Swelling Velocity Research Articles

(Digital Presentation) 4D Printing of Inter-Crosslinking Network Structure Gel with Hinge Structure

4D printing [1] is a new interdisciplinary research area made possible by the merger of scientific developments in additive manufacturing and smart materials [2]. It is a technology that allows 3D printed objects to be deformed over time by applying specific external stimuli [3] and is currently attracting attention as a technology to program biological-like movements into the internal structure of 3D printed objects. In previous research, the movement and deformation of the model has been controlled by devising the shape of the structure, such as a bilayer structure consisting of two materials with different physical properties [4]. However, it is difficult to realize the deformation in different directions simultaneously. The purpose of this research is to develop a 4D printing technology that can simultaneously deform each part of the same object in any direction.To develop a 4D printing technology that can simultaneously deform each part of the same object in any direction, we analyzed the principle of 4D printing by swelling. We measured the swelling rate, swelling speed, compression test, and deformation amount in order to investigate the effects of material and laser irradiation frequency. As a result, it was confirmed that the swelling rate and swelling velocity increased when the amount of the initiator, TPO, was increased from a specific laser irradiation frequency. It was also confirmed that the Young's modulus increased with the increase in the number of laser irradiation. Finally, based on these results, the deformation was measured by varying the amount of initiator and the number of laser irradiations, and it was confirmed that the deformation increased with increasing the amount of initiator and the specific number of irradiations.References Skylar Tibbits, " 4D printing: multi-material shape change", Archit. Des. 84, 116–121 (2014). https://doi.org/10.1002/ad.1710MD Nahin Islam Shiblee, Kumkum Ahmed, Ajit Khosla, Masaru Kawakami, Hidemitsu Furukawa, "3D printing of shape memory hydrogels with tunable mechanical properties." Soft Matter 2018, 14, 7809. https://doi.org/10.1039/C8SM01156GKumkum Ahmed, MD Nahin Islam Shiblee, Ajit Khosla, Larry Nagahara, Thomas Thundat, and Hidemitsu Furukawa. "Recent progresses in 4D printing of gel materials." Journal of The Electrochemical Society 167, no. 3 (2020): 037563. https://doi.org/10.1149/1945-7111/ab6e60MD Nahin Islam Shiblee, Kumkum Ahmed, Masaru Kawakami, Hidemitsu Furukawa, "4D Printing of Shape-Memory Hydrogels for Soft-Robotic Functions." Adv. Mater. Technol. 2019, 4, 1900071. https://doi.org/10.1002/admt.201900071

A novel model for determination of apparent diffusion coefficient of gaseous solvent mixture-heavy oil system with consideration of swelling effect and density variation

A reliable estimation of the apparent diffusion coefficient (D) of gaseous solvent mixtures (GSMs) in heavy oil (HO) is necessary for the design of GSM-based recovery techniques. In this study, diffusion measurements of GSM-HO systems were carried out at various temperatures (25°C to 54.2°C) and pressures (5 to 10 MPa). Then, a novel mathematical model was proposed to describe the diffusion process of GSMs in HO considering the oil swelling effect and density variation. The oil swelling effect was described with a newly developed density model of GSM-HO systems. Finally, the developed model was solved via a numerical method to determine the D of GSMs in HO and the dynamic processes of HO swelling under varied temperature and pressure conditions. The results indicated that the D values at the measured temperatures and pressures ranged from 3.81-22.62×10−10 m2•s−1. The average D value of the GSMs increased with temperature and pressure. The GSM concentration in HO, the height of the GSM-HO interface, and the swelling velocity of HO rapidly increased at the early stage and then slowly increased over time. The maximum GSM concentration was observed at the GSM-HO interface.

Detailed Modeling of Cork-Phenolic Ablators in Preparation for the Post-flight Analysis of the QARMAN Re-entry CubeSat

This work deals with the analysis of the cork P50, an ablative thermal protection material (TPM) used for the heat shield of the qarman Re-entry CubeSat. Developed for the European Space Agency (ESA) at the von Karman Institute (VKI) for Fluid Dynamics, qarman is a scientific demonstrator for Aerothermodynamic Research. The ability to model and predict the atypical behavior of the new cork-based materials is considered a critical research topic. Therefore, this work is motivated by the need to develop a numerical model able to respond to this demand, in preparation to the post-flight analysis of qarman. This study is focused on the main thermal response phenomena of the cork P50: pyrolysis and swelling. Pyrolysis was analyzed by means of the multi-physics Computational Fluid Dynamics (CFD) code argo, developed at Cenaero. Based on a unified flow-material solver, the Volume Averaged Navier–Stokes (VANS) equations were numerically solved to describe the interaction between a multi-species high enthalpy flow and a reactive porous medium, by means of a high-order Discontinuous Galerkin Method (DGM). Specifically, an accurate method to compute the pyrolysis production rate was implemented. The modeling of swelling was the most ambitious task, requiring the development of a physical model accounting for this phenomenon, for the purpose of a future implementation within argo. A 1D model was proposed, mainly based on an a priori assumption on the swelling velocity and the resolution of a nonlinear advection equation, by means of a Finite Difference Method (FDM). Once developed, the model was successfully tested through a matlab code, showing that the approach is promising and thus opening the way to further developments.

Уремический синдром вызывает нарушение деформационно-функциональных характеристик эритроцитов у пациентов хронического гемодиализа

End stage of chronic kidney disease (CKD-V) is associated with alterations in erythrocyte structure and functions which are the potential risk factors to interrupt erythrocyte proper activity however the mechanisms of such changes remain understudied. We used laser diffraction approach for investigation of CKD and hemodialysis (HD) effects on deformability of CKD-V patients red blood cells. HD did not affect red blood cell (RBCs) deformability however we showed two-stage alteration in renal patients’ RBCs deformability corresponding to the time of HD treatment or/and susceptibility to uremic syndrome. The first stage was characterized by increase in initial velocity of cell swelling (Vi) and decrease in the time to peak hemolysis rate (Tmax), and indicated the increase in RBCs fragility in patients receiving HD treatment up to 25 months (Group 1). The second stage outlined the decrease in Vi and increase in Tmax, that indicated the increase in rigidity of RBCs in patients receiving HD treatment from 25 months to 250 months (Group 2). In interdialytic periods the increase in concentration of uremic toxins (urea, uric acid) was detected, at the same time there were no changes in sodium and glucose concentrations. The increase in uremic toxins lead to osmolality accrual up to 330 mOsm/kg in patients of Group1 before HD, up to 340mOsm/kg in patients of Group 2 before HD. In summary, HD did not affect the functional parameters of RBCs, however our data clearly indicated the two-stage deformability alteration in renal patients’ RBCs that is triggered by uremic syndrome and potentially may lead to renal anemia and cardio-vascular complications specifically attributed to CKD-V patients.

RNA-Seq analysis unveils gene regulation of fruit size cooperatively determined by velocity and duration of fruit swelling in peach.

Fruit swelling determines fruit size and usually occurs in two distinct time periods in peach. However, little is known about the gene regulation of fruit swelling. In this study, measurements of longitudinal and transverse diameters in developing and ripening peach fruits unveiled two periods of fruit swelling: the first swelling ends at approximately 65 days after flower blooming (DAFB) and the second swelling starts at approximately 75 DAFB. Comparisons of diameters sizes and development periods among cultivars and accessions revealed a cooperative regulation of swelling velocity and swelling duration, which leads to final determination of fruit size. Furthermore, RNA-sequencing was conducted for fruits at the initial swelling, non-swelling interval between the two swellings (hereafter, 'the interval'), second swelling and ripening stages. A total of 110 and 128 differentially expressed genes were screened from fruits in the first and second swelling, respectively. Besides, the nine most differentially expressed genes located within the reported quantitative trait locations (QTLs) of fruit size in peach were detected in both the first and second swelling stages. Those genes have been reported to be involved in mediating cell size, which indicates the occurrence of both cell proliferation and cell expansion in each of the two major periods of fruit swelling. In addition, a potential gene regulation network is proposed herein and could be used to elucidate the molecular mechanism of peach fruit swellings mediated by multiple key genes.

Determination of the swelling velocity of different wood species and tissues depending on the cutting direction on microtome section level

Abstract Swelling velocity in dependence on the anatomical cutting direction of yew [Taxus baccata L.] and boxwood [Buxus sempervirens L.] was determined at temperature of 20 °C and at relative humidity of 10% and 100%. The investigations, conducted on a microtome section level, showed a similar behaviour for specimens of both wood species. It was possible to determine that the swelling velocity for yew and boxwood increases in its anatomical cutting directions. The longitudinal direction showed the lowest value, the tangential direction, by distinction, the highest value. Furthermore, a significant influence of early wood and late wood content on the swelling velocity for yew was detected.

