A mid-infrared focusing grating coupler with a single circular arc element based on germanium on silicon

• Xiaojun Zhu,
• Shuai Li,
• Ang Sun,
• Yongquan Pan,
• Wen Liu,
• Yue Wu,
• Guoan Zhang and
• Yuechun Shi

Beilstein J. Nanotechnol. 2023, 14, 478–484, doi:10.3762/bjnano.14.38

• -silicon; mid-infrared; Introduction The mid-infrared (MIR) spectrum region covers the absorption band of most organic and inorganic matter. Thus, it has a broad application prospect in gas detection, environmental monitoring, lidar, free space optical communication, and remote sensing technologies [1][2

• is called “fingerprint spectrum region” (FSR) [1][4]. Many small biological molecules have unique and identifiable absorption spectra in the MIR band of 6–15 μm [1][5]. It is of great application value to develop photonic biosensors in this FSR. The spectral transparency window of germanium can fully

Mixed oxides with corundum-type structure obtained from recycling can seals as paint pigments: color stability

• Dienifer F. L. Horsth,
• Julia de O. Primo,
• Nayara Balaba,
• Fauze J. Anaissi and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 467–477, doi:10.3762/bjnano.14.37

• ) coloration of the mixed oxides was confirmed by XPS and visible-light absorption measurements. The colorimetric stability of the oxides in acid and alkaline environments was evaluated. After 240 h of exposure to harsh environments, both pigments demonstrated stability and showed no strong color difference

• assignment is based on the intrinsic light absorption characteristics of the pigment due to the presence of a chromophore ion [8]. Different transition metals such as V, Cr, Mn, Fe, Co, Ni, and Cu have been used for this purpose [9]. Using inorganic compounds in the synthesis tends to increase the chemical

• characteristic Fe3+ satellites at higher binding energies (shifted by ca. 9 eV from Fe 2p3/2) [27], similar to that reported in [28]. Electronic spectroscopy In the UV–vis absorption spectrum of sample 1 (Figure 5a), the prominent band with a maximum centered at 588 nm can be attributed to the 4A2→4T2 transition

Conjugated photothermal materials and structure design for solar steam generation

• Chia-Yang Lin and
• Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

• materials (PTMs) have attracted significant interest because of their advantages over metallic and inorganic PTMs in terms of high light absorption, designable molecular structures, flexible morphology, and solution processability. We review here the recent progress in solar steam generation devices based

• and describe commonly used conjugated organic materials and structural designs. Keywords: absorption; conjugated molecules; energy transfer; photothermal materials; solar steam generation; Review Introduction With the rapid development of the world economy, global water shortages are occurring

• efficiency in solar steam generation (SSG), three factors must be considered, namely solar light absorption, photothermal conversion efficiency, and vaporization efficiency (Figure 1). In addition, the cost of the materials must be taken into consideration as large quantities at low cost are required

Evaluation of electrosynthesized reduced graphene oxide–Ni/Fe/Co-based (oxy)hydroxide catalysts towards the oxygen evolution reaction

• Karolina Cysewska,
• Marcin Łapiński,
• Marcin Zając,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2023, 14, 420–433, doi:10.3762/bjnano.14.34

• probably inhibited the electrodeposition process of NiFe and CoNiFe on its surface. This may be the reason for the slower stabilization of the synthesis current density observed in the chronoamperograms (Figure 1a). X-ray diffraction, X-ray photoemission spectroscopy and X-ray absorption spectroscopy

• Figure 3a–d shows the X-ray absorption spectra (XAS) of the L3 edge of nickel (a), iron (b), cobalt (c), and carbon (d) in the studied catalysts. The appearance of a shoulder peak at the L3 edge of the nickel (Figure 3a) at 855 eV indicates the presence of oxides in the structure of the catalysts (Ni in

• absorption edges at 285.2 and 293.7 eV correspond to the excitation of electrons in the sp2 network into the π* band (C=C) and σ* band (C–C), respectively [32][33]. The signals observed at 287.2 eV (σ*: C–O and/or π*: C–OH), 288.4 eV (σ*: C–O), 290.1 eV (π*: C=O) and 291.6 eV (π*: O–C=O) correspond to a

