Plasmid DNA isolation using amino-silica coated magnetic nanoparticles (ASMNPs)

A simple and efficient approach for the rapid isolation of plasmid DNA from crude cell lysates has been described. The approach took advantage of the amino-modified silica coated magnetic nanoparticles (ASMNPs) with positive zeta potential at neutral pH and superparamagnetism under the external magnetic fields. As a demonstration, the pEGFP-N3 plasmid has been concentrated and isolated from the E. coli DH5α transformed with pEGFP-N3 plasmid through electrostatic binding between the positive charge of the amino group of ASMNPs and the negative charge of the phosphate groups of the plasmid DNA. Then the pEGFP-N3 plasmid has been released easily and quickly from the pEGFP-N3 plasmid-ASMNPs complexes with 3 M NaCl. The entire procedure could be carried out by the aid of external magnetic fields in 15 min and eliminate the need of phenol, cesium chloride gradients or other noxious reagents and complexes operation. Moreover, the pEGFP-N3 plasmid obtained by this approach retains biological activity that can be suitable for restriction enzyme digestion and cells transfection with expression of green fluorescence protein.     

HC-HDSD: A method of hypergraph construction and high-density subgraph detection for inferring high-order epistatic interactions

Detecting epistatic interactions, or nonlinear interactive effects of Single Nucleotide Polymorphisms (SNPs), has gained increasing attention in explaining the “missing heritability” of complex diseases. Though much work has been done in mapping SNPs underlying diseases, most of them constrain to 2-order epistatic interactions. In this paper, a method of hypergraph construction and high-density subgraph detection, named HC-HDSD, is proposed for detecting high-order epistatic interactions. The hypergraph is constructed by low-order epistatic interactions that identified using the normalized co-information measure and the exhaustive search. The hypergraph consists of two types of vertices: real ones representing main effects of SNPs and virtual ones denoting interactive effects of epistatic interactions. Then, both maximal clique centrality algorithm and near-clique mining algorithm are employed to detect high-density subgraphs from the constructed hypergraph. These high-density subgraphs are inferred as high-order epistatic interactions in the HC-HDSD. Experiments are performed on several simulation data sets, results of which show that HC-HDSD is promising in inferring high-order epistatic interactions while substantially reducing the computation cost. In addition, the application of HC-HDSD on a real Age-related Macular Degeneration (AMD) data set provides several new clues for the exploration of causative factors of AMD.     

水溶性碳纳米粒子的制备及其在DNA和单核苷酸多态性分析中的应用

利用电化学氧化的方法制备了水溶性好、粒径为7～12nm的碳纳米粒子,该碳纳米粒子通过π-π相互作用吸附荧光标记的单链DNA探针,并能有效地猝灭其荧光．当单链DNA探针与匹配的DNA目标分子杂交形成双链DNA时,猝灭的荧光被恢复,由此可以检测1-200nmol／L的DNA目标分子。此外,在碳纳米粒子存在时,由荧光标记的DNA探针和DNA目标分子形成的双链DNA的熔解温度可以简便地被测定,当双链DNA有错配碱基时,其熔解温度降低,由此可方便、快速地分析单核苷酸多态性．     

DNA assay based on monolayer-barcoded nanoparticles for mass spectrometry in combination with magnetic microprobes

Mass spectrometry (MS) based methodology offers simple, fast and sensitive diagnosis. While it has become the predominate approach in biomolecular analysis, it has not been suitable for analyzing nucleic acid due to its low ionization efficiency. We report herein on a DNA assay based on monolayer-barcoded nanoparticles that were encoded with reporter mass molecules, which act as surrogate molecules for the matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF MS) identification of target DNA through mass spectrometry in combination with magnetic microprobes. This assay demonstrated high MS sensitivity, with the ability to detect target DNA at femtomolar (10⁻¹⁵ M) levels. This inaugural effort using combined techniques is significant because it showed an extraordinary analytical capability for differentiating the single nucleotide polymorphism (SNP), which comprises the most abundant source of genetic variation in the human genome. We also report herein the feasibility of MS detection of two target DNAs that have the same mass but different nucleotide base composition, which classic MS methodology is inherently unable to differentiate.     

