Temperature and electrostatics effects on charged poly(N-isopropylacrylamide) microgels at the interface

Yang, Yan; Maldonado-Valderrama, Julia; Martín-Molina, Alberto

doi:10.1016/j.molliq.2020.112678

Cited by 22 publications

(13 citation statements)

References 58 publications

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“…A similar trend has been observed for charged thermoresponsive PNIPAM-based microgels [ 45 , 46 , 47 ]. This increase of µ e with the temperature is usually explained by a reduction of the friction of the particles when they shrink and also in terms of the effective charge of the particles.…”

Section: Resultssupporting

confidence: 82%

“…However, it has already been discussed that the presence of Ca 2+ promotes the adsorption of mGel− at this lowest concentration. Figure 8 shows that adsorbed mGel− also develops an elastic network in the presence of Ca 2+ , which is more elastic for swollen mGel−, similar to the higher elasticity of swollen microgels in pure water subphase [ 46 ].…”

Section: Resultsmentioning

confidence: 98%

“…In summary, the uniform increase of SP obtained below and above the VPPT ( Figure 4 A,B) is indicative of the existence of a single interaction regime between mGel+ in the swollen and shrunken states corresponding to the interaction of flattened shells until the collapse of the monolayer [ 59 ]. The electrostatic repulsion between cores prevents the existence of interaction regimes at closer interparticle distances [ 46 ]. The SP-A isotherms obtained for swollen and collapsed mGel+ showed no significant differences, suggesting that in this case, the flattening upon spreading prevails over the temperature-induced swelling state of mGel [ 60 ].…”

Section: Resultsmentioning

confidence: 99%

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Complexation of DNA with Thermoresponsive Charged Microgels: Role of Swelling State and Electrostatics

Maldonado-Valderrama

Yang

Jimenez-Guerra

et al. 2022

Gels

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Micro- and nanogels are being increasingly used to encapsulate bioactive compounds. Their soft structure allows large loading capacity while their stimuli responsiveness makes them extremely versatile. In this work, the complexation of DNA with thermoresponsive microgels is presented. To this end, PEGylated charged microgels based on poly-N-isopropylacrylamide have been synthesized, allowing one to explore the electrostatics of the complexation. Cationic microgels complexate spontaneously by electrostatic attraction to oppositely charged DNA as demonstrated by electrophoretic mobility of the complexes. Then, Langmuir monolayers reveal an increased interaction of DNA with swollen microgels (20 °C). Anionic microgels require the presence of multivalent cations (Ca2+) to promote the complexation, overcoming the electrostatic repulsion with negatively charged DNA. Then again, Langmuir monolayers evidence their complexation at the surface. However, the presence of Ca2+ seems to induce profound changes in the interaction and surface conformation of anionic microgels. These alterations are further explored by measuring adsorbed films with the pendant drop technique. Conformational changes induced by Ca2+ on the structure of the microgel can ultimately affect the complexation with DNA and should be considered in the design. The combination of microstructural and surface properties for microgels offers a new perspective into complexation of DNA with soft particles with biomedical applications.

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Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

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Complexation of DNA with Thermoresponsive Charged Microgels: Role of Swelling State and Electrostatics

Maldonado-Valderrama

Yang

Jimenez-Guerra

et al. 2022

Gels

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“…However, these coatings were found to be unstable under physiological conditions since the contact point between the particle and surface is limited [ 270 ]. From this point of view, nanogels, as being soft deformable colloidal particles, can stick to the surface firmly and create remarkably homogenous coatings [ 271 , 272 ]. Nanogel-based surface coatings can be easily prepared by physical adsorption without requiring any harsh chemical procedures such as grafting or covalent binding [ 268 ].…”

Section: Antimicrobial Nanogel Surface Coatings For Biomedical Applicationsmentioning

confidence: 99%

Nanogels: A novel approach in antimicrobial delivery systems and antimicrobial coatings

Keskin

Forson

et al. 2021

Bioactive Materials

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The implementation of nanotechnology to develop efficient antimicrobial systems has a significant impact on the prospects of the biomedical field. Nanogels are soft polymeric particles with an internally cross-linked structure, which behave as hydrogels and can be reversibly hydrated/dehydrated (swollen/shrunken) by the dispersing solvent and external stimuli. Their excellent properties, such as biocompatibility, colloidal stability, high water content, desirable mechanical properties, tunable chemical functionalities, and interior gel-like network for the incorporation of biomolecules, make them fascinating in the field of biological/biomedical applications. In this review, various approaches will be discussed and compared to the newly developed nanogel technology in terms of efficiency and applicability for determining their potential role in combating infections in the biomedical area including implant-associated infections.

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“…Dark micro-BAM images were obtained for π < 5 mN/m, indicative of a lack of interaction corresponding to a 2D gas (results not shown). As the π increased in the monolayer, bright spots appeared more numerous for POL + HA, possibly owing to the formation of small aggregates [44]. Apart from the bright spots, large brighter domains The microBAM allowed us to follow the changes in the morphology of the monolayer as the compression proceeded, as well as the possible effect of HA in the POL monolayer.…”

Section: Compression Isotherm and Microbammentioning

confidence: 99%

Effect of Hyaluronic Acid and Pluronic-F68 on the Surface Properties of Foam as a Delivery System for Polidocanol in Sclerotherapy

et al. 2020

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The use of foams to deliver bioactive agents and drugs is increasing in pharmaceutics. One example is the use of foam as a delivery system for polidocanol (POL) in sclerotherapy, with the addition of bioactive compounds to improve the delivery system being a current subject of study. This work shows the influence of two bioactive additives on the structure and stability of POL foam: hyaluronic acid (HA) and Pluronic-F68 (F68). HA is a natural non-surface-active biopolymer present in the extracellular matrix while F68 is a surface-active poloxamer that is biocompatible with plasma-derived fluids. Both additives increase the bulk viscosity of the sample, improving foam stability. However, HA doubled and F68 quadruplicated the foam half lifetime of POL. HA reduced the size and polydispersity of the bubble size distribution and increased the surface elasticity with respect to POL. Both facts have a positive impact in terms of foam stability. F68 also altered bubble structure and increased surface elasticity, again contributing to the enhancement of foam stability. The surface characterization of these systems is important, as in foam sclerotherapy it is crucial to assure the presence of POL at the surface of the bubbles in order to deliver the sclerosant agent in the target vein.

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Temperature and electrostatics effects on charged poly(N-isopropylacrylamide) microgels at the interface

Cited by 22 publications

References 58 publications

Complexation of DNA with Thermoresponsive Charged Microgels: Role of Swelling State and Electrostatics

Complexation of DNA with Thermoresponsive Charged Microgels: Role of Swelling State and Electrostatics

Nanogels: A novel approach in antimicrobial delivery systems and antimicrobial coatings

Effect of Hyaluronic Acid and Pluronic-F68 on the Surface Properties of Foam as a Delivery System for Polidocanol in Sclerotherapy

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