Shape-Changing Tubular Hydrogels

Raghavan, Srinivasa R.; Fernandes, Neville J; Cipriano, Bani H.

doi:10.3390/gels4010018

Cited by 6 publications

(7 citation statements)

References 19 publications

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“…al. also shows that, for tubular hydrogels with identical composition, this characteristic time for diffusion depends strongly on the wall thickness as well [25]. Since the crosslinker ratio X is maintained as a constant, it can also be argued that t r increases (rate of polymer chain Table 2 Diffusion parameters for a polymer sample of hollow cylindrical geometry, fully immersed in water for 1 hour (For the measurement of n, K in the following networks: p < 0.0001; calculated using the repeated measure ANOVA) relaxation decreases) only slightly with concentration, that too as a result of any physical bonding only such as chain entanglements, hydrogen bonding, etc.…”

Section: Sorption Kineticsmentioning

confidence: 83%

Section: Water Sorption Studiesmentioning

confidence: 99%

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Swellable catheters based on a dynamic expanding inner diameter

Tennankore

Brunette

Cox

et al. 2021

J Mater Sci: Mater Med

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Intravenous (IV) fluid administration is critical for all patients undergoing care in a hospital setting. In-patient hospital practice, surgeries, and emergency care require functional IVs for fluid replacement and medication administration. Proper placement of IVs is vital to providing medical services. The ease of placement of an IV catheter, however, depends not only on the size of the catheter but also on provider experience and patient demographics such as age, body mass index, hydration status, and medical comorbidities present challenges to successful IV placement. Smaller diameter IV placement can improve success and there are instances where multiple small diameter catheters are placed for patient care when larger bore access is unattainable. Smaller inner-diameter catheters for anesthesia have functional constraints. Ideally, there would be a smaller catheter for placement that could function as a larger catheter for patient care. One solution is the idea of functionally responsive catheters. Here, we evaluated tubular-shaped hydrogels as potential functional catheters that can increase in inner diameter through fluid swelling using cross-linked homopolymers of polyacrylamide, PAM (10–40% w/w), and their copolymers with 0–8% w/w Poly-(Ethylene Glycol)-Diacrylate, PEGDA. For the PAM gels, the water transport mechanism was shown to be concentration-dependent Fickian diffusion, with the less concentrated gels exhibiting increasingly anomalous modes. Increasing the PEGDA content in the network yielded an initial high rate of water uptake, characterized by Case II transport. The swelling kinetics depended strongly on the sample geometry and boundary conditions. Initially, in a submerged swelling, the annulus expands symmetrically in both outward and inward directions (it thickens), reducing the internal diameter by up to 70%. After 1 h, however, the inner diameter increases steadily so that at equilibrium, there is a net (>100%) increase in all the dimensions of the tube. The amount of linear swelling at equilibrium depended only on the polymer volume fraction as made, while the rate of inner diameter expansion depended on the hydrophilicity of the matrix and the kinetics of sorption. This study serves as proof of concept to identify key parameters for the successful design of hydrogel-based catheter devices with expanding inner-diameters for applications in medical care.

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Section: Sorption Kineticsmentioning

confidence: 83%

Section: Water Sorption Studiesmentioning

confidence: 99%

Swellable catheters based on a dynamic expanding inner diameter

Tennankore

Brunette

Cox

et al. 2021

J Mater Sci: Mater Med

View full text Add to dashboard Cite

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“…These shape-changing gels may reverse their shape if the pH or temperature is restored to its original state. Many shape-changing gels are originally in the form of flat films that are self-folded or rolled into particular shapes such as tubes [13]. These can be incredibly useful for cell implantations.…”

Section: Shape-changing Gelsmentioning

confidence: 99%

“…These can be incredibly useful for cell implantations. For example, during the implantation of bone marrow cells, the hydrogel can be turned into a tubular shape once inside the bone to ensure maximum surface area contact between the hydrogel and the bone, resulting in more cell proliferation and leading to faster cell delivery [13]. Having these hydrogels with changing shapes is an incredible innovation for the future of cell delivery, as their versatility makes them excellent candidates for such applications.…”

