Expression of concern: An 'on-demand' photothermal antibiotic release cryogel patch: evaluation of efficacy on an model for skin wound infection.

Expression of concern for 'An 'on-demand' photothermal antibiotic release cryogel patch: evaluation of efficacy on an model for skin wound infection' by Léa Rosselle, , , 2020, , 5911-5919, https://doi.org/10.1039/D0BM01535K.

Self-Assembly of Cyclodextrin-Coated Nanoparticles:Fabrication of Functional Nanostructures for Sensing and Delivery.

In recent years, the bottom-up approach has emerged as a powerful tool in the fabrication of functional nanomaterials through the self-assembly of nanoscale building blocks. The cues embedded at the molecular level provide a handle to control and direct the assembly of nano-objects to construct higher-order structures. Molecular recognition among the building blocks can assist their precise positioning in a predetermined manner to yield nano- and microstructures that may be difficult to obtain otherwise.

Photothermally Active Cryogel Devices for Effective Release of Antimicrobial Peptides: On-Demand Treatment of Infections.

There has been significant interest in the use of peptides as antimicrobial agents, and peptide containing hydrogels have been proposed as biological scaffolds for various applications. Limited stability and rapid clearance of small molecular weight peptides pose challenges to their widespread implementation. As a common approach, antibacterial peptides are physically loaded into hydrogel scaffolds, which leads to continuous release through the passive mode with spatial control but provides limited control over drug dosage.

Bioengineered elastin- and silk-biomaterials for drug and gene delivery.

Advances in medical science have led to diverse new therapeutic modalities, as well as enhanced understanding of the progression of various disease states. These findings facilitate the design and development of more customized and exquisite drug delivery systems that aim to improve therapeutic indices of drugs to treat a variety of conditions. Synthetic polymer-based drug carriers have often been the focus of such research.

An 'on-demand' photothermal antibiotic release cryogel patch: evaluation of efficacy on an ex vivo model for skin wound infection.

A myriad of topical therapies and dressings are available to the clinicians for wound healing skin, but only a very few have shown their effectiveness in promoting wound repair due to challenges in controlling drug release. To address this issue, in this work, a near infrared (NIR)-light activable cryogel based on butyl methacrylate (BuMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) incorporated with reduced graphene oxide (rGO) was fabricated. The obtained cryogel provides the required hydrophilicity beneficial for wound treatment.

Silk Fibroin Microneedle Patches for the Sustained Release of Levonorgestrel.

The sustained release of levonorgestrel, a contraceptive, from silk-based microneedle patches was demonstrated for transdermal delivery. Modifications in the formulation of the silk protein and drug loading enabled the tuning of drug loading and release rates from the microneedle patches over time. Sustained drug release reached up to 100 days when the drug was loaded directly inside the microneedles, while release continued for more than a year when the drug was loaded inside microparticles prior to casting inside the microneedle patches.

Thiol-Reactive Clickable Cryogels: Importance of Macroporosity and Linkers on Biomolecular Immobilization.

Macroporous cryogels that are amenable to facile functionalization are attractive platforms for biomolecular immobilization, a vital step for fabrication of scaffolds necessary for areas like tissue engineering and diagnostic sensing. In this work, thiol-reactive porous cryogels are obtained via photopolymerization of a furan-protected maleimide-containing poly(ethylene glycol) (PEG)-based methacrylate (PEGFuMaMA) monomer. A series of cryogels are prepared using varying amounts of the masked hydrophilic PEGFuMaMA monomer, along with poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate, a hydrophilic monomer and cross-linker, respectively, in the presence of a photoinitiator.

Tunable Biodegradable Silk-Based Memory Foams with Controlled Release of Antibiotics.

Sustained, local delivery of the antibiotic ciprofloxacin under different formats from porous silk protein-based memory foam systems was studied. Similarly, protease XIV was incorporated during processing to provide control of the degradation kinetics of the silk materials. In vitro antibiotic release studies combined with degradation assessments were utilized to assess the mechanisms and kinetics of release from the silk materials.

Extended release formulations using silk proteins for controlled delivery of therapeutics.

Introduction: Silk is a promising biomaterial for controlled delivery of therapeutics and has a unique protein chemistry that can be tuned to form different carrier formats. The protein has been studied for sustained release depot systems for the targeted or localized delivery of drugs.

Areas Covered: An overview of natural silk proteins for controlled delivery of therapeutics is provided, with a focus on the features of silk proteins that allow them to be useful tools for controlled delivery.

Surfactant-Free Direct Access to Porphyrin-Cross-Linked Nanogels for Photodynamic and Photothermal Therapy.

Photosensitizing nanogels were obtained through a surfactant-free single-step protocol by using a porphyrin-based cross-linker for stabilizing self-assembled nanosized aggregates of thermoresponsive copolymers. Nanogels with varying amounts of porphyrin retained the singlet oxygen generation ability of the porphyrin core and were also capable of inducing temperature increase upon irradiation at 635 nm. Photoinduced killing efficiency was tested against three cell lines: human breast adenocarcinoma (MDA-MB-231 and MCF7) and pancreatic adenocarcinoma (AsPC-1) cells, and a predominant photodynamic mechanism at 450 nm and a mixed photodynamic and photothermal effect at 635 nm was observed.

Multi-Functional Nanogels as Theranostic Platforms: Exploiting Reversible and Nonreversible Linkages for Targeting, Imaging, and Drug Delivery.

Nanogels that are amenable to facile multi-functionalization with imaging, therapeutic, and targeting agents are attractive theranostic platforms for addressing challenges in conventional diagnostics and therapy. In this work, reactive copolymers containing poly(ethylene glycol), maleimide, and pendant hydroxyl groups as side chains are used to construct nanogels by employing their thermoresponsive self-assembly in aqueous media. Subsequent cross-linking of these nanosized aggregates with dithiols using thiol-maleimide chemistry yields nanogels containing maleimide, thiol, and hydroxyl groups.

"Clickable" Nanogels via Thermally Driven Self-Assembly of Polymers: Facile Access to Targeted Imaging Platforms using Thiol-Maleimide Conjugation.

Multifunctionalizable nanogels are fabricated using thermally driven self-assembly and cross-linking of reactive thermoresponsive copolymers. Nanogels thus fabricated can be easily conjugated with various appropriately functionalized small molecules and/or ligands to tailor them for various applications in delivery and imaging. In this study, a poly(ethylene glycol)-methacrylate-based maleimide-bearing copolymer was cross-linked with a dithiol-based cross-linker to synthesize nanogels.