Rapid one-pot fabrication of magnetic calcium phosphate nanoparticles immobilizing DNA and iron oxide nanocrystals using injection solutions for magnetofection and magnetic targeting

This is the first report on rapid (5–30 min) one-pot fabrication of magnetic calcium phosphate (CaP) nanoparticles (NPs) co-immobilizing DNA and iron oxide (IO) nanocrystals with high immobilization efficiencies (DNA (～90%) and IO (～70%)). NPs were fabricated via coprecipitation under clean bench in supersaturated CaP solutions using DNA, IO-based MRI contrast agent, and infusion quality source solutions (even the water used was of injectable quality) that ensured high safety level of the fabrication process and product. Prepared DNA-IO-CaP NPs exhibited strong magnetic property allowing their noncontact manipulation by external magnet. These NPs were smaller than 500 nm, had relatively large negative zeta potential showing stable dispersion without any additional surfactant, and exhibited no significant cytotoxicity under the tested transfection conditions. The IO content of these NPs was significantly varied and by adjusting the initial IO concentration, DNA-IO-CaP NPs with gene delivery capability to CHO-K1 cells as high as that of the IO-free DNA-CaP NPs without external magnetic field were prepared. Fabricated DNA-IO-CaP NPs showed significantly improved gene delivery capability under external magnetic field compared to the IO-free DNA-CaP NPs. Thus, the present coprecipitation process can be considered as a novel technique to fabricate multifunctional CaP-based NPs to achieve magnetofection and targeted delivery.     

A comprehensive in Silico analysis of the functional and structural impact of single nucleotide polymorphisms (SNPs) in the human IL-33 gene

Interleukin 33 (IL-33) is the latest member of the IL-1 cytokine family, which plays both pro - and anti-inflammatory functions. Numerous Single-nucleotide polymorphisms (SNPs) in the IL-33 gene have been recognized to be associated with a vast variety of inflammatory disorders. SNPs associated studies have become a crucial approach in uncovering the genetic background of human diseases. However, distinguishing the functional SNPs in a disease-related gene from a pool of both functional and neutral SNPs is a major challenge and needs multiple experiments of hundreds or thousands of SNPs in candidate genes. This study aimed to identify the possible deleterious SNPs in the IL-33 gene using bioinformatics predictive tools. The nonsynonymous SNPs (nsSNPs) were analyzed by SIFT, PolyPhen, PROVEAN, SNP&GO, MutPred, SNAP, PhD SNP, and I-Mutant tools. The Non-coding SNPs (ncSNPs) were also analyzed by SNPinfo and RegulomeDB tools. In conclusion, our in-silico analysis predicted 5 nsSNPs and 22 ncSNPs as potential candidates in the IL-33 gene for future genetic association studies.     

Ultrasound assisted syntheses of a nano-structured two-dimensional mixed-ligand cadmium(II) coordination polymer and direct thermolyses for the preparation of cadmium(II) oxide nanoparticles

A nano-sized mixed-ligand Cd(II) coordination polymer, {[Cd(bpa)(4,4′-bipy)₂(H₂O)₂](ClO₄)₂}_n (1); bpa = trans-1,2-bis(4-pyridyl)ethane and 4,4′-bipy = 4,4′-bipyridine, has been synthesized by a sonochemical method and characterized by IR and ¹H NMR spectroscopy. Compound 1 grows in one dimension by two different bridging ligands, 4,4′-bipy and bpa. The thermal stability of compound 1 in the bulk form and nano-sized was studied by thermogravimetric (TG) and differential thermal analysis (DTA). The crystallinity of this compound was studied by X-ray powder diffraction and compared with an XRD simulation of the single crystal data. CdO nanoparticles were obtained by direct calcination at 500 °C and decomposition in oleic acid at 200 °C of the nano-sized compound 1. The obtained cadmium(II) oxide nano-particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).     

四氧化三铁/单壁碳纳米管磁性复合纳米粒子分散固相微萃取-高效液相色谱法测定牛奶中的香精添加剂

通过化学键合的方法制备单壁碳纳米管包覆的四氧化三铁（Fe₃O₄/CNTs）磁性复合纳米粒子。首先用水热法合成磁性Fe₃O₄纳米粒子,并进行硅烷氨基化处理,羧基化的单壁碳纳米管通过1-（3-二甲基氨基丙基）-3-乙基碳二亚胺（EDC）和N-羟基琥珀酰亚胺（NHS）交联剂反应修饰到Fe₃O₄纳米颗粒表面。合成的Fe₃O₄/CNTs复合纳米粒子具有很高的磁响应度和很好的分散能力,是一种很好的分散固相萃取剂。本研究将合成的Fe₃O₄/CNTs纳米粒子用于分散固相微萃取富集牛奶中的香精添加剂,并与高效液相色谱分析联用,实现了香兰素和乙基香兰素的快速高效富集和高灵敏度检测,两者的检出限达10 μg/L,回收率大于92%。本研究表明,合成的Fe₃O₄/CNTs磁性复合粒子是一种很好的奶制品中香兰素添加剂的样品前处理富集材料。     

