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Injectable in situ forming, biodegradable and extracellular matrix (ECM) mimicking hydrogels have great possibilities in tissue engineering. Simple and easily translated methods, while circumventing toxicity, stability and scale-up issues, are in great demand for the preparation of these hydrogels. This paper aims to investigate how the borate complexation of oxidized carboxymethyl cellulose (CMC), followed by Schiff's reaction with gelatin without using any extraneous cross-linking agents can lead to the development of injectable, cost-effective, biodegradable ECM mimics for cartilage tissue engineering. Tuning of gelation kinetics and cross-linking density of the system is easily achievable by just adjusting the concentration of components. Hydrogels reveal porous structure, biodegradability and biocompatibility with negligible inflammatory response and minimal reactive oxygen species (ROS) generation. The hydrogel integrates well with host cartilage tissue, thereby stabilizing it and preventing further degeneration, which is essential for osteoarthritis management. Migration of chondrocytes seeded on the surface of the gel to the interior is envisaged as a cell attracting property of the matrix to guide tissue repair in cartilage defects. Chondrocytes exhibit cluster formation within the matrix and support proliferation and functionality. These results support the potential of this hydrogel as an injectable cost-effective matrix for cartilage tissue engineering.

Biopolymeric hydrogels that mimic the properties of extracellular matrix have great potential in promoting cellular migration and proliferation for tissue regeneration. The authors reported earlier that rapidly gelling, biodegradable, injectable hydrogels can be prepared by self-crosslinking of periodate oxidized alginate and gelatin in the presence of borax, without using any toxic crosslinking agents. The present paper investigates the suitability of this hydrogel as a minimally invasive injectable, cell-attractive and adhesive scaffold for cartilage tissue engineering for the treatment of osteoarthritis. Time and frequency sweep rheology analysis confirmed gel formation within 20 s. The hydrogel integrated well with the cartilage tissue, with a burst pressure of 70 +/- 3 mmHg, indicating its adhesive nature. Hydrogel induced negligible inflammatory and oxidative stress responses, a prerequisite for the management and treatment of osteoarthritis. Scanning electron microscopy images of primary murine chondrocytes encapsulated within the matrix revealed attachment of cells onto the hydrogel matrix. Chondrocytes demonstrated viability, proliferation and migration within the matrix, while maintaining their phenotype, as seen by expression of collagen type II and aggrecan, and functionality, as seen by enhanced glycosoaminoglycan (GAG) deposition with time. DNA content and GAG deposition of chondrocytes within the matrix can be tuned by incorporation of bioactive signaling molecules such as dexamethasone, chondroitin sulphate, platelet derived growth factor (PDGF-BB) and combination of these three agents. The results suggest that self-crosslinked oxidized alginate/gelatin hydrogel may be a promising injectable, cell-attracting adhesive matrix for neo-cartilage formation in the management and treatment of osteoarthritis. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Iodinated contrast media (ICM) are persistent and ubiquitous water pollutants. Because of their high water solubility and biochemical stability, their phase-separation and recovery from the aquatic environment is very difficult. Here, borate was chosen as a complexing agent of the two diagnostic aids iomeprol and iopamidol in order to provide them with a negative charge and to fix the resulting adducts on Dowex 1X4 ion exchangers. A systematic characterization study of the complex by means of capillary zone electrophoresis and 11B NMR revealed that iomeprol and iopamidol interact with borate anions in aqueous solutions giving a 1:1 single-charged adduct and that the association constant at 25 °C for both contrast agents is highest at pH 10.5. These findings allowed the proper calibration of experimental parameters for further batch adsorption–desorption trials, where the two ICM were shown to be almost completely removed from the water phase and released from the solid sorbents in mild conditions, enabling the recovery of functional resin.

Boron neutron capture therapy (BNCT) is based on the capture of thermal neutrons by boron 10 ((10)B) nuclei that have been selectively delivered to tumor cells. The amount of 10-30 μg of boron for g of tumor mass is needed to attain an acceptable therapeutic advantage. Despite that the potentialities of BNCT have been demonstrated in several preclinical studies, this technique has not yet been fully accepted in the armory of tools for tumor treatment. This is partly due to the differences in the uptake and distribution of (10)B among patients and also to the uncertainty found in the determination of tumor-to-blood (10)B concentration ratio. Attention is now being payed to use the main imaging techniques to determine the in vivo biodistribution of BNCT agents. Most of the work has been devoted to the most promising BNCT agents, namely BPA, BSH and carborane derivatives. This review surveys studies carried out over the last decade, and outlines the role that NMR, PET and SPECT imaging may have to improve the efficacy of BNCT.

A series of newly designed (glycerol)borate based ionic liquids were synthesized and characterized. The synthesis of these ionic liquids involves, first, the preparation of the bis(glycerol)boric acid(s) followed by neutralization with the appropriate base, [cat]OH. Ionic liquids bearing inorganic (Li(+), Na(+), K(+)) or organic cations have been prepared and characterized. The ability of the bis(glycerol)borate anions to undergo dissociation reaction in the presence of water, depending on cation nature, was investigated by NMR. Theoretical calculations were also performed to evaluate the relative stability of the possible bis(glycerol)borate isomers as nude ions or as ion pairs with Li(+), Na(+), and H(+). Important information about the structural features of H[Gly(2)B] useful to rationalize the chemical behavior have been obtained.