‑mPEG assemblies (optimize per lab needs). Item‑specific validated protocols are not provided.

1. PDA‑mPEG Vesicle Preparation and Photopolymerization

• Dissolve PDA‑mPEG (and optional co‑lipids/ligands) at total 1–5 mg/mL in chloroform. Cast a thin film in a round‑bottom flask; dry under vacuum ≥2 h.
• Hydrate with HEPES buffer (10 mM, 150 mM NaCl, pH 7.4) to 0.1–1.0 mg/mL lipid concentration at 30–45°C while vortexing.
• Sonicate (bath or probe with cooling) or extrude through 200/100 nm membranes to obtain small unilamellar vesicles.
• Anneal at 25–40°C for 2–12 h protected from light to enhance ordering.
• Irradiate with 254–365 nm UV for 1–10 min while stirring on ice; monitor color change. Store polymerized vesicles at 4°C, protected from light.

2. Solvent‑Injection Assembly (Chlorine‑free)

• Prepare a 5–10 mg/mL solution in ethanol or 2‑MeTHF.
• Inject into 10–20× volume of buffer under vigorous stirring at room temperature.
• Dialyze or spin‑filter to remove residual solvent; proceed to UV polymerization as above.

3. Langmuir–Blodgett Film with UV Fixation

• Spread CHCl3 solution on water subphase; allow solvent to evaporate.
• Compress to 20–35 mN/m; irradiate with UV to polymerize; transfer to solid substrate.

Quality checks: DLS for size/PDI, UV–Vis for chromic bands, optional Raman for ene–yne backbone signatures.

Biological Roles

This compound is not a natural metabolite; it is a synthetic amphiphile designed for materials/sensing research. No biological activity is claimed. The following points describe general, literature‑based roles of its components in research contexts:

• PEG segment: Poly(ethylene glycol) is widely used to confer “stealth” properties (reduced protein adsorption, decreased nonspecific interactions) to surfaces and colloids. PEG chains of ~1 kDa provide a short hydrophilic corona that improves colloidal stability while minimally increasing hydrodynamic size.
• Pentacosadiynoic acid (PDA) segment: Long‑chain diacetylenic lipids can pack into ordered assemblies (vesicles/monolayers). Upon UV activation, the diacetylene polymerizes to polydiacetylene, producing chromic transitions that report on local perturbations (membrane insertion, surfactant binding, temperature/pH changes). These responses underpin numerous bioanalytical sensing formats.
• Amphiphile behavior: PDA–mPEG conjugates form mixed assemblies with other lipids or amphiphiles that can embed recognition elements (e.g., biotinylated lipids, peptides). The PEG corona can reduce nonspecific cell/protein interactions in in vitro assays, facilitating selective readouts in complex biological buffers.

Research use only: The product is intended strictly for laboratory research; no clinical, diagnostic, or therapeutic applications are implied. For work involving cells or biomolecules, evaluate cytocompatibility and endotoxin levels as needed for the specific assay; such attributes are not specified for this item and, if critical, must be validated by the user.

Buffer Applications

This material is not a buffer reagent and does not define solution pH. However, it is commonly formulated in buffers during assembly and testing of vesicles/films (general guidance):

• Suitable hydration buffers (literature/practice):
  • HEPES (10–20 mM, pH 7.2–7.5) with 100–150 mM NaCl for vesicle formation and stability.
  • PBS (1×, pH 7.4) for biological assays; note phosphate can influence assembly with certain co‑lipids.
  • Tris (10–20 mM, pH 7.4–8.0) for some surface deposition protocols; avoid prolonged exposure at elevated temperature to limit ester hydrolysis.
• Additives: 0.02–0.05% NaN3 to prevent microbial growth in stored dispersions; divalent cations (Mg2+/Ca2+) can modulate packing and responsiveness—optimize per assay.
• Ionic strength and temperature: control salt and temperature during annealing to promote ordering before UV polymerization (literature).

Item‑specific buffer compatibility, pH stability ranges, and ionic strength limits: Not specified for this item; refer to CoA/Spec Sheet. Users should verify aggregation size (DLS) and optical signatures (UV–Vis) in the chosen buffer, as buffer composition can shift chromic behavior of polydiacetylene assemblies.