Electrophoretic analysis of sequence variability in three mitochondrial DNA regions for ascaridoid parasites of human and animal health significance

Sequence variability in three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunits 1 and 4 (nad1 and nad4), among and within Toxocara canis, T. cati, T. malaysiensis, T. vitulorum and Toxascaris leonina from different geographical origins was examined by a mutation-scanning approach. A portion of the cox1 gene (pcox1), a portion of the nad1 and nad4 genes (pnad1 and pnad4) were amplified separately from individual ascaridoid nematodes by polymerase chain reaction and the amplicons analyzed by single-strand conformation polymorphism (SSCP). Representative samples displaying sequence variation in SSCP profiles were subjected to sequencing in order to define genetic markers for their specific identification and differentiation. While the intra-specific sequence variations within each of the five ascaridoid species were 0.2-3.7% for pcox1, 0-2.8% for pnad1 and 0-2.3% for pnad4, the inter-specific sequence differences were significantly higher, being 7.9-12.9% for pcox1, 10.7-21.1% for pnad1 and 12.9-21.7% for pnad4, respectively. Phylogenetic analyses based on the combined sequences of pcox1, pnad1 and pnad4 revealed that the recently described species T. malaysiensis was more closely related to T. cati than to T. canis. These findings provided mtDNA evidence for the validity of T. malaysiensis and also demonstrated clearly the usefulness and attributes of the mutation-scanning sequencing approach for studying the population genetic structures of these and other nematodes of socio-economic importance.     

Screening of mixed poly(ethylene oxide) solutions for microchip separation of double-stranded DNA using an orthogonal design approach

We describe a quick and systematic optimization of molecular weights (MWs) and concentrations of a series of mixed poly(ethylene oxide) (PEO) matrices for separating specific double-stranded DNA fragments on polymethylmethacrylate-based microchips by using an orthogonal design (ORD) approach. The mixed matrices are composed of PEOs in four MW ranges (M(w) 8 x 10(6), 1 x 10(6), 4 x 10(5), and 1 x 10(5)) with varying concentration ratios. In the mixed solutions, PEO with an intermediate MW of 4 x 10(5) is found to be a dominant factor for separating small DNA fragment pairs (e.g., 82 and 88 bp), while PEO with a high MW of 8 x 10(6) plays an important role in separating intermediate and large fragments (e.g., 271 and 281 bp, 506 and 517 bp, 7 and 10 kbp). High-concentration PEO mixtures give better resolution for short fragments, while dilute PEO mixtures show better resolution for long fragments. The optimized matrices are suitable for high-resolution separation of multiplex polymerase chain reaction-amplified products and restriction digest fragments ranging in size from 20 bp to 40 kbp within 4 min at a constant field strength of 177 V/cm. The experimental results indicate the robustness and speediness of the ORD to screen the contribution of PEO MWs and to tune optimally the PEO concentration ratio of different MWs with reference to the performance of specific DNA fragments separated.     

Rapid label-free visual assay for the detection and quantification of viral RNA using peptide nucleic acid (PNA) and gold nanoparticles (AuNPs)

A rapid label-free visual assay for the detection of viral RNA using peptide nucleic acid (PNA) probes and gold nanoparticles (AuNPs) is presented in this study. Diagnosis is a crucial step for the molecular surveillance of diseases, and a rapid visual test with high specificity could play a vital role in the management of viral diseases. In this assay, the specific agglomerative behavior of PNA with gold nanoparticles was manipulated by its complementation with viral RNA. The assay was able to detect 5–10 ng of viral RNA from various biological samples, such as allantoic fluids, cell culture fluids and vaccines, in 100 μl of test solution. The developed assay was more sensitive than a hemagglutination (HA) test, a routine platform test for the detection of Newcastle disease virus (NDV), and the developed assay was able to visually detect NDV with as little as 0.25 HA units of virus. In terms of the specificity, the test could discriminate single nucleotide differences in the target RNA and hence could provide visual viral genotyping/pathotyping. This observation was confirmed by pathotyping different known isolates of NDV. Further, the PNA-induced colorimetric changes in the presence of the target RNA at different RNA to PNA ratios yielded a standard curve with a linear coefficient of R² = 0.990, which was comparable to the value of R² = 0.995 from real-time PCR experiments with the same viral RNA. Therefore, the viral RNA in a given samples could be quantified using a simple visual spectrophotometer available in any clinical laboratory. This assay may find application in diagnostic assays for other RNA viruses, which are well known to undergo mutations, thus presenting challenges for their molecular surveillance, genotyping and quantification.     

