⁸⁹Sr-Radiolabeling Service

⁸⁹Sr-radiolabeling service focuses on the development of novel beta-emitting therapeutics and utilizes the bone-seeking nature of Strontium-89 for the construction of radiopharmaceuticals aimed at the palliative therapy of painful bone metastases. Alfa Cytology has the specialized radiochemistry and the facilities needed to develop and manufacture custom ⁸⁹Sr labeled compounds and provides high-purity, radiopharmaceutical grade, therapeutic agents for advanced preclinical studies.

Introduction to ⁸⁹Sr Isotopes

Strontium-89 (⁸⁹Sr) is a radioisotope that is produced in a reactor. It is used to relieve pain associated with bone metastases. As a calcium mimetic, ⁸⁹Sr chloride, when injected into the bloodstream, is selectively taken up and retained in the areas of the bone where osteoblastic activity is high, effectively targeting cancerous lesions in the bone. ⁸⁹Sr is a beta-minus (β^-) emitting isotope with a 50.5-day-long half-life. The emitted high-energy beta rays attack and destroy the surrounding tumor cells, thus minimizing malignancy, lessening pain, and improving the individual's life.

⁸⁹Sr-Labeling for Radiopharmaceuticals

⁸⁹Sr-radiolabeling creates powerful beta-emitting agents for radionuclide therapy focused on bone tissue. This service uses the calcium-mimetic nature of Strontium-89, enabling its preferential localization to areas of elevated osteoblastic activity, including painful bone metastases. Work involves the custom conjugation of ⁸⁹Sr to diverse targeting vectors, including simple salts and sophisticated chelates, to fabricate therapeutic radiopharmaceuticals for palliative care and innovative research on skeletal disorders, enhancing the research.

Fig 1. Schematic of a ⁸⁹Sr-labeled molecule interacting with a target cell.

⁸⁹Sr 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 ⁸⁹Sr Labeling

The advantages of ⁸⁹Sr labeling for therapeutic applications are rooted in its unique fusion of an innate biological targeting mechanism with the potent, localized energy of a pure beta-emitting radionuclide.

Our Services

Alfa Cytology's specialized expertise in radiochemistry, alongside the necessary facilities, enables the safe handling and conjugation of the long-lived therapeutic beta-emitter, Strontium 89. We have the ability to synthesize ⁸⁹Sr-labeled compounds of high purity and therapeutic-grade agents to strengthen the innovative development of bone-targeted therapies.

Custom ⁸⁹Sr Conjugation Service

The ⁸⁹Sr conjugation service applies bespoke conjugation chemistry to arm novel vectors (e.g., bisphosphonates or peptides) with the potent long-lived beta-emitter strontium-89 to enable the development of next-generation bone targeting radiotherapeutics.

Small-Molecule Radionuclide Conjugate (SMRC)

Antibody-Radionuclide Conjugate (ARC)

Peptide-Radionuclide Conjugate (PRC)

siRNA-Radionuclide Conjugate

Workflow for Developing ⁸⁹Sr-Radiolabeled Small-Molecule Conjugates

⁸⁹Sr Custom Radiosynthesis

For each targeting molecule, our custom radiosynthesis service is designed and executed in a stepwise fashion, guaranteeing that your ⁸⁹Sr-labeled conjugate achieves the peak specific activity and best biological activity.

• Design Labeling Position: A collaborative analysis of your small molecule's structure-activity relationship is the foundation of the work. Our radiochemists select optimal labeling positions that least affect target binding and pharmacokinetics. Then, we choose or design a better macrocyclic chelator, like a functionalized DOTA, to ensure a robust complex in vivo.
• Precursor Synthesis & Characterization: After finishing the design phase, we create the non-radioactive "cold" precursor through chemical synthesis. This precursor is the exact small molecule-chelator conjugate positioned to undergo radiolabeling. This important intermediate undergoes extensive purification and is deeply characterized by rigorous analytical methods.
• Radiolabeling Optimization: Having a completely characterized precursor, we meticulously adjust the radiolabeling conditions. This entails optimizing parameters like the concentration of the precursor, the pH of the reaction, temperature, and the duration of the reaction to maximize the radiochemical yield (RCY) and the radiolabeling efficiency.
• Custom Radiosynthesis: The specialized radiochemistry team executes the ⁸⁹Sr-labeling synthesis. It is done with great care in our state-of-the-art laboratory by skilled radiochemists and consistently yields the expected crude radiolabeled product, which is then delivered for the important purification steps and quality control.

Purification & Quality Control

The compound is evaluated post-labeling for successful incorporation of ⁸⁹Sr. The analytical techniques employed for confirming the success of isotopic labeling, as well as the purity and stability of the compound, include liquid chromatography, mass spectrometry, and scintillation counting. These all ultimately ensure the compound's biological studies requisites are fulfilled.

In Vitro Evaluation

In vitro tests are performed to evaluate the biological properties of the ⁸⁹Sr-labeled radiopharmaceutical. This includes studying its interaction with target receptors, cellular uptake, metabolic stability, and other pharmacological properties.

In Vivo Evaluation

The last part includes an in vivo assessment so as to characterize pharmacokinetics, biodistribution, and overall behavior of the radiolabeled compound. There are some imaging techniques as well as radiometric methods for the tissue distribution studies of the ⁸⁹Sr-labeled compound that offer information on its therapeutic potential, safety, and tissue targeting.

Applications of ⁸⁹Sr-Radiolabeling

The applications of ⁸⁹Sr-radiolabeling are centered on leveraging its intrinsic calcium-mimetic properties to deliver a potent, long-term therapeutic dose of beta-particle radiation specifically to the skeletal system.

Having on board with the professional research teams and with the research and development capabilities, Alfa Cytology not only provides services for ⁸⁹Sr radiolabeling R&D, but also many other nuclides associated services as well like isotope labeling and custom synthesis. Also, we have knowledge on improving the drug delivery systems and improving the therapy effectiveness. In case your project gets stuck in some areas of the process, please don't hesitate to reach out to us for bespoke services as well as solutions designed to fulfill your unique requirements.

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