Experimental determination and modelling of the swelling speed of a hydrogel polymer

When a hydrophilic intraocular lens material is immersed, its volume and mass start increase due to the diffusion of water (or isotonic saline solution) reaching a quasi-equilibrium in a time scale of several hours. Here, we present a combination of atomic force and confocal microscopy to measure the axial swelling speed of such polymers in distilled water. The measurements are used for the experimental verification of a simplistic finite element model developed for engineering applications in COMSOL environment. The model is calibrated with the temporal change of the sample mass. The swelling velocity is found to be inversely proportional to the square root of time.

Spore liberation in mosses revisited.

The ability to perform hygroscopic movements has evolved in many plant lineages and relates to a multitude of different functions such as seed burial, flower protection or regulation of diaspore release. In most mosses, spore release is controlled by hygroscopic movements of the peristome teeth and also of the spore capsule. Our study presents, for the first time, temporally and spatially well-resolved kinematic analyses of these complex shape changes in response to humidity conditions and provides insights into the sophisticated functional morphology and anatomy of the peristome teeth. In Brachythecium populeum the outer teeth of the peristome perform particularly complex hygroscopic movements during hydration and desiccation. Hydration induces fast inward dipping followed by partial re-straightening of the teeth. In their final shape, wet teeth close the capsule. During desiccation, the teeth perform an outward flicking followed by a re-straightening which opens the capsule. We present a kinematic analysis of these shape changes and of the underlying functional anatomy of the teeth. These teeth are shown to be composed of two layers which show longitudinal gradients in their material composition, structure and geometry. We hypothesize that these gradients result in (i) differences in swelling/shrinking capacity and velocity between the two layers composing the teeth, and in (ii) a gradient of velocity of swelling and shrinking from the tip to the base of the teeth. We propose these processes explain the observed movements regulating capsule opening or closing. This hypothesis is corroborated by experiments with isolated layers of peristome teeth. During hydration and desiccation, changes to the shape and mass of the whole spore capsule accompany the opening and closing. Results are discussed in relation to their significance for humidity-based regulation of spore release.

Reshapable polymeric hydrogel for controlled soft-tissue expansion: In vitro and in vivo evaluation

Tissue expansion is the process by which extra skin is generated using a device that applies pressure from underneath the skin. Over the course of weeks to months, stretching by this pressure creates a flap of extra tissue that can be used to cover a defect area or enclose a permanent implant. Conventional tissue expanders require a silicone shell inflated either by external injections of saline solution or air, or by internal osmotic pressure generated by a hydrophilic polymer. In this study, a shell-free tissue expander comprised only of a chemically cross-linked biocompatible polymeric hydrogel is developed. The cross-linked network of hydrophilic polymer provides for intrinsically controlled swelling in the absence of an external membrane. The new type of hydrogel expanders were characterized in vitro as well as in vivo using a rat-skin animal model. It was found that increasing the hydrophobic polyester content in the hydrogel reduced the swelling velocity to a rate and volume that eliminate the danger of premature swelling rupturing the sutured area. Additionally, increasing the crosslinking density resulted in enough mechanical strength of the hydrogel to allow for complete post-swelling removal, without the hydrogel cracking or crumbling. No systemic toxicity was noted with the expanders and histology showed the material to be highly biocompatible. These expanders have an advantage of tissue expansion without requiring an external silicone membrane, and thus, they can be cut or reshaped at the time of implantation for applications in small or physically constrained regions of the body.

Human erythrocyte ammonium transport is mediated by functional interaction of ammonium (RhAG) and anion (AE1) transporters

The ammonia/ammonium (NH3/NH 4 + ) influx into red blood cells (RBCs) is mediated by surface glycoprotein RhAG that forms a structural complex with anion exchanger 1 (AE1, band 3). Owing to the activity of this complex, RBCs exposed to the isosmotic ammonium buffer swell and finally lyse. Isoosmotic NH 4 + -containing media alters the pH gradient in RBCs (intracellular alkalosis in response to NH3/NH 4 + influx) and triggers the AE1 activity resulting in redundant chloride and water influx and finally in cell swelling. Here we demonstrate that the ammonia/ammonium transport in human RBCs depends on the pH (pH optimum 7.4 ± 0.1), temperature (Q10 2.6 ± 0.3), HCO 3 − concentration (EC50 4.7 ± 0.3 mM), and AE1 function. The data confirm functional interactions between AE1 and RhAG. The initial velocity of cell swelling increased almost 50-fold in the isosmotic ammonium buffer containing 25 mM HCO 3 − (37°C) in comparison to the reaction in the same buffer without HCO 3 − . This indicates that the reaction is facilitated mostly by the carrier proteins, not just owing to the simple diffusion of NH3 across the erythrocyte membrane. We demonstrate that pHi reaches its maximum value much faster than the volume increase does. These data suggest that there is no direct correlation between pHi changes and the influx of NH3/NH 4 + . Taken together, our data show that the RhAG and AE1 complex activity enables erythrocytes to be ammonia/ammonium storage sites in order to maintain the physiological blood ammonia/ammonium equilibrium.

