## 1 Introduction
To better define the role of \(\upmu\)-FT-IR in radiobiology and, hence, to fully exploit its potential in the study of the effects related to proton beam exposure, MCF10A cells can represent a significant model since molecular changes induced in MCF10A cells by proton irradiation have also been investigated by monitoring the production of immunological molecules and gene expression profiles [10; 25; 26]. [PERSON] et al. [25] focused their attention on radiation-induced global methylation changes in MCF-10A cells following exposure to a proton beam of 45 MeV and an 8 Gy dose. This aspect plays an important role since ionizing radiation is known to influence the methylation status changes in many tumor suppressor genes and oncogenes. In this study, MCF-10A cells showed more hypermethylation than the MCF-7 cancerous cell line. This means that the normal cell is more resistant to the proton beam with respect to genomic instability. These results support the hypothesis that proton beam irradiation induces cellular activity changes through genes related to cell-to-cell signaling or DNA repair. In addition, proton beam exposure inhibits the proliferation of the MCF10A cell line. [PERSON] et al. [10] investigated the effects of proton beam irradiation on MCF-10A in terms of loss of reproductive capacity using 0.5, 2, 4, 6, and 9 Gy. Dose-response effects were tested using a clonogenic assay and showed that survival curves were affected by these treatments. They also evaluated the relative expression of cytokines, chemokines, and growth factors produced by MCF-10A cells after proton irradiation with the above-mentioned doses when assayed 24, 48, and 72 h after radiation exposure. The cited immunological factors were chosen according to their involvement in the cell radiation responses, and they showed significant dose-dependent alterations after proton exposure. [PERSON] evaluated the MCF-10A cell radioresponse features following exposure to a clinically relevant 200 MeV proton beam using the micronucleus assay. These studies evidenced the relevant sensitivity of MCF-10A cells, and the ratio of the parameters obtained by fitting the dose-response curve was proposed as a measure of the impact of dose fractionation to determine the biologically effective dose [26]. In a recent study, viability, survival fraction, senescence, apoptosis, and necrosis were investigated in MCF-10A cells treated with 0, 0.5, 2, and 4 Gy doses and fixed at 24, 48, and 72 h after proton irradiation [27]. Cell growth behavior was strongly affected by the radiation dose and the viability of the exposed MCF-10A cells at the three examined time points showed a dose-dependent trend. A linear-quadratic model describing the variation in cell survival at low and high doses successfully fit the survival data. The results of the assay for radiation-induced apoptosis and necrosis demonstrated that these processes were strongly dependent on the dose. The induction of apoptosis and necrosis cell death pathways is not the most relevant effect due to proton exposure. In fact, the exposed cells are also forced to undergo premature senescence. In particular, a small increase in senescence with time was found in unexposed cells: such a senescence increase is due to aging. On the contrary, a strong time- and dose-dependent increase in senescence is caused by proton irradiation, particularly 48 and 72 h after exposure. The same authors [27] also reported the results of a detailed analysis obtained using Raman microspectroscopy (\(\upmu\)-RS) for monitoring two distinct subcellular compartments: the nucleolus and nucleoplasm, at different times after exposure to different proton doses. \(\upmu\)-RS investigation showed the occurrence of modifications to the phosphate groups in DNA and RNA and changes in protein and lipid components. In addition, a ratiometric approach indicated that nucleic acid components are more damaged than proteins and lipids.