Variability of water uptake studies of biomedical polymers

Valenzuela, Loreto M.; Michniak, B. B.; Kohn, Joachim

doi:10.1002/app.33485

Cited by 24 publications

(29 citation statements)

References 81 publications

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“…Polymer films of thickness ~200 μm were compression molded using a Carver Press (Fred S. Carver Inc.) as described previously [7]. After molding, films were either quenched by fast cooling or annealed at 10ºC above T g for at least 20 h before incubation.…”

Section: Methodsmentioning

confidence: 99%

“…Several groups have studied water uptake and hydration of polymer films using different techniques. Methods such as gravimetric analysis [6], thermogravimetric analysis (TGA), and 3 H-radiolabeled water ( 3 H 2 O) [7] are commonly used to study of the kinetics of hydration, but they do not provide information on the interactions between polymer and water molecules, and about spatial distribution of the water in the polymer. This knowledge of the distribution of water is important for understanding hydrolytic degradation: water rich areas of the polymer are expected to degrade faster than other areas [8].…”

Section: Introductionmentioning

confidence: 99%

“…The main advantage of using 3 H 2 O to measure water content is its accuracy at low levels of water uptake (< 2%) [7]. Other simpler methods such as gravimetric measurements allow accurate measurements only at higher levels of water uptake.…”

Section: Introductionmentioning

confidence: 99%

“…Changes in the polymer backbone or pendent chain lengths affect polymer properties such as glass transition temperature ( T g ) and surface hydrophobicity [28]. Water uptake in polyarylates has been shown to be dependent on the polymer structure and processing methods [7]. Total water uptake ranges from less than 3 to more than 250% after 28 days of incubation in water at 37ºC, depending on the polymer structure and the initial molecular weight (MW).…”

Section: Introductionmentioning

confidence: 99%

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Multiscale analysis of water uptake and erosion in biodegradable polyarylates

Valenzuela

Zhang

Flach

et al. 2012

Polymer Degradation and Stability

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The role of hydration in degradation and erosion of materials, especially biomaterials used in scaffolds and implants, was investigated by studying the distribution of water at length scales from 0.1 nm to 0.1 mm using Raman spectroscopy, small-angle neutron scattering (SANS), Raman confocal imaging, and scanning electron microscopy (SEM). The measurements were demonstrated using L-tyrosine derived polyarylates. Bound- and free- water were characterized using their respective signatures in the Raman spectra. In the presence of deuterium oxide (D2O), H-D exchange occurred at the amide carbonyl but was not detected at the ester carbonyl. Water appeared to be present in the polymer even in regions where there was little evidence for N-H to N-D exchange. SANS showed that water is not uniformly dispersed in the polymer matrix. The distribution of water can be described as mass fractals in polymers with low water content (~5 wt%), and surface fractals in polymers with larger water content (15 to 60 wt%). These fluctuations in the density of water distribution are presumed to be the precursors of the ~ 20 μm water pockets seen by Raman confocal imaging, and also give rise to 10–50 μm porous network seen in SEM. The surfaces of these polymers appeared to resist erosion while the core of the films continued to erode to form a porous structure. This could be due to differences in either the density of the polymer or the solvent environment in the bulk vs. the surface, or a combination of these two factors. There was no correlation between the rate of degradation and the amount of water uptake in these polymers, and this suggests that it is the bound-water and not the total amount of water that contributes to hydrolytic degradation.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Multiscale analysis of water uptake and erosion in biodegradable polyarylates

Valenzuela

Zhang

Flach

et al. 2012

Polymer Degradation and Stability

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“…The capacities for binding gases increase with increasing the water content. The water contents of the particles are determined via thermogravimetrical analysis [29]. We present two probable reasons for this phenomenon.…”

Section: Unique Properties Of Wsc-sa Hydrogel Particlesmentioning

confidence: 99%

Versatile particles from water-soluble chitosan and sodium alginate for loading toxic or bioactive substance

You

Xiao

Zhang

et al. 2015

International Journal of Biological Macromolecules

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Caffeine‐reinforced Collagen as Localized Microenvironmental Trans‐Browning Bio‐Matrix for Soft Tissue Repair and Regeneration in Bariatric Condition

Sreekumar,

Vijayan,

Gangaraj

et al. 2023

Advanced Biology

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The wound exudates, hypoperfusion of the subcutaneous fat layer, and poor vasculature worsen wound management in obese subjects. In the current study, a multifunctional Caffeine‐reinforced collagen biomaterial is developed that can simultaneously modulate lipid metabolism and angiogenesis in obese wound microenvironments for faster tissue regeneration. The biomaterial is fabricated specialized for obese conditions to initiate simultaneous lipolysis and angiogenesis locally in the hypoxic subcutaneous fat in wound margins of obese subjects. Caffeine‐reinforced collagen biomatrix shows better structural integrity, thermal stability, bio‐compatibility, and lesser proteolytic susceptibility. Caffeine‐collagen biomaterial promote angiogenesis, fibroblast migration, and localized browning of white adipocytes to activate thermogenesis in the subcutaneous fat layer at the wound site. Full‐thickness excision wound healing studies performed in obese C57BL6 mice shows faster wound closure within day 9 when compare to control mice. The Caffeine‐reinforced collagen biomaterial remodeled the wound site locally by activating fibroblast to secrete collagen, activate endothelial cells to promote angiogenesis, and induce browning in white adipocytes in subcutaneous fat. The study opens a new direction in bariatric tissue regenerative medicine by locally modulating lipid metabolism, angiogenesis, and trans‐browning at the injured site for faster complete restoration of the damaged tissue.

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Variability of water uptake studies of biomedical polymers

Cited by 24 publications

References 81 publications

Multiscale analysis of water uptake and erosion in biodegradable polyarylates

Multiscale analysis of water uptake and erosion in biodegradable polyarylates

Versatile particles from water-soluble chitosan and sodium alginate for loading toxic or bioactive substance

Caffeine‐reinforced Collagen as Localized Microenvironmental Trans‐Browning Bio‐Matrix for Soft Tissue Repair and Regeneration in Bariatric Condition

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