Simple and low-temperature synthesis of NiO nanoparticles through solid-state thermal decomposition of the hexa(ammine)Ni(II) nitrate, [Ni(NH3)6](NO3)2, complex

NiO nanoparticles with an average size of about 12 nm were easily prepared via the thermal decomposition of hexa(ammine)Ni(II) nitrate complex, [Ni(NH₃)₆](NO₃)₂, at low temperature of 250 °C. The product was characterized by thermal analysis (TGA/DTA), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), UV-Vis spectroscopy, BET specific surface area measurement, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and magnetic measurement. The magnetic measurement revealed a small hysteresis loop at room temperature, confirming a superparamagnetic (weak ferromagnetic) nature of the synthesized NiO nanoparticles. Indeed, the NiO nanoparticles prepared by this method could be an appropriate semiconductor material due to the optical band gap of 3.35 eV which shows a red shift in comparison with the previous reports. This method is simple, fast, safe, low-cost and also suitable for industrial production of high purity NiO nanoparticles for applied purposes.     

Preparation of poly(lactide-co-glycolide-co-caprolactone) nanoparticles and their degradation behaviour in aqueous solution

The tri-component copolymer poly(lactide-co-glycolide-co-caprolactone) (PLGC) was synthesized to prepare nanoparticles by the modified spontaneous emulsification solvent diffusion method (modified-SESD method); and the method was also modified by using the Tween60 instead of poly(vinyl alcohol) (PVA) as dispersing agent. The obtained nanoparticles have spherical shape and good particle distribution with mean size in the range from 100 to 200 nm. The in vitro degradation behaviour of PLGC nanoparticles was investigated. It was found that PLGC nanoparticles could remain stable during the degradation with no agglomeration. Compared with PLA and PLGA nanoparticles, the degradation rate of PLGC nanoparticles is faster. After 9 weeks of hydrolysis, the M_n of PLGC is less by 10% of the original M_n. The mean radius of the nanoparticles increases from 68 nm to 80 nm continuously during the first stage, and after 4 weeks of degradation, the particles' size decreases gradually from 80 nm to about 40 nm. These results suggest that the PLGC nanoparticles may show degradation-controlled drug release behaviour and seem to be a promising drug delivery system.     

Multi-walled carbon nanotubes modified with iron oxide and silver nanoparticles (MWCNT-Fe3O4/Ag) as a novel adsorbent for determining PAEs in carbonated soft drinks using magnetic SPE-GC/MS method

The synthesis of compounds with an excellent adsorption capability plays an essential role to remove contaminants such as phthalic acid esters (PAEs) with potential carcinogenic characteristics from different food products. In this context, for the first time, a novel adsorbent (MWCNT-Fe₃O₄/Ag) was synthesized by using iron (magnetic agent), and silver (catalytic and surface enhancer agent) to further approach in a magnetic SPE-GC/MS method for determining of PAEs in carbonated soft drink samples. The limit of detection (LOD) and limit of quantification (LOQ) values of MSPE-GC/MS were determined in six PAEs as a range of 10.8–22.5 and 36–75 ng/L, respectively. Also, the calibration curves of PAEs were linear (R₂ = 0.9981–0.9995) over the concentration level of 10.000 ng/L and the recoveries of the six PAEs were ranging from 96.60% to 109.22% with the RSDs less than 8%. Moreover, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and transmission electron microscopy analyses (TEM) were utilized to characterize the produced MWCNT-Fe₃O₄/Ag. Based on the findings, the surface of MWCNT is relatively uniform, which became coarser after loading with Fe₃O₄/Ag particles. Also, EDX spectrum showed the carbon (C), iron (Fe), oxygen (O), Ag and copper (Cu) are the main components of synthesized MWCNTs-Fe₃O₄/Ag. The successful adhesion of Fe₃O₄/Ag on the texture of MWCNTs using a co-precipitation method was confirmed by XRD and FT-IR assays. Additionally, excellent crystallinity and clear lattice nanocrystals fringes of prepared MWCNT-Fe₃O₄/Ag was demonstrated by TEM analysis. Based on the obtained VSM images, the prepared sorbent (MWCNT-Fe₃O₄/Ag) has the good magnetic performance for magnetic separation and extraction processes. It was concluded that the synthesized MWCNT-Fe₃O₄/Ag could be used as an efficient adsorbent for determining contaminants such as PAEs in different beverage samples.     

