Micro‐/Nano‐Structures on Biodegradable Magnesium@PLGA and Their Cytotoxicity, Photothermal, and Anti‐Tumor Effects

Abstract

The size and structural control of particulate carriers for imaging agents and therapeutics are constant themes in designing smart delivery systems. This is motivated by the causal relationship between geometric parameters and functionalities of delivery vehicles. Here, both in vitro and in vivo, the controlling factors for cytotoxicity, photothermal, and anti‐tumor effects of biodegradable magnesium@poly(lactic‐co‐glycolic acid (Mg@PLGA) particulate carriers with different sizes and shell thicknesses are investigated. Mg@PLGA microspheres fabricated by microfluidic emulsification are shown to have higher Mg encapsulation efficiency, 87%, than nanospheres by ultrasonic homogenization, 50%. The photothermal and anti‐tumor effects of Mg@PLGA spheres are found to be dictated by their Mg content, irrelevant to size and structural features, as demonstrated in both in vitro cell assays and in vivo mice models. These results also provide important implications for designing and fabricating stimuli‐responsive drug delivery vehicles.

In Vitro Degradation and Photoactivated Antibacterial Activity of a Hemin-CaP Microsphere-Loaded Coating on Pure Magnesium

“…Firstly, the thermal conductivity of pure Mg is higher than that of MAO [ 32 ], which benefited the transfer of heat from the surface of the substrate to the solution. Secondly, the increased temperature of the solution further promoted the corrosion of pure Mg and produced heat [ 36 , 66 ]. As shown in Figure 7 d, the temperature of the MAO/PMTMS@(Hemin-CaP) coating exhibited a stable on-off behavior.…”

Multifunctional inorganic biomaterials: New weapons targeting osteosarcoma

“…In vivo experiments, Mg particles exhibit excellent photothermal effects for tumor eradication and Mg ions released from PLGA/Mg porous scaffolds could promote bone regeneration, which gives the PLGA/Mg scaffolds dual functions of inhibiting OS recurrence and continuously repairing bone defects. On the other hand, after intra-tumoral injection, Zhou et al found that micro-scale Mg/PLGA exhibited stronger cytotoxicity, PTT, and anti-tumor effect than nano-scale Mg/PLGA ( Zhou et al, 2021 ). This inspires the design of Mg scaffolds in the reconstruction of bone defects after osteosarcoma surgery.…”

“…2 Magnesium, zinc, and their alloy Mg, Zn, and their alloys exert excellent anti-tumor effects by influencing the metabolism and phenotype of tumor cells, inducing tumor cell proliferation inhibition, cell cycle arrest, and cell apoptosis (Krol et al, 2017;Zhou et al, 2021). Studies by Wu et al have shown that magnesium-zinc alloy can inhibit the proliferation of osteosarcoma cell line U20S cells by arresting the G2/M phase of the cell cycle, and promote the apoptosis of U20S tumor cells through a mitochondrial-dependent pathway; at the same time, the alloy solution can inhibit the metastasis of U20S tumor cells through the MAPK pathway (Wu et al, 2016).…”

Poly(Lactic Acid)-Based Microparticles for Drug Delivery Applications: An Overview of Recent Advances

“…The photothermal and anti-tumor effects of MgPLGA spheres were determined by their Mg content, irrelevant to their structural features and size, as shown in in vitro cell assays and in vivo mice models. These results provided important implications for designing and fabricating stimuli-responsive drug delivery vehicles [90]. Subha et al used beeswax and PLGA as wall materials in order to obtain sustained and controlled release of Capecitabine, an anticancer drug [91].…”