Controlled Lipid Self-Assembly for Scalable Manufacturing of Next-Generation Immune Stimulating Complexes

Ivan S Pires; Kaiyuan Ni; Mariane Bandeira Melo; Na Li; Elana Ben-Akiva; Laura Maiorino; Jonathan Dye; Kristen A Rodrigues; DongSoo Yun; Byungji Kim; Ryan R Hosn; Paula T Hammond; Darrell J Irvine

doi:10.1016/j.cej.2023.142664

Controlled Lipid Self-Assembly for Scalable Manufacturing of Next-Generation Immune Stimulating Complexes

Chem Eng J. 2023 May 15:464:142664. doi: 10.1016/j.cej.2023.142664. Epub 2023 Mar 29.

Authors

Ivan S Pires^{1

2}, Kaiyuan Ni¹, Mariane Bandeira Melo^{1

3}, Na Li¹, Elana Ben-Akiva¹, Laura Maiorino¹, Jonathan Dye¹, Kristen A Rodrigues^{4

5

3

6}, DongSoo Yun¹, Byungji Kim¹, Ryan R Hosn¹, Paula T Hammond^{1

2}, Darrell J Irvine^{1

7

8

3

6

9}

Affiliations

¹ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 500 Main Street, Cambridge, MA 02142, United States.
² Department of Chemical Engineering, Massachusetts Institute of Technology, 25 Ames Street, Cambridge, MA 02142, United States.
³ Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02139, United States.
⁴ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, MA, MA 02139, United States.
⁵ Harvard-MIT Health Sciences and Technology Program, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
⁶ Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, United States.
⁷ Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
⁸ Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States.
⁹ Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.

Abstract

Immune stimulating complexes (ISCOMs) are safe and effective saponin-based adjuvants formed by the self-assembly of saponin, cholesterol, and phospholipids in water to form cage-like 30-40 nm diameter particles. Inclusion of the Toll-like receptor 4 agonist monophosphoryl lipid A (MPLA) in ISCOM particles yields a promising next-generation adjuvant termed Saponin-MPLA NanoParticles (SMNP). In this work, we detail protocols to produce ISCOMs or SMNP via a tangential flow filtration (TFF) process suitable for scalable synthesis and Good Manufacturing Practice (GMP) production of clinical-grade adjuvants. SMNP or ISCOM components were solubilized in micelles of the surfactant MEGA-10, then diluted below the critical micelle concentration (CMC) of the surfactant to drive ISCOM self-assembly. Assembly of ISCOM/SMNP particles using the purified saponin QS-21 used in clinical-grade saponin adjuvants was found to require controlled stepwise dilution of the initial micellar solution, to prevent formation of undesirable kinetically-trapped aggregate species. An optimized protocol gave yields of ~77% based on the initial feed of QS-21 and the final SMNP particle composition mirrored the feed ratios of the components. Further, samples were highly homogeneous with comparable quality to that of material prepared at lab scale by dialysis and purified via size-exclusion chromatography. This protocol may be useful for clinical preparation of ISCOM-based vaccine adjuvants and therapeutics.

Keywords: SMNP; adjuvants; immune stimulating complexes; monophosphoryl lipid A; saponin; tangential flow filtration; vaccines.

Abstract

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