Optimization and comparison of CD4‐targeting lipid–polymer hybrid nanoparticles using different binding ligands

Abstract

Monoclonal antibodies and peptides are conjugated to the surface of nanocarriers (NCs) for targeting purposes in numerous applications. However, targeting efficacy may vary with their specificity, affinity, or avidity when linked to NCs. The physicochemical properties of NCs may also affect targeting. We compared the targeting efficacy of the CD4 binding peptide BP4 and an anti-CD4 monoclonal antibody (CD4 mAb) and its fragments, when conjugated to lipid-coated poly(lactic-co-glycolic) acid nanoparticles (LCNPs). Negatively charged LCNPs with cholesteryl butyrate in the lipid layer (cbLCNPs) dramatically reduced nonspecific binding, leading to higher targeting specificity, compared to neutral or positively charged LCNPs with DOTAP (dtLCNP). cbLCNPs surface conjugated with a CD4 antibody (CD4-cbLCNPs) or its fragments (fCD4-cbLCNPs), but not BP4, showed high binding in vitro to the human T cell line 174xCEM, and preferential binding to CD3+ CD14-CD8- cells from pigtail macaque peripheral blood mononuclear cells. CD4-cbLCNPs showed 10-fold higher binding specificity for CD4+ than CD8+ T cells, while fCD4-cbLCNPs demonstrated the highest binding level overall, but only three-fold higher binding specificity. This study demonstrates the importance of ζ-potential on NC targeting and indicates that CD4 mAb and its fragments are the best candidates for delivery of therapeutic agents to CD4+ T cells. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1177-1188, 2018.

Design Optimization of Tumor Vasculature-Bound Nanoparticles

“…The set of design variables has been expanded to include nanoparticle avidity because it has an impact on nanoparticle distribution 41 . Multidimensional search schemes give rigorous optimization a computational advantage over brute force methods that change one variable at a time.…”

Hybrid nanocarriers incorporating mechanistically distinct drugs for lymphatic CD4 + T cell activation and HIV-1 latency reversal

“…S5A). However, because chol-but reduces nonspecific cell binding ( 34 ), we kept it in our formulations for the subsequent targeting and animal studies.…”

“…We have previously shown that conjugating an anti-CD4 monoclonal antibody (mAb) to our optimized cbLCNPs led to high specificity for CD4 + T cells ( 34 ). Here, we conjugated an anti-CD4 mAb to our Ing3A-cbLCNPs (Fig.…”

“…This was consistent with other reported studies that bigger nanoparticles might be more easily trapped at the injection site instead of efficiently draining to the LN ( 3 , 35 ). Because of their desirable trafficking properties, as well as the increased targeting specificity reported previously ( 34 ), we moved forward with smaller CD4-targeted cbLCNPs for all animal studies.…”

“…For DiR or DiD fluorescent LCNPs, 1% (w/w) (DiR or DiD to PLGA) DiR or DiD dissolved in ethyl acetate was added to PLGA/ethyl acetate solution right before LCNP synthesis. Anti-CD4 mAbs were conjugated to synthesize LCNPs via maleimide-functionalized DSPE-PEG in the lipid bilayer as described previously ( 23 , 34 ). In brief, the mAb was thiolated using Traut’s reagents and then incubated with LCNPs in PBS (containing 5 mM EDTA) for 2 hours.…”