TY  - JOUR
AB  - Sensitive measurement of the optoacoustic (OA, also photoacoustic) properties of cells in flow is highly desirable, as it provides information about the optical absorption properties of cellular compounds. Hence, optoacoustic spectral characteristics can deliver information about the cell state or disease parameters, but can also be used for high-throughput cell sorting by intrinsic properties without additional fluorescence labeling. The current implementation of optoacoustic measurements of cells in a microfluidic context typically relies on piezoelectric (ultrasound) transducers attached to the microfluidic chip, whereby the transducer records the ultrasound signal originating from absorbing species in cells when excited by laser pulses. The arrangement of the transducer outside of the microfluidic chip leads to the challenge of signal integration over a larger area and coupling interlayer effects resulting in attenuation and a reduction of sensitivity. Moreover, the placement of the bulky transducer outside of the chip prevents the exploitation of the full advantages of microfluidics. As a solution, we demonstrate the use of point-source optimized interdigital transducers (pIDTs) directly fabricated on the surface of the microfluidic chip for the detection of surface acoustic waves (SAW) from single cells in continuous flow. The SAW is excited by bulk acoustic waves originating from the optoacoustic effect of absorbing species inside the cells illuminated by laser light. The use of these highly focused pIDTs and on-chip lithographically fabricated hard-wall microchannels allows the detection of SAW with a spatial resolution on the order of the cell diameter directly on-chip, offering the possibility of miniaturization, parallelization, and cheap mass production.
AU  - Göllner, S.
AU  - Colditz, M.*
AU  - Huang, Y.
AU  - Schmidt, H.*
AU  - Winkler, A.S.*
AU  - Stiel, A.-C.
C1  - 73476
C2  - 56849
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 14903-14911
TI  - Chip-based optoacoustic single cell detection in flow using point-source optimized surface acoustic wave transducers.
JO  - ACS Appl. Mater. Interfaces
VL  - 17
IS  - 10
PB  - Amer Chemical Soc
PY  - 2025
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - Biodegradable poly(β-amino) esters (PBAEs) have been a focus of interest for delivering therapeutic siRNA for several years. While no approved therapies are on the market yet, our study aims to advance PBAE-based treatments for currently "undruggable" diseases. The PBAEs used in this study are based on a recently reported step-growth copolymerization, which results in polymers with a unique balance of lipophilicity and positive charge, thereby showcasing diverse properties. Upon incubation with siRNA, these PBAEs form a unique structure and topology, which we classify as a subtype of classical polyplex, termed "micelle-embedded polyplexes" (mPolyplexes). The impact of different nebulizers on the physicochemical performance of these nanoparticles was investigated, and it was found that various mPolyplexes can be nebulized using vibrating-mesh nebulizers without the loss of gene silencing activity nor a change in physicochemical properties, setting them apart from other nanoparticles such as marketed LNPs. Finally, their therapeutic application was tested ex vivo in human precision-cut lung slices from patients with lung fibrosis. mPolyplexes mediated 52% gene silencing of matrix metalloprotease 7 (MMP7) and a downstream effect on collagen I (Col I) with 33% downregulation as determined via qPCR.
AU  - Müller, J.T.*
AU  - Kromer, A.P.E.*
AU  - Ezaddoustdar, A.*
AU  - Alexopoulos, I.*
AU  - Steinegger, K.M.*
AU  - Porras-Gonzalez, D.L.
AU  - Berninghausen, O.*
AU  - Beckmann, R.*
AU  - Braubach, P.*
AU  - Burgstaller, G.
AU  - Wygrecka, M.*
AU  - Merkel, O.M.*
C1  - 73384
C2  - 57033
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 11861-11872
TI  - Nebulization of RNA-loaded micelle-embedded polyplexes as a potential treatment of idiopathic pulmonary fibrosis.
JO  - ACS Appl. Mater. Interfaces
VL  - 17
IS  - 8
PB  - Amer Chemical Soc
PY  - 2025
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - Titanium dioxide (TiO2) shows significant potential as a self-cleaning material to inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and prevent virus transmission. This study provides insights into the impact of UV-A light on the photocatalytic inactivation of adsorbed SARS-CoV-2 virus-like particles (VLPs) on a TiO2 surface at the molecular and atomic levels. X-ray photoelectron spectroscopy, combined with density functional theory calculations, reveals that spike proteins can adsorb on TiO2 predominantly via their amine and amide functional groups in their amino acids blocks. We employ atomic force microscopy and grazing-incidence small-angle X-ray scattering (GISAXS) to investigate the molecular-scale morphological changes during the inactivation of VLPs on TiO2 under light irradiation. Notably, in situ measurements reveal photoinduced morphological changes of VLPs, resulting in increased particle diameters. These results suggest that the denaturation of structural proteins induced by UV irradiation and oxidation of the virus structure through photocatalytic reactions can take place on the TiO2 surface. The in situ GISAXS measurements under an N2 atmosphere reveal that the virus morphology remains intact under UV light. This provides evidence that the presence of both oxygen and UV light is necessary to initiate photocatalytic reactions on the surface and subsequently inactivate the adsorbed viruses. The chemical insights into the virus inactivation process obtained in this study contribute significantly to the development of solid materials for the inactivation of enveloped viruses.
