Description

Biotin-dPEG®4-amido-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11386, permits biotin labeling of liposomes and micelles by attaching a biotin label to the lipid 1,2-Distearoyl-SN-glycero-3-phosphoethanolamine (DSPE) through a very long (169 atoms, 186.3 Å) single molecular weight, discrete chain length PEG (dPEG®) spacer. The dPEG® spacer has a mass comparable to the polymer PEG2000 commonly used in liposomes and micelles, but unlike polymer PEG, which consists of a diverse and intractable mixture of PEG chain lengths and molecular weights, the dPEG® spacer is a high-purity, single molecule product. The non-immunogenic dPEG® spacer increases the hydrodynamic volume of the molecule, improving its water solubility. In liposomes and micelles, the conjugate’s increased hydrodynamic volume may help hide the carrier construct from the immune system and prevent opsonization.

The biotin label of QBD-11386, biotin-dPEG®4-amido-dPEG®24-amido-dPEG®24-DSPE can be used in therapeutic antibody pretargeting to improve radioimmunotherapy in liposomal and micellar carriers and reduce off-target effects. In addition, the product can be mixed with other DSPE products from Quanta BioDesign with different reactive, protective, or functional groups.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

Description

Carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11385, consists of the lipid 1,2-Distearoyl-SN-glycero-3-phosphoethanolamine (DSPE) conjugated to a long (152 atoms, 180.0 Å), single molecular weight, discrete polyethylene glycol (dPEG®) spacer that has been functionalized with 5(6)-carboxyfluorescein. The dPEG® spacer consists of two dPEG®24 linkers joined by an amide bond, making the spacer effectively a dPEG®48 product with a molecular weight of slightly more than 2,000 Daltons (i.e., equivalent to a PEG2000). The product is designed for use in liposomes and micelles where a fluorescent dye label is needed. The carboxyfluorescein dye has an absorbance maximum (λex) of 497 nm and an emission maximum (λem) of 524 nm, with an extinction coefficient of 63303 M-1 cm-1 at 497 nm, and an A280 correction factor of 0.18.

Liposomes and micelles are often coated with traditional, polymeric PEG2000 (a polymer PEG having an average molecular weight of 2,000 Daltons) at a density of about 5 – 8 mole%. A polymer PEG2000 consists of an intractable mixture of different chain lengths and molecular weights of PEG, making analysis difficult. Unlike a traditional, non-uniform (that is, dispersed) PEG2000, QBD-11385, carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE is a single, uniform product. Carboxyfluorescein-dPEG®24-amido-dPEG®24-DSPE is designed to provide a convenient dye label for liposomes, micelles, and other lipid nanoparticles. This allows labeled liposomes and micelles to be tracked over time.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

Description

DOTA-tris(acid)-amido-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11384, is designed incorporation of lanthanide radionuclides into liposomes or micelles for transport and delivery in radiopharmaceutical applications such as radioimaging and radiotherapeutics. The molecule consists of the macrocycle 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) coupled to a long (152 atoms, 180.0 Å) single molecular weight, discrete polyethylene glycol (dPEG®) spacer and terminated with 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE). The dPEG® spacer consists of two dPEG®24 linkers joined by an amide bond with the functional groups at either end. Effectively, this is a dPEG®48 spacer with a molecular weight slightly more than 2000 Daltons (PEG2000).

DOTA, a highly popular bifunctional chelator, forms thermodynamically stable, kinetically inert complexes with Ln(III) ions, such as yttrium. Thus, DOTA has become the preferred ligand for targeted radiopharmaceutical applications that use lanthanide isotopes. QBD-11384 can be used in liposomes or micelles to deliver metal radioisotopes to targets of interest in vitro or in vivo for imaging or therapeutic applications. The dPEG® surface coating will reduce or eliminate opsonization. Consequently, more liposomes or micelles will reach the target, leading to higher effectiveness and lower dosing requirements.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.