Section: Shape-changing Gelsmentioning

confidence: 99%

“…Therefore, hydrogels can undergo conformational transitions, in response to a stimulus, this can include chemical or physical stimuli. Shape-changing hydrogels can be created by stacking different hydrogel layers that each react to a different stimulus [13]. Based on the different methods of polymerization such as suspension, block, solution, and emulsion, hydrogels may also be classified as homopolymer or copolymer [9,14].…”

Section: Introductionmentioning

confidence: 99%

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Recent Progress in Biopolymer-Based Hydrogel Materials for Biomedical Applications

Mahmood

Patel

Hickson

et al. 2022

IJMS

114

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Hydrogels from biopolymers are readily synthesized, can possess various characteristics for different applications, and have been widely used in biomedicine to help with patient treatments and outcomes. Polysaccharides, polypeptides, and nucleic acids can be produced into hydrogels, each for unique purposes depending on their qualities. Examples of polypeptide hydrogels include collagen, gelatin, and elastin, and polysaccharide hydrogels include alginate, cellulose, and glycosaminoglycan. Many different theories have been formulated to research hydrogels, which include Flory-Rehner theory, Rubber Elasticity Theory, and the calculation of porosity and pore size. All these theories take into consideration enthalpy, entropy, and other thermodynamic variables so that the structure and pore sizes of hydrogels can be formulated. Hydrogels can be fabricated in a straightforward process using a homogeneous mixture of different chemicals, depending on the intended purpose of the gel. Different types of hydrogels exist which include pH-sensitive gels, thermogels, electro-sensitive gels, and light-sensitive gels and each has its unique biomedical applications including structural capabilities, regenerative repair, or drug delivery. Major biopolymer-based hydrogels used for cell delivery include encapsulated skeletal muscle cells, osteochondral muscle cells, and stem cells being delivered to desired locations for tissue regeneration. Some examples of hydrogels used for drug and biomolecule delivery include insulin encapsulated hydrogels and hydrogels that encompass cancer drugs for desired controlled release. This review summarizes these newly developed biopolymer-based hydrogel materials that have been mainly made since 2015 and have shown to work and present more avenues for advanced medical applications.

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Real‐time Observation of Macroscopic Helical Morphologies under Optical Microscope: A Curious Case of π–π Stacking Driven Molecular Self‐assembly of an Organic Gelator Devoid of Hydrogen Bonding

et al. 2023

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Supramolecular assemblies such as tubules/ helix/double helix/helical tape etc. are usually submicron objects preventing direct observation under optical microscope. Chiral-pure form of these assemblies is important for potential applications. Herein, we report a rare phenomenon wherein a DMSO gel of a simple terpyridine derivative [(4-CNPhe)4PyTerp] produced macroscopic helical morphologies (μm length scale) which could be observed under optical microscope, formation of which could be monitored by optical videography, stable enough to withstand acidic vapour, robust enough to display reversible gel $ sol in response to acidic and ammonia vapour and sturdy enough to be maneuvered with a needle. These properties appeared to be unique to the title compound as the other related derivatives failed to display such assembly structures. SXRD and MD simulation studies suggested that weak interactions (π-π stacking) played a crucial role in the self-assembly process.

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Shape-Changing Tubular Hydrogels

Cited by 6 publications

References 19 publications

Swellable catheters based on a dynamic expanding inner diameter

Swellable catheters based on a dynamic expanding inner diameter

Recent Progress in Biopolymer-Based Hydrogel Materials for Biomedical Applications

Real‐time Observation of Macroscopic Helical Morphologies under Optical Microscope: A Curious Case of π–π Stacking Driven Molecular Self‐assembly of an Organic Gelator Devoid of Hydrogen Bonding

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