AU  - Kohantorabi, M.*
AU  - Ugolotti, A.*
AU  - Sochor, B.*
AU  - Rössler, J.
AU  - Wagstaffe, M.*
AU  - Meinhardt, A.*
AU  - Beck, E.E.*
AU  - Dolling, D.S.*
AU  - Garcia, M.B.*
AU  - Creutzburg, M.*
AU  - Keller, T.F.*
AU  - Schwartzkopf, M.*
AU  - Vayalil, S.K.*
AU  - Thuenauer, R.*
AU  - Guédez, G.*
AU  - Löw, C.*
AU  - Ebert, G.
AU  - Protzer, U.
AU  - Hammerschmidt, W.
AU  - Zeidler, R.
AU  - Roth, S.V.*
AU  - Di Valentin, C.*
AU  - Stierle, A.*
AU  - Noei, H.*
C1  - 71038
C2  - 55868
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 37275-37287
TI  - Light-induced transformation of virus-like particles on TiO2.
JO  - ACS Appl. Mater. Interfaces
VL  - 16
IS  - 28
PB  - Amer Chemical Soc
PY  - 2024
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - We demonstrate the use of DNA origami to create virus-trapping nanoshells that efficiently neutralize hepatitis B virus (HBV) in cell culture. By modification of the shells with a synthetic monoclonal antibody that binds to the HBV envelope, the effective neutralization potency per antibody is increased by approximately 100 times compared to using free antibodies. The improvements in neutralizing the virus are attributed to two factors: first, the shells act as a physical barrier that blocks the virus from interacting with host cells; second, the multivalent binding of the antibodies inside the shells lead to stronger attachment to the trapped virus, a phenomenon known as avidity. Pre-incubation of shells with HBV and simultaneous addition of both components separately to cells lead to comparable levels of neutralization, indicating rapid trapping of the virions by the shells. Our study highlights the potential of the DNA shell system to rationally create antivirals using components that, when used individually, show little to no antiviral effectiveness.
AU  - Willner, E.M.*
AU  - Kolbe, F.
AU  - Momburg, F.*
AU  - Protzer, U.
AU  - Dietz, H.*
C1  - 70653
C2  - 55706
SP  - 25836-25842
TI  - Hepatitis B virus neutralization with DNA origami nanoshells.
JO  - ACS Appl. Mater. Interfaces
VL  - 16
IS  - 20
PY  - 2024
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - Many pathogenic bacteria are getting more and more resistant against antibiotic treatment and even become up to 1.000× times more resilient in the form of a mature biofilm. Thus, one is currently prospecting for alternative methods for treating microbial infections, and photodynamic therapy is a highly promising approach by creating so-called reactive oxygen species (ROS) produced by a photosensitizer (PS) upon irradiation with light. Unfortunately, the unspecific activity of ROS is also problematic as they are harmful to healthy tissue as well. Notably, one knows that uncontrolled existence of ROS in the body plays a major role in the development of cancer. These arguments create need for advanced theranostic materials which are capable of autonomous targeting and detecting the existence of a biofilm, followed by specific activation to combat the infection. The focus of this contribution is on mesoporous organosilica colloids functionalized by orthogonal and localized click-chemistry methods. The external zone of the particles is modified by a dye of the Hoechst family. The particles readily enter a mature biofilm where adduct formation with extracellular DNA and a resulting change in the fluorescence signal occurs, but they cannot cross cellular membranes such as in healthy tissue. A different dye suitable for photochemical ROS generation, Acridine Orange, is covalently linked to the surfaces of the internal mesopores. The spectral overlap between the emission of Hoechst with the absorption band of Acridine Orange facilitates energy transfer by Förster resonance with up to 88% efficiency. The theranostic properties of the materials including viability studies were investigated in vitro on mature biofilms formed by Pseudomonas fluorescens and prove the high efficacy.
AU  - Bronner, H.*
AU  - Brunswig, F.
AU  - Pluta, D.*
AU  - Krysiak, Y.*
AU  - Bigall, N.*
AU  - Plettenburg, O.
AU  - Polarz, S.*
C1  - 67744
C2  - 54053
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 14067-14076
TI  - Cooperative functionalities in porous nanoparticles for seeking extracellular DNA and targeting pathogenic biofilms via photodynamic therapy.