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• absorbed light to heat by these particles, has led to thriving research regarding the utilization of plasmonic nanoparticles for a myriad of applications. The design of conventional nanomaterials for PT conversion has focussed predominantly on the manipulation of photon absorption through bandgap

• engineering, doping, incorporation, and modification of suitable matrix materials. Plasmonic nanomaterials offer an alternative and attractive approach in this regard, through the flexibility in the excitation of surface plasmons. Specific advantages are the considerable improved bandwidth of the absorption

• , a higher efficiency of photon absorption, facile tuning, as well as flexibility in the synthesis of plasmonic nanomaterials. This review of plasmonic PT (PPT) research begins with a theoretical discussion on the plasmonic properties of nanoparticles by means of the quasi-static approximation, Mie

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

• Akif Hakan Kurt,
• Elif Berna Olutas,
• Fatma Avcioglu,
• Hamza Karakuş,
• Mehmet Ali Sungur,
• Cansu Kara Oztabag and
• Muhammet Yıldırım

Beilstein J. Nanotechnol. 2023, 14, 362–376, doi:10.3762/bjnano.14.31

• infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The characteristic surface plasmon resonance (SPR) absorption band has been found at 417 and 424 nm for Ch/Q- and Ch/CA-Ag NPs, respectively. The formation of a chitosan shell comprising quercetin and caffeic acid, which surround the

• nanoparticles The absorption spectra of quercetin, caffeic acid, chitosan, Ch-, Ch/Q-, and Ch/CA-Ag NPs were recorded on a UV–vis double-beam spectrophotometer (Hitachi U-2900) at wavelengths of 200 to 800 nm at 1.0 nm intervals with a quartz cell of 1.0 cm light path. Fourier-transform infrared (FTIR) spectra

• was calculated from the obtained results. Results and Discussion The characterization of the synthesized silver nanoparticles (Ag NPs) was carried out by using UV–vis absorption spectroscopy at ambient temperature. Figure 2 shows the UV–vis absorption measurement results of different Ag NPs, which are

Quasi-guided modes resulting from the band folding effect in a photonic crystal slab for enhanced interactions of matters with free-space radiations

• Kaili Sun,
• Yangjian Cai,
• Uriel Levy and
• Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 322–328, doi:10.3762/bjnano.14.27

• the kx direction, which is the same as for the GMs. The total Q-factor (Qtotal) of a resonance observed in the far-field spectrum is determined by the Q-factors of radiation (Qrad) and absorption (Qabs) [26]: Because the absorption loss of materials is not considered here, that is, Qabs is infinite

• all GMs are infinite since we ignore the material absorption in the lossless dielectrics. When the period-doubling perturbation is applied and the new QGMs are formed because of the folding of the FBZ, the coupling efficiency between free-space radiation and the QGMs is still very low, leading to the

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• inactivate pathogens. The term “photocatalysis” refers to chemical reactions that use light and a photocatalyst (basically a semiconductor). A few of the requirements that an effective photocatalyst system should satisfy include high sunlight absorption, an appropriate gap (1.5–2.8 eV), long-term charge

• orbitals, as opposed to the valence band of TiO2, which is made up entirely of O 2p orbitals. The mobility of the photogenerated charge carriers is increased by the well-dispersed Bi 6s orbital. Due to their distinctive structure, Bi-based photocatalysts exhibit a steeper absorption edge in the visible

• layer of the structure more quickly than those in a 3-D structure. It is important to note that an effective photocatalyst should have the following properties: (a) strong absorption both of UV and visible light (i.e., a suitable bandgap value, usually less than 3.0 eV); (b) thermal, chemical, and

Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

• Makoto Komiyama

Beilstein J. Nanotechnol. 2023, 14, 218–232, doi:10.3762/bjnano.14.21

• the use of upconversion nanoparticles to convert NIR to shorter-wavelength light for photoreactions. These nanoparticles usually contain rare-earth metal ions, which have long-living excited states. Thus, they achieve sequential energy absorption and convert two or more low-energy (NIR) photons into

