Marking the entry‑level medium‑molecular‑weight grade within the azide‑terminated PCL family, this 5 kDa polymer brings enhanced chain entanglement and higher intrinsic crystallinity relative to 2K and 3K low‑molecular‑weight analogues. The terminal azide group supports robust copper‑catalyzed azide‑alkyne cycloaddition (CuAAC), forming irreversible triazole linkages with alkyne‑modified proteins, aptamers and targeting ligands. Thanks to longer polyester chains, hydrolytic erosion slows substantially, shifting experimental suitability away from short‑lived in vitro assays toward multi‑week cell studies and early subcutaneous animal model work. Formulation researchers select this grade to build click‑functionalized particulate carriers that retain structural integrity throughout biological evaluation, without the extremely slow degradation exhibited by 10K and higher PCL‑N3 materials.
Key Features: ‑ Medium‑length poly(ε‑caprolactone) backbone capped with azide end‑group; tolerates short‑term aqueous exposure during nanoparticle preparation without compromising click‑reaction activity ‑ Noticeable chain entanglement improves colloidal stability after nanoprecipitation, greatly reducing premature particle disassembly compared to 2K / 3K low‑MW variants ‑ Moderate hydrolytic degradation kinetics; maintains stable particle and scaffold morphology across multi‑week experimental cycles before gradual matrix erosion ‑ High chemical orthogonality toward endogenous biomolecular groups; no cross‑reaction with thiols, amines or hydroxyls, guaranteeing high‑fidelity CuAAC click coupling ‑ Spectroscopically validated azide end‑group conversion; low residual monomer and catalyst content compatible with cell‑level testing and preliminary subcutaneous in‑vivo trials
Applications: ‑ Azide‑bearing polymeric nanoparticles and micelles for multi‑week drug release profiling and cellular interaction research after CuAAC ligand conjugation ‑ Click‑mediated surface functionalization of electrospun thin‑film scaffolds for subcutaneous biomimetic cell culture models ‑ Fabrication of triazole‑linked polymer‑ligand and polymer‑protein conjugates for preliminary passive‑targeting small‑animal prototype assessment ‑ Formulation bridging fast‑eroding low‑MW PCL‑N3 and mechanically robust high‑molecular‑weight azide‑terminated PCL materials ‑ Laboratory screening of click‑activated particulate carriers prior to transitioning to high‑MW implant‑oriented polymer formulations
Handling & Storage: Store dried polymer powder at −20 °C under dry inert‑gas protection. While azide groups possess superior hydrolytic stability versus maleimide, sustained moisture exposure will still gradually degrade end‑group performance. Equilibrate sealed vials fully to room temperature inside a desiccator before opening to avoid water condensation contaminating solid samples. Prepare working solutions with anhydrous organic solvents immediately before experiments; long‑term storage of dissolved polymer stocks is not recommended. Intended exclusively for laboratory research; not authorized for human clinical usage.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.