⁶⁸Ga-Radiolabeling Service

Using the cyclotron-independent ⁶⁸Ge/⁶⁸Ga generator system, ⁶⁸Ga radiolabeling facilitates the synthesis of PET tracers for peptides and small molecules in precision diagnostics. Alfa Cytology possesses the specialized expertise to develop robust, kit-based formulations and compliant processes for ⁶⁸Ga-conjugates, ensuring consistent and superior agents for seamless application.

Introduction to ⁶⁸Ga Isotopes

Gallium-68 (⁶⁸Ga) is a positron-emitting radionuclide that is revolutionized for targeted PET imaging thanks to its availability from a Germanium-68/Gallium-68 generator, which eliminates the need for a local cyclotron. Gallium-68 has a half-life of 68 minutes, which equates to the rapid pharmacokinetics of small molecules and peptides, which is beneficial for imaging 1-2 hours post administration. ⁶⁸Ga forms highly stable complexes with macrocyclic chelators, which allow for the development of highly specific diagnostic tools used in precision oncology.

⁶⁸Ga-Labeling for PET Imaging

Gallium-68 (⁶⁸Ga) labeling is a key methodology for PET radiopharmaceuticals, distinguished by its use of a ⁶⁸Ge/⁶⁸Ga generator for cyclotron-independent, on-demand production. The half-life of ⁶⁸Ga is 68 minutes, which is short, and for this reason, it is very well suited for conjugation with small molecules and peptides that have high pharmacokinetic rates. The coordination chemistry with macrocyclic chelators such as DOTA is simple and, therefore, capable of being kit-style prepared. This has been important for the increased use of targeted PET imaging for precision oncology and other fields.

Fig.1 The four main steps of the 68Ga-radiolabeling procedure. (Nelson BJB, et al., 2022)

⁶⁸Ga Radiopharmaceutical

Disclaimer: Alfa Cytology focuses on providing preclinical research services. This table is for information exchange purposes only. This table is not a treatment plan recommendation. For guidance on treatment options, please visit a regular hospital.

Advantages of ⁶⁸Ga-Labeling

Our Services

With the advanced knowledge of chelation with Gallium-68, Alfa Cytology enables easy conversion of new peptides and small molecules into applicable PET imaging agents. This guarantees the consistent supply of ⁶⁸Ga-radiopharmaceuticals of high purity and robust characterization, which is essential for our collaborators to make rapid and informed decisions based on data during the development of their therapeutics.

Custom ⁶⁸Ga Conjugation Service

Using specialized chelation chemistry, the ⁶⁸Ga conjugation service synthesizes an agent for PET imaging with exceptional performance by stably bonding Gallium-68 with various targeting vectors, particularly peptides, small molecules, and other vectors exhibiting swift in vivo kinetics.

Small-Molecule Radionuclide Conjugate (SMRC)

Antibody-Radionuclide Conjugate (ARC)

Peptide-Radionuclide Conjugate (PRC)

siRNA-Radionuclide Conjugate

Workflow for Developing ⁶⁸Ga-Radiolabeled Peptide Conjugates

⁶⁸Ga Custom Peptide Labeling

• Strategy & Reagent Selection: This began with a detailed analysis of the sequence and structure of the peptide to determine the best chelator and conjugation strategy. Such preliminary planning guarantees high specificity and preservation of the biological activity of the molecule.
• Precursor Preparation: In this stage, we focus on carefully attaching the peptide to the chosen chelator, then proceeding to purification and validation of the resultant complex. This step also establishes the precise identity, purity, and appropriateness of the precursor for use in the radiosynthesis.
• Protocol Optimization: Systematic adjustments of key parameters like buffer setup, pH, temperature, and precursor concentrations lead to an optimization of the entire process. Such a data-informed strategy offers a strong and dependable protocol for achieving the highest possible radiochemical yield.
• Custom Radiosynthesis: Conducted with an automated synthesis module under existing conditions for safety and consistency. This controlled process yields the crude ⁶⁸Ga-labeled peptide conjugate ready for purification.

Purification & Quality Control

The verification of successful incorporation of ⁶⁸Ga comes after labeling. Confirmatory analytical methods, including liquid chromatography (LC), mass spectrometry (MS), and scintillation counting, determine the compound's isotope labeling accuracy, purity, and structural stability, ensuring that it is then regarded as suitable for use in biological research.

In Vitro Evaluation

In vitro tests are performed to evaluate the biological properties of the ⁶⁸Ga-labeled radiopharmaceutical. This includes studying its interaction with target receptors, cellular uptake, metabolic stability, and other pharmacological properties.

In Vivo Evaluation

This critical phase involves the quantitative biodistribution and pharmacokinetic (PK) studies, which seek to quantify the agent's retention in the different compartments of the body and the rate of elimination out of the body. In the next step, PET imaging is done in the corresponding disease models to ensure the specific target engagement and to ensure the diagnostic capability of the agent by in vivo blocking tests.

Applications of ⁶⁸Ga-Radiolabeling

⁶⁸Ga-radiolabeling leverages its convenient generator-based production and short half-life to enable high-resolution PET imaging of molecular targets using vectors with rapid pharmacokinetics, such as peptides and small molecules.

Alfa Cytology's team has mastered rapid, generator-based, radiolabeling chemistry of Gallium-68, focusing on developing stable kit-based formulations for new peptides and small molecules. For more information on tailored project collaboration, we invite you to reach out. Our team will gladly assist you in converting your targeting molecule into a state-of-the-art PET imaging agent.

Reference

1. Nelson BJB, et al. (2022). Good practices for ⁶⁸Ga radiopharmaceutical production. EJNMMI Radiopharm Chem. 22;7(1):27.

For research use only. Not intended for any clinical use.