• , insulin was orally delivered [98]. N-Acetyl-ʟ-cysteine enhances the mucoadhesion of the drug to enhance its biological absorption, whereas arginine promotes the intestinal absorption of insulin. The composite was sufficiently water-soluble and applicable to the oral delivery of insulin, which is mostly

Concentration-dependent photothermal conversion efficiency of gold nanoparticles under near-infrared laser and broadband irradiation

• Vikas,
• Raj Kumar and
• Sanjeev Soni

Beilstein J. Nanotechnol. 2023, 14, 205–217, doi:10.3762/bjnano.14.20

• attain higher efficiencies for the nanoparticles whose absorption wavelength is different from the irradiation wavelength. Lower concentrations (1.25–5 µg/mL) of such nanoparticles show 2–3 times higher efficiency under NIR broadband irradiation. For GNRs of sizes 10 × 38 nm and 10 × 41 nm, the different

• nanoparticles shifts due to changes in the surrounding medium [14][17][26]. Thus, the same laser source may lose its suitability for applications such as photothermal therapeutics, photoacoustic imaging, and drug delivery. Also, the maximum absorption of the incident radiation is desired, which depends on the

• optical absorption characteristics of the nanoparticles. Thus, a broadband irradiation source may be useful in which the full width half maximum of the optical output can be tuned to suit the optical absorption characteristics of the nanoparticles. To the best of our knowledge, the measurement of the

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

• Zoran M. Marković,
• Milica D. Budimir,
• Martin Danko,
• Dušan D. Milivojević,
• Pavel Kubat,
• Danica Z. Zmejkoski,
• Vladimir B. Pavlović,
• Marija M. Mojsin,
• Milena J. Stevanović and
• Biljana M. Todorović Marković

Beilstein J. Nanotechnol. 2023, 14, 165–174, doi:10.3762/bjnano.14.17

• toluene solution of CQDs has a strong broad absorption band at 248 nm with a shoulder at 224 nm, which represents the π–π* transition of C=C bonds. Apart from this broad band, there is a shoulder peak at 330 nm corresponding to the n–π* transition of C=O [32]. In the visible light region, at 444 nm, there

• is a weak absorption peak caused by surface state of CQDs [33][34]. Figure S2c (Supporting Information File 1) shows PL spectra of CQDs. It is obvious that the emission of CQDs does not depend on the excitation wavelength. Regardless of the excitation wavelengths the emission is located at 545 nm

• shows that the absorption of DPBF solution in both vials is nearly identical. This means that the CQDs/PU sample does not produce singlet oxygen, which confirms the previous results obtained by EPR and luminescence at 1270 nm. Ge et al. reported earlier that graphene quantum dots generate singlet oxygen

Antimicrobial and mechanical properties of functionalized textile by nanoarchitectured photoinduced Ag@polymer coating

• Jessica Plé,
• Marine Dabert,
• Helene Lecoq,
• Sophie Hellé,
• Lydie Ploux and
• Lavinia Balan

Beilstein J. Nanotechnol. 2023, 14, 95–109, doi:10.3762/bjnano.14.11

• increases with exposure time, which indicates an increase in NP concentration. Since the absorption peak is 426 nm for the Ag@PEG600DA/PETIA coating, the particles are expected to be slightly smaller than those of the Ag@PEG600DA film. This can be explained by the fact that the PETIA comonomer is a

• reflectance, mainly diffuse. The underlying metallic layer appears brown and exhibits an absorption band at 430 nm, linked to the plasmon resonance of AgNPs (Figure 8c), trapped inside the polymer matrix. To better understand this sudden decrease in reflectance, the surface was characterized by SEM (Figure 8c

Combining physical vapor deposition structuration with dealloying for the creation of a highly efficient SERS platform

