Nanocarriers in topical photodynamic therapy.

INTRODUCTION: Photodynamic therapy (PDT) has gained significant attention due to its superiority over conventional treatments. In the context of skin cancers and nonmalignant skin diseases, topical application of photosensitizer formulations onto affected skin, followed by illumination, offers distinct advantages. Topical PDT simplifies therapy by providing easy access to the skin, increasing drug concentration within the target area, and confining residual photosensitivity to the treated skin. However, the effectiveness of topical PDT is often hindered by challenges such as limited skin penetration or photosensitizer instability. Additionally, the hypoxic tumor environment poses further limitations. Nanocarriers present a promising solution to address these challenges. AREAS COVERED: The objective of this review is to comprehensively explore and highlight the role of various nanocarriers in advancing topical PDT for the treatment of skin diseases. The primary focus is to address the challenges associated with conventional topical PDT approaches and demonstrate how nanotechnology-based strategies can overcome these challenges, thereby improving the overall efficiency and efficacy of PDT. EXPERT OPINION: Nanotechnology has revolutionized the field of PDT, offering innovative tools to combat the unfavorable features of photosensitizers and hurdles in PDT. Nanocarriers enhance skin penetration and stability of photosensitizers, provide controlled drug release, reduce needed dose, increase production of reactive oxygen species, while reducing side effects, thereby improving PDT effectiveness.

Enrichment of phosphoproteins for proteomic analysis using immobilized Fe(III)-affinity adsorption chromatography.

We described an efficient protocol to strongly enrich phosphoproteins from mixtures of total cellular proteins using homemade, recyclable Fe(III)-affinity columns. An integral feature of the method is the use of a detergent cocktail that allows use of different pHs for total protein extraction (pH 6.8) and for subsequent affinity capture of phosphoproteins (pH 3.4). Affinity captured proteins from rat fibroblasts were fractionated on 2D gels and random selection was identified by mass spectrometry. More than 85% of identified proteins were previously known to be phosphorylated. The specificity of the method was further validated by isolating proteins from (32)P labeled cells. Our comparison of the clusters of acidic residues in the captured proteins with acidic clusters in proteins of the rat genome indicates that affinity for phosphate groups dominates over adsorption of proteins with acidic clusters.