Synergistic Effects of Multimodal Polydopamine Coating on NaGdF4@NaYF4:Nd3+ Nanostructured Alginate Microspheres through the Combination of Chemotherapy and Photothermal Therapy
来源：ACS Publications
Nanophosphors have gained substantial attention in recent years for both the diagnosis and treatment of cancer. Near-infrared optical imaging based on Nd3+-doped rare-earth nanophosphors is widely used for deep penetration tissue imaging. The present work aims to develop a hierarchical structure of polydopamine (PDA)-coated alginate microspheres encapsulated with NaGdF4@NaYF4:Nd3+ and cisplatin to achieve enhanced photothermal therapy (PTT) alongside providing optical imaging, MRI, and CT multimodal imaging capabilities. The obtained microspheres were subjected to physicochemical characterization, absorption/emission features, radical scavenging potential, drug release, and antibacterial efficacy. Further, the irradiation of microspheres under an 808 nm NIR laser revealed an effective conversion of light energy into a temperature upsurge to 51.3 °C with a conversion efficiency of 53.3%. The hydrophilic NaGdF4@NaYF4:Nd3+ nanophosphors demonstrated significant fluorescence in the NIR range, longitudinal and transverse magnetic resonance relaxivity (r1 = 12.65 mM–1 s–1, r2 = 17.1 mM–1 s–1), and X-ray attenuation capacity of 132 HU. Moreover, cell culture analysis in the presence and absence of NIR irradiation against MG63 cell lines highlights the anticancer potential of the microspheres. These results suggest the potential of prepared microspheres as multifunctional nanotheranostic agents.
The current study aims to develop cisplatin and NaGdF4@NaYF4:Nd3+-loaded alginate microspheres. Surface functionalization has been enabled with the aid of dopamine due to its postulates of NIR absorbance, excellent biocompatibility, and hydrophilicity. Moreover, polydopamine (PDA) coating offers the unique advantages of self-polymerization ability and photothermal property.Thus, PDA-coated cisplatin/NaGdF4@NaYF4:Nd3+-loaded alginate microspheres have been investigated for their synergistic effects through photothermal therapy. In addition, the NIR, MRI, and CT features of the resultant microspheres have been evaluated alongside their drug release capacity and antibacterial activity.