Development of chitosan nanoparticles for anticancer drug delivery systems

Chitosan is a natural polymer that is often used in nanotechnology because it has such useful properties as biodegradability and biocompatibility. Chitosan has many benefits, but they are outweighed by drawbacks such insolubility, aggregation at physiological pH, and insufficient cargo release in the cytosol. In order to obtain chitosan nanoparticles that can be used as drug delivery systems, we optimized the synthesis technology by selecting MES buffer pH 6.3 and using a BSA coating step to reduce nanoparticle aggregation. Deposition of the chemotherapeutic agent etoposide in chitosan nanoparticles has been proven and confirmed by IR spectra, although future experiments are needed to tune conditions for stronger interactions. The chitosan nanoparticles that we have obtained can become suitable nanomaterials for biomedical applications as promising carriers for drug delivery

Permafrost Deep Organic Matter: The IPA Yedoma Action Group

Die Action Group "The Yedoma Region: A Synthesis of Circum-Arctic Distribution and Thickness" der Internationalen Permafrost Assoziation (IPA) hat es zum Ziel die Verbreitung und Mächtigkeit von Yedoma Permafrost, einem spätpleitozänen sehr eisreichem Permafrost, zu quantifizieren. Yedoma ist durch Eisgehalte von bis zu 80vol% sehr anfällig gegenüber Erwärmung. Denn wenn das Bodeneis schmilzt und abgeführt wird sind Absenkungen der Bodenoberflächen von mehr als 30 Metern möglich, was deutliche Auswirkungen hat auf die Landschaft, samt Infrastruktur und menschlicher Landnutzung. Als Produkt dieses Projektes möchten wir hier eine circum-arktische Karte präsentieren. Diese Daten werden als Grundlage dazu dienen, den Kohlenstoffpool von Yedoma Ablagerungen realistisch in computergestützte Modelle zu implementieren und die zukünftigen Auswirkungen von Thermokarst und Thermoerosion auf die Treibhausgasemissionen abzuschätzen

Nanomechanical Signatures in Glioma Cells Depend on CD44 Distribution in IDH1 Wild-Type but Not in IDH1R132H Mutant Early-Passage Cultures

Atomic force microscopy (AFM) recently burst into biomedicine, providing morphological and functional characteristics of cancer cells and their microenvironment responsible for tumor invasion and progression, although the novelty of this assay needs to coordinate the malignant profiles of patients’ specimens to diagnostically valuable criteria. Applying high-resolution semi-contact AFM mapping on an extended number of cells, we analyzed the nanomechanical properties of glioma early-passage cell cultures with a different IDH1 R132H mutation status. Each cell culture was additionally clustered on CD44+/− cells to find possible nanomechanical signatures that differentiate cell phenotypes varying in proliferative activity and the characteristic surface marker. IDH1 R132H mutant cells compared to IDH1 wild-type ones (IDH1wt) characterized by two-fold increased stiffness and 1.5-fold elasticity modulus. CD44+/IDH1wt cells were two-fold more rigid and much stiffer than CD44-/IDH1wt ones. In contrast to IDH1 wild-type cells, CD44+/IDH1 R132H and CD44-/IDH1 R132H did not exhibit nanomechanical signatures providing statistically valuable differentiation of these subpopulations. The median stiffness depends on glioma cell types and decreases according to the following manner: IDH1 R132H mt (4.7 mN/m), CD44+/IDH1wt (3.7 mN/m), CD44-/IDH1wt (2.5 mN/m). This indicates that the quantitative nanomechanical mapping would be a promising assay for the quick cell population analysis suitable for detailed diagnostics and personalized treatment of glioma forms

Development of chitosan nanoparticles for anticancer drug delivery systems

Chitosan is a natural polymer that is often used in nanotechnology because it has such useful properties as biodegradability and biocompatibility. Chitosan has many benefits, but they are outweighed by drawbacks such insolubility, aggregation at physiological pH, and insufficient cargo release in the cytosol. In order to obtain chitosan nanoparticles that can be used as drug delivery systems, we optimized the synthesis technology by selecting MES buffer pH 6.3 and using a BSA coating step to reduce nanoparticle aggregation. Deposition of the chemotherapeutic agent etoposide in chitosan nanoparticles has been proven and confirmed by IR spectra, although future experiments are needed to tune conditions for stronger interactions. The chitosan nanoparticles that we have obtained can become suitable nanomaterials for biomedical applications as promising carriers for drug delivery

Development of chitosan nanoparticles for anticancer drug delivery systems

Chitosan is a natural polymer that is often used in nanotechnology because it has such useful properties as biodegradability and biocompatibility. Chitosan has many benefits, but they are outweighed by drawbacks such insolubility, aggregation at physiological pH, and insufficient cargo release in the cytosol. In order to obtain chitosan nanoparticles that can be used as drug delivery systems, we optimized the synthesis technology by selecting MES buffer pH 6.3 and using a BSA coating step to reduce nanoparticle aggregation. Deposition of the chemotherapeutic agent etoposide in chitosan nanoparticles has been proven and confirmed by IR spectra, although future experiments are needed to tune conditions for stronger interactions. The chitosan nanoparticles that we have obtained can become suitable nanomaterials for biomedical applications as promising carriers for drug delivery

Nanomechanical Signatures in Glioma Cells Depend on CD44 Distribution in IDH1 Wild-Type but Not in IDH1R132H Mutant Early-Passage Cultures