Green Alternatives

While the amphiphile itself is the intended material, greener choices focus on processing solvents and energy inputs.

Greener processing strategies (literature/best practice):

• Replace chlorinated solvents: Use ethanol or isopropanol for dissolution/injection methods instead of chloroform/DCM when feasible. For thin‑film routes, ethanol/tert‑butanol mixtures can aid film formation though uniformity may be lower than with CHCl3.
• Solvent recovery: Employ rotary evaporation with cold‑trap to capture and recycle organics; use minimal solvent volumes and high‑solids formulations.
• Aqueous assembly: Favor direct aqueous dispersion using mild heating and sonication, or microfluidic solvent‑exchange, reducing organic load.
• Energy: Prefer low‑pressure mercury lamps or LEDs (near‑UV) with narrowband emission and timed exposure for PDA polymerization, limiting energy consumption and heat.

Comparison (general):

• Chloroform vs ethanol
  • Pros (CHCl3): excellent solubility, smooth films; Cons: toxic, ozone‑depleting potential, hazardous waste.
  • Pros (EtOH): greener, low toxicity, easy to remove; Cons: slower dissolution, potential ester hydrolysis over time, less uniform films.
• THF vs 2‑MeTHF
  • Pros (THF): high solvency, well‑known; Cons: peroxide former, fossil‑based.
  • Pros (2‑MeTHF): bio‑derived, lower miscibility with water can aid phase separation; Cons: different evaporation profile, odor.

Note: Validate assembly quality (DLS, cryo‑TEM) after solvent changes; polymerization efficiency of diacetylene motifs depends strongly on nanoscale packing, which can shift with solvent history.

Pharmaceutical Uses

No clinical use is claimed or supported. For research/formulation studies (general literature context):

• Excipient model: PDA–mPEG amphiphiles can serve as model PEGylated lipids/surfactants to study colloidal stability, stealth behavior, and stimuli‑responsive reporting in prototype delivery systems or coatings.
• Surface modification: The PEG corona offers antifouling characteristics for research‑scale device coatings and biosensor surfaces; the PDA core can be photopolymerized to create robust, colored/fluorescent films for analytical readouts.
• Comparators: Useful as a nonionic PEGylated amphiphile comparator when benchmarking different PEG lengths or terminal functionalities on nanoparticle stability.
• Regulatory/compendial status: Not specified for this item; no pharmacopeial monograph is indicated. Any use in regulated products would require independent qualification.

Important: For research use only. Not for human or veterinary use, not for diagnostic or therapeutic applications. Endotoxin/bioburden, residual solvent content, and trace impurity specifications are not provided for this item and must be established by the user if relevant to preclinical formulation research.

Physical Properties

Item‑specific numerical specifications (mp, bp, density, refractive index, water/peroxide/metal limits, UV cutoff): Not specified for this item; refer to CoA/Spec Sheet.

General/literature characteristics for PDA–mPEG conjugates (PEG Mn ~1000):

• Physical state: typically a white to off‑white waxy solid or viscous paste at ambient temperature, transitioning to a pourable melt modestly above room temperature due to PEG1000 softening (literature/general for mPEG1000 materials).
• Amphiphilicity: forms micelles/vesicles/films in water depending on formulation and co‑lipids; critical aggregation behavior depends on temperature and ionic strength (literature).
• Solubility (qualitative):
  • Water: PEG segment imparts partial to good dispersibility; complete dissolution may require warming and/or co‑solvent. Aggregation is common (literature).
  • Organic: soluble in polar organics (THF, chloroform, dichloromethane, acetone, ethanol); limited solubility in alkanes (literature).
• Thermal/photochemical behavior: diacetylene moiety undergoes topochemical polymerization in ordered assemblies under UV (e.g., 254–365 nm) or heat, producing conjugated polydiacetylene with characteristic chromism (blue→red) (literature).
• Polydispersity: PEGylated materials are inherently polydisperse in n (degree of polymerization), giving a distribution of MWs and broad thermal transitions (literature).

Notes for practitioners:

• For film‑hydration methods, use volatile, anhydrous organics to cast uniform films; gentle heating (30–45°C) may aid dissolution of the waxy solid (general best practice).
• Avoid prolonged UV exposure unless intentional polymerization is desired; protect from light during handling (practical tip).

