This low‑molecular‑weight carboxyl‑terminated poly(ε‑caprolactone) features short aliphatic polyester chains with terminal carboxylic acid groups, built for carbodiimide‑mediated amide coupling workflows targeting amine‑bearing biomolecules. Compared against higher‑MW PCL‑COOH variants, the 2 kDa grade delivers low crystallinity and excellent solubility across common anhydrous organic solvents, paired with fast hydrolytic turnover. The exposed carboxyl moiety enables covalent linkage with peptides, proteins and amine‑modified small molecules via EDC/NHS activation. Researchers select this polymer for rapidly eroding nanoparticle prototypes and transient bioconjugate constructs, ideal for short‑term in vitro assays and preliminary transient in‑vivo evaluation, without the long‑residence properties seen in medium‑ and high‑molecular‑weight PCL‑COOH materials.
Key Features: ‑ Short‑chain low‑crystallinity PCL backbone functionalized with terminal carboxylic‑acid group, optimized for EDC/NHS‑activated amide bond formation with amine‑containing substrates ‑ Superior solubility in DCM, THF and chloroform, supporting convenient nanoprecipitation and solution‑phase carbodiimide coupling setups ‑ Fast hydrolytic erosion behaviour; polymeric matrix undergoes rapid mass loss over short experimental windows with minimal persistent residual accumulation ‑ Tunable surface charge after nanoparticle assembly; terminal‑COOH groups introduce negative surface potential to colloidal particle systems ‑ Spectroscopically validated carboxyl end‑group fidelity; low residual catalyst burden suitable for proof‑of‑concept biological laboratory screening
Applications: ‑ Fast‑degrading carboxyl‑functionalized micelles and nanoparticles for short‑term drug‑loading and cellular‑level in‑vitro investigations ‑ EDC/NHS‑driven surface modification of substrates to immobilize amine‑rich peptides for transient cell‑interaction assay workflows ‑ Synthesis of short‑lived polymer‑biomolecule amide‑linked conjugates designed for acute biological assessment, not suited for long‑term implant studies ‑ Exploratory ligand‑conjugation method screening prior to scaling experimental workflows toward higher‑molecular‑weight PCL‑COOH polymer grades ‑ Bench‑scale formulation optimisation for negatively‑charged polyester nanoparticle prototypes
Handling & Storage: Store lyophilized polymer powder at −20 °C under dry inert‑gas atmosphere and shield samples from moisture. Although carboxylic‑acid termini exhibit good intrinsic chemical stability, sustained humid conditions may trigger unintended ester‑chain hydrolysis and compromise molecular‑weight distribution. Allow sealed vials to achieve full room‑temperature equilibration within a desiccator before opening to prevent water condensation contaminating solid samples. Prepare working solutions with anhydrous organic solvents right before experiments; avoid long‑term storage of dissolved polymer aliquots. This product is for laboratory‑research‑only deployment and is not validated for human clinical applications.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.