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In the treatment of obesity, nutritional and behavioral modifications are difficult to implement and maintain. Since vegetable consumption is a fundamental part of many dietary interventions and daily nutrient requirements, we developed a novel cellulose-based superabsorbent hydrogel (CB-SAH) platform, inspired by the composition and mechanical properties of raw vegetables, as a mechanobiological therapy. The CB-SAHs properties were studied in a simulated gastrointestinal environment, while their impact on gut tissue was investigated by an ex vivo organ culture (EVOC) model. Functional fibers and raw vegetables were used as reference. CB-SAHs demonstrated orders of magnitude higher elasticity in comparison to the tested functional fibers, however performed similar to the tested raw vegetables. Notably, the biomimetic CB-SAHs with elasticity levels similar to raw vegetables showed benefits in preserving and regulating the gut tissue in the EVOC model. Non-systemic oral mechanotherapeutics based on this technology were advanced through clinical studies, with a first product cleared as an aid for weight management in the US and Europe., (© 2021. The Author(s).)

Herein, we propose the fabrication of a new carrier with core/shell structure-inner core of cellulose acetate (CA) coated by a micrometric layer of chitosan (CS)-fabricated through an integrated process, which combines Electro Dynamic Atomization (EDA) and layer-by-layer (LbL) technique. We demonstrate that CA based microspheres possess a unique capability to relevantly retain the drugs-that is, Ketoprofen Lysinate (KL)-along the gastric tract, while providing a massive release along the intestine. CS shell slightly influences the morphology and water retention under different pH conditions, improving drug encapsulation without compromising drug release kinetics. In vitro studies in simulated gastric and intestine fluids (SGF, SIF) with physiological enzymes, show a moderate release of LSK during the first 2 h (ca. 20% at pH 2), followed by a sustained release during the next 6 h (ca. 80% at pH 7). The obtained results demonstrate that CA-based microspheres hold strong potential to be used as carriers for a delayed oral administration of anti-inflammatory drugs. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2636-2644, 2018., (© 2018 Wiley Periodicals, Inc.)

Physical foaming combined with microwave-induced curing was used in this study to develop an innovative device for bone tissue regeneration. In the first step of the process, a stable physical foaming was induced using a surfactant (i.e. pluronic) as blowing agent of a homogeneous blend of Sodium salt of carboxymethylcellulose (CMCNa) and polyethylene glycol diacrylate (PEGDA700) solution. In the second step, the porous structure of the scaffold was chemically stabilized by radical polymerization induced by a homogeneous rapid heating of the sample in a microwave reactor. In this step 2,2-Azobis[2-(2-imidazolin-2 yl)propane]Dihydrochloride was used as thermoinitiator (TI). CMCNa and PEGDA were mixed with different blends to correlate the properties of final product with the composition. The chemical properties of each sample were evaluated by spectroscopy analysis ATR-IR (before and after curing) in order to maximize reaction yield, and optimize kinetic parameters (i.e. time curing, microwave power). The stability of the materials was evaluated in vitro by degradation test in Phosphate Buffered Saline. Biological analyses were performed to evaluate the effect of scaffold materials on cellular behavior in terms of proliferation and early osteogenic differentiation of human Mesenchymal Stem Cells. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 726-733, 2016., (© 2015 Wiley Periodicals, Inc.)

Purpose: The aim of this project was to study the proliferation and differentiation of human Mesenchymal Stem Cells (hMSCs) onto a cellulose-based hydrogel for bone tissue engineering., Methods: Modified-cellulose hydrogel was prepared via double esterification crosslinking using citric acid. The response of human Mesenchymal Stem Cells (hMSCs) in terms of cell proliferation and differentiation into osteoblastic phenotype was evaluated by using Alamar blue assay and Alkaline phosphatase activity., Results: The results showed that CMCNa and CMCNa_CA have no negative effect on hMSC, adhesion and proliferation. Moreover, the increase of the ALP expression for CMCNa_CA confirms the ability of the hydrogels to support the osteoblastic differentiation., Conclusions: The cellulose-based hydrogels have a potential application as filler in bone tissue regeneration.