Quality and Grades

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

Context and implications for this product type:

• PEGylated amphiphiles are typically characterized by average molecular weight (Mn), polydispersity (Đ), substitution level (here: mono‑functional mPEG end group), and residual solvent/moisture. Because the PEG chain is inherently polydisperse, reported MWs are nominal and method‑dependent (Mn vs. Mw; GPC/SEC vs. MALDI). Item‑specific values are provided on the Certificate of Analysis when applicable.
• Stabilizers: None specified. In practice, PDA‑containing materials are often shipped and stored protected from light to minimize unintended topochemical polymerization; the provided cold‑chain logistics support stability.
• What the shipping/storage indicate: Shipped in an ice chest with ice pads and stored at −20°C suggests attention to limiting thermal/photochemical history and hydrolysis of the ester linkage during transit and storage.
• Recommended quality checks by users (general):
  • Visual: homogeneous waxy solid without discoloration (blue/red hue may indicate partial PDA polymerization in films, not necessarily in bulk solid).
  • NMR (1H/13C) in CDCl3/CD3OD to confirm PEG signals and long‑chain PDA resonances; disappearance of –COOH signal consistent with esterification (general practice).
  • FTIR: ester carbonyl ~1735 cm⁻1; alkyne signatures for diacetylene (weak).
  • SEC/GPC (in HFIP or THF) to assess PEG distribution if critical to application.
• UV–Vis baselines: Low UV‑absorbing solvents are recommended when measuring PDA chromism; item‑specific UV cutoff is not specified.

Reaction and Applications

This product is primarily a self‑assembling, stimuli‑responsive materials building block rather than a stoichiometric small‑molecule reagent.

Key application areas (literature/general):

• Polydiacetylene (PDA) colorimetric/fluorimetric platforms: Upon assembly into ordered films/vesicles and UV activation, the diacetylene segment polymerizes topochemically to yield conjugated PDA backbones that display chromism (blue→red) and fluorescence changes in response to environmental perturbations (temperature, pH, amphiphile insertion, ligand binding via co‑functional lipids).
• Amphiphile self‑assembly: Forms micelles/vesicles; the PEG corona imparts colloidal stability and antifouling behavior, facilitating biosensing in complex media.
• Composite materials: Blending with functional lipids or PEGylated ligands (e.g., biotin‑PEG‑lipids) enables specific recognition while PDA provides signal transduction.
• Surface science: Langmuir–Blodgett/Schaefer deposition of monolayers; UV polymerization locks in patterns and allows optical readout.
• Nanofabrication: Write‑once photopatterning of PDA domains in pre‑assembled films; subsequent post‑functionalization via noncovalent interactions.

Practical considerations:

• Preorganization is essential: polymerization occurs efficiently only when diacetylene units are aligned (typical headgroup spacing ~4.9–5.0 Å, literature). Achieve this by slow annealing of vesicles (e.g., near the chain melting regime) before UV exposure.
• Control composition: mixing with saturated co‑lipids can tune packing and responsiveness; excessive PEGylation may hinder crystallinity and reduce polymerization efficiency.
• Quantify conversion: follow by UV–Vis (blue band ~620–650 nm; red band ~530–550 nm, literature) and Raman signatures of ene–yne backbones.

Reaction Conditions

Polymerization/assembly conditions below are general literature guidance for diacetylene amphiphiles and should be optimized experimentally. Item‑specific conditions are not specified for this product.

• Vesicle preparation (thin‑film hydration, literature):
  • Dissolve amphiphile(s) in chloroform or THF, cast a thin film, dry under vacuum ≥2 h.
  • Hydrate with buffer (e.g., 10 mM HEPES, 150 mM NaCl, pH 7.4) at 25–45°C while vortexing.
  • Sonicate or extrude (100–200 nm membranes) to narrow size distribution; anneal near chain ordering temperature (e.g., 25–50°C) for several hours to promote diacetylene alignment.
• Polymerization (literature):
  • UV: Irradiate assembled vesicles/films at 254–365 nm for minutes to tens of minutes, on ice or controlled temperature, protected from ambient light otherwise. Monitor UV–Vis for growth of the blue band (~620–650 nm) transitioning to red band (~530–550 nm with stimuli).
  • Thermal: Gentle heating can also induce polymerization in ordered phases but may broaden chromic response.
• Film/monolayer methods (literature):
  • Spread from CHCl3 on water surface in a Langmuir trough; compress to target surface pressure (e.g., 20–35 mN/m), then UV‑polymerize and transfer to substrates.
• Solvent displacement:
  • Inject ethanol/THF solution into stirred buffer; remove residual solvent by dialysis; proceed with UV polymerization.

