Background and purposeNanogels (NGs) are promising drug delivery tools but are typically limited to hydrophilic drugs. Many potential new drugs are hydrophobic. Our study systematically investigates amphiphilic NGs with varying hydrophobicity, but similar colloidal features to ensure comparability. The amphiphilic NGs used in this experiment consist of a hydrophilic polymer network with randomly distributed hydrophobic groups. For the synthesis we used a new synthetic platform approach. Their amphiphilic character allows the encapsulation of hydrophobic drugs. Importantly, the hydrophilic/hydrophobic balance determines drug loading and biological interactions. In particular, protein adsorption to NG surfaces is dependent on hydrophobicity and critically determines circulation time. Our study investigates how network hydrophobicity influences protein binding, biocompatibility and cellular uptake.MethodsBiocompatibility of the NGs was examined by WST-1 assay in monocytic-like THP-1 cells. Serum protein corona formation was investigated using dynamic light scattering and two-dimensional gel electrophoresis. Proteins were identified by liquid chromatography-tandem mass spectrometry. In addition, cellular uptake was analyzed via flow cytometry.ResultsAll NGs were highly biocompatible. The protein binding patterns for the two most hydrophobic NGs were very similar to each other but clearly different from the hydrophilic ones. Overall, protein binding was increased with increasing hydrophobicity, resulting in increased cellular uptake.ConclusionOur study supports the establishment of structure–property relationships and contributes to the accurate balance between maximum loading capacity with low protein binding, optimal biological half-life and good biocompatibility. This is an important step to derive design principles of amphiphilic NGs to be applied as drug delivery vehicles.

The circadian clock coordinates the timing of several cellular processes including transcription, the cell cycle, and metabolism. Disruptions in the clock machinery trigger the abnormal regulation of cancer hallmarks, impair cellular homeostasis, and stimulate tumourigenesis. Here we investigated the role of a disrupted clock by knocking out or knocking down the core-clock (CC) genes ARNTL, PER2 or NR1D1 in cancer progression (e.g., cell proliferation and invasion) using colorectal cancer (CRC) cell lines HCT116, SW480 and SW620, from different progression stages with distinct clock phenotypes, and identified mechanistic links from the clock to altered cancer-promoting cellular properties. We identified MACC1 (metastasis-associated in colon cancer 1), a known driver for metastasis and an EMT (epithelial-to-mesenchymal transition)-related gene, to be significantly differentially expressed in CC manipulated cells and analysed the effect of MACC1 manipulation (knockout or overexpression) in terms of circadian clock phenotype as well as cancer progression. Our data points to a bi-directional MACC1-circadian clock interplay in CRC, via CC genes. In particular, knocking out MACC1 reduced the period of oscillations, while its overexpression increased it. Interestingly, we found the MACC1 protein to be circadian expressed in HCT116 WT cells, which was disrupted after the knockout of CC genes, and identified a MACC1-NR1D1 protein–protein interaction. In addition, MACC1 manipulation and CC knockout altered cell invasion properties of HCT116 cells, pointing to a regulation of clock and cancer progression in CRC, possibly via the interaction of MACC1 with core-clock genes.

Metastasis represents the most lethal attribute of cancer and critically limits successful therapies in many tumor entities. The clinical need is defined by the fact that all cancer patients, who have or who will develop distant metastasis, will experience shorter survival. Thus, the ultimate goal in cancer therapy is the restriction of solid cancer metastasis by novel molecularly targeted small molecule based therapies. Biomarkers identifying cancer patients at high risk for metastasis and simultaneously acting as key drivers for metastasis are extremely desired. Clinical interventions targeting these key molecules will result in high efficiency in metastasis intervention. In result of this, personalized tailored interventions for restriction and prevention of cancer progression and metastasis will improve patient survival. This review defines crucial biological steps of the metastatic cascade, such as cell dissemination, migration and invasion as well as the action of metastasis suppressors. Targeting these biological steps with tailored therapeutic strategies of intervention or even prevention of metastasis using a wide range of small molecules will be discussed.