Publications by authors named "Gokce Engudar"

Molecular imaging using positron emission tomography (PET) provides sensitive detection and mapping of molecular targets. While cancer-associated fibroblasts and integrins have been proposed as targets for imaging of pancreatic ductal adenocarcinoma (PDAC), herein, spatial transcriptomics and proteomics of human surgical samples are applied to select PDAC targets. We find that selected cancer cell surface markers are spatially correlated and provide specific cancer localization, whereas the spatial correlation between cancer markers and immune-related or fibroblast markers is low.

View Article and Find Full Text PDF

Background: Targeted radionuclide therapy is established as a highly effective strategy for the treatment of metastatic tumors; however, the co-development of suitable imaging companions to therapy remains significant challenge. Theranostic isotopes of terbium (Tb, Tb, Tb, Tb) have the potential to provide chemically identical radionuclidic pairs, which collectively encompass all modes of nuclear decay relevant to nuclear medicine. Herein, we report the first radiochemistry and preclinical studies involving Tb- and Tb-labeled crown-αMSH, a small peptide-based bioconjugate suitable for targeting melanoma.

View Article and Find Full Text PDF

Superior bifunctional chelating ligands, which can sequester both α-emitting radionuclides (Ac, Bi) and their diagnostic companions (Tb, In), remain a formidable challenge to translating targeted alpha therapy, with complementary diagnostic imaging, to the clinic. HnoneupaX, a chelating ligand with an unusual diametrically opposed arrangement of pendant donor groups, has been developed to this end. HnoneunpaX preferentially complexes Ln and An ions, forming thermodynamically stable (pLa = 17.

View Article and Find Full Text PDF

Background: The radionuclide Ga-68 is commonly used in nuclear medicine, specifically in positron emission tomography (PET). Recently, the interest in producing Ga-68 by cyclotron irradiation of [Zn]Zn nitrate liquid targets is increasing. However, current purification methods of Ga-68 from the target solution consist of multi-step procedures, thus, leading to a significant loss of activity through natural decay.

View Article and Find Full Text PDF

Terbium radioisotopes (Tb, Tb, Tb, Tb) offer a unique class of radionuclides which encompass all four medicinally relevant nuclear decay modalities (α, , γ, /e), and show high potential for the development of element-matched theranostic radiopharmaceuticals. The goal of this study was to design, synthesise, and evaluate the suitability of crown-TATE as a new peptide-conjugate for radiolabelling of [Tb]Tb and [Tb]Tb, and to assess the imaging and pharmacokinetic properties of each radiotracer in tumour-bearing mice. [Tb]Tb-crown-TATE and [Tb]Tb-crown-TATE were prepared efficiently under mild conditions, and exhibited excellent stability in human serum (>99.

View Article and Find Full Text PDF

The difluoromethyl group plays an important role in modern medicinal and agrochemistry. While several difluoromethylation reagents have been reported, these typically rely on difluoromethyl carbenes or anions, or target specific processes. Here, we describe a conceptually unique and general process for O-H, N-H and C-H difluoromethylation that involves the formation of a transient dithiole followed by facile desulfurative fluorination using silver(I) fluoride.

View Article and Find Full Text PDF

Targeted Alpha Therapy (TAT) has shown very high potential for the treatment of cancers that were not responsive to other therapy options (e.g., β therapy and chemotherapy).

View Article and Find Full Text PDF

Human insulin (HI) has fascinating metal-facilitated self-assembly properties that are essential for its biological function. HI has a natural Zn binding site and we have previously shown that covalently attached abiotic ligands (e.g.

View Article and Find Full Text PDF

Introduction: Radiotherapy of cancer requires both alpha- and beta-particle emitting radionuclides, as these radionuclide types are efficient at destroying different types of tumors. Both classes of radionuclides require a vehicle, such as an antibody or a polymer, to be delivered and retained within the tumor. Polyglutamic acid (pGlu) is a polymer that has proven itself effective as a basis of drug-polymer conjugates in the clinic, while its derivatives have been used for pretargeted tumor imaging in a research setup.

View Article and Find Full Text PDF

Long circulating liposomes entrapping iodinated and radioiodinated compounds offer a highly versatile theranostic platform. Here we report a new methodology for efficient and high-yield loading of such compounds into liposomes, enabling CT/SPECT/PET imaging and I-radiotherapy. The CT contrast agent diatrizoate was synthetically functionalized with a primary amine, which enabled its remote loading into PEGylated liposomes by either an ammonium sulfate- or a citrate-based pH transmembrane gradient.

View Article and Find Full Text PDF

Significant progress in the characterization of protein corona has been made. However, insights on how the corona affects the aggregation of nanoparticles (NPs) and consequent biological identity are still lacking. Here, we examined how the corona formed from four major serum proteins, immunoglobulin G (IgG), fibrinogen (FBG), apolipoprotein A1 (ApoA1), and human serum albumin (HSA), over a range of concentrations affects the aggregation of gold NPs (AuNPs).

View Article and Find Full Text PDF

At the nano-bio interface, human plasma differentially interacts with engineered nanomaterials through the creation of protein coronas, which in turn become primary determinants of both the pharmacokinetics and pharmacodynamics of circulating nanoparticles. Here, for the first time, the specific binding kinetics of the four major corona forming proteins (human serum albumin, fibrinogen, ApoA1, and polyclonal IgG) are determined for gold nanoparticles (AuNPs). Using a multiplexed surface plasmonic assay, highly reproducible measurements of on rate (k(on)), off rate (k(off)), and disassociation constant (K(D)), in addition to relative amounts of protein binding, are obtained.

View Article and Find Full Text PDF