by Keyword: Polyethylene glycol

Andrian, T, Pujals, S, Albertazzi, L, (2021). Quantifying the effect of PEG architecture on nanoparticle ligand availability using DNA-PAINT Nanoscale Advances 3, 6876-6881

The importance of PEG architecture on nanoparticle (NP) functionality is known but still difficult to investigate, especially at a single particle level. Here, we apply DNA Point Accumulation for Imaging in Nanoscale Topography (DNA-PAINT), a super-resolution microscopy (SRM) technique, to study the surface functionality in poly(lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) NPs with different PEG structures. We demonstrated how the length of the PEG spacer can influence the accessibility of surface chemical functionality, highlighting the importance of SRM techniques to support the rational design of functionalized NPs.

JTD Keywords: chain-length, density, plga, surface, systems, Chain-length, Density, Dna, Microscopy technique, Nanoparticles, Nanoscale topography, Paint, Peg spacers, Plga, Poly lactide-co-glycolide, Poly-lactide-co-glycolide, Polyethylene glycols, Polylactide-co-glycolide, Single-particle, Super-resolution microscopy, Superresolution microscopy, Surface, Surface chemicals, Surface functionalities, Systems

Abramov A, Maiti B, Keridou I, Puiggalí J, Reiser O, Díaz DD, (2021). A pH-Triggered Polymer Degradation or Drug Delivery System by Light-Mediated Cis/Trans Isomerization of o-Hydroxy Cinnamates Macromolecular Rapid Communications 42,

A new methodology for the pH-triggered degradation of polymers or for the release of drugs under visible light irradiation based on the cyclization of ortho-hydroxy-cinnamates (oHC) to coumarins is described. The key oHC structural motif can be readily incorporated into the rational design of novel photocleavable polymers via click chemistry. This main-chain moiety undergoes a fast photocleavage when irradiated with 455 nm light provided that a suitable base is added. A series of polyethylene glycol-alt-ortho-hydroxy cinnamate (polyethylene glycol (PEG)(n)-alt-oHC)-based polymers are synthesized and the time-dependent visible-light initiated cleavage of the photoactive monomer and polymer is investigated in solution by a variety of spectroscopic and chromatographic techniques. The photo-degradation behavior of the water-soluble poly(PEG(2000)-alt-oHC) is investigated within a broad pH range (pH = 2.1-11.8), demonstrating fast degradation at pH 11.8, while the stability of the polymer is greatly enhanced at pH 2.1. Moreover, the neat polymer shows long-term stability under daylight conditions, thus allowing its storage without special precautions. In addition, two water-soluble PEG-based drug-carrier molecules (mPEG(2000)-oHC-benzhydrol/phenol) are synthesized and used for drug delivery studies, monitoring the process by UV-vis spectroscopy in an ON/OFF intermittent manner.

JTD Keywords: coumarins, drug delivery, e/z-double bond isomerization, o-hydroxy cinnamates, polymer degradation, Aliphatic compounds, Antioxidant activity, Antitumor, Chromatographic techniques, Chromatography, Cis/trans isomerization, Controlled drug delivery, Coumarin derivatives, Coumarins, Drug delivery, Drug delivery system, E/z-double bond isomerization, Films, Hydrogels, Image enhancement, Light, Long term stability, O-hydroxy cinnamates, Particles, Photoactive monomers, Photodegradation, Polyethylene glycols, Polyethylenes, Polymer degradation, Responsive polymers, Salts, Structural motifs, Synthesis (chemical), Targeted drug delivery, Visible light photocatalysis, Visible-light irradiation

Hoyos-Nogués, Mireia, Buxadera-Palomero, Judit, Ginebra, Maria-Pau, Manero, José María, Gil, F. J., Mas-Moruno, Carlos, (2018). All-in-one trifunctional strategy: A cell adhesive, bacteriostatic and bactericidal coating for titanium implants Colloids and Surfaces B: Biointerfaces 169, 30-40

Strategies to inhibit initial bacterial adhesion are extremely important to prevent infection on biomaterial surfaces. However, the simultaneous attraction of desired eukaryotic cells remains a challenge for successful biomaterial-host tissue integration. Here we describe a method for the development of a trifunctional coating that repels contaminating bacteria, kills those that adhere, and promotes osteoblast adhesion. To this end, titanium surfaces were functionalized by electrodeposition of an antifouling polyethylene glycol (PEG) layer and subsequent binding of a peptidic platform with cell-adhesive and bactericidal properties. The physicochemical characterization of the samples via SEM, contact angle, FTIR and XPS analysis verified the successful binding of the PEG layer and the biomolecules, without altering the morphology and topography of the samples. PEG coatings inhibited protein adsorption and osteoblast-like (SaOS-2) attachment; however, the presence of cell adhesive domains rescued osteoblast adhesion, yielding higher values of cell attachment and spreading compared to controls (p < 0.05). Finally, the antibacterial potential of the coating was measured by live/dead assays and SEM using S. sanguinis as a model of early colonizer in oral biofilms. The presence of PEG layers significantly reduced bacterial attachment on the surfaces (p < 0.05). This antibacterial potential was further increased by the bactericidal peptide, yielding values of bacterial adhesion below 0.2% (p < 0.05). The balance between the risk of infection and the optimal osteointegration of a biomaterial is often described as “the race for the surface”, in which contaminating bacteria and host tissue cells compete to colonize the implant. In the present work, we have developed a multifunctional coating for a titanium surface that promotes the attachment and spreading of osteoblasts, while very efficiently inhibits bacterial colonization, thus holding promise for application in bone replacing applications.

JTD Keywords: Polyethylene glycol, Antibacterial, Osteointegration, Multifunctionality, Peptides, Titanium

Serra, T., Navarro, M., Planell, J. A., (2012). Fabrication and characterization of biodegradable composite scaffolds for tissue engineering Innovative Developments in Virtual and Physical Prototyping 5th International Conference on Advanced Research and Rapid Prototyping (ed. Margarida, T., Ferreira, D.), Taylor & Francis (Leiria, Portugal) VR@P, 67-72

In this study, polylactic acid (PLA) and polyethylene glycol (PEG) were combined with soluble CaP glass particles and processed by rapid prototyping to obtain fully biodegradable structures for Tissue Engineering applications. The obtained 3D biodegradable structures were characterized in terms of their architecture and mechanical properties. The scaffold morphology, internal micro-architecture and mechanical properties were evaluated using Scanning Electron Microscopy (SEM), micro-computed tomography (micro-CT) and mechanical testing, respectively. Well defined structures with pore size of 350-400μm (in the axial view), struts width of approximately 70-80μm, and a porosity ranging between 60-65% were obtained. The combination RP and PLA/PEG/CaP glass turned into promising fully degradable, mechanically stable, bioactive and biocompatible composite scaffolds for TE.

JTD Keywords: Axial view, Biodegradable composites, Composite scaffolds, Glass particles, Mechanically stable, Micro architectures, Micro computed tomography (micro-CT), Poly lactic acid, Scaffold morphology, Tissue engineering applications, Well-defined structures, Bioactive glass, Mechanical properties, Mechanical testing, Polyethylene glycols, Polymer blends, Rapid prototyping, Scaffolds (biology), Scanning electron microscopy, Computerized tomography