In the present study, we have produced a sodium carboxymethylcellulose (CMC) hydrogel from a bacterial cellulose etherification reaction with chloroacetic acid in an alkaline medium. Bacterial cellulose (BC) was synthesized via economical and environmentally friendly methods using the Gluconacetobacter xylinus bacterium. After purification, freeze-drying, and milling, BC microparticles were dispersed in NaOH solution for different time periods before the etherification reaction. This has allowed the understanding of the alkalinization effect on BC modification. All synthesized CMC were soluble in water, and FTIR and XRD analyses confirmed the etherification reaction. The bath of BC in NaOH solution affects both molecular weight and degree of substitution. SEM analysis revealed the change of BC microstructure from fibrous-like to a smooth, uniform structure. The CMC-0 h allowed the production of crosslinked hydrogel after dehydrothermal treatment. Such hydrogel has been characterized rheologically and has shown a water absorption of 35 times its original weight. The optimization of the CMC produced from BC could pave the way for the production of ultrapure hydrogel to be applied in the healthcare and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Abstract: Biodegradable cellulose-based hydrogels are attracting increasing interest in the academic and industrial fields thanks to their high swelling capacity and reproducibility, which allow many novel applications. These properties are enabled by amplification effect of their sensitiveness on a molecular level, translated into macroscopic effects such as a change in swelling degree. The monitoring of the hydrogel state is a crucial step for understanding the response of the hydrogel to external environment. Accordingly, the major aim of this study is to exploit ultrasound to characterize the swelling and degradation of cellulose-based hydrogel with different blend of molecular weight and degree of substitutions. The ultrasonic sensor used herein relies on the determination of a Pulse-echo time of flight. This technique provides dimensional information, thanks to its capability of monitoring the thickness of the swollen/unswollen hydrogel during sorption mechanism. Furthermore, by combining these data with a rheological characterization, the degree of crosslink and its modification during multiple swelling/deswelling cycles (due to ion strength variation) has been monitored. This technique could be an effective, alternative, fast and non-destructive method for real-time hydrogel characterization.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Physical foaming combined with microwave-induced curing was used in this study to develop an innovative device for bone tissue regeneration. In the first step of the process, a stable physical foaming was induced using a surfactant (i.e. pluronic) as blowing agent of a homogeneous blend of Sodium salt of carboxymethylcellulose (CMCNa) and polyethylene glycol diacrylate (PEGDA700) solution. In the second step, the porous structure of the scaffold was chemically stabilized by radical polymerization induced by a homogeneous rapid heating of the sample in a microwave reactor. In this step 2,2-Azobis[2-(2-imidazolin-2 yl)propane]Dihydrochloride was used as thermoinitiator (TI). CMCNa and PEGDA were mixed with different blends to correlate the properties of final product with the composition. The chemical properties of each sample were evaluated by spectroscopy analysis ATR-IR (before and after curing) in order to maximize reaction yield, and optimize kinetic parameters (i.e. time curing, microwave power). The stability of the materials was evaluated in vitro by degradation test in Phosphate Buffered Saline. Biological analyses were performed to evaluate the effect of scaffold materials on cellular behavior in terms of proliferation and early osteogenic differentiation of human Mesenchymal Stem Cells. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 726-733, 2016. [ABSTRACT FROM AUTHOR]

In this work, an innovative cellulose-based superabsorbent polymer (SAP) was experimentally assessed as an environmentally friendly alternative to acrylate-based SAPs, for the optimization of water consumption in agriculture. The cellulose-based SAP was synthesized and tested for its swelling capability in different aqueous media. The effectiveness of the SAP in agricultural applications was then evaluated by analyzing its performance after several absorption/desorption cycles, over a period of approximately 80 days, upon addition to different types of soil, i.e., white and red soil, for the cultivation of two varieties of plants typical of the Mediterranean area (tomatoes and chicory). The results confirmed that SAP-amended soil can store a considerable amount of water and can release it gradually to the plant roots when needed. The adoption of the proposed SAP in cultivations could thus represent a promising solution for the rationalization of water resources, especially in desert areas. [ABSTRACT FROM AUTHOR]

The article presents a study on the synthesis of cellulose-based hydrogels from pharmaceutical and food grade cellulose derivatives . The researchers showed that such hydrogels have good swelling properties in water solutions mimicking the environmental conditions of the stomach and the intestine and good biocompatibility. The experimental results indicated that cellulose-based hydrogels might be a scientifically valid dietary adjuvant in treating obesity and overweight.