Atomic force microscopy (AFM) recently burst into biomedicine, providing morphological and functional characteristics of cancer cells and their microenvironment responsible for tumor invasion and progression, although the novelty of this assay needs to coordinate the malignant profiles of patients’ specimens to diagnostically valuable criteria. Applying high-resolution semi-contact AFM mapping on an extended number of cells, we analyzed the nanomechanical properties of glioma early-passage cell cultures with a different IDH1 R132H mutation status. Each cell culture was additionally clustered on CD44+/− cells to find possible nanomechanical signatures that differentiate cell phenotypes varying in proliferative activity and the characteristic surface marker. IDH1 R132H mutant cells compared to IDH1 wild-type ones (IDH1wt) characterized by two-fold increased stiffness and 1.5-fold elasticity modulus. CD44+/IDH1wt cells were two-fold more rigid and much stiffer than CD44-/IDH1wt ones. In contrast to IDH1 wild-type cells, CD44+/IDH1 R132H and CD44-/IDH1 R132H did not exhibit nanomechanical signatures providing statistically valuable differentiation of these subpopulations. The median stiffness depends on glioma cell types and decreases according to the following manner: IDH1 R132H mt (4.7 mN/m), CD44+/IDH1wt (3.7 mN/m), CD44-/IDH1wt (2.5 mN/m). This indicates that the quantitative nanomechanical mapping would be a promising assay for the quick cell population analysis suitable for detailed diagnostics and personalized treatment of glioma forms

Cobalt(II) Complexes Based on Benzylmalonate Anions Exhibiting Field-Induced Single-Ion Magnet Slow Relaxation Behavior

The reaction of (NBu4)2Bzmal (where Bzmal2− is benzylmalonate dianion) with Co(OAc)2∙4H2O gives the [Co(Bzmal)(EtOH)(H2O)]n 2D-polymer (1). The addition of 2,2′-bipyridine (bpy) to the starting system results in the [Co(Bzmal)(bpy)2]·H2O·EtOH molecular complex (2). Their molecular and crystal structures were analyzed by single-crystal X-ray crystallography. An analysis of the static magnetic data supported by the SA-CASSCF/NEVPT2 calculations revealed the presence of easy-plane magnetic anisotropy in both complexes. The AC susceptibility data confirm that both complexes show a slow field-induced (HDC = 1000 Oe) magnetic relaxation behavior

Cell and Tissue Nanomechanics: From Early Development to Carcinogenesis

Cell and tissue nanomechanics, being inspired by progress in high-resolution physical mapping, has recently burst into biomedical research, discovering not only new characteristics of normal and diseased tissues, but also unveiling previously unknown mechanisms of pathological processes. Some parallels can be drawn between early development and carcinogenesis. Early embryogenesis, up to the blastocyst stage, requires a soft microenvironment and internal mechanical signals induced by the contractility of the cortical actomyosin cytoskeleton, stimulating quick cell divisions. During further development from the blastocyst implantation to placenta formation, decidua stiffness is increased ten-fold when compared to non-pregnant endometrium. Organogenesis is mediated by mechanosignaling inspired by intercellular junction formation with the involvement of mechanotransduction from the extracellular matrix (ECM). Carcinogenesis dramatically changes the mechanical properties of cells and their microenvironment, generally reproducing the structural properties and molecular organization of embryonic tissues, but with a higher stiffness of the ECM and higher cellular softness and fluidity. These changes are associated with the complete rearrangement of the entire tissue skeleton involving the ECM, cytoskeleton, and the nuclear scaffold, all integrated with each other in a joint network. The important changes occur in the cancer stem-cell niche responsible for tumor promotion and metastatic growth. We expect that the promising concept based on the natural selection of cancer cells fixing the most invasive phenotypes and genotypes by reciprocal regulation through ECM-mediated nanomechanical feedback loop can be exploited to create new therapeutic strategies for cancer treatment

Synthesis, Structure and Photoluminescence Properties of Cd and Cd-Ln Pentafluorobenzoates with 2,2′:6′,2′-Terpyridine Derivatives

Six new complexes [Cd(tpy)(pfb)2] (1, tpy = 2,2′:6′,2″-terpyridine), [Ln2Cd2(tpy)2(pfb)10] (Ln = Eu (2Eu), Tb (2Tb)), [Ln2Cd2(tbtpy)2(pfb)10]·2MeCN (Ln = Eu (3Eu), Tb (3Tb), tbtpy = 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine), [Eu2Cd2(tppz)(pfb)10]n (4, tppz = 2,3,5,6-tetra-(pyridin-2-yl)pyrazine) based on pentafluorobenzoic acid (Hpfb) have been prepared and investigated. The effect of tridentate ligands on geometry heterometallic scaffolds synthesized complexes is discussed. The supramolecular crystal structures of the new compounds are stabilized by π-π, C-F···π, C-H···O, C-H...F, F….F interactions. Non-covalent interactions have been studied using Hirschfeld surface analysis. The obtained compounds were characterized by single-crystal and powder X-ray diffraction, luminescence spectroscopy, IR spectroscopy, CHN analysis. Complexes 2Ln and 3Ln exhibit metal-centered photoluminescence, but the presence of ligand luminescence bands indicates incomplete energy transfer from the d-block to the lanthanide ion