Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 15 3 2025 09 25 The Use of Rare Earth Glass Microspheres and Graphene Quantum Dots Glass Microspheres for Biological Applications: Cancer Insight 627 636 10.34172/apb.025.45113 EN Jéssica Ingrid Faria De Souza https://orcid.org/0000-0001-8827-9736 Natália Cristina Gomes-da-Silva Filipe Ferreira Ascenção Beatriz Da Silva Batista Luciana Magalhães Rebelo Alencar Pierre Basílio Almeida Fechine Eduardo Ricci-Junior Ralph Santos-Oliveira https://orcid.org/0000-0002-0905-481X Journal Article 10.34172/apb.025.45113 2025 01 02 2025 07 19 Purpose: This study explores the use of glass microspheres doped with rare earth elements, specifically samarium (Sm) and neodymium (Nd), and graphene quantum dots (GQDs) in biological applications, particularly cancer therapy. Methods: Glass microspheres were synthesized using an eco-friendly approach with recycled glass and subsequently doped with Sm, Nd, or GQDs. The samples were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In vitro cytotoxicity was assessed in MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines. Results: In vitro assays demonstrated that these doped microspheres significantly reduced cell viability in breast (MCF-7) and prostate (DU-145) cancer cell lines. The GQD microspheres showed a marked reduction in cell proliferation, attributed to mechanisms involving apoptosis and reactive oxygen species (ROS) production. Sm and Nd microspheres also decreased cell survival, with Nd microspheres showing the highest efficacy. Conclusion: The study highlights the potential of rare earth elements and GQDs in developing advanced nanotherapeutic agents for cancer treatment, emphasizing their role in disrupting cellular functions and promoting cytotoxic effects in tumor cells.