Glioblastoma (GBM) is the most aggressive and treatment-resistant primary brain tumor in adults. Despite current multimodal therapies, including surgery, radiation, and temozolomide chemotherapy, patient outcomes remain poor. Enhancing tumor radiosensitivity through biocompatible nanomaterials could provide a promising integrative strategy for improving therapeutic effectiveness. This study aims to evaluate the potential of bovine serum albumin-coated copper oxide nanoparticles (BSA@CuO-NPs) to enhance radiosensitivity in U87-MG cells under clinically relevant X-ray irradiation. In brief, BSA@CuO-NPs were synthesized via carbodiimide crosslinking and characterized by DLS, SEM, and zeta potential analysis. U87-MG cells were treated with BSA@CuO-NPs alone or in combination with X-ray irradiation (2 Gy). Cytotoxicity was assessed using the MTT assay, while radiosensitization was evaluated through clonogenic survival analysis. Apoptosis induction and DNA damage were analyzed via Annexin V staining and γ-H2AX immunofluorescence, respectively. The results revealed that BSA@CuO-NPs showed good colloidal stability and biocompatibility compared with uncoated CuO-NPs. When combined with irradiation, BSA@CuO-NPs significantly decreased clonogenic survival (p < 0.05) and increased apoptotic cell death compared to irradiation alone. Immunofluorescence demonstrated increased γ-H2AX focus formation, indicating higher DNA double-strand breaks in the combination group. In conclusion, BSA@CuO-NPs enhance the effects of ionizing radiation by increasing DNA damage and apoptosis in U87-MG cells, indicating their potential as combined radiosensitizers. These results support further research into albumin-coated metal oxide nanoparticles as adjuncts to standard radiotherapy for the management of GBM. One challenge in this context is the effective delivery of nanoparticles to GBM. However, the stability of BSA@CuO-NPs in physiological solutions could help overcome this obstacle.

Osteoporosis is characterized by an imbalance between osteoblastic bone formation and osteoclastic bone resorption, leading to an increased risk of fractures. The water-soluble matrix (WSM) of nacre exhibits osteoinductive properties in osteoblastic cells, both in vitro and in vivo. However, its release from natural nacre remains challenging due to its solid and compact surface. This study aimed to prepare nano-nacre particles with smaller diameters than intact aragonite crystals to enhance WSM release and to investigate its effects on osteoblast differentiation. Size analysis and SEM imaging showed that the nano-nacre particles had an average size of about 600 nm. Furthermore, their effects on osteoblast differentiation and mineralization were evaluated through qPCR and ARS assay. The results showed that WSM significantly upregulated key osteogenic genes, including RUNX2, ALP, and OCN, in a dose- and time-dependent manner over 14 days, with fold-changes ranging from 1.6 to 3.6. Additionally, the mineralization effects showed calcium deposition levels comparable to those of the positive group. These findings suggest that WSM may be a promising soluble factor for osteoblast differentiation and mineralization. Therefore, understanding the effects of the WSM from H. diversicolor nano-nacre particles on osteoblasts in vitro may provide evidence suggesting that it could be a promising anti-osteoporosis agent.

Radiotherapy (RT) is a standard treatment for cervical cancer, but its efficacy is often limited by tumor hypoxia and low radiosensitivity. Radiosensitizers that enhance RT without dose escalation are therefore of clinical interest. Alpha-mangostin (AM), a xanthone from Garcinia mangostana, exhibits anticancer and ROS-inducing properties. This study evaluated whether AM enhances radiosensitivity in vitro. Cytotoxicity (0–35 µM) was assessed by the MTT assay, and radiation sensitivity (0–6 Gy) was assessed by clonogenic survival. γ-H2AX immunofluorescence, cell cycle distribution, apoptosis induction, and clonogenic survival assessments were used to investigate the radiosensitization effect. AM showed dose-dependent cytotoxicity in HeLa cells at an inhibitory concentration 20 (IC20) of 13.67 µM while sparing fibroblasts. The radiation lethal dose 20 (LD20) was 1.4 Gy. However, combination treatment used AM at 12 µM (IC14) combined with 2 Gy (LD30) irradiation to avoid 50% cell death. AM enhanced G2/M arrest by 21.10% (p < 0.01) versus controls. In combination treatment, AM significantly increased γ-H2AX-positive cells to 48.2% (p < 0.0001), elevated apoptosis to 39.48% (p < 0.0001), and decreased clonogenic survival to 28% (p < 0.0001) compared with control. A combination index of about 0.9 indicated synergism. Therefore, AM effectively radiosensitized HeLa cells via increased DNA double-strand breaks and G2/M arrest.

Radiosensitizers are being investigated to improve the therapeutic efficacy of radiotherapy by enhancing tumor cell sensitivity while minimizing damage to normal tissues. Dihydroquinine (DHQ), a naturally occurring Cinchona alkaloid with diverse biological activities, has not previously been evaluated for radiosensitizing potential. In this study, human cervical cancer (HeLa) cells were pretreated with an IC20 concentration of DHQ and exposed to 6 MV X-ray irradiation. Clonogenic survival was assessed after irradiation at 2, 4, and 6 Gy, while intracellular ROS, γ-H2AX immunofluorescence, and apoptosis were evaluated following DHQ pretreatment and 2 Gy irradiation. DHQ pretreatment reduced clonogenic survival, yielding sensitizer enhancement ratio values of 1.37 and 1.55 at surviving fractions of 0.20 and 0.37, respectively, indicating modest-to-moderate enhancement of radiosensitivity. DHQ was also associated with increased ROS production, elevated γ-H2AX positivity, and enhanced apoptosis compared with irradiation alone. These findings suggest that DHQ enhances the radiation response in HeLa cells and is associated with increased radiation-induced cellular responses. Although the radiosensitizing effect was modest, the consistent findings across multiple biological endpoints support further investigation of DHQ as a potential adjunct to radiotherapy. Further studies are warranted to validate these findings in more clinically relevant preclinical models.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with radioresistance and limited treatment options. Titanium dioxide nanoparticles (TiO₂-NPs) have attracted attention as potential radiosensitizers because they can enhance radiation-induced oxidative stress. This study evaluated the radiosensitizing effects of BSA-adsorbed TiO₂-NPs in MDA-MB-231 TNBC cells exposed to clinically relevant 6 MV X-ray irradiation. FITC-based cellular association, as an indicator of potential nanoparticle uptake, metabolic activity, clonogenic survival, sensitizer enhancement ratio (SER), reactive oxygen species (ROS), γ-H2AX positivity, and apoptosis were assessed. Flow cytometric analysis showed that approximately 55% of cells were FITC-positive after 24 h of exposure, while approximately 90% metabolic activity was maintained at the selected concentration (25 µg/mL). Combined treatment significantly reduced the surviving fraction from 0.81 to 0.37 after 2 Gy irradiation and yielded SER values of 1.21 and 1.59 at SER₁₀ and SER₃₇, respectively. In addition, combined treatment produced the greatest increases in intracellular ROS generation, γ-H2AX positivity, and apoptosis compared with either treatment alone. These findings indicate that BSA-adsorbed TiO₂-NPs increase the radiosensitivity of TNBC cells under clinically relevant megavoltage irradiation and support their further evaluation as potential radiosensitizers for breast cancer radiotherapy.