A multiple functional supramolecular system for synergetic treatments of hepatocellular carcinoma

In the current times, achieving specific targeted and controllable drug delivery remains one of the major challenges in the treatment of hepatocellular carcinoma (HCC). The present study reported the development of a multiple functional indocyanine green (ICG)-cyclodextrin (CD) system, wherein loaded etoposide (EPS) was used as the model chemotherapeutic drug. In the developed system, ICG segment served as a photosensitizer for photothermal therapy (PTT) and the targeting moiety, which was primarily attributed to the specific retention properties in HCC tissues. The Ex vivo evaluation showed that ICG-CD@EPS exhibited a laser-triggered release profile with the photothermal efficiency and cytotoxicity towards HepG2 cells. In vivo evaluation suggested that ICG could navigate the systems to HCC tissues and retained at the site for 48 h, producing a drug accumulation in HCC. Further, laser irradiation boosted EPS release and local hyperthermia effects in HCC. Thus, the present study explored a novel and specific HCC targeting mechanism, and provided a feasible and controllable strategy for synergistic PTT and chemotherapy treatments for HCC.

Disease-Related Protein Variants of the Highly Conserved Enzyme PAPSS2 Show Marginal Stability and Aggregation in Cells

Cellular sulfation pathways rely on the activated sulfate 3'-phosphoadenosine-5'-phosphosulfate (PAPS). In humans, PAPS is exclusively provided by the two PAPS synthases PAPSS1 and PAPSS2. Mutations found in the PAPSS2 gene result in severe disease states such as bone dysplasia, androgen excess and polycystic ovary syndrome. The APS kinase domain of PAPSS2 catalyzes the rate-limiting step in PAPS biosynthesis. In this study, we show that clinically described disease mutations located in the naturally fragile APS kinase domain are associated either with its destabilization and aggregation or its deactivation. Our findings provide novel insights into possible molecular mechanisms that could give rise to disease phenotypes associated with sulfation pathway genes.

Cellular ATP Levels Determine the Stability of a Nucleotide Kinase

The energy currency of the cell ATP, is used by kinases to drive key cellular processes. However, the connection of cellular ATP abundance and protein stability is still under investigation. Using Fast Relaxation Imaging paired with alanine scanning and ATP depletion experiments, we study the nucleotide kinase (APSK) domain of 3'-phosphoadenosine-5'-phosphosulfate (PAPS) synthase, a marginally stable protein. Here, we show that the in-cell stability of the APSK is determined by ligand binding and directly connected to cellular ATP levels. The observed protein stability change for different ligand-bound states or under ATP-depleted conditions ranges from ΔGf 0 = -10.7 to +13.8 kJ/mol, which is remarkable since it exceeds changes measured previously, for example upon osmotic pressure, cellular stress or differentiation. The results have implications for protein stability during the catalytic cycle of APS kinase and suggest that the cellular ATP level functions as a global regulator of kinase activity.

Polymeric and Lipid Membranes-From Spheres to Flat Membranes and vice versa

Membranes are important components in a number of systems, where separation and control of the flow of molecules is desirable. Controllable membranes represent an even more coveted and desirable entity and their development is considered to be the next step of development. Typically, membranes are considered on flat surfaces, but spherical capsules possess a perfect "infinite" or fully suspended membranes. Similarities and transitions between spherical and flat membranes are discussed, while applications of membranes are also emphasized.

Formaldehyde-free melamine microcapsules as core/shell delivery systems for encapsulation of volatile active ingredients

The release of volatile bioactive molecules, such as fragrances, can be controlled by microencapsulation in core–shell polymeric delivery systems.