Tissue mimicking phantoms have been widely reported to be an important tool for development, optimisation and performance testing of ultrasound-based diagnostic techniques. In particular, modern applications of tissue mimicking phantoms often include characterisation of the nonlinear behaviour of experimental ultrasound contrast agents. In such cases, the tissue-mimicking materials should be chosen not only based on the values of their density, speed of sound and attenuation coefficient, but also considering their effect on the appearance of “native harmonics” due to nonlinear distortion of ultrasound signal during propagation. In a previous paper it was demonstrated that a cellulose-based hydrogel is suitable to simulate nonlinear acoustical behaviour of liver tissue for thicknesses up to 8 cm. In this paper we present the experimental characterisation of the nonlinear acoustical behaviour of a different polyethylene glycol diacrylate (PEGDA)-based hydrogel, in order to assess whether and how it can improve the performances and overcome some limitations of the cellulose-based hydrogel as liver tissue-mimicking material. Samples of pig liver tissue, cellulose-based hydrogel and PEGDA-based hydrogel were insonified in a through-transmission set-up, employing 2.25-MHz pulses with different mechanical index (MI) values. Second harmonic and first harmonic amplitudes were extracted from the spectra of received signals and their difference was then used to compare sample behaviours. Obtained results show how a new more accurate and combined experimental model of linear and nonlinear acoustical behaviour of liver tissue is feasible. In fact, a further confirmation of the cellulose-based hydrogel effectiveness to precisely simulate the liver tissue for penetration depths up to 8 cm was provided, and it was also shown that the employment of the PEGDA-based hydrogel can extend the range of useful tissue-mimicking material thicknesses up to 11 cm, moreover allowing a considerable improvement of the time stability and behaviour reliability of the corresponding manufactured phantoms. [ABSTRACT FROM AUTHOR]

The article discusses a study of the preparation of superabsorbent hydrogels crosslinked with citric acid. The hydrogels were prepared using the cellulose derivatives sodium carboxymethylcellulose (CMCNa) and hydroxyethylcellulose (HEC). The increase in volume variation process in solution is attributed to the carboxylic groups in CMCNa structure. Results indicate the ability of the prepared hydrogel to reduce primary and production costs.

Native harmonics generated by nonlinear distortion of ultrasound during propagation in a medium may cause misinterpretations in spectral analysis when studying contrast agents. The aim of this paper is to quantitatively evaluate nonlinear propagation effects of diagnostic ultrasound pulses in biological tissues and to assess whether a cellulose-based hydrogel can be a suitable material for tissue mimicking purposes. Hydrogel and pig liver tissue samples of various thicknesses were insonified in a through-transmission set-up, employing 2.25-MHz pulses with different mechanical index (MI) values (range 0.06–0.60). Second harmonic and first harmonic amplitudes were extracted from spectra of received signals and their ratio was then used to compare hydrogel and liver behaviours. Resulting trends are very similar for sample thicknesses up to 8 cm and highlight a significant increase in nonlinearity for MI > 0.3, for both liver and hydrogel. A numerical procedure was also employed to calculate pressure distribution along the beam axis: these theoretical results showed a very good agreement with experimental data in the low pressure range, though failed in predicting the MI threshold. In conclusion, the hydrogel resulted to be a suitable material for manufacturing tissue mimicking phantoms, in particular to study contrast agent behaviour with a “low power approach”. [ABSTRACT FROM AUTHOR]