Expected outcomes (literature): robust chromic response to perturbations (surfactants, pH, temperature). Exact wavelengths, quantum yields, and conversion depend on packing, co‑lipid ratio, and irradiation conditions and must be empirically established.

Safety and Handling

Authoritative safety information must be obtained from the product SDS.

Item‑specific GHS 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 safety considerations for PDA–mPEG amphiphiles (literature/practice):

• Expected hazards: Low volatility, low acute inhalation risk. May cause skin/eye irritation. PEGs are generally of low toxicity, but the diacetylene lipid segment can be irritant; handle as a laboratory chemical.
• Photochemical reactivity: The diacetylene can polymerize under UV/heat when preorganized; protect bulk material and solutions from direct UV light unless polymerization is intended. Polymerization is exothermically mild but can change material properties.
• Incompatibilities: Strong oxidizers (may attack aliphatic chain/PEG), strong acids/bases (can hydrolyze ester linkage), and radical initiators/UV inducers (unintended polymerization).
• PPE: Lab coat, safety glasses, and chemically resistant gloves (e.g., nitrile). Use in a well‑ventilated area or fume hood when handling organic solutions or casting films.
• First aid (overview; consult SDS):
  • Skin: Wash with soap/water. Remove contaminated clothing.
  • Eyes: Rinse cautiously with water for several minutes; seek medical advice if irritation persists.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.
  • Inhalation of vapors/solvent: Move to fresh air; seek medical attention if symptoms occur.
• Waste: Collect solutions/films as organic laboratory waste per institutional and local regulations.

Solvent Selection

This amphiphile dissolves/disperses best in moderately polar organics and aqueous media with appropriate formulation. Item‑specific solubility limits are not specified; guidance below is based on literature/practice for PDA–PEG conjugates.

• Polarity/miscibility (general):
  • Good solvents: chloroform, dichloromethane, THF, acetone, ethanol, isopropanol. Warm methanol can work but may promote hydrolysis over time.
  • Aqueous systems: dispersible upon film hydration, ethanol injection, or solvent exchange; PEG segment aids colloidal stability.
  • Poor solvents: alkanes/hexanes (limited), highly nonpolar media.
• Use scenarios:
  • Thin‑film hydration: dissolve in CHCl3 or THF (with any co‑lipids), rotary‑evaporate to a thin film, then hydrate with buffer to form vesicles or micelles.
  • Solvent displacement/ethanol injection: dissolve amphiphile in ethanol/THF and inject into aqueous buffer under stirring, then remove organic by dialysis/evaporation.
  • Surface deposition: spread from CHCl3 on water subphase for Langmuir films before UV polymerization (literature for PDA lipids).
• Choosing vs alternatives:
  • For greener processing, ethanol/IPA can replace chlorinated solvents at some cost to solubility/film uniformity.
  • PEG1000 balance: compared to PDA‑mPEG500, the 1000 Da PEG is more water‑dispersible; compared to PDA‑mPEG2000, it forms tighter assemblies with lower corona thickness (tradeoff between colloidal stability and packing).
• Practical tips:
  • Filter organic solutions (0.2 µm PTFE) before film casting to remove particulates.
  • Protect solutions from UV; store cooled and use fresh to minimize hydrolysis/polymerization.

Storage and Reconstitution

Item‑specific storage and shipping:

• Storage conditions: Store at −20°C (per Product Data). Protect from light.
• Shipped in: Ice chest + ice pads (per Product Data) to maintain a cold chain.

General handling recommendations for this product type:

• Keep container tightly closed under inert headspace if possible (dry nitrogen/argon) to minimize oxidative degradation and moisture ingress.
• Protect from UV/strong light to avoid unintended diacetylene polymerization.
• Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent condensation.

