Structure–Function Assessment of Mannosylated Poly(β-amino esters) upon Targeted Antigen Presenting Cell Gene Delivery

Abstract

Antigen presenting cell (APC) gene delivery is a promising avenue for modulating immunological outcomes toward a desired state. Recently, our group developed a delivery methodology to elicit targeted and elevated levels of APC-mediated gene delivery. During these initial studies, we observed APC-specific structure-function relationships with the vectors used during gene delivery that differ from current non-APC cell lines, thus, emphasizing a need to re-evaluate vector-associated parameters in the context of APC gene transfer. Thus, we describe the synthesis and characterization of a second-generation mannosylated poly(β-amino ester) library stratified by molecular weight. To better understand the APC-specific structure-function relationships governing polymeric gene delivery, the library was systematically characterized by (1) polymer molecular weight, (2) relative mannose content, (3) polyplex biophysical properties, and (4) gene delivery efficacy. In this library, polymers with the lowest molecular weight and highest relative mannose content possessed gene delivery transfection efficiencies as good as or better than commercial controls. Among this group, the most effective polymers formed the smallest polymer-plasmid DNA complexes (∼300 nm) with moderate charge densities (<10 mV). This convergence in polymer structure and polyplex biophysical properties suggests a unique mode of action and provides a framework within which future APC-targeting polymers can be designed.

In situ pneumococcal vaccine production and delivery through a hybrid biological-biomaterial vector

“…The polymer used in this study, D4A4-Man, was synthesized in a four-step reaction as previously described (fig. S7) ( 3 , 4 , 18 , 19 ). Briefly, in step 1, allyl-α- d -mannopyranoside (ADM) was synthesized by dissolving 3 g of d (+)-mannose and 18 mg of p -toluenesulfonyl chloride in allyl alcohol (20 ml) at 90°C under reflux for 24 hours.…”

Influence of molecular weight upon mannosylated bio-synthetic hybrids for targeted antigen presenting cell gene delivery

“…Aside from gene delivery, polymer addition improved hybrid-mediated cytotoxicity in a dose-dependent manner (Figure 3B) and with exception of a few polymers (D3mA5, D5A4, and D5A4-Man), mediated negligible cytotoxicity (>95% viability) at the highest polymer dose. Decreased cytotoxicity is the result of positive polymer degradation properties [19, 20] and charge-mediated bacterial attenuation [21]. …”

Extended Polysaccharide Analysis within the Liposomal Encapsulation of Polysaccharides System

“…Such downstream formulation steps likely influenced the structural integrity of the liposomal construct, as we also observed previously [ 20 ] (as opposed to the more passive encapsulation of polysaccharide within newly formed liposomes), thus exacerbating differences observed upon initial polysaccharide liposomal encapsulation. Variation in liposomal encapsulation likely also reflects inherent differences in polysaccharide molecular weight and chemical structure, noting that similar variation in polymeric macromolecules can have a strong influence on vaccine delivery vehicles [ 29 , 30 ]. Though liposomal size and Zeta potential remain relatively stable, variations observed (especially for surface charge) are likely correlated to protein/alum addition and the corresponding impact upon polysaccharide encapsulation.…”