Reactive Nanoparticles Derived from Polysaccharide Phenyl Carbonates

Abstract

Polysaccharide (PS) based nanoparticles (NP) are of great interest for biomedical applications. A key challenge in this regard is the functionalization of these nanomaterials. The aim of the present work was the development of reactive PS-NP that can be coupled with an amino group containing compounds under mild aqueous conditions. A series of cellulose phenyl carbonates (CPC) and xylan phenyl carbonates (XPC) with variable degrees of substitution (DS) was obtained by homogeneous synthesis. The preparation of PS-NP by self-assembling of these hydrophobic derivatives was studied comprehensively. While CPC mostly formed macroscopic aggregates, XPC formed well-defined spherical NP with diameters around 100 to 200 nm that showed a pronounced long-term stability in water against both particle aggregation as well as cleavage of phenyl carbonate moieties. Using an amino group functionalized dye it was demonstrated that the novel XPC-NP are reactive towards amines. A simple coupling procedure was established that enables direct functionalization of the reactive NP in an aqueous dispersion. Finally, it was demonstrated that dye functionalized XPC-NP are non-cytotoxic and can be employed in advanced biomedical applications.

Composite nanoparticles derived by self-assembling of hydrophobic polysaccharide derivatives and lignin

“…The aqueous lignin particle dispersions also displayed a much more pronounced tendency towards sedimentation compared to the other experiments. For particles obtained by dialysis of PS derivatives, smaller particles (CA: 200 to 270 nm, NP 4, 7, and 11; XPC: 130 to 200 nm, NP 15, 18, and 22; CAPh: 270 to 400 nm, NP 16, 29, and 33) with a narrower size distribution (PDI ≤ 0.2) were obtained, which is in accordance with previous reports (Schulze et al 2016(Schulze et al , 2019aGericke et al 2021).…”

“…The PDI values were ≤ 0.2 in almost all experiments and 0.3 when the highest lignin mass concentrations of 4 mg/ml were employed. XPC on its own has been reported to form well-defined PS-NPs (Gericke et al 2021). The present findings indicate that lignin is well incorporated within the XPC nanomatrix.…”

“…This behavior can be exploited to create stimuli responsive NPs, e.g., for drug release purposes (Wang et al 2016). XPC has been reported to form very stable reactive PS-NPs with a narrow size distribution that enable direct functionalization of the particles, e.g., with dyes and proteins (Gericke et al 2021). Organosolv lignin from Miscanthus x giganteus was employed in this study because of its a comparably high purity (e.g., regarding residual PS) and narrow molecular weight distribution (Rumpf et al 2020).…”

Direct Functionalization of Polysaccharide‐Based Xylan Phenyl Carbonate Nanoparticles with Tumor Cell Specific Antibodies

“…This last step was performed with an excess of reagent (about 3 equivalents per reactive group in the whole bulk material) to block the remaining reactive XPC moieties and avoid undesired reactions in the biological experiments such as binding of proteins in vivo . Previous experiments have demonstrated that this approach does not impact the particle size and shape and yields biocompatible NP [14b] . For unmodified XPC‐NP, a mean particle diameter of 250 nm was determined by DLS measurements (Figure 4).…”

“…In addition, dye‐labeled XPC‐NP were of interest in order to later visualize the tumor cell targeting upon antibody conjugation. It has been demonstrated previously that XPC‐NP are reactive towards compounds with amino moieties, which enabled direct immobilization of dyes on the particle surface subsequent to NP preparation by the dialysis approach [14b] . However, this could potentially block some of the reactive PC moieties that are required for the later immobilization of antibodies.…”