Couplings between swelling and shear in saturated slit nanopores: a molecular simulation study.

In this article, the coupling between swelling and shear in liquid saturated slit nanopores is studied using molecular dynamics simulations on Lennard-Jones systems. First, the consistency of the simulations using thermodynamics and direct routes is validated when dealing separately with swelling and shear. Then, the coupling between swelling and shear is explored by displacing the solid walls in one direction while letting them move freely on the other. Results indicate that shear can induce swelling and vice versa because of the confined fluid phase structure. This phenomenon, which is neglected in poromechanics modeling, may be non-negligible in highly structured microporous systems, such as clays. It implies that the response to a variation in the external load can be a combination of volumetric and shear deformations, because of the fluid. Finally, we explore the behavior induced by solid walls moving at a constant velocity. Interestingly, when the wall velocity exceeds the swelling velocity, the instantaneous states of the system are no longer at equilibrium and the averaged pore width slightly increases with increasing shear rate.

Eccentric exercise transiently affects mice skeletal muscle mitochondrial function

Eccentric exercise (EE) is known to induce damage and dysfunction in skeletal muscle. However, the possible role of mitochondrial (dys)function, including the vulnerability to mitochondrial permeability transition pore (MPTP) opening, is unclear. Therefore, this study aimed to analyze the impact of a single acute bout of downhill running on skeletal muscle mitochondrial function. Thirty 12-week-old Charles River CD1 male mice were randomly assigned into control (C) or exercised groups. EE consisted of 120 min of downhill treadmill running at a -16° gradient. Exercised animals were sacrificed immediately (Ecc0h) and 48 h (Ecc48h) after the end of the running bout. Plasma and skeletal muscles were then obtained. Muscle mitochondrial function, including oxygen consumption prior to and after anoxia and reoxygenation, membrane potential, and MPTP opening, were evaluated. Respiratory chain complexI, II, and V activities were determined. EE significantly increased plasma creatine kinase activity (119.4 ± 5.6 vs. 1061.3 ± 46.3 vs. 256.8 ± 15.3 U·L(-1), C, Ecc0h and Ecc48h, respectively) and myoglobin and interleukin-6 content. Impaired state 3 and respiratory control ratio (8.4 ± 0.4 vs. 5.6 ± 0.9 vs. 8.4 ± 0.5, C, Ecc0h and Ecc48h, respectively), as well as increased susceptibility to MPTP opening, seen by cyclosporin A-sensitive high swelling amplitude, lower time to maximal swelling velocity (313.8 ± 17.7 vs. 244.5 ± 19.4 vs. 298.5 ± 8.7 s, C, Ecc0h and Ecc48h, respectively), and calcium release immediately after the end of exercise (C vs. Ecc0h) were observed. EE induced a transient impairment in the activity of complex V (C vs. Ecc0h). No significant changes from the C group were observed 48 h after the end of EE (C vs. Ecc48h) in any analyzed parameters. In conclusion, prolonged EE transiently impaired mice skeletal muscle mitochondrial function and increased susceptibility to calcium-induced MPTP opening.

Characterization of the carbonization process of expandable graphite/silicone formulations in a simulated fire

The fire performance of curable-silicone based coatings containing expandable graphite (EG) is evaluated in hydrocarbon fire scenario (standard UL1709) using a lab-scale furnace test. From 5% to 25% of expandable graphite is incorporated in the silicone matrix to make the coating swell during the fire experiment. Fire performance of 25%EG/silicone-based coating is better than that of commercial intumescent paint used as reference. This is explained by a high swelling velocity (18%/s), a high expansion (3400%), an impressive cohesion of the char and a low heat conductivity at high temperature (0.35 W/K m at 500 °C). To elucidate this way of charring, the residue after fire testing was analyzed by scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction. It is shown that the char is composed of two main parts: the top is composed of quartz and amorphous silica which coat graphite flakes and the heart of the char is composed of graphite flakes embedded in degraded silicone forming a complex structure. It is shown that, the good cohesion of the char is due to: (i) the presence of the undegraded silicone matrix; and (ii) the coating of graphite pellets by silicone.