• Adrien Chauvin,
• Walter Puglisi,
• Damien Thiry,
• Cristina Satriano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 83–94, doi:10.3762/bjnano.14.10

• adsorption isotherm curve of RhB [49][50]. The plateau in the SERS response observed between 10−8 and 10−10 mol·L−1 can be assigned to either the saturation of the chemical sites (i.e., no supplementary absorption is made) or to the fact that RhB continued to be absorbed outside of the hot spot [6][51

Frontiers of nanoelectronics: intrinsic Josephson effect and prospects of superconducting spintronics

• Anatolie S. Sidorenko,
• Horst Hahn and
• Vladimir Krasnov

Beilstein J. Nanotechnol. 2023, 14, 79–82, doi:10.3762/bjnano.14.9

• frequency range, switching from the superconducting to the resistive state due to absorption of a 10 GHz external signal [19]. Achieving a large coherent gain of the receiver, up to a factor of three, of the emitted power from two simultaneously biased arrays of Josephson junctions compared to that of the

Two-step single-reactor synthesis of oleic acid- or undecylenic acid-stabilized magnetic nanoparticles by thermal decomposition

• Mykhailo Nahorniak,
• Pamela Pasetto,
• Jean-Marc Greneche,
• Volodymyr Samaryk,
• Sandy Auguste,
• Anthony Rousseau,
• Nataliya Nosova and
• Serhii Varvarenko

Beilstein J. Nanotechnol. 2023, 14, 11–22, doi:10.3762/bjnano.14.2

• visible at 1577 and 1524 cm−1 and a band at 432 cm−1 corresponds to the vibrations of Fe–O or С–СН3 [29][30]. At the end of the first stage (SFin Stage1), the absorption bands corresponding to the acetylacetonate ligand or acetylacetone residues are not observed. The absorption band at 432 cm−1 also

• SFin Stage1, Figure S2 and Figure S3 in Supporting Information File 1) formed due to the exchange reaction of acetylacetonate and a higher acid show several absorption bands which were absent in the spectra of reactants and 1-octadecene (Table 2). The low-intensity absorption band at 1741–1742 cm−1

• , which appeared in the spectra of the reaction mixture of both oleate and undecylate complexes in octadecene, corresponds to vibrations of the carbonyl group of free unassociated acid. This band is not observed in the spectra of pure acids. The absorption band at 1711 cm−1 in both cases can be attributed

Atmospheric water harvesting using functionalized carbon nanocones

• Fernanda R. Leivas and
• Marcia C. Barbosa

Beilstein J. Nanotechnol. 2023, 14, 1–10, doi:10.3762/bjnano.14.1

• different processes to develop AWH such as condensing and collecting moisture, cooling ambient air below its dew point [10][11], and using chemical and physical processes involving absorption and adsorption [9][12][13]. Many of these mechanisms are inspired by structures found in nature (biomimetic designs

Electrical and optical enhancement of ITO/Mo bilayer thin films via laser annealing

• Abdelbaki Hacini,
• Ahmad Hadi Ali,
• Nurul Nadia Adnan and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2022, 13, 1589–1595, doi:10.3762/bjnano.13.133

• before and after laser annealing. The bandgap energy Eg was determined using the following equation (Tauc relation) [28]: where α is the absorption coefficient, hν is the photon energy; A is a constant, Eg is the bandgap energy, n = 0.5 for a direct bandgap, and n = 2 for an indirect bandgap. The bandgap

Observation of collective excitation of surface plasmon resonances in large Josephson junction arrays

• Roger Cattaneo,
• Mikhail A. Galin and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2022, 13, 1578–1588, doi:10.3762/bjnano.13.132

• suppression of Is corresponds to the absorbed MW power, Pa ≃ ≃ 30 nW. Thus, we can perform an absolute calibration of the absorbed power as a function of the detector resistance, as shown in Figure 6f. The absorbed power depends on the absorption efficiency, γ, the antenna area, Aa, and the power density

• the source of approx. 100 μW, taking into account losses on the way to the detector via diffraction on optical windows and a set of low-temperature MW filters (Zitex). Such an estimation indicates that the absorption efficiency γ of our detector is indeed not far from the optimal. However, the overall

