Representing the entry‑level medium‑molecular‑weight grade within carboxyl‑terminated poly(ε‑caprolactone) portfolio, this 5 kDa polymer delivers enhanced chain entanglement and higher crystallinity relative to 2K and 3K low‑MW counterparts. The terminal carboxylic acid group can be conveniently activated via EDC/NHS chemistry to form stable amide linkages with amine‑containing proteins, aptamers and targeting ligands. Extended aliphatic chains decelerate hydrolytic erosion and greatly improve colloidal integrity after nanoprecipitation. It shifts experimental suitability away from short‑lived acute assays toward multi‑week cell‑culture studies and early‑stage subcutaneous in‑vivo validation. Formulation scientists select this grade to build anionic functionalized particulate carriers that retain morphological stability throughout biological testing, without the ultra‑slow degradation exhibited by 10K and higher‑molecular‑weight PCL‑COOH variants.
Key Features: ‑ Medium‑length PCL backbone terminated with carboxylic acid moiety; tolerates brief aqueous exposure during nanoparticle formulation without severe loss of coupling reactivity ‑ Noticeable chain entanglement reinforces particle dimensional stability, effectively suppressing premature disassembly compared with 2 K / 3 K low‑MW analogues ‑ Moderate hydrolytic erosion profile; preserves particle and scaffold morphology across multi‑week experimental cycles before gradual bulk mass loss ‑ Endowed with tunable negative surface potential after nanoparticle assembly, allowing precise adjustment of cell‑particle interaction and cellular uptake behaviours ‑ Spectroscopically validated carboxyl end‑group conversion; low residual monomer and catalyst content suitable for cell‑level assays and preliminary subcutaneous small‑animal trials
Applications: ‑ Carboxyl‑functionalized anionic nanoparticles and micelles for multi‑week drug‑release profiling and cellular interaction investigations after EDC/NHS ligand immobilization ‑ EDC/NHS‑mediated surface bio‑modification of electrospun thin‑film scaffolds for subcutaneous biomimetic tissue‑culture model construction ‑ Synthesis of amide‑bonded polymer‑biomolecule conjugates for preliminary passive‑targeting prototype assessment in small‑animal subcutaneous settings ‑ Formulation bridging fast‑eroding low‑MW PCL‑COOH and mechanically robust high‑molecular‑weight carboxyl‑terminated PCL polymers ‑ Bench‑scale screening of anionic particulate carriers prior to advancing toward implant‑oriented high‑MW polymer formulations
Handling & Storage: Store lyophilized polymer powder at −20 °C under dry inert‑gas protection. Though carboxyl groups possess inherent chemical stability, sustained moisture exposure will trigger random ester‑chain hydrolysis and alter molecular‑weight distribution. Equilibrate sealed vials fully to room temperature inside a desiccator before opening to avoid water‑vapour‑induced sample contamination. Prepare working solutions with anhydrous organic solvents immediately prior to experiments; long‑term storage of dissolved polymer stocks is not recommended. Intended exclusively for laboratory research; not authorised for human clinical usage.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.