Studies on swelling kinetics for HPC/PAN thermo‐sensitive blending films

A series of thermo‐sensitive blending films was prepared from hydroxypropylcellulose (HPC) and polyacrylonitrile (PAN). The effects of materials ratio, pH value, and temperature on the swelling velocity of these blending films were studied. At temperatures above the lower critical solution temperature (LCST), different results are found after dipping blend film samples in acid or alkaline solutions, respectively. At a pH value of 1.4, the swelling velocity of HPC/PAN blended films increased with the HPC content. The films' swelling was mainly controlled by polymer chain relaxation. For a pH value of 7.4 the mechanism responsible for the swelling is the water molecules' diffusion. The swelling velocity was also affected by temperature and pH. Copyright © 2009 John Wiley & Sons, Ltd.

Evaluation of pool swell velocity during large break loss of coolant accident in boiling water reactor Mark III containment design

Abstract In boiling water reactor (BWR) design, safety scenarios such as main steam line break need to be evaluated. After the main steam line break, the steam will fill the upper dry well of the containment. It will then enter the vertical vent and eventually flow into the suppression pool via horizontal vents. The steam will create large bubbles in the suppression pool and cause the pool to swell. The impact of the pool swell on the equipment inside the pool and containment structure needed to be evaluated for licensing. GE has conducted a series of one-third scale three-vent air tests in supporting the horizontal vent pressure suppression system used in Mark III containment design for General Electric BWR plants. During the test, the air–water interface locations were tracked by conductivity probes. The pressure was measured at many locations inside the test rig as well. The purpose of the test was to provide a basis for the pool swell load definition for the Mark III containment. In this paper, a transient three-dimensional CFD model to simulate the one-third scale Mark III suppression pool swell process is illustrated. The Volume of Fluid (VOF) multiphase model is used to explicitly track the interface between the water liquid and the air. The CFD results such as flow velocity, pressure, interface locations are compared to the data from the test. Through comparisons, a technical approach to numerically model the pool swell phenomenon is established and benchmarked.

Synthesis, characterization, mucoadhesion and biocompatibility of thiolated carboxymethyl dextran–cysteine conjugate

This study was aimed at improving the mucoadhesive properties of carboxymethyl dextran by the covalent attachment of cysteine. Mediated by a carbodiimide, l-cysteine was covalently attached to the polymer. The resulting CMD–cysteine conjugate (CMD- 273 conjugate) displayed 273 ± 20 μmol thiol groups per gram of polymer (mean ± S.D.; n = 3). Within 2 h the viscosity of an aqueous mucus/CMD- 273 conjugate mixture pH 7.4 increased at 37 °C by more than 85% compared to a mucus/carboxymethyl dextran mixture indicating enlarged interactions between the mucus and the thiolated polymer. Due to the immobilization of cysteine, the swelling velocity of the polymer was significantly accelerated ( p < 0.05). In aqueous solutions the CMD- 273 conjugate was capable of forming inter- and/or intramolecular disulfide bonds. Because of this crosslinking process within the polymeric network, the cohesive properties of the conjugate were also improved. Tablets comprising the unmodified polymer disintegrated within 15 min, whereas tablets of the CMD- 273 conjugate remained stable for 160 min (means ± S.D.; n = 3). Results from LDH and MTT assays on Caco-2 cells revealed 4.96 ± 0.98% cytotoxicity and 94.1 ± 0.9% cell viability for the CMD- 273 conjugate, respectively. Controlled release of model compound from CMD- 273 conjugate tablets was observed over 6 h. These findings suggest that CMD- 273 conjugate is a promising novel polymer for drug delivery systems providing improved mucoadhesive and cohesive properties, greater stability and biocompatibility.

