Synthesis, proteolytic stability, and in vitro evaluation of DOTA conjugated p160 peptide based radioconjugates: [177Lu]Lu-DOTA-p160.

In this work, we describe the synthesis, in vitro stability, and preliminary biological evaluation of [177Lu]Lu-DOTA-p160 peptide-based radiopharmaceuticals. Our findings highlight that all DOTA-p160-peptide radioconjugates exhibit favorable proteolytic and enzymatic stability with a prolonged half-life in human plasma and serum. Cell uptake studies carried out on MCF-7 cell line revealed saturable binding of the radioconjugates in the nanomolar range, thereby demonstrating their promising potential in the imaging and therapy of breast tumors.

Synthesis, characterization, and relaxation studies of Gd-DO3A conjugate of chlorambucil as a potential theranostic agent.

DO3A-based macrocycles serve as attractive templates from which clinically useful theranostic agents can be obtained after coupling with molecular targeted therapeutic drugs. In this study, we describe the chemical synthesis, relaxation, and cytotoxicity studies of a new DO3A conjugate of chlorambucil (CHL) as a magnetic resonance imaging (MRI) theranostic agent. A convenient route of synthesis is reported, which allowed conjugation of the macrocyclic ligand (DO3A) to the chemotherapeutic drug (CHL) via tyrosine for the preparation of an attractive chelate-drug ensemble (DO3A-TR-CHL). The structures of all intermediates and final compound have been determined by 1 H, 13 C NMR, and MS. The efficacy of DO3A-TR-CHL as a non-ionic magnetic contrast agent was tested by performing relaxometric studies on its gadolinium complex. The complex exhibited relaxivities (7.11 mm-1 /s) higher than that of currently used MR contrast agents and showed enhanced contrast in T1 -weighted images. MTT assays revealed that both DO3A-TR-CHL and Gd(III)-DO3A-TR-CHL conjugates exhibited dose-dependent toxicity and an enhanced antiproliferative activity against tumor (A549 and HeLa) cell lines compared to that of parent drug (CHL), thereby demonstrating their potential to be used as a magnetic resonance imaging theranostic for improved molecular imaging and therapy of human cancers.

Bioconjugated iron oxide nanocubes: synthesis, functionalization, and vectorization.

A facile bottom-up approach for the synthesis of inorganic/organic bioconjugated nanoprobes based on iron oxide nanocubes as the core with a nanometric silica shell is demonstrated. Surface coating and functionalization protocols developed in this work offered good control over the shell thickness (8-40 nm) and enabled biovectorization of SiO2@Fe3O4 core-shell structures by covalent attachment of folic acid (FA) as a targeting unit for cellular uptake. The successful immobilization of folic acid was investigated both quantitatively (TGA, EA, XPS) and qualitatively (AT-IR, UV-vis, ζ-potential). Additionally, the magnetic behavior of the nanocomposites was monitored after each functionalization step. Cell viability studies confirmed low cytotoxicity of FA@SiO2@Fe3O4 conjugates, which makes them promising nanoprobes for targeted internalization by cells and their imaging.

SiO2@Fe2O3 core-shell nanoparticles for covalent immobilization and release of sparfloxacin drug.

Silica-coated Fe(2)O(3) nanoparticles were synthesized as carriers for the covalent immobilization and release of antimicrobial drug sparfloxacin (SPFX). SPFX-loaded nanoparticles exhibited time-dependent drug release, with no measurable in vitro cytotoxicity, making the drug@nanoparticle conjugates potentially relevant for nanomedicine applications.