Preclinical Evaluation of a Lead Specific Chelator (PSC) Conjugated to Radiopeptides for ²⁰³Pb and ²¹²Pb-Based Theranostics

203Pb and 212Pb have emerged as promising theranostic isotopes for image-guided α-particle radionuclide therapy for cancers. Here, we report a cyclen-based Pb specific chelator (PSC) that is conjugated to tyr3-octreotide via a PEG2 linker (PSC-PEG-T) targeting somatostatin receptor subtype 2 (SSTR2). PSC-PEG-T could be labeled efficiently to purified 212Pb at 25 °C and also to 212Bi at 80 °C. Efficient radiolabeling of mixed 212Pb and 212Bi in PSC-PEG-T was also observed at 80 °C. Post radiolabeling, stable Pb(II) and Bi(III) radiometal complexes in saline were observed after incubating [203Pb]Pb-PSC-PEG-T for 72 h and [212Bi]Bi-PSC-PEG-T for 5 h. Stable [212Pb]Pb-PSC-PEG-T and progeny [212Bi]Bi-PSC-PEG-T were identified after storage in saline for 24 h. In serum, stable radiometal/radiopeptide were observed after incubating [203Pb]Pb-PSC-PEG-T for 55 h and [212Pb]Pb-PSC-PEG-T for 24 h. In vivo biodistribution of [212Pb]Pb-PSC-PEG-T in tumor-free CD-1 Elite mice and athymic mice bearing AR42J xenografts revealed rapid tumor accumulation, excellent tumor retention and fast renal clearance of both 212Pb and 212Bi, with no in vivo redistribution of progeny 212Bi. Single-photon emission computed tomography (SPECT) imaging of [203Pb]Pb-PSC-PEG-T and [212Pb]Pb-PSC-PEG-T in mice also demonstrated comparable accumulation in AR42J xenografts and renal clearance, confirming the theranostic potential of the elementally identical 203Pb/212Pb radionuclide pair

Preclinical Evaluation of a Lead Specific Chelator (PSC) Conjugated to Radiopeptides for 203Pb and 212Pb-Based Theranostics

203Pb and 212Pb have emerged as promising theranostic isotopes for image-guided α-particle radionuclide therapy for cancers. Here, we report a cyclen-based Pb specific chelator (PSC) that is conjugated to tyr3-octreotide via a PEG2 linker (PSC-PEG-T) targeting somatostatin receptor subtype 2 (SSTR2). PSC-PEG-T could be labeled efficiently to purified 212Pb at 25 °C and also to 212Bi at 80 °C. Efficient radiolabeling of mixed 212Pb and 212Bi in PSC-PEG-T was also observed at 80 °C. Post radiolabeling, stable Pb(II) and Bi(III) radiometal complexes in saline were observed after incubating [203Pb]Pb-PSC-PEG-T for 72 h and [212Bi]Bi-PSC-PEG-T for 5 h. Stable [212Pb]Pb-PSC-PEG-T and progeny [212Bi]Bi-PSC-PEG-T were identified after storage in saline for 24 h. In serum, stable radiometal/radiopeptide were observed after incubating [203Pb]Pb-PSC-PEG-T for 55 h and [212Pb]Pb-PSC-PEG-T for 24 h. In vivo biodistribution of [212Pb]Pb-PSC-PEG-T in tumor-free CD-1 Elite mice and athymic mice bearing AR42J xenografts revealed rapid tumor accumulation, excellent tumor retention and fast renal clearance of both 212Pb and 212Bi, with no in vivo redistribution of progeny 212Bi. Single-photon emission computed tomography (SPECT) imaging of [203Pb]Pb-PSC-PEG-T and [212Pb]Pb-PSC-PEG-T in mice also demonstrated comparable accumulation in AR42J xenografts and renal clearance, confirming the theranostic potential of the elementally identical 203Pb/212Pb radionuclide pair

The use of biotechnologies in textile processing and environmental sustainability: An emerging market context

The research aims to critically discuss key new biotechnologies in textile processing and examines the foundation of the resistance to adoption of such technologies in emerging markets. Using semi-structured interviews and the scientific literature, the paper draws on experts’ opinions about enzyme applications; at the same time, the paper interrogates policymakers and economic operators about the barriers to biotechnology adoption in emerging markets. The paper finds that the application of biotechnologies in textile processing is an environmentally sustainable alternative to traditional chemical processing. Enzymatic processing involves less water and energy, thus causing less environmental degradation. The research builds on strategic management tools, such as Lewin force field analysis and change framework to examine drivers and barriers to enzymatic processing specifically in the textile sector in developing economies. This has enabled the paper to suggest more vigorous and systematic actions from both policymakers and economic actors for greater environmental sustainability. The research contributes to raise awareness about the environmental consequences of older textile processing methods and defuses the argument that new technologies are out of reach for emerging market economic actors. Biotechnologies in the form of enzymatic processing represent strategic opportunities for emerging markets in economic, environmental and public health terms