This study reports, for the first time, lanthanum oxide (La₂O₃) nanoparticles (NPs) that simultaneously suppress osteosarcoma MG63 cell proliferation and promote normal Vero cell viability, a dual effect not previously documented for La₂O₃ or similar metal oxide NPs. Physico-chemical characterization revealed a unique needle-like morphology, cubic crystallinity, and dispersion stability in DMSO without acidic dispersants, properties that can influence cellular uptake, ROS modulation, and biocompatibility. Comprehensive characterization (fluorescence spectroscopy, particle size/zeta potential, Raman, XRD, TGA, ATR-FTIR, and TEM) confirmed structural stability and surface chemistry relevant to biological interactions.La₂O₃ NPs exhibited broad-spectrum antibacterial activity (Gram-positive Streptococcus pyogenes, Bacillus cereus; Gram-negative Escherichia coli, Pseudomonas aeruginosa) and strong enzymatic/non-enzymatic antioxidant capacity, supporting potential use in implant coatings and infection control. MTT assays demonstrated dose-dependent cytotoxicity in MG63 cells, with enhanced proliferation in Vero cells. In zebrafish embryos, developmental toxicity assays yielded an LC₅₀ of 2.6 mg/mL higher (less toxic) than values reported for Ag NPs (~0.3–1 mg/mL) with normal development at lower concentrations and dose-dependent malformations (e.g., impaired somite formation and skeletal deformities) at higher doses. Collectively, these findings position La₂O₃ NPs as a multifunctional platform for oncology and regenerative medicine, uniquely combining selective anticancer activity, normal cell support, antimicrobial and antioxidant functions, and a defined developmental safety margin.

This book chapter on neurodegeneration research provides an explicit discussion on the present scenario, challenges, and future directions in the field. The chapter delves into critical insights into disease pathogenesis, therapeutic interventions, ethical considerations, and clinical trials, offering a holistic perspective on the complexities of neurodegenerative disorders. By exploring ethical frameworks, clinical translation, global health implications, and collaborative endeavors, the chapter underscores the importance of interdisciplinary approaches, patient-centered care, and innovative technologies in driving progress towards understanding, diagnosing, and treating neurodegeneration. As researchers, healthcare providers, policymakers, and stakeholders continue to navigate ethical dilemmas, translate scientific discoveries into clinical practice, and address global health disparities, the collective efforts in neurodegeneration research aim to improve outcomes, enhance patient care, and ultimately make a meaningful impact on individuals affected by these challenging conditions.