Single-step extraction of small-diameter single-walled carbon nanotubes in the presence of riboflavin

• Polina M. Kalachikova,
• Anastasia E. Goldt,
• Eldar M. Khabushev,
• Timofei V. Eremin,
• Timofei S. Zatsepin,
• Elena D. Obraztsova,
• Konstantin V. Larionov,
• Liubov Yu. Antipina,
• Pavel B. Sorokin and
• Albert G. Nasibulin

Beilstein J. Nanotechnol. 2022, 13, 1564–1571, doi:10.3762/bjnano.13.130

• spectrum of Tuball SWCNTs after extraction features a distinctive S11 transition of SWCNTs at 990 nm, corresponding to (6,5)-chirality (Figure 3), unresolved before separation. The obtained absorption bands are slightly redshifted compared to the standard wavelengths of (6,5)-SWCNT absorption, which could

• as the first fraction. Optical characterization UV–vis–NIR spectroscopy measurements were performed using a Perkin-Elmer Lambda 1050 spectrophotometer in the wavelength range of 400–1300 nm to avoid the immense absorption of water in the NIR and minimize the interference of riboflavin absorption with

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• chemical, thermal, and charge transport properties, which can shift the light absorption of TiO2 to the visible region [29][30][31][32]. An emerging new material in optoelectronics is g-C3N4 (bandgap of 2.65–2.7 eV) because it has an appropriate band structure with suitable energy levels regarding TiO2

• spectroscopy (DRS) was carried out to measure the optical bandgap of the semiconductor materials through the Tauc method using the absorption coefficient α of the material, according to Equation 1 [42]: where h, ν, Eg, and B are the Planck constant, the frequency of the photon, the bandgap energy, and a

• −1 [48]. Also, FTIR spectroscopy is used as an extremely effective technique for studying the vibrational states of organic bonds in g-C3N4 materials using the vibrational peaks of C–N bonds between 1640 and 1200 cm−1. A very strong absorption peak at 807.2 cm−1 characterizes the fluctuation of tri-s

Non-stoichiometric magnetite as catalyst for the photocatalytic degradation of phenol and 2,6-dibromo-4-methylphenol – a new approach in water treatment

• Joanna Kisała,
• Anna Tomaszewska and
• Przemysław Kolek

Beilstein J. Nanotechnol. 2022, 13, 1531–1540, doi:10.3762/bjnano.13.126

• previous publication of ours [19]. The absorption spectra of the catalysts showed noticeable differences (Figure 1b). Using the absorption spectra, the electron gap energies for M1 and M2 were determined to be 0.11 V and 1.75 V, respectively (Table 1) [20]. Phase identification of the magnetite structure

• multimeter (CPC 411, Elmetron, Poland). External standards of seven concentration levels ranging from 1 × 10−5 to 1 × 10−3 mol·L−1 were used to quantify bromide ions. X-ray diffraction measurements of M1 (red), M2 (blue) (a), and UV–vis absorption spectra of M1 (red) and M2 (blue) (b). Figure 1a and 1b were

A TiO₂@MWCNTs nanocomposite photoanode for solar-driven water splitting

• Anh Quynh Huu Le,
• Ngoc Nhu Thi Nguyen,
• Hai Duy Tran,
• Van-Huy Nguyen and
• Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

• -scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and linear sweep voltammetry. The results show that the TiO2@MWCNTs nanocomposite has an optical bandgap of 2.5 eV, which is a significant improvement in visible-light absorption capability compared to TiO2 (3.14 eV). The

• been developed to increase the absorption of visible solar light [6][7]. Notably, carbon nanotubes (CNTs) are a promising material for visible-light absorption [8]. A combination of TiO2 with CNTs can effectively enhance the separation of e−/h+ pairs based on the high electric conductivity of CNTs

