Upenyu Muza

Dr. Upenyu Muza

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 December 2020 in Proceedings of the National Academy of Sciences
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SLSushil Lathwal
Sushil Lathwal
SYSaigopalakrishna S. Yerneni
Saigopalakrishna S. Yerneni
SBSusanne Boye
Susanne Boye
UMUpenyu Muza
Upenyu Muza
STShuntaro Takahashi
Shuntaro Takahashi
Krzysztof MatyjaszewskiKrzysztof Matyjaszewski
Krzysztof Matyjaszewski
Exosomes are emerging as ideal drug delivery vehicles due to their biological origin and ability to transfer cargo between cells. However, rapid clearance of exogenous exosomes from the circulation as well as aggregation of exosomes and shedding of surface proteins during storage limit their clinical translation. Here, we demonstrate highly controlled and reversible functionalization of exosome surfaces with well-defined polymers that modulate the exosome’s physiochemical and pharmacokinetic properties. Using cholesterol-modified DNA tethers and complementary DNA block copolymers, exosome surfaces were engineered with different biocompatible polymers. Additionally, polymers were directly grafted from the exosome surface using biocompatible photo-mediated atom transfer radical polymerization (ATRP). These exosome polymer hybrids (EPHs) exhibited enhanced stability under various storage conditions and in the presence of proteolytic enzymes. Tuning of the polymer length and surface loading allowed precise control over exosome surface interactions, cellular uptake, and preserved bioactivity. EPHs show fourfold higher blood circulation time without altering tissue distribution profiles. Our results highlight the potential of precise nanoengineering of exosomes toward developing advanced drug and therapeutic delivery systems using modern ATRP methods.


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NKNataliya Kiriy
Nataliya Kiriy
SÖSezer özenler
Sezer özenler
PVPauline Voigt
Pauline Voigt
OKOliver Kobsch
Oliver Kobsch
Jochen Meier-HaackJochen Meier-Haack
Jochen Meier-Haack
BVBrigitte Voit
Brigitte Voit
State-of-the-art Li batteries suffer from serious safety hazards caused by the reactivity of lithium and the flammable nature of liquid electrolytes. This work develops highly efficient solid-state electrolytes consisting of imidazolium-containing polyionic liquids (PILs) and lithium bis(trifluoromethane sulfonyl)imide (LiTFSI). By employing PIL/LiTFSI electrolyte membranes blended with poly(propylene carbonate) (PPC), we addressed the problem of combining ionic conductivity and mechanical properties in one material. It was found that PPC acts as a mechanically reinforcing component that does not reduce but even enhances the ionic conductivity. While pure PILs are liquids, the tricomponent PPC/PIL/LiTFSI blends are rubber-like materials with a Young’s modulus in the range of 100 MPa. The high mechanical strength of the material enables fabrication of mechanically robust free-standing membranes. The tricomponent PPC/PIL/LiTFSI membranes have an ionic conductivity of 10−6 S·cm−1 at room temperature, exhibiting conductivity that is two orders of magnitude greater than bicomponent PPC/LiTFSI membranes. At 60 °C, the conductivity of PPC/PIL/LiTFSI membranes increases to 10−5 S·cm−1 and further increases to 10−3 S·cm−1 in the presence of plasticizers. Cyclic voltammetry measurements reveal good electrochemical stability of the tricomponent PIL/PPC/LiTFSI membrane that potentially ranges from 0 to 4.5 V vs. Li/Li+. The mechanically reinforced membranes developed in this work are promising electrolytes for potential applications in solid-state batteries.

5 March 2021 in Analytical Science Advances
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UMUpenyu Muza
Upenyu Muza
SBSusanne Boye
Susanne Boye
ALAlbena Lