Molecular imaging of HER2 receptor: Targeting HER2 for imaging and therapy in nuclear medicine

Surface-functionalised polymeric nanoparticles for breast cancer treatment: processes and advances

The World Health Organization (WHO) reported that of all the non-communicable diseases, cancer is considered the second cause of death worldwide. This has driven the big pharma companies to prioritise anticancer products in their pipeline. In addition, research has focused on exploration of new anticancer molecules and design of suitable dosage forms to achieve effective drug delivery to the tumour site. Nanotechnology is a valuable tool to build nano delivery systems with controlled and targeted drug release properties. Nanoparticles can be fabricated by robust, scalable and economic techniques using various polymers. Moreover, specific functional groups can be introduced to the surface of nanoparticles enabling targeting to a specific tissue; besides, they exhibit versatile drug release patterns according to the rate of polymer degradation. This review outlines the processes and advances in surface functionalisation of nanoparticles employed for treatment of breast cancer. The therapeutic molecules, the polymers used to fabricate nanoparticles, the techniques used to prepare the nanoparticles have been reviewed with a focus on the processes employed to functionalise these nanoparticles with suitable ligands to target different types of breast cancer.

Preparation, Characterization, and Radiolabeling of Anti-HER2 scFv With Technetium Tricarbonyl and Stability Studies

Breast cancer is the most common diagnosed cancer, and the second cause of cancer death among women, worldwide. HER2 overexpression occurred in approximately 15% to 20% of breast cancers. Invasive biopsy method has been used for detection of HER2 overexpression. HER2-targeted imaging via an appropriate radionuclide is a promising method for sensitive and accurate identification of HER2+ primary and metastatic lesions. 99mTc-anti-HER2 scFv can specifically target malignancies and be used for diagnosis of the cancer type and metastasis as well as treatment of breast cancer. We radiolabeled anti-HER2 scFv that was expressed in Escherichia coli and purified through Ni-NTA resin under native condition with 99mTc-tricarbonyl formed from boranocarbonate. HER2-based ELISA, BCA, TLC, and HPLC were used in this study. In the current study, anti-HER2 scFv was lyophilized before radiolabeling. It was found that freeze-drying did not change the binding activity of anti-HER2 scFv to HER2. Results demonstrated direct anti-HER2 scFv radiolabeling by 99mTc-tricarbonyl to hexahistidine sequence (His-tag) without any changes in biological activity and radiochemical purity of around 98%. Stability analysis revealed that 99mTc-anti-HER2 scFv is stable for at least 24 h in PBS buffer, normal saline, human plasma proteins, and histidine solution.

The Current and Future Roles of Precision Oncology in Advanced Breast Cancer

Breast cancer is a common but heterogeneous disease characterized by several biologic features, including tumor grade, hormone receptor status, human epidermal growth factor receptor 2 status, and gene expression assays. These biologic and genomic features drive treatment decisions. In the advanced disease setting, inter- and intrapatient tumor heterogeneity is increasingly recognized as a challenge for optimizing treatment. Recent evidence and the recent approval of novel radiopharmaceuticals have increased recognition and acceptance of the potential of molecular imaging as a biomarker to impact and guide management decisions for advanced breast cancer.

Evaluation of chicken chorioallantoic membrane model for tumor imaging and drug development: Promising findings

BACKGROUND

The chicken chorioallantoic membrane (CAM) model is a potential alternative to the mouse model based on the 3R principles. However, its value for determination of the in vivo behaviors of radiolabeled peptides through positron emission tomography (PET) imaging needed investigation. Herein, the chicken CAM tumor models were established, and their feasibility was evaluated for evaluating the imaging properties of radiolabeled peptides using a 68 Ga-labeled HER2 affibody.

METHODS

Two human breast cancer cell lines were inoculated into chicken CAM and mice, respectively. The tumor-targeting potential and pharmacokinetic profile of a 68 Ga-labeled affibody, 68 Ga-MZHER, in both tumor models were also determined.

RESULTS

The tumor-formation time in chicken CAM model was shorter than that of mouse model. The uptake values of human epithelial growth factor receptor-2 (HER2)-positive Bcap37 tumors in chicken CAM and mouse models were 5.36 ± 0.26% ID/g and 5.26 ± 0.43% ID/g at 30 min postinjection of 68 Ga-MZHER, respectively. At the same time points, the uptake values of HER2-negative MDA-MB-231 tumors in the chicken CAM models and mouse models were 1.57 ± 0.15% ID/g and 1.67 ± 0.25% ID/g, respectively. Ex vivo biodistribution confirmed that more radioactivity accumulated in Bcap37 tumors than in MDA-MD-231 tumors in both CAM and mouse models.

CONCLUSION

In this study, the CAM tumor model was successfully prepared. The chicken CAM model is a novel tool for quickly determining the in vivo properties of radiolabeled peptides targeting biomarkers. It may be beneficial for early monitoring of the therapeutic effect of a new drug through PET imaging with specific peptides.

RNA nanostructures for targeted drug delivery and imaging

The RNA molecule plays a pivotal role in many biological processes by relaying genetic information, regulating gene expression, and serving as molecular machines and catalyzers. This inherent versatility of RNA has fueled significant advancements in the field of RNA nanotechnology, driving the engineering of complex nanoscale architectures toward biomedical applications, including targeted drug delivery and bioimaging. RNA polymers, serving as building blocks, offer programmability and predictability of Watson-Crick base pairing, as well as non-canonical base pairing, for the construction of nanostructures with high precision and stoichiometry. Leveraging the ease of chemical modifications to protect the RNA from degradation, researchers have developed highly functional and biocompatible RNA architectures and integrated them into preclinical studies for the delivery of payloads and imaging agents. This review offers an educational introduction to the use of RNA as a biopolymer in the design of multifunctional nanostructures applied to targeted delivery in vivo, summarizing physical and biological barriers along with strategies to overcome them. Furthermore, we highlight the most recent progress in the development of both small and larger RNA nanostructures, with a particular focus on imaging reagents and targeted cancer therapeutics in pre-clinical models and provide insights into the prospects of this rapidly evolving field.

Reviving a Classic Antigen with a Cutting-Edge Approach: Nanobodies for HER2+ Breast Cancer

The serendipitous discovery of nanobodies (NBs) around two decades ago opened the door to new possibilities for innovative strategies, particularly in cancer treatment. These antigen-binding fragments are derived from heavy-chain-only antibodies naturally found in the serum of camelids and sharks. NBs are an appealing agent for the progress of innovative therapeutic strategies because they combine the advantageous assets of smaller molecules and conventional monoclonal antibodies (mAbs). Moreover, the possibility to produce NBs using bacterial systems reduces manufacturing expenses and speeds up the production process, making them a feasible option for the development of new bio-drugs. Several NBs have been developed over the past 10 years and are currently being tested in clinical trials for various human targets. Here, we provide an overview of the notable structural and biochemical characteristics of NBs, particularly in their application against HER2, an extracellular receptor that often gets aberrantly activated during breast cancer tumorigenesis. The focus is on the recent advancements in diagnostic and therapeutic research up to the present date.