Poly(amino acid)-based thermoresponsive molecularly imprinted magnetic nanoparticles for specific recognition and release of lysozyme

In this study, poly(amino acid)-based thermoresponsive molecularly imprinted magnetic nanoparticles for recognition and release of lysozyme was prepared via surface imprinting method. For constructing the molecularly imprinted polymer (MIP) layer, amino acid-based thermoresponsive monomer (N-methacryloyl-l-alanine methyl ester, MA-L-Ala-OMe) was mainly selected for the functional monomer along with N,N′-methylenebis(acrylamide) as the crosslinker. The resultant magnetic MIP nanoparticles were characterized in detail. Meanwhile, the dynamic light scattering studies and swelling ratios measurements were carried out for demonstrating the thermoresponsive property of the imprinted nanoparticles. The prepared magnetic MIP nanoparticles showed good adsorption capacity and selective recognition properties to lysozyme. Moreover, the fast adsorption process could reach equilibrium within 15 min. Importantly, the capture and release of lysozyme could be easily realized simply by altering the temperature of aqueous solution. Furthermore, the prepared imprinted nanoparticles were applied to separate lysozyme from the real egg white samples. The results proved that the thermoresponsive MIPs based on MA-L-Ala-OMe have great potential for selectively enriching target proteins in real samples.     

Development of a sensitive detection method of cancer biomarkers in human serum (75%) using a quartz crystal microbalance sensor and nanoparticles amplification system

A simple and sensitive sensor method for cancer biomarkers [prostate specific antigen (PSA) and PSA-alpha 1-antichymotrypsin (ACT) complex] analysis was developed, to be applied directly with human serum (75%) by using antibody modified quartz crystal microbalance sensor and nanoparticles amplification system. A QCM sensor chip consisting of two sensing array enabling the measurement of an active and control binding events simultaneously on the sensor surface was used in this work. The performance of the assay and the sensor was first optimised and characterised in pure buffer conditions before applying to serum samples. Extensive interference to the QCM signal was observed upon the analysis of serum. Different buffer systems were then formulated and tested for the reduction of the non-specific binding of sera proteins on the sensor surface. A PBS buffer containing 200 μg mL⁻¹ BSA, 0.5 M NaCl, 500 μg mL⁻¹ dextran and 0.5% Tween 20, was then selected which eliminated the interfering signal by 98% and enabled the biomarker detection assay to be performed in 75% human serum. By using Au nanoparticles to enhance the QCM sensor signal, a limit of detection of 0.29 ng mL⁻¹ PSA and PSA-ACT complex (in 75% serum) with a linear dynamic detection range up to 150 ng mL⁻¹ was obtained. With the achieved detection limit in serum samples, the developed QCM assay shows a promising technology for cancer biomarker analysis in patient samples.     

Effects of Zinc oxide nanoparticles on the morphology and viscoelastic properties of polyamide 6/poly(butylene terephthalate) blends

The morphology of polyamide 6/poly(butylene terephthalate)(PA6/PBT, 70/30, W/W) blends filled with pristine Zinc oxide(ZnO) nanoparticles and ZnO surface-modified by γ-glycidoxypropyltrimethoxysilane(K-ZnO) was investigated. The incorporation of ZnO and K-ZnO by one-step compounding both resulted in a smaller size and narrower distribution of PBT domains and the effect of ZnO was greater than K-ZnO. To reveal the underlying mechanism, two-step compounding in which ZnO or K-ZnO was premixed with PA6 or PBT was conducted and the finest morphology was achieved when mixing PA6 with premixed PBT/ZnO. Transmission electron microscopy(TEM) demonstrated that ZnO was distributed in PBT in all cases and K-ZnO was enriched at the interface except when K-ZnO was premixed with PBT. ZnO and K-ZnO caused a deterioration in the melt rheological properties of PBT, which played a dominating role in the morphological changes. In addition, the interfacial localization of K-ZnO enhanced the dynamic rheological properties of PA6/PBT blends substantially.     

