Translating innovative nanomaterials to medical products requires efficient manufacturing techniques that enable large-scale high-throughput synthesis and high reproducibility. Drug carriers in... Show moreTranslating innovative nanomaterials to medical products requires efficient manufacturing techniques that enable large-scale high-throughput synthesis and high reproducibility. Drug carriers in medicine embrace a complex subset of tasks calling for multi-functionality. Here, we report the synthesis of pro-drug-loaded core cross-linked polymeric micelles (CCPMs) in a continuous flow process, which combines the commonly separated steps of micelle formation, core cross-linking, functionalization, and purification into a single process. Redox-responsive CCPMs are formed from thiol-reactive polypept(o)ides of polysarcosine-block-poly(S-ethylsulfonyl-l-cysteine) and functional cross-linkers based on dihydrolipoic acid hydrazide for pH-dependent release of paclitaxel. The precisely controlled microfluidic self-assembly and purification process allows the production of spherical micelles (Dh = 35 nm) with low polydispersity values (PDI<0.1) while avoiding toxic organic solvents and additives with unfavorable safety profiles. Self-assembly and cross-linking via slit interdigital micromixers produce 350-700 mg of CCPMs/h per single system, while purification by online tangential flow filtration successfully removes impurities (unimer ≤ 0.5%). The formed paclitaxel-loaded CCPMs possess the desired pH-responsive release profile, display stable drug encapsulation, an improved toxicity profile compared to Abraxane, and therapeutic efficiency in the B16F1-xenotransplanted zebrafish model. The combination of reactive polymers, functional cross-linkers, and microfluidics enables the continuous-flow synthesis of therapeutically active CCPMs in a single process. This article is protected by copyright. All rights reserved. Show less
Alberg, I.; Kramer, S.; Schinnerer, M.; Hu, Q.Z.; Seidl, C.; Leps, C.; ... ; Zentel, R. 2020
The current understanding of nanoparticle-protein interactions indicates that they rapidly adsorb proteins upon introduction into a living organism. The formed protein corona determines thereafter... Show moreThe current understanding of nanoparticle-protein interactions indicates that they rapidly adsorb proteins upon introduction into a living organism. The formed protein corona determines thereafter identity and fate of nanoparticles in the body. The present study evaluates the protein affinity of three core-crosslinked polymeric nanoparticles with long circulation times, differing in the hydrophilic polymer material forming the particle surface, namely poly(N-2-hydroxypropylmethacrylamide) (pHPMA), polysarcosine (pSar), and poly(ethylene glycol) (PEG). This includes the nanotherapeutic CPC634, which is currently in clinical phase II evaluation. To investigate possible protein corona formation, the nanoparticles are incubated in human blood plasma and separated by asymmetrical flow field-flow fractionation (AF4). Notably, light scattering shows no detectable differences in particle size or polydispersity upon incubation with plasma for all nanoparticles, while in gel electrophoresis, minor amounts of proteins can be detected in the particle fraction. Label-free quantitative proteomics is additionally applied to analyze and quantify the composition of the proteins. It proves that some proteins are enriched, but their concentration is significantly less than one protein per particle. Thus, most of the nanoparticles are not associated with any proteins. Therefore, this work underlines that polymeric nanoparticles can be synthesized, for which a protein corona formation does not take place. Show less
