Self-restoring polymer brushes under tribological stress and the biomedical applications

ABSTRACTFor biological and mechanical systems involving moving parts, surface slipperiness is often a critical attribute for their optimal functions. Surface grafting with hydrophilic polymers is a powerful means to render materials slippery in aqueous environment. In “inverted grafting-to approach”, the hydrophilic polymer chains of amphiphilic diblock copolymers dispersed within a poly(dimethylsiloxane) (PDMS) network are selectively segregated upon exposure to aqueous solution. This allows formation of extremely stable brush-like polymer layers. Tribological application of inverted grafting-to approach was successfully demonstrated with PDMS-block-poly(acrylic acid) (PDMS-b-PAA) dispersed within thin PDMS films on PDMS blocks by showing friction coefficients (µ) of ca 10-2 to 10-3, depending on the load, pH and buffer salinity in the absence of other external re-supply of PAA chains. Further manipulations of the thin PDMS film incorporating PDMS-b-PAA to optimize the tribological properties are presented. Lastly, first trials to employ PAA-grafted PDMS surface to generate in-vitro mucosae model are also presented and discussed.

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Hydrogels: A Versatile Drug Delivery Carrier Systems

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2012.5.3.1 ◽

1970 ◽

Vol 5 (3) ◽

pp. 1745-1756

Author(s):

L H Baldaniya ◽

Sarkhejiya N A

Keyword(s):

Drug Delivery ◽

Protein Delivery ◽

Structural Integrity ◽

Healing Process ◽

Polymer Chains ◽

Wound Healing Process ◽

Aqueous Environment ◽

Preparation Methods ◽

Control Drug

Hydrogels are the material of choice for many applications in regenerative medicine due to their unique properties including biocompatibility, ﬂexible methods of synthesis, range of constituents, and desirable physical characteristics. Hydrogel (also called Aquagel) is a network of polymer chains that are hydrophilic, sometimes found as a colloidal gel in which water is the dispersion medium. Hydrogels are highly absorbent (contain ~99.9% water), natural or synthetic polymers. Hydrogel also possess a degree of flexibility very similar to natural tissue, due to its significant water content. It can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures. Also serve as adhesives or barriers between tissue and material surfaces. The positive effect of hydrogels on wounds and enhanced wound healing process has been proven. Hydrogels provide a warm, moist environment for wound that makes it heal faster in addition to its useful mucoadhesive properties. Moreover, hydrogels can be used as carriers for liposomes containing variety of drugs, such as antimicrobial drugs. Hydrogels are water swollen polymer matrices, with a tendency to imbibe water when placed in aqueous environment. This ability to swell, under biological conditions, makes it an ideal material for use in drug delivery and immobilization of proteins, peptides, and other biological compounds. Hydrogels have been extensively investigated for use as constructs to engineer tissues in vitro. This review describes the properties, classification, preparation methods, applications, various monomer used in formulation and development of hydrogel products.

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Amphiphilic diblock copolymers inhibit the formation of encrustation on the surface of biodegradable ureteral stents in vitro and in vivo

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2020.125667 ◽

2021 ◽

Vol 610 ◽

pp. 125667

Author(s):

Yu Zhang ◽

Jin Qi ◽

Hechun Chen ◽

Chengdong Xiong

Keyword(s):

Diblock Copolymers ◽

Ureteral Stents ◽

Amphiphilic Diblock Copolymers

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Surface functionalization by smart binary polymer brushes to tune physico-chemical characteristics at biointerfaces

e-Polymers ◽

10.1515/epoly.2005.5.1.794 ◽

2005 ◽

Vol 5 (1) ◽

Author(s):

Petra Uhlmann ◽

Nikolay Houbenov ◽

Sergiy Minko ◽

Manfred Stamm

Keyword(s):

Polymer Brushes ◽

Structural Changes ◽

Surface Engineering ◽

Surface Characteristics ◽

Polymer Chains ◽

Aqueous Environment ◽

Binary Polymer ◽

Physico Chemical ◽

Versatile Tool ◽

Model Protein

AbstractPolymer brushes consist of an assembly of polymer chains that are attached by one end to the surface with sufficient grafting density. Binary brushes constituted from two incompatible polymers can be used in the form of ultrathin polymeric layers as a versatile tool for surface engineering to tune physicochemical surface characteristics as wettability, surface charge, chemical composition or morphology, and furthermore to create responsive surface properties. It is also possible to fix surface structures obtained in this way by (photo)crosslinking of the layers. Mixed brushes of oppositely charged polyelectrolytes are representing a special case of responding surfaces, which are sensitive to changes of the pH in aqueous environment. It is shown that structural changes occur in the plateau region of the adsorption isotherm of a model protein and that changes of the pH also cause changes in the structure of the adsorbed protein layer.