A new approach to extraction and preconcentration of Ce(III) from aqueous solutions using magnetic reduced graphene oxide decorated with thioglycolic-acid-capped CdTe QDs

In the present study, a nanocomposite consisting of magnetic reduced graphene oxide decorated with thioglycolic-acid-capped CdTe quantum dots (TGA/CdTe QDs/Fe₃O₄/rGO) was synthesised using simple ‘hydrothermal method’ and applied as a nanosorbent for extraction and preconcentration of cerium (Ce)(III) from aqueous solutions prior to inductively coupled plasma-optical emission spectroscopy detection. Under the optimised extraction conditions, the calibration graph for Ce(III) was linear in a concentration range of 0.1–511.0 μg L^?1 with a correlation coefficient of 0.9986. A detection limit of 0.1 μg L^?1 Ce(III) with an enrichment factor of 125 was obtained. Precisions, expressed as relative standard deviation for single-sorbent repeatability and sorbent-to-sorbent reproducibility, were 3.6% and 9.1% (n = 5), respectively. Finally, spiked sea, mineral and tap waters were analysed to evaluate the performance of the proposed method. The high recoveries indicated that the suggested protocol was acceptable for determination of Ce(III) ions in the water samples. The use of QDs and study of their ability for preconcentration of metal ions is an important achievement towards designing novel adsorbents with high efficiency.     

DNA binding and cleavage behaviors of copper(II) complexes with amidino-O-methylurea and N-methylphenyl-amidino-O-methylurea,and their antibacterial activities

The two designed copper(II) complexes, [Cu(L^1m)₂]Cl₂ (1) (L^1m = amidino-O-methylurea) and [Cu(L^2m)₂]Cl₂ (2) (L^2m = N-methylphenyl-amidino-O-methylurea), have been investigated for their interaction with calf thymus DNA by utilizing the absorption titration method, viscometric studies and thermal denaturation. The cleavage reaction on pBR322 DNA has been monitored by agarose gel electrophoresis. The results suggest that the two complexes can bind to DNA by non-intercalative modes and exhibit nuclease activities in which supercoiled plasmid DNA is converted to the linear form. Complex 2, with an intrinsic binding constant (K_b) of 1.16 × 10⁵ M⁻¹, shows a higher binding efficiency and a better nuclease activity than complex 1, with a K_b value of 5.67 × 10⁴ M⁻¹. Their DNA cleavage potential can be significantly enhanced by hydrogen peroxide, indicating an oxidative cleavage process. Further examination of the antibacterial activities against Campylobacter has revealed inhibition zones of 9.0 (for 1) and 14.5 mm (for 2), which are in agreement with their minimum inhibitory concentration (MIC) values of 1.56 and 0.78 mg mL⁻¹, respectively. The substantially better reactivity of 2 results from the aromatic moieties on the side chain of the L^2m ligand which act as an additional binding site.     

A Mathematical Radiobiological Model (MRM) to Predict Complex DNA Damage and Cell Survival for Ionizing Particle Radiations of Varying Quality

Predicting radiobiological effects is important in different areas of basic or clinical applications using ionizing radiation (IR); for example, towards optimizing radiation protection or radiation therapy protocols. In this case, we utilized as a basis the ‘MultiScale Approach (MSA)’ model and developed an integrated mathematical radiobiological model (MRM) with several modifications and improvements. Based on this new adaptation of the MSA model, we have predicted cell-specific levels of initial complex DNA damage and cell survival for irradiation with ¹¹Β, ¹²C, ¹⁴Ν, ¹⁶Ο, ²⁰Νe, ⁴⁰Αr, ²⁸Si and ⁵⁶Fe ions by using only three input parameters (particle’s LET and two cell-specific parameters: the cross sectional area of each cell nucleus and its genome size). The model-predicted survival curves are in good agreement with the experimental ones. The particle Relative Biological Effectiveness (RBE) and Oxygen Enhancement Ratio (OER) are also calculated in a very satisfactory way. The proposed integrated MRM model (within current limitations) can be a useful tool for the assessment of radiation biological damage for ions used in hadron-beam radiation therapy or radiation protection purposes.