Targeting of the Mitochondrial TET1 Protein by Pyrrolo[3,2-b]pyrrole Chelators.

Targeting of epigenetic mechanisms, such as the hydroxymethylation of DNA, has been intensively studied, with respect to the treatment of many serious pathologies, including oncological disorders. Recent studies demonstrated that promising therapeutic strategies could potentially be based on the inhibition of the TET1 protein (ten-eleven translocation methylcytosine dioxygenase 1) by specific iron chelators. Therefore, in the present work, we prepared a series of pyrrolopyrrole derivatives with hydrazide (1) or hydrazone (2-6) iron-binding groups. As a result, we determined that the basic pyrrolo[3,2-b]pyrrole derivative 1 was a strong inhibitor of the TET1 protein (IC50 = 1.33 µM), supported by microscale thermophoresis and molecular docking. Pyrrolo[3,2-b]pyrroles 2-6, bearing substituted 2-hydroxybenzylidene moieties, displayed no significant inhibitory activity. In addition, in vitro studies demonstrated that derivative 1 exhibits potent anticancer activity and an exclusive mitochondrial localization, confirmed by Pearson's correlation coefficient of 0.92.

In vitro and in vivo testing of nanofibrous membranes doped with alaptide and L-arginine for wound treatment.

We have prepared a candidate biocompatible construct for skin wound healing based on electrospun polycaprolactone (PCL) nanofibrous membranes. The membrane material was loaded either with L-arginine or with alaptide, or with a mixture of both bioactive components. Alaptide is a spirocyclic synthetic dipeptide, an analogue of melanocyte-stimulating hormone release-inhibiting factor. L-arginine is an amino acid with a basic guanidine side chain. It is a direct precursor of nitric oxide, which plays a pivotal role in skin repair. The presence and the distribution of the additives were proved with high-performance liquid chromatography, Fourier-transform infrared spectroscopy and Raman spectroscopy. The influence of L-arginine and alaptide on the morphology of the membrane was characterized using scanning electron microscopy. No statistically significant correlation between fiber diameter and drug concentration was observed. The membranes were then tested in vitro for their cytotoxicity, using primary human dermal fibroblasts, in order to obtain the optimal concentrations of the additives for in vivo tests in a rat model. The membranes with the highest concentration of L-arginine (10 wt. %) proved to be cytotoxic. The membranes with alaptide in concentrations from 0.1 to 2.5 wt.%, and with the other L-arginine concentrations (1 and 5 wt.%), did not show high toxicity. In addition, there was no observed improvement in cell proliferation on the membranes. The in vivo experiments revealed that membranes with 1.5 wt.% of alaptide or with 1.5 wt.% of alaptide in combination with 5 wt.% of L-arginine markedly accelerated the healing of skin incisions, and particularly the healing of skin burns, i.e. wounds of relatively large extent. These results indicate that our newly-developed nanofibrous membranes are promising for treating wounds with large damaged areas, where a supporting material is needed.

Raman spectroscopic discrimination of normal and cancerous lung tissues.

Raman spectroscopy is non-destructive method that allows monitoring of biological tissues with minimal intervention. FT-Raman (λex 1064 nm) and NIR-Vis-Raman (λex 785 nm) spectroscopic measurements were used in ex vivo analysis of normal, non-cancerous abnormal and cancerous lung tissues. Spectroscopic discrimination of the lung tissue samples was made by the use of the ratio of characteristic bands and multivariate statistical methods (PCA, LDA). The combination of Raman spectroscopy and multivariate statistics may have a diagnostic potential for recognizing of cancer lesions in lung.

Silica-based nanoparticles are efficient delivery systems for temoporfin.

BACKGROUND: Drug targeting using functionalized nanoparticles to advance their transport to the dedicated site became a new standard in novel anticancer methods Anticancer photodynamic therapy also takes benefit from using nanoparticles by means of increasing targeting efficiency and decreased side effect. With this in mind, the silica-based nanoparticles, as drug delivery systems for the second-generation photosensitizer 5,10,15,20-tetrakis(m-hydroxyphenyl) chlorin (temoporfin) were developed. METHODS: In order to determine the stability and therapeutic performance of the selected nanomaterials in physiological fluids, their physicochemical properties (i.e. size, polydispersity, zeta potential) were measured by dynamic light scattering technique and the diameter and the morphology of the individual particles were visualized by a transmission electron microscopy. Their efficacy was compared with commercial temoporfin formulation in terms of in vitro phototoxicity in 4T1 (murine mammary carcinoma) and of in vivo anticancer effect in Nu/Nu mice bearing MDA-MB-231 tumors. RESULTS AND CONCLUSIONS: The two types of silica nanoparticles, porous and non-porous and with different surface chemical modification, were involved and critically compared within the study. Their efficacy was successfully demonstrated and was shown to be superior in comparison with commercial temoporfin formulation in terms of in vitro phototoxicity and cellular uptake as well as in terms of in vivo anticancer effect on human breast cancer model. Temoporfin-loaded silica nanoparticles also passed through the blood-brain barrier showing potential for the treatment of brain metastases.