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Opsonisation of nanoparticles prepared from poly(β-hydroxybutyrate) and poly(trimethylene carbonate)-b-poly(malic acid) amphiphilic diblock copolymers: Impact on the in vitro cell uptake by primary human macrophages and HepaRG hepatoma cells

International Journal of Pharmaceutics ◽

10.1016/j.ijpharm.2016.09.048 ◽

2016 ◽

Vol 513 (1-2) ◽

pp. 438-452 ◽

Cited By ~ 6

Author(s):

Elise Vene ◽

Ghislaine Barouti ◽

Kathleen Jarnouen ◽

Thomas Gicquel ◽

Claudine Rauch ◽

...

Keyword(s):

Malic Acid ◽

Diblock Copolymers ◽

Hepatoma Cells ◽

Cell Uptake ◽

Trimethylene Carbonate ◽

Human Macrophages ◽

Amphiphilic Diblock Copolymers

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Corrigendum to “Amphiphilic diblock copolymers inhibit the formation of encrustation on the surface of biodegradable ureteral stents in vitro and in vivo” [Colloids Surf. A: Physicochem. Eng. Asp. 610 (2021) 125667]

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2021.126997 ◽

2021 ◽

pp. 126997

Author(s):

Yu Zhang ◽

Jin Qi ◽

Hechun Chen ◽

Chengdong Xiong

Keyword(s):

Diblock Copolymers ◽

Ureteral Stents ◽

Amphiphilic Diblock Copolymers

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Multi-Stimuli-Responsive Mesoporous Membranes and Effect of Molecular Architecture on Thermo- and pH-Responsive Behavior of the grafted Block Copolymer brushes

10.26434/chemrxiv.7037699 ◽

2019 ◽

Author(s):

Yanchun Tang ◽

Kohzo Ito ◽

Hideaki Yokoyama

Keyword(s):

Polymer Brushes ◽

Diblock Copolymers ◽

Neutron Reflectivity ◽

Molecular Architecture ◽

Stimuli Responsive ◽

Responsive Polymer ◽

The Matrix ◽

Stable Part ◽

Copolymer Brushes ◽

Mesoporous Membranes

In this study, we prepared ultrafiltration membranes with a decoupled responses of filtration property to temperature and pH. The membrane preparation method was developed based on our previous work. We utilized methanol-supercritical carbon dioxide (methanol-scCO2) selective swelling method to introduce nanopores to block copolymers containing poly(diethylene glycol) methyl ether methacrylate (PMEO2MA), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and polystyrene (PS) blocks. Formation of the mesoporous barrier layer with PS being the mechanically stable part of the matrix was driven by selective swelling of the PMEO2MA-b-PDMAEMA domains. Due to the selective swelling of PMEO2MA or PDMAEMA domains to introduce pores, the interior of the pores are covered with PMEO2MA or PDMAEMA blocks after pore formation. The PMEO2MA-b-PDMAEMA polymer brushes are naturally attached on the pore walls and worked as functional gates. PMEO2MA is a non-toxic, neutral thermo-responsive polymer with LCST at 26 ᴼC. PDMAEMA is a typical weak polyelectrolyte with pKa value at 7.0-7.5 and also a thermo-responsive polymer revealed a LCST of 20-80 °C in aqueous solution. Therefore, these membranes were expected to have multi dimensions as function of the combination of temperature and pH. Moreover, to understand the detail of the temperature and pH depended conformation transitions of PMEO2MA-b-PDMAEMA brushes, those diblock copolymers were end-tethered on flat substrates and analyzed via neutron reflectivity (NR).

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