Background

Breast cancer (BC) is the most common malignancy in women and one of the three most common cancers worldwide, along with lung and colon cancer (Harbeck and Gnant 2017). Adenosine triphosphate (ATP; energy source for survival) is produced in normal cells via two pathways: glycolysis and mitochondrial oxidative phosphorylation (OXPHOS). However, even in an aerobic environment, cancer cells gain ATP from glycolysis rather than OXPHOS, despite the glycolysis producing 2 ATP less than the OXPHOS that generates 36 ATP per glucose molecule. Notably, mitochondrial OXPHOS is not necessarily defective in cancer cells, but cancer cells mostly depend on glycolysis due to its acceleration than OXPHOS in ATP generation, and this is favorable for growth and proliferation. This metabolic reprogramming is recognized as the Warburg effect, and it is the cancer hallmark that is induced by oncogenic events and aggressively contributes to cancer progression in a harsh microenvironment (Dias et al. 2019; Shiratori et al. 2019).

The tumor microenvironment (TME) is an immunosuppressive microenvironment generated by cancer cells to regulate tumor growth, promote tumor immune evasion, and serve as a source of tumor-promoting factors (TPF) (Whiteside 2008; Shi et al. 2020). TPF has included growth factors, cytokines, extracellular matrix proteins, and hypoxia challenge as well as p53, which promote growth, survival, and metastatic spread of cancer cells (Han et al. 2014; Owusu et al. 2017). The TME is the network of cells such as immune cells, cancer-associated fibroblasts, and promoting factors (i.e., cytokines, growth factors, and hormones) associated with the extracellular matrix and surrounding vasculature that encloses cancer cells. The formation of this TME essentially relies on tumor metabolism, and therefore, it is characterized by high acidity and hypoxia (Shi et al. 2020). Additionally, the study by Vaughan et al. (2013) demonstrated that aerobic glycolysis is induced by the expression of oncogene and TME mediators. Furthermore, aerobic glycolysis leads to the accumulation of lactate in the TME, which results in stabilization of hypoxia-inducible factor (HIF), and subsequently stimulates transforming growth factor- beta (TGF-β) that in turn enhances aerobic glycolysis (Hua et al. 2020). Moreover, among the numerous regulators or mediators of cancer metabolism, peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α) is emerging as a promoter of carcinogenesis and an essential controller of multiple metabolic pathways in cancer (Tan et al. Full size image

The composition of the synthesized DDM sample is analyzed by EDX (Fig. 1b), where the presence of O, C, Cl, and Mg was confirmed, and the presence of Mg and O atoms was correlated to the core MgO-NPs. Moreover, the presence of O, C, and Cl corresponds to the DA, 2DG, HA, and FA multi-shell structures in the synthesized sample.

Elemental map**s were performed selectively on the synthesized DDM samples to further illustrate the core–shell structural features of the samples, and the images are depicted in Fig. 1c. These images demonstrated the existence of the elements Mg, C, Cl, and O, which agreed with the preceding EDX results. Furthermore, those elements were distributed uniformly. The images confirmed that both Mg (blue color) and O (green color) atoms were located in the same places, confirming the core structure, and the other layers (C, O, and Cl) indicate the distribution of the organic shells structure on the core MgO-NPs.

The SEM image of the synthesized DDM sample is shown in Fig. 1d. The surface behavior reveals dark layers that represent the outer shells (HA and FA; organic shells) with remarkable smooth agglomerates. This could be due to the occupation of a large number of layers at the grain boundary, which could control the grain growth. In addition, the MgO-NPs in the core represented the bright aggregate particles, confirming the promising core–shell structure.

An HR-TEM image of the core–shell structure of the synthesized DDM is shown in Fig. 1e. The synthesized composite possessed a semi-spherical structure with diameter sizes ranging from 149.36 to 97.43 nm, with an average size of 123.38 nm. It must be noted that the condensed particles were attributed to the core MgO-NPs while the faint layers corresponded to the shell layers of DDM, which were entirely validated by color in the map**/SEM images and indicated the successful formation of core–shell construction.

The FTIR spectrum of the synthesized DDM is presented in Fig. 1f. For the current nanocomposite, the characteristic vibration peak at 680 cm−1 was assigned to the stretching mode of MgO (in the core) and other assigned peaks for the shells were formed and were in good agreement with the literature. After conducting a comparative FTIR analysis of bare MgO-NPs, a peak located at 3040 cm−1 was assigned to the –OH stretching region. Another peak located at 731 cm−1 was appointed to the stretching mode of the Mg-O core, which slightly shifted as compared with Mg-O in the synthesized nanocomposite due to the absence of organic shells. After the FTIR conduct of the bare MgO-NPs and the confirmation of the functional groups’ presence as represented in the synthesized nanocomposite, the formation of core–shell construction was successfully indicated. The literature comparison was achieved between the FTIR data of bare FA (Mohammed 2014), HA (Reddy and Karunakaran 2013), DCA (Yang et al. 2018), 2DG (** et al. 2019), and bare MgO-NPs (Balakrishnan et al. 2020). It must be noted that the connection type between the outer organic shells and the chemical reactions on the surface of MgO-NPs was by intramolecular hydrogen bonding (weak bond) as described before, which was not present in bare FA, HA, DCA, 2DG, and bare MgO-NPs that indicated the incorporation behavior between outer layers (FA, HA, DCA, and 2DG) as indicated by a weak bond as described in recent publications (El-Batal et al. 2022). On the other hand, broadband and the change presented at 3725 cm−1 in the case of the synthesized DDM (Fig. 1f) is related to the presence of hydroxyl groups and is attributed to OH-stretching, and was changed in the case of bare MgO-NPs (3040 cm−1), which indicates the formation of intermolecular hydrogen bonding between FA, HA, DCA, 2DG, and the synthesized core MgO-NPs. The incorporation behavior was detected in our FTIR results as new peaks formed in the nanocomposite that were not present in bare MgO-NPs as a minor shifting in the bare peaks (weak physical bond; Van der Waals forces) (Uppuluri et al. 2000; Bonn and Hunger 2021).

Characterization of AF (HA-FA-Amygdaline@Fe2O3)

The XRD diffractogram of the synthesized HA-FA-Amygdaline@Fe2O3 sample showed a high-degree hematite (Fe2O3) in the core. An XRD system was conducted to study the crystal composition and state of the incorporated Fe2O3 NPs (Fig. 2a). The XRD models agree with the specific Fe2O3 original (JCPDS No. 33-0664). The unique peaks was looked at the next 2θ at 24.18°, 33.16°, 35.55°,40.69°, 49.42°, 54.19°, 57.49°, 62.19°, and 64.18° corresponding to 012, 104, 110, 113, 024, 116, 018, 214, and 300 planes, respectively, and showing its standard cubic spinel composition (Karade et al. 2019). There are no unknown crystalline phases or impurities in the Fe2O3 NPs, which represent a high concentration in the core. This matches with the unique composition of the complete Fe2O3 crystal with a rhombohedral centered hexagonal building (R3c space system) (Sharma 2017; Zeng et al. 2017; Fouad et al. 2019; Tadic et al. 2019; Liang et al. Full size image