This study reports the preparation of alginate (Alg) beads incorporating different amounts of halloysite nanotubes (HNTs) and kaolin (K) in the presence of Ca²⁺ ions to compare their drug loading and release behaviors. The resulting composites, HNTs@Alg and K@Alg, were characterized using FTIR, SEM–EDS, XRD, and XPS analyses. Chlortetracycline hydrochloride (CTC) was employed as a model antibiotic to evaluate their drug delivery performance. The concentration of Alg and the incorporation of HNTs or K markedly influenced the adsorption capacity and release profile. The maximum drug loading capacities were 48.12 ± 1.4 mg/g for HNTs, 40.1 ± 1.2 mg/g for K, 59.85 ± 2.3 mg/g for HNTs@Alg-1 (1 g HNTs and 1% Alg), and 68.74 ± 2.1 mg/g for K@Alg-1 (1 g K and 1% Alg). The inclusion of Alg enhanced sustained release, extending beyond 100 h. Among the composite beads, HNTs@Alg-1 showed superior CTC release behavior compared to K@Alg-1. Furthermore, antibacterial assays confirmed that the CTC-loaded beads effectively inhibited E. coli and S. aureus, demonstrating maintained drug activity after encapsulation. Both systems effectively prolonged CTC release and exhibited antibacterial efficacy, highlighting their potential as controlled drug delivery matrices for wound treatment applications.

Auger-emitting radionuclides, exemplified by Pd-103, exhibit considerable therapeutic potential in cancer treatment due to their high cytotoxicity and localized biological impact. Despite these advantages, the separation of such radionuclides presents a complicated challenge, requiring intricate and time-intensive “wet chemistry” methods attributed to the exceptional chemical inertness of the associated metals. This study proposes an innovative solution to this separation challenge through the design and implementation of a piece of radionuclide separation equipment (RSE). The equipment employs a dry distillation approach, capitalizing on differences in partial vapor pressures between irradiated and resulting radioactive metals, with a diffusion-driven extraction method applied to separate Pd-103 radionuclides generated via the proton irradiation of Rh-103 at cyclotron. Our optimization endeavors focused on determining the optimal temperature for effective metal separation and adjusting the diffusion, evaporation, and deposition rates, as well as addressing chemical impurities. The calculations indicate 17% ± 2% separation efficiency with our RSE. Approximately 77 ± 2% and 49 ± 2% of the deposited Pd-103 were isolated on substrates of Nb foil and ZnO-covered W disc, respectively. The proposed innovative dry distillation method that has been experimentally tested offers a promising alternative to conventional separation techniques, enabling enhanced purity and cost-efficient cancer treatment strategies.

Background/Objectives: The ¹⁰³Pd/^103mRh in vivo generator represents a promising Auger electron-emitting system, in which both parent and daughter radionuclides emit predominantly Auger electrons with minimal accompanying radiation. This study investigates the release dynamics of daughter radionuclides from the ¹⁰³Pd/^103mRh in vivo generator and evaluates the underlying mechanisms governing bond rupture and daughter retention. Methods: Cyclotron irradiation of rhodium foils was performed in two separate batches, followed by radionuclide separation using conventional wet chemistry and a novel dry distillation technique. The purified ¹⁰³Pd radionuclide was used to radiolabel DOTA-TATE, phthalocyanine-TATE, and DOTA-TOC chelators. The resulting complexes were immobilized on Strata-X and Strata-C18 solid-phase extraction columns. Scheduled elution experiments were conducted to quantify the release of the ^103mRh daughter radionuclide. Results: The measured ^103mRh release rates were 9.8 ± 3.0% and 9.6 ± 2.7% from Strata-X columns with DOTA-TATE and phthalocyanine-TATE, respectively, and 10.5 ± 2.7% and 12.0 ± 0.5% from Strata-X and Strata-C18 columns, respectively, with DOTA-TOC. These values are significantly lower than the ~100% release predicted based on the reported Auger electron yield of 186%. One explanation for this difference could be potential inconsistencies in decay data that may require correction; this needs further investigation. The results further demonstrated that delocalized π-electrons, introduced via phthalocyanine-based chelation, did not mitigate daughter release. Conclusions: The low observed daughter nuclide release represents a favorable characteristic for the future clinical translation of the ¹⁰³Pd/^103mRh Auger emitter pair. The findings support the conclusion that Auger electron cascades, rather than nuclear recoil energy, dominate bond rupture processes.

Auger-emitting radionuclides exemplified by Pd-103, exhibit considerable therapeutic potential in cancer treatment due to their heightened cytotoxicity and localized biological impact. Despite these advantages, the separation of such radionuclides presents a complicated challenge, requiring intricate and time-intensive "wet chemistry" methods attributed to the exceptional chemical inertness of the associated metals. This study proposes an innovative solution to this separation challenge through the design and implementation of a radionuclide separation equipment (RSE). The equipment employs a dry distillation approach, capitalizing on differences in partial vapor pressures between irradiated and resulting radioactive metals, with a diffusion-driven extraction method applied to separate Pd-103 radionuclides generated via proton irradiation of Rh-103 at the ATOMKI MGC-20 cyclotron. Optimization endeavors focused on determining the optimal temperature for effective metal separation, adjusting diffusion, evaporation, and deposition rates, as well as addressing chemical impurities. Calculations indicate 17 % ± 2 % separation efficiency with our RSE. Approximately 77% ± 2% and 49% ± 2% of the deposited Pd-103 were isolated on substrates of Nb foil and ZnO-covered W disk, respectively. The proposed innovative dry distillation method that has been experimentally tested, offers a promising alternative to conventional separation techniques, enabling enhanced purity and cost-efficient cancer treatment strategies.

Background/Objectives: Palladium-103 (¹⁰³Pd) is an Auger electron-emitting radionuclide with nanometer-scale penetration ranges that result in highly localized energy deposition, making it well suited for molecularly targeted radionuclide therapy. However, efficient production, separation, and in vivo evaluation workflows remain limited. This study aimed to establish a scalable workflow for the production, separation, purification, radiolabeling, and preclinical assessment of ¹⁰³Pd for theranostic applications. Methods: ¹⁰³Pd was produced via the ¹⁰³Rh(p,n)¹⁰³Pd reaction. An upgraded dry-distillation radionuclide separation equipment (RSE) enabled high-efficiency separation from irradiated rhodium foils, while a cotton-assisted acid recovery process yielded purified ¹⁰³Pd suitable for radiolabeling. Chelation with NOTA and DOTA-TATE was performed, and radiochemical purity was assessed using iTLC, SPE, and a C18 column. In vivo SPECT/CT imaging was conducted in NMRI Nu/Nu mice and in a canine model with spontaneous liver metastatic spread of insulinoma, injected with [¹⁰³Pd]Pd-labeled compounds. Results: The upgraded RSE achieved separation efficiencies of 64–86% and overall recovery yields of 81–94%, outperforming conventional wet-chemistry methods. Radiolabeling produced stable complexes with >95% radiochemical purity. SPECT/CT imaging confirmed in vivo stability in mice. In the canine model, a slight reduction in tumor size and increased glucose levels were observed during 24 days post-systemic application of 520 MBq of ¹⁰³Pd-DOTA-TATE radioactivity. Conclusions: This study establishes a complete and efficient radiochemical and preclinical pipeline for ¹⁰³Pd, demonstrating its feasibility as a theranostic radionuclide. The combination of high-yield production, robust separation chemistry, and localized Auger-mediated energy deposition highlights ¹⁰³Pd as a promising candidate for future targeted radionuclide therapy applications.