The articular cartilage is an avascular and aneural tissue and its injuries result mostly in osteoarthritic changes and formation of fibrous tissue. Efforts of scientists worldwide are focused on restoration of cartilage with increase in life quality of patients. Novel polymeric polyhydroxybutyrate/chitosan (PCH) porous 3D scaffolds were developed and characterized. The rat mesenchymal stem cells (MSCs) were seeded in vitro on PCH scaffolds by a simple filtration of MSCs suspension over scaffolds using syringe. The chondrogenesis of cell-scaffold constructs was carried out in supplemented chondrogenic cultivation medium. After 2 and 4 weeks of in vitro culturing cell-scaffold constructs in chondrogenic differentiation medium, the cartilage extracellular matrix components like glycosaminoglycans and collagens were identified in scaffolds by biochemical assays and histological and immunohistochemical staining. Preliminary in vivo experiments with acellular scaffolds, which filled the artificially created cartilage defect in sheep knee were done and evaluated. Cells released from the bone marrow cavity have penetrated into acellular PCH scaffold in cartilage defect and induced tissue formation similar to hyaline cartilage. The results demonstrated that PCH scaffolds supported chondrogenic differentiation of MSCs in vitro. Acellular PCH scaffolds were successfully utilized in vivo for reparation of artificially created knee cartilage defects in sheep and supported wound healing and formation of hyaline cartilage-like tissue.
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http://dx.doi.org/10.1007/s12010-019-03021-1 | DOI Listing |
Inorg Chem
September 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str., 28, 119991 Moscow, Russia.
A series of structurally similar trinuclear macrocyclic copper(I) and silver(I) pyrazolate complexes bearing various short-bite diphosphine RPCH(R')PR ligands are reported. Upon diphosphine coordination, the planar geometry of the initial complexes undergoes bending along the line between two metal atoms coordinated to the phosphorus moieties. The complexes based on dcpm ligands (R = cyclohexyl, R' = H, Ph) do not exhibit dynamic behavior in solution at room temperature on the P NMR time scale as it was previously observed for similar trinuclear copper complexes bearing the dppm (R = Ph, R' = H) scaffold.
View Article and Find Full Text PDFDalton Trans
June 2024
Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Reaction of a sterically demanding iminophosphorano-phosphine, PhPCHPhPNAr* (here onwards referred to as PCPNAr*; Ar* = 2,6-dibenzhydryl-4-methylphenyl), (1) with [Ru(η--cymene)Cl] yielded three different types of complex, [RuCl{(η--cymene)(PCPNAr*)-κ-}] (2), [RuCl{(P(O)CPNAr*)(κ-,)(-η-arene)}] (3) and [RuCl{(POCPNAr*)(κ-,)(-η-arene)}] (4), depending on the reaction conditions CH activation, tethered η-arene coordination, -metallation or PN bond cleavage/rearrangement reactions. Interestingly, a similar reaction in CHCN in the presence of AgBF resulted in the insertion of CHCN into the PN bond to form a novel metallacycle [Ru(NCMe){(PCPN(CH)CNAr*)-κ-,,}][BF] (5) containing 4- and 5-membered rings an aza-Wittig type reaction. Complex 4 showed very good catalytic activity in the transfer hydrogenation of carbonyl compounds.
View Article and Find Full Text PDFInt J Biol Macromol
July 2024
The First Hospital of Jilin University, Changchun 130000, China. Electronic address:
The continuous stimulation of periodontitis leads to a decrease in the number of stem cells within the lesion area and significantly impairing their regenerative capacity. Therefore, it is crucial to promote stem cell homing and regulate the local immune microenvironment to suppress inflammation for the regeneration of periodontitis-related tissue defects. Here, we fabricated a novel multifunctional bilayer nanofibrous membrane using electrospinning technology.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2024
Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.
The utility of unconventional noncovalent interactions (NCIs) such as chalcogen bonding has lately emerged as a robust platform to access synthetically difficult glycosides stereoselectively. Herein, we disclose the versatility of a phosphonochalcogenide (PCH) catalyst to facilitate access into the challenging, but biologically interesting 7-membered ring α,α'-C-disubstituted oxepane core through an α-selective strain-release C-glycosylation. Methodically, this strategy represents a switch from more common but entropically less desired macrocyclizations to a thermodynamically favored ring-expansion approach.
View Article and Find Full Text PDFJ Am Chem Soc
April 2024
Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227 Dortmund, Germany.
The use of noncovalent interactions (NCIs) has received significant attention as a pivotal synthetic handle. Recently, the exploitation of unconventional NCIs has gained considerable traction in challenging reaction manifolds such as glycosylation due to their capacity to facilitate entry into difficult-to-access sugars and glycomimetics. While investigations involving oxacyclic pyrano- or furanoside scaffolds are relatively common, methods that allow the selective synthesis of biologically important iminosugars are comparatively rare.
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