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Raweewan Thiramanas1,2 ,* Shuai Jiang2 ,* Johanna Simon,1,2 Katharina Landfester,2 Volker Mailänder1,2 1Dermatology Clinic, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz 55131, Germany; 2Physical Chemistry of Polymers, Max Planck Institute for Polymer Research, Mainz, 55128, Germany*These authors contributed equally to this workCorrespondence: Katharina Landfester; Volker Mailänder Email landfest@mpip-mainz.mpg.de; mailaend@mpip-mainz.mpg.deIntroduction: Adoptive T-cell immunotherapy emerged as a powerful and promising cancer therapy, as the problem regarding the immuno-reaction between different donors and recipients can be avoided. However, this approach is challenging. After long cultivation and expansion under laboratory media conditions, T-cells are losing their viability and function due to immune checkpoint proteins, leading to decreased efficiency in killing cancer cells. Therefore, a new strategy to improve T-cell survival and function is needed. With the advantages of nanotechnology and the biocompatibility of silica-based material, silica nanocapsules (SiNCs) provide an ideal delivery system to transport therapeutic biomolecules to T-cells. Up to now, there is a lack of cellular uptake studies of nanocarriers towards T-cells.Methods: We systematically studied the influence of various physicochemical properties such as sizes, core hydrophobicities, surface charges, and surface functionalities of SiNC for their impact on cellular uptake and toxicity in CD8+ T-cells by flow cytometry and confocal laser scanning microscopy. Cytokine secretion assay was performed using the enzyme-linked immunosorbent assay. To identify suitable uptake conditions for SiNCs into CD8+ T-cells, the impact of human serum in cell culture medium was also investigated.Results: The major impact on cellular uptake and toxicity was found to be size- and dose-dependent. Smaller sizes of SiNCs than 100 nm caused significant toxicity to the cells. It was found that the formed protein corona reduced the toxicity of the SiNCs. However, it also inhibited their uptake.Conclusion: Overall, we present a set of different criteria for a suitable design of nanocarriers and cell culture conditions, which need to be carefully considered for T-cell immunotherapy in vitro to facilitate uptake while avoiding toxicity.Keywords: silica nanocapsule, T-cells, nanocarriers, cellular uptake, toxicity, protein corona

Verena Grützner,1 Ronald E Unger,1 Grit Baier,2 Lars Choritz,3 Christian Freese,1 Thomas Böse,1 Katharina Landfester,2 C James Kirkpatrick11REPAIR-Lab, Institute of Pathology, University Medical Center, Mainz, 2Max Planck Institute for Polymer Research, Mainz, Germany; 3Department of Ophthalmology, University Clinic, Magdeburg, GermanyAbstract: Responsive, theranostic nanosystems, capable of both signaling and treating wound infections, is a sophisticated approach to reduce the most common and potentially traumatizing side effects of burn wound treatment: slowed wound healing due to prophylactic anti-infective drug exposure as well as frequent painful dressing changes. Antimicrobials as well as dye molecules have been incorporated into biodegradable nanosystems that release their content only in the presence of pathogens. Following nanocarrier degradation by bacterial enzymes, any infection will thus emit a visible signal and be effectively treated at its source. In this study, we investigated the effect of fluorescent-labeled hyaluronan nanocapsules containing polyhexanide biguanide and poly-L-lactic acid nanoparticles loaded with octenidine on primary human dermal microvascular endothelial cells, which play a major role in cutaneous wound healing. Microscopic and flow cytometric analysis indicated a time-dependent uptake of both the nanocapsules and the nanoparticles. However, enzyme immunoassays showed no significant influence on the expression of pro-inflammatory cell adhesion molecules and cytokines by the endothelial cells. Under angiogenic-stimulating conditions, the potential to form capillary-like structures in co-culture with dermal fibroblasts was not inhibited. Furthermore, cytotoxicity studies (the MTS and crystal violet assay) after short- and long-term exposure to the materials demonstrated that both systems exhibited less toxicity than solutions of the antiseptic agents alone in comparable concentrations. The results indicate that responsive antimicrobial nanocomposites could be used as an advanced drug delivery system and a promising addition to current best practice wound infection prophylaxis with few side effects.Keywords: enzyme-responsive nanosystems, burn wound infection, endothelial cells, wound healing

Stephanie Tomcin,1 Grit Baier,1 Katharina Landfester,1 Volker Mailänder1,21Max Planck Institute for Polymer Research, 2University Medical Center of the Johannes Gutenberg University, III Medical Clinic, Mainz, GermanyAbstract: For successful design of a nanoparticulate drug delivery system, the fate of the carrier and cargo need to be followed. In this work, we fluorescently labeled poly(n-butylcyanoacrylate) (PBCA) nanocapsules as a shell and separately an oligonucleotide (20 mer) as a payload. The nanocapsules were formed by interfacial anionic polymerization on aqueous droplets generated by an inverse miniemulsion process. After uptake, the PBCA capsules were shown to be round-shaped, endosomal structures and the payload was successfully released. Cy5-labeled oligonucleotides accumulated at the mitochondrial membrane due to a combination of the high mitochondrial membrane potential and the specific molecular structure of Cy5. The specificity of this accumulation at the mitochondria was shown as the uncoupler dinitrophenol rapidly diminished the accumulation of the Cy5-labeled oligonucleotide. Importantly, a fluorescence resonance energy transfer investigation showed that the dye-labeled cargo (Cy3/Cy5-labeled oligonucleotides) reached its target site without degradation during escape from an endosomal compartment to the cytoplasm. The time course of accumulation of fluorescent signals at the mitochondria was determined by evaluating the colocalization of Cy5-labeled oligonucleotides and mitochondrial markers for up to 48 hours. As oligonucleotides are an ideal model system for small interfering RNA PBCA nanocapsules demonstrate to be a versatile delivery platform for small interfering RNA to treat a variety of diseases.Keywords: drug delivery, mitochondria, miniemulsion, colocalization

We present here an experimental and theoretical study of the application of two-dimensional exchange nuclear magnetic resonance spectroscopy (NMR) to the investigation of the rotational diffusion of colloidal particles. The theoretical discussion includes the nature of the NMR frequency time-correlation function where the NMR interaction is represented by the chemical shift anisotropy (CSA). Time-correlation functions for the isotropic rotational diffusion of a suspension of colloidal particles containing single and multiple sites are derived in addition to time-correlation functions for the rotational diffusion of a suspension of symmetric top particles containing an isotropic distribution of a single CSA interaction. Simulations of two-dimensional exchange spectra for particles undergoing isotropic rotational diffusion are presented. We performed two-dimensional exchange NMR experiments on a colloidal suspension of spherical poly(methyl methacrylate) (PMMA) particles which were synthesized with a 20% enrichment in 13C at the carbonyl site. Rotational diffusion time-correlation functions determined from the experimental exchange spectra are consistent with the composition of the colloidal suspension. Detailed explanations of the syntheses of the enriched methyl 13C-(carbonyl)-methacrylate monomer and the small quantities of 20% enriched 13C-(carbonyl)-poly(methyl methacrylate) microspheres used for this study are presented. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]