Cytotoxicity of PEG-Coated Gold and Gold-Iron Alloy Nanoparticles: ROS or Ferroptosis?

Nanomedicine relies on the exploitation of nanoscale constructs for therapeutic and diagnostic functions. Gold and gold-iron alloy nanoparticles (NPs) are two examples of nanomaterials with favorable features for use in nanomedicine. While gold NPs have been studied extensively in the last decades, they are not biodegradable.

Polyurethane films formation from microcrystalline cellulose as a polyol and cellulose nanocrystals as additive: Reactions favored by the low viscosity of the source of isocyanate groups used.

To simultaneously form films while synthesizing solvent-free and catalyst-free bio-based polyurethanes, hexamethylene diisocyanate trimer was selected as an isocyanate group source to produce a low-viscosity reaction medium for dispersing high contents of microcrystalline cellulose (MCC, polyol) and cellulose nanocrystals (CNC). Castor oil was used as an additional polyol source. Up to 80 % of the MCC was dispersed, producing a film exhibiting the highest T (72 °C), tensile strength (18 MPa), and Young's modulus (522.

Photoantibacterial Poly(vinyl)chloride Films Applying Curcumin Derivatives as Bio-Based Plasticizers and Photosensitizers.

Herein we describe the design of natural curcumin ester and ether derivatives and their application as potential bioplasticizers, to prepare photosensitive phthalate-free PVC-based materials. The preparation of PVC-based films incorporating several loadings of newly synthesized curcumin derivatives along with their standard solid-state characterization is also described. Remarkably, the plasticizing effect of the curcumin derivatives in the PVC material was found to be similar to that observed in previous PVC-phthalate materials.

Tumor radiosensitization by photobiomodulation.

Purpose: To investigate the safety of photobiomodulation therapy (PBM) in tumors and its potential as a radiosensitizer when combined with radiotherapy.

Methods: We have performed in vitro experiments in A431 cells to assess proliferation and cell cycle after PBM, as well as clonogenic assay and H2AX-gamma immunolabeling to quantify double strand breaks after the combination of PBM and radiation. In vivo experiments in xenografts included Kaplan-Meier survival analysis, optical coherence tomography (OCT) and histological analysis.

Photobiomodulation effects on photodynamic therapy in HNSCC cell lines.

A combination of metabolic modifications by light stimulus and photodynamic action is very attractive. Photobiomodulation therapy (PBMT) comprehends a vast range of applications and has been shown to be suitable to ease morbidities caused by chemotherapy and radiation, such as mucositis and dermatitis. The current study investigates the effects of near-infrared PBMT combined with porphyrin-based photodynamic therapy (PDT) in squamous cell carcinoma cell lines SCC-25 and SCC-4.

Dissolving microneedles containing aminolevulinic acid improves protoporphyrin IX distribution.

One important limitation of topical photodynamic therapy (PDT) is the limited tissue penetration of precursors. Microneedles (MNs) are minimally invasive devices used to promote intradermal drug delivery. Dissolving MNs contain drug-associated to polymer blends, dissolving after insertion into skin, allowing drug release.

A threshold dose distribution approach for the study of PDT resistance development: A threshold distribution approach for the study of PDT resistance.

Photodynamic therapy (PDT) is a technique with well-established principles that often demands repeated applications for sequential elimination of tumor cells. An important question concerns the way surviving cells from a treatment behave in the subsequent one. Threshold dose is a core concept in PDT dosimetry, as the minimum amount of energy to be delivered for cell destruction via PDT.

Determination of the threshold dose distribution in photodynamic action from in vitro experiments.

The concept of threshold in photodynamic action on cells or microorganisms is well observed in experiments but not fully explored on in vitro experiments. The intercomparison between light and used photosensitizer among many experiments is also poorly evaluated. In this report, we present an analytical model that allows extracting from the survival rate experiments the data of the threshold dose distribution, ie, the distribution of energies and photosensitizer concentration necessary to produce death of cells.