• . Herein, a TiO2@MWCNTs nanocomposite photocatalyst is synthesized via a simple hydrolysis method. The coupling of TiO2 and MWCNTs aims to limit the recombination of photogenerated electrons and holes, to improve the visible-light absorption of the photoanode under solar irradiation, and to enhance the

In search of cytotoxic selectivity on cancer cells with biogenically synthesized Ag/AgCl nanoparticles

• Mitzi J. Ramírez-Hernández,
• Mario Valera-Zaragoza,
• Omar Viñas-Bravo,
• Ariana A. Huerta-Heredia,
• Miguel A. Peña-Rico,
• Erick A. Juarez-Arellano,
• David Paniagua-Vega,
• Eduardo Ramírez-Vargas and
• Saúl Sánchez-Valdes

Beilstein J. Nanotechnol. 2022, 13, 1505–1519, doi:10.3762/bjnano.13.124

• give rise to a collective oscillation known as surface plasmon effect [34]. This effect can be monitored by UV–vis spectroscopy, where metal nanoparticles absorb radiation at different wavelengths depending on their size [36]. The UV–vis absorption spectra of the reactions at different temperatures are

• shown in Figure 4. The absence of absorption of visible radiation is evident in the AgNO3 salt and in the pineapple peel extract. Instead, reactions at different temperatures showed absorption in this region of the electromagnetic spectrum. Furthermore, differences in the maximum values of the

• absorption curves can be observed. Although in the reaction at room temperature (Ag/AgCl-Troom) the absorption maximum was not obvious, and it was in the case of the other reactions, the absorption maxima were easily identified. Ag/AgCl-T60 shows absorption maximum at 452 nm, Ag/AgCl-T80 at 484 nm, and Ag

Facile preparation of Au- and BODIPY-grafted lipid nanoparticles for synergized photothermal therapy

• Yuran Wang,
• Xudong Li,
• Haijun Chen and
• Yu Gao

Beilstein J. Nanotechnol. 2022, 13, 1432–1444, doi:10.3762/bjnano.13.118

• specificity and minimal invasiveness, it has attracted a great deal of attention as complementary modality for conventional cancer therapy options [1]. Gold nanoparticles (AuNPs) can absorb light and generate heat from light absorption because of the surface plasmon resonance (SPR) phenomenon and the tunable

• near-infrared (NIR) absorption [2]. Various gold nanoscale platforms, including nanostars, nanorods, nanospheres, nanoshells, and nanocages, have been designed as PTAs for PTT. Gold nanorods (ca. 50 nm), nanoshells (ca. 130 nm), and nanoparticles with large sizes (>50 nm) are suitable for PTT because

• of strong NIR absorption [3]. However, particles with larger size are likely to have long resident times and slow elimination in tissues, which may lead to long-term toxicity. Commercially available AuNPs with particle sizes of 10–30 nm can be synthesized by the classical Turkevich method [4]. Rats

Orally administered docetaxel-loaded chitosan-decorated cationic PLGA nanoparticles for intestinal tumors: formulation, comprehensive in vitro characterization, and release kinetics

• Sedat Ünal,
• Osman Doğan and
• Yeşim Aktaş

Beilstein J. Nanotechnol. 2022, 13, 1393–1407, doi:10.3762/bjnano.13.115

• obstacles for successful treatment [15]. The low permeability of nanoformulations through the mucus layer prevents sufficient absorption of the drug and causes clearance of molecules which do not reach adequate retention time in the GIT [53]. Thus, increasing the retention time of the NPs on the mucus layer

• absorption of drugs. Therefore, the Caco-2 cell line derived from a human colorectal carcinoma was employed to simulate the epithelial cell layer. A monolayer of cells should have a transepithelial electrical resistance of around 500 Ω·cm2 to show similarity with intestinal lumen [70][71][72]. In Table 5

• -coated PLGA NPs. As a result, CS-coated PLGA NPs improved the oral absorption and remarkably increased the cellular uptake compared to unmodified PLGA NPs [74]. Conclusion Currently, many anticancer agents used in chemotherapy are administered parenterally. Significant advances in the field of oral