Product number 11094, m-dPEG®12-amido-dPEG®24-DSPE, is designed for use in liposomes and micelles. The product contains a lipophilic tail of 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) and a hydrophilic head consisting of a methoxy-terminated, single molecular weight, discrete polyethylene glycol (dPEG®).

Targeted delivery to cells of payloads such as toxins, peptides, or oligonucleotides is increasingly accomplished using liposomes or micelles. However, without a polyethylene glycol (PEG) coating on the surface, liposomes and micelles clear quickly from the bloodstream via opsonization by the reticuloendothelial system (RES). A sufficiently dense coating of PEG creates a hydrophilic, flexible, steric barrier around the PEGylated liposomes and micelles, thus preventing opsonin proteins from binding to the liposomal or micellar surface. Consequently, liposomes and micelles circulate longer in the bloodstream, which therefore results in lower dosing requirements for the payload.

Phosphatidylethanolamine (PE) conjugated to PEG is frequently used for PEGylated liposomes. DSPE-PEG is the most studied of all PEG-PE conjugates. Several reports show that the optimal PEG molecular weight for a DSPE-PEG conjugate is approximately 2 kilodaltons. This mass of PEG in the conjugate appears to provide the optimum balance between preventing opsonization of the liposome and maintaining effective cellular uptake of PEGylated liposomes. Larger molecular weight PEGs inhibit cellular uptake without providing any additional protection from opsonization.

Unlike traditional, disperse polymer PEGs (Đ > 1), Quanta BioDesign’s dPEG® products are designed as single molecular weight products with discrete chain lengths (Đ = 1). This simplifies product analysis because there is no intractable mixture of chain lengths and molecular weights as is the nature of polymeric PEGs. Simplified product analysis saves time and money for cost conscious companies seeking to develop new delivery technologies for diagnostic, therapeutic, or imaging applications. To learn more about our dPEG® technology, please click here. For answers to our frequently asked questions please click here.

Product number 11094, m-dPEG®12-amido-dPEG®24-DSPE, is a useful tool for creating, developing, or improving liposomes and micelles. The methoxy terminus of the hydrophilic dPEG® head of PN11094 helps maintain a neutral charge for the molecule while contributing to the surface protection against opsonization of the liposomes or micelles in which it is used. The dPEG® spacer has nearly optimum mass for surface protection, while the lipophilic DSPE tail inserts stably into the lipophilic portion of a liposome or micelle.

Application References:

  1. Hermanson, G. T. Chapter 18, PEGylation and Synthetic Polymer Modification. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 787-838. Click here now for a review of Greg’s book and a link to purchase it.
  2. Hermanson, G. T. Chapter 21, Liposome Conjugates and Derivatives. Bioconjugate Techniques, 3rd edition. Academic Press: New York, 2013, 921-949.
  3. Che, J.; Okeke, C. I.; Zhong-Bo, H. and Xu, J. DSPE-PEG: A Distinctive Component in Drug Delivery System. Curr Pharm Design, 2015, 21(12), 1598-1605.
  4. Zalipsky, S. Chemistry of Polyethylene-Glycol Conjugates with Biologically-Active Molecules. Adv Drug Deliv Rev, 1995, 16(2-3), 157-182.
  5. Parr, M. J.; Ansell, S. M.; Choi, L. S.; Cullis, P. R. Factors Influencing the Retention and Chemical Stability of Poly(Ethylene Glycol)-Lipid Conjugates Incorporated into Large Unilamellar Vesicles. Biochimica et Biophysica Acta (BBA) – Biomembranes, 1994, 1195(1), 21–30.
  6. Pozzi, D.; Colapicchioni, V.; Caracciolo, G.; Piovesana, S.; Capriotti, A. L.; Palchetti, S.; Grossi, S. D.; Riccioli, A.; Amenitsch, H.; Laganà, A. Effect of Polyethyleneglycol (PEG) Chain Length on the Bio–Nano-Interactions between PEGylated Lipid Nanoparticles and Biological Fluids: From Nanostructure to Uptake in Cancer Cells. Nanoscale, 2014, 6(5), 2782–2792.
  7. Sugiyama, I.; Sadzuka, Y. Change in the Character of Liposomes as a Drug Carrier by Modifying Various Polyethyleneglycol-Lipids. Biological and Pharmaceutical Bulletin, 2013, 36(6), 900–906.
  8. Li, T.; Takeoka, S. Enhanced Cellular Uptake of Maleimide-Modified Liposomes via Thiol-Mediated Transport. Int J Nanomedicine, 2014, 9, 2849–2861.
  9. Mitchell, N.; Kalber, T. L.; Cooper, M. S.; Sunassee, K.; Chalker, S. L.; Shaw, K. P.; Ordidge, K. L.; Badar, A.; Janes, S. M.; Blower, P. J.; et al. Incorporation of Paramagnetic, Fluorescent and PET/SPECT Contrast Agents into Liposomes for Multimodal Imaging. Biomaterials, 2013, 34(4), 1179–1192.
  10. Zhang, L.; Chan, J. M.; Gu, F. X.; Rhee, J.-W.; Wang, A. Z.; Radovic-Moreno, A. F.; Alexis, F.; Langer, R.; Farokhzad, O. C. Self-Assembled Lipid−Polymer Hybrid Nanoparticles: A Robust Drug Delivery Platform. ACS Nano, 2008, 2(8), 1696–1702.
  11. Hadinoto, K.; Sundaresan, A.; Cheow, W. S. Lipid–Polymer Hybrid Nanoparticles as a New Generation Therapeutic Delivery Platform: A Review. European Journal of Pharmaceutics and Biopharmaceutics, 2013, 85(3, Part A), 427–443.
  12. Noble, G. T.; Stefanick, J. F.; Ashley, J. D.; Kiziltepe, T.; Bilgicer, B. Ligand-Targeted Liposome Design: Challenges and Fundamental Considerations. Trends in Biotechnology 2014, 32 (1), 32–45.

Additional information

Weight .5 oz
Dimensions .75 × .75 × 2 in

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