Rethinking Thin-Layer Chromatography for Screening Technetium-99m Radiolabeled Polymer Nanoparticles

Thin-layer chromatography (TLC) is commonly employed to screen technetium-99m labeled polymer nanoparticle batches for unreduced pertechnetate and radio-colloidal impurities. Although this method is widely accepted, our findings applying radiolabeled PLGA/PLA-PEG nanoparticles underscore its lack of transferability between different settings and its limitations as a standalone quality control tool. While TLC profiles may appear similar for purified and radiocolloid containing nanoparticle formulations, their in vivo behavior can vary significantly, as demonstrated by discrepancies between TLC results and single-photon emission computed tomography (SPECT) and biodistribution data. This highlights the urgent need for a case-by-case evaluation of TLC methods for each specific nanoparticle type. Our study revealed that polymeric nanoparticles cannot be considered analytically uniform entities in the context of TLC analysis, emphasizing the complex interplay between nanoparticle composition, radiolabeling conditions, and subsequent biological behavior.

pH-temperature dual-sensitive nucleolipid-containing stealth liposomes anchored with PEGylated AuNPs for triggering delivery of doxorubicin

Liposomes (Lip) are useful nanocarriers for drug delivery and cancer nanomedicine because of their ability to efficiently encapsulate drugs with different physical and chemical properties. The pH gradient between normal and tumoral tissues, and their rapid metabolism that induces hyperthermia encourage the development of pH- and thermo-sensitive Lip for delivering anticancer drugs. Nucleolipids have been studied as scaffolding material to prepare Lip, mainly for cancer therapy. Herein, we report for the first time the use of 1,2-dipalmitoyl-sn-glycero-3-(cytidine diphosphate) (DG-CDP) to develop pH/thermo-sensitive nucleolipid-containing stealth Lip stabilized by combination with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol, anchored with NH₂-PEGylated gold nanoparticles (PEG-AuNPs, 15 nm) for triggering delivery of doxorubicin (Dox). The optimal composition of DPPC, DG-CDP and cholesterol (94:3:3) was established by Langmuir isotherms. Unloaded and Dox-loaded Lip and AuNPs-Lip exhibited nano-scale sizes (415-650 nm), acceptable polydispersity indexes (<0.33), spherical shapes, and negative Z-potential (-23- -6.6 mV) due to the phosphate groups of DG-CDP, which allowed the anchoring with positively charged AuNPs. High EE% were achieved (>78%) and although efficient control in the Dox release towards different receptor media was observed, the release of Dox from PEG-AuNPs-Lip-Dox was significantly triggered at acidic pH and hyperthermia temperature, demonstrating its responsiveness to both stimuli. Dox-loaded Lip showed high cytotoxic activity against MDA-MB-231 breast cancer cells and SK-OV-3 ovarian cancer cells, suggesting that Dox was released from these nanocarriers over time. Overall, the liposomal formulations showed promising properties as stimuli-responsive nanocarriers for cancer nanomedicine, with prospects for hyperthermia therapy.

Recent Progress in Technetium-99m-Labeled Nanoparticles for Molecular Imaging and Cancer Therapy

Nanotechnology has played a tremendous role in molecular imaging and cancer therapy. Over the last decade, scientists have worked exceptionally to translate nanomedicine into clinical practice. However, although several nanoparticle-based drugs are now clinically available, there is still a vast difference between preclinical products and clinically approved drugs. An efficient translation of preclinical results to clinical settings requires several critical studies, including a detailed, highly sensitive, pharmacokinetics and biodistribution study, and selective and efficient drug delivery to the target organ or tissue. In this context, technetium-99m (^99mTc)-based radiolabeling of nanoparticles allows easy, economical, non-invasive, and whole-body in vivo tracking by the sensitive clinical imaging technique single-photon emission computed tomography (SPECT). Hence, a critical analysis of the radiolabeling strategies of potential drug delivery and therapeutic systems used to monitor results and therapeutic outcomes at the preclinical and clinical levels remains indispensable to provide maximum benefit to the patient. This review discusses up-to-date ^99mTc radiolabeling strategies of a variety of important inorganic and organic nanoparticles and their application to preclinical imaging studies.

Silver Ions Detection via Nucleolipids Self-Assembly

A novel hybrid bioinspired amphiphile featuring a cytosine moiety, which self-assembles into liposomes can be used to detect silver ions in aqueous media. The coordination of Ag⁺ ions by the nucleotide moiety increases membrane rigidity, which enhances the fluorescence of a common reporter, Thioflavin T. Ag⁺ can be sensed even at trace concentrations (3 ppb) with great specificity over other metals ions. These nucleotide based supramolecular structures can be used to detect silver ions in drinking water, demonstrating the robustness of this approach.

Cytidine and ribothymidine nucleolipids synthesis, organogelation, and selective anion and metal ion responsiveness

Nucleolipids of 2′,3′-O-diacylatedribothymidine supports the organogelation by utilizing inherent self-base pairing and solvent mediated bifurcated H-bonding and hydrophobic effect. These organogels exhibits unusual Hg²⁺ mediated base pairing.

Lipid and Nucleic Acid Chemistries: Combining the Best of Both Worlds to Construct Advanced Biomaterials

Hybrid synthetic amphiphilic biomolecules are emerging as promising supramolecular materials for biomedical and technological applications. Herein, recent progress in the field of nucleic acid based lipids is highlighted with an emphasis on their molecular design, synthesis, supramolecular properties, physicochemical behaviors, and applications in the field of health science and technology. In the first section, the design and the study of nucleolipids are in focus and then the glyconucleolipid family is discussed. In the last section, recent contributions of responsive materials involving nucleolipids and their use as smart drug delivery systems are discussed. The supramolecular materials generated by nucleic acid based lipids open new challenges for biomedical applications, including the fields of medicinal chemistry, biosensors, biomaterials for tissue engineering, drug delivery, and the decontamination of nanoparticles.

Cation Tuning of Supramolecular Gel Properties: A New Paradigm for Sustained Drug Delivery

Hydrogels formed by the self-assembly of low-molecular-weight gelators (LMWGs) are promising scaffolds for drug-delivery applications. A new biocompatible hydrogel, resulting from the self-assembly of nucleotide-lipid salts can be safely injected in vivo. The resulting hydrogel provides sustained-release of protein for more than a week.

Small Molecule Radiopharmaceuticals - A Review of Current Approaches

Radiopharmaceuticals are an integral component of nuclear medicine and are widely applied in diagnostics and therapy. Though widely applied, the development of an “ideal” radiopharmaceutical can be challenging. Issues such as specificity, selectivity, sensitivity, and feasible chemistry challenge the design and synthesis of radiopharmaceuticals. Over time, strategies to address the issues have evolved by making use of new technological advances in the fields of biology and chemistry. This review presents the application of few advances in design and synthesis of radiopharmaceuticals. The topics covered are bivalent ligand approach and lipidization as part of design modifications for enhanced selectivity and sensitivity and novel synthetic strategies for optimized chemistry and radiolabeling of radiopharmaceuticals.

Targeted theranostic liposomes: rifampicin and ofloxacin loaded pegylated liposomes for theranostic application in mycobacterial infections

Theranostic liposomes as effective drug delivery systems for the management of infections.