Reconstitution (general guidance; item‑specific solvent limits not specified):

• For stock solutions: dissolve at 1–50 mg/mL in chloroform, THF, or ethanol with gentle warming (30–40°C) if needed; vortex until homogeneous. Filter through 0.2 µm PTFE for film casting.
• For aqueous dispersions: employ thin‑film hydration or solvent‑injection followed by dialysis/filtration. Maintain neutral pH to limit ester hydrolysis; avoid prolonged heating in water.

Stability notes:

• Avoid repeated freeze–thaw of solutions; prepare aliquots. Solid material is generally more stable than solutions.
• Do not expose assembled dispersions to prolonged UV unless polymerization is intended; store polymerized vesicles at 4°C, protected from light, and use within days to weeks depending on assay.

For any item‑specific parameters (water content limits, residual solvent, shelf life), refer to the CoA/Spec Sheet.

Structure and Identity

Pentacosadiynoic acid‑mPEG (MW 1000) is an amphiphilic conjugate comprising a diacetylene long‑chain fatty acid (pentacosadiynoic acid, PDA; C25 with a conjugated –C≡C–C≡C– segment) esterified to a monomethoxy‑terminated polyethylene glycol block (mPEG, nominal Mn ≈1000 Da).

• SKU: P1440273
• Product name: Pentacosadiynoic acid‑mPEG (MW 1000)
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• CID: 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: The PEG block is nominally ~1000 Da (label); overall conjugate is polydisperse (literature/general for PEGylates). Item‑specific average MW: Not specified for this item; refer to CoA/Spec Sheet.

Structural features (general, literature):

• Hydrophobic PDA tail: linear C25 with a terminal carboxyl that is typically ester‑linked to PEG; contains a conjugated diacetylene (–C≡C–C≡C–) capable of topochemical polymerization upon UV or thermal activation when preorganized in assemblies.
• Hydrophilic head: monomethoxy PEG chain (–O–(CH2CH2O)n–CH3) providing water solubility/stealth character; single chain terminates in methoxy (non‑reactive end).
• 2D description: A long saturated/unsaturated aliphatic chain bearing a central conjugated diyne, ending in an ester linkage to a flexible PEG coil capped with methoxy; overall forms an amphiphile with one hydrophobic tail and one hydrophilic polymer head (surfactant‑like).

Synthetic Utility

As supplied, pentacosadiynoic acid‑mPEG (MW 1000) is a functional amphiphile rather than a versatile small‑molecule building block. Its principal “synthetic” value lies in directed supramolecular assembly and subsequent in situ photopolymerization of the diacetylene motif.

• Functional groups and reactivity (general):
  • Conjugated diacetylene: undergoes topochemical 1,4‑addition polymerization in preorganized phases, yielding a conjugated ene–yne backbone (polydiacetylene). Not typically used for stepwise covalent synthesis in solution.
  • Ester linkage: susceptible to hydrolysis under strong acid/base or prolonged aqueous heating; otherwise stable under neutral conditions used for assembly.
  • PEG chain: terminal methoxy is non‑reactive; backbone inert under most conditions.
• Retrosynthetic/workflow perspective:
  • Employed to create polymerizable domains within vesicles/films; after UV polymerization, the resulting PDA networks can be further over‑coated or interfaced with other materials.
  • Can be co‑assembled with functional amphiphiles bearing ligands (e.g., biotin, peptides) to impart recognition while PDA provides the optical transduction channel.
• Related transformations (literature):
  • Langmuir film compression and UV fixation to obtain crosslinked monolayers.
  • Thermal annealing to tune chromic phase and domain size.

If a reactive PEG terminus is required for conjugation chemistry (e.g., NHS, azide, maleimide), select a different PEGylated diacetylene lipid with the desired end‑group; the present mPEG is methoxy‑capped (non‑reactive) by design.

Target Specificity

Not applicable. This product is not an antibody, enzyme inhibitor, or targeted ligand. It has no defined biological “target specificity.” In sensor assemblies, specificity arises from co‑assembled recognition elements (e.g., biotin‑lipids, receptor‑mimicking amphiphiles), not from PDA‑mPEG itself.