PH‐Sensitive Polyacrylic Acid (PAA) Hydrogels Trapped with Polysodium‐p‐Styrenesulfonate (PSS)

The preparation of a new type of semi‐interpenetration network system of polyacrylic acid (PAA) hydrogel trapped with polysodium‐p‐styrenesulfonate (PSS) is presented. The structure and response properties of PAA/PSS were investigated by Fourier transform infrared (FTIR) analysis and pH and ionic intensity stimuli‐responsive measurement. The FTIR analysis proved the successful intermingling of PSS into PAA. The swelling behavior of PAA hydrogel in an alkaline environment was improved due to the addition of PSS. As the ionic concentration in solution increased, the swelling rate of PAA decreased after adding PSS. However, the swelling velocity of the pure PAA is quicker than that of the PAA/PSS samples since the PSS will enhance the entanglement of this hydrogel network and slow down the swelling velocity. Multi‐interactions between the PAA hydrogel network and trapped PSS chains, including electrostatic repulsive interaction, entanglement interaction, ionic intensity interaction, and osmotic pressure, were proposed to explain the earlier‐mentioned experimental phenomena.

Synthesis and in vitro characterization of a novel poly(acrylic acid)-glutathione conjugate

The purpose of the present study was to improve the multifunctional properties of poly(acrylic acid) by the covalent attachment of glutathione. The adhesive properties of poly(acrylic acid)-glutathione (PAA-GSH) conjugate were evaluated in vitro on freshly excised porcine mucosa via tensile studies and the rotating cylinder method. The permeation enhancing effect of the conjugate in combination with glutathione was evaluated in Ussing chambers by using sodium fluoresceine as model compound. The resulting PAA-GSH conjugate displayed 353.7 ± 41.8 (n = 3) μmol immobilized free thiol groups and 309.8 ± 27.3 (n = 3) μmol disulfide bonds per gram polymer. In aqueous solutions, the modified polymer demonstrated improved cohesive properties. Due to the immobilization of glutathione, the swelling velocity of the polymer was 4-fold accelerated. Tensile studies showed that the mucoadhesive properties of poly(acrylic acid) were strongly improved by the covalent attachment of glutathione. The adhesion time of PAA-GSH was more than 14-fold higher in comparison to unmodified poly(acrylic acid). Furthermore, the conjugate exhibited a 1.77-fold higher permeation enhancing effect compared with the control. According to the results of the present study, PAA-GSH conjugate represents a very promising novel thiomer for the development of various mucoadhesive drug delivery systems.

Cross-linked high amylose starch derivatives for drug release: II. Swelling properties and mechanistic study

Acetate (Ac-), aminoethyl (AE-), and carboxymethyl (CM-) high amylose starch cross-linked 6 (HASCL-6) derivatives were previously shown to control the release of drugs over 20 h from monolithic tablets highly loaded (up to 60% drug). This report describes the swelling characteristics, which allow a better understanding of the mechanisms involved in the control of the drug release from the said polymeric matrices. The tablet swelling of HASCL-6, Ac-HASCL-6, and AE-HASCL-6 was found to not be affected by the ionic strength and by the pH between 1.2 (gastric) and 7 (intestinal), whereas the swelling of CM-HASCL-6 was shown to depend on both ionic strength and pH of the release medium. For all the studied polymers the drug loading did not change the equilibrium swelling ratio but affected the initial swelling velocity, seemingly due to the competition between drug and polymer for water uptake, a phenomenon probably influenced by the loading and the drug solubility. It was also shown that the increase of ionic strength would slightly increase the drug release time probably by decreasing the amount of free water still available to solubilize the drug present into the matrix.

Cross-linked high amylose starch derivatives for drug releaseII. Swelling properties and mechanistic study

Acetate (Ac-), aminoethyl (AE-), and carboxymethyl (CM-) high amylose starch cross-linked 6 (HASCL-6) derivatives were previously shown to control the release of drugs over 20 h from monolithic tablets highly loaded (up to 60% drug). This report describes the swelling characteristics, which allow a better understanding of the mechanisms involved in the control of the drug release from the said polymeric matrices. The tablet swelling of HASCL-6, Ac-HASCL-6, and AE-HASCL-6 was found to not be affected by the ionic strength and by the pH between 1.2 (gastric) and 7 (intestinal), whereas the swelling of CM-HASCL-6 was shown to depend on both ionic strength and pH of the release medium. For all the studied polymers the drug loading did not change the equilibrium swelling ratio but affected the initial swelling velocity, seemingly due to the competition between drug and polymer for water uptake, a phenomenon probably influenced by the loading and the drug solubility. It was also shown that the increase of ionic strength would slightly increase the drug release time probably by decreasing the amount of free water still available to solubilize the drug present into the matrix.