JO  - ACS Appl. Mater. Interfaces
VL  - 15
IS  - 11
PB  - Amer Chemical Soc
PY  - 2023
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - We investigated the adsorption of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), the virus responsible for the current pandemic, on the surface of the model catalyst TiO2(101) using atomic force microscopy, transmission electron microscopy, fluorescence microscopy, and X-ray photoelectron spectroscopy, accompanied by density functional theory calculations. Three different methods were employed to inactivate the virus after it was loaded on the surface of TiO2(101): (i) ethanol, (ii) thermal, and (iii) UV treatments. Microscopic studies demonstrate that the denatured spike proteins and other proteins in the virus structure readsorb on the surface of TiO2 under thermal and UV treatments. The interaction of the virus with the surface of TiO2 was different for the thermally and UV treated samples compared to the sample inactivated via ethanol treatment. AFM and TEM results on the UV-treated sample suggested that the adsorbed viral particles undergo damage and photocatalytic oxidation at the surface of TiO2(101) which can affect the structural proteins of SARS-CoV-2 and denature the spike proteins in 30 min. The role of Pd nanoparticles (NPs) was investigated in the interaction between SARS-CoV-2 and TiO2(101). The presence of Pd NPs enhanced the adsorption of the virus due to the possible interaction of the spike protein with the NPs. This study is the first investigation of the interaction of SARS-CoV-2 with the surface of single crystalline TiO2(101) as a potential candidate for virus deactivation applications. Clarification of the interaction of the virus with the surface of semiconductor oxides will aid in obtaining a deeper understanding of the chemical processes involved in photoinactivation of microorganisms, which is important for the design of effective photocatalysts for air purification and self-cleaning materials.
AU  - Kohantorabi, M.*
AU  - Wagstaffe, M.*
AU  - Creutzburg, M.*
AU  - Ugolotti, A.*
AU  - Kulkarni, S.*
AU  - Jeromin, A.*
AU  - Krekeler, T.*
AU  - Feuerherd, M.
AU  - Herrmann, A.
AU  - Ebert, G.
AU  - Protzer, U.
AU  - Guédez, G.*
AU  - Löw, C.*
AU  - Thuenauer, R.*
AU  - Schlueter, C.*
AU  - Gloskovskii, A.*
AU  - Keller, T.F.*
AU  - Di Valentin, C.*
AU  - Stierle, A.*
AU  - Noei, H.*
C1  - 67424
C2  - 54170
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 8770-8782
TI  - Adsorption and inactivation of SARS-CoV-2 on the surface of anatase TiO2(101).
JO  - ACS Appl. Mater. Interfaces
VL  - 15
IS  - 6
PB  - Amer Chemical Soc
PY  - 2023
SN  - 1944-8244
ER  - 

TY  - JOUR
AB  - Poly(ether ether ketone) (PEEK) is a promising material in biomedical engineering due to its suitable mechanical properties and excellent chemical resistance and biocompatibility. However, the biological inertness of PEEK limits its applications. In this study, we developed a facile approach of immersion to generate a biocompatible and bioactive PEEK that induced osteodifferentiation. First, micro-pores on the surface of PEEK were introduced by concentrated sulfuric acid and subsequent water immersion, followed by the hydrothermal treatment to reduce residual sulfuric acid. Subsequently, the sulfonated PEEK surface was activated by the oxygen plasma treatment and then coated with a poly(dopamine) (PDA) layer by immersion into the dopamine solution. Finally, the tripeptide Arg-Gly-Asp (RGD) was integrated onto the PDA-coated surface of PEEK by immersion into the RGD peptide solution. The surface characteristics (physical chemistry and biological properties) and the ability to form bonelike apatite were systematically investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle analysis, the Archimedes' fluid saturation method, ellipsometry, a quartz crystal microbalance with dissipation monitoring, cell proliferation, real-time reverse transcription polymerase chain reaction analysis, alizarin red staining, immunocytochemistry staining, and simulated body fluid immersion. Collectively, the modified PEEK showed a significantly improved ability to promote cell proliferation, osteogenic differentiation, and bonelike apatite formation in vitro as compared to the PEEK control. These results demonstrate that combined facile surface modifications for PEEK enhance its bioactivity and biocompatibility, and induce osteodifferentiation. This study presents a strategy for broadening the use of PEEK in the application of orthopedic implants and could be industrially scalable in future.
AU  - Zhu, Y.
AU  - Cao, Z.*
AU  - Peng, Y.*
AU  - Hu, L.*
AU  - Güney, T.
AU  - Tang, B.*
C1  - 56618
C2  - 47206
CY  - 1155 16th St, Nw, Washington, Dc 20036 Usa
SP  - 27503-27511
TI  - Facile surface modification method for synergistically enhancing the biocompatibility and bioactivity of poly(ether ether ketone) that induced osteodifferentiation.
JO  - ACS Appl. Mater. Interfaces
VL  - 11
IS  - 31
PB  - Amer Chemical Soc
PY  - 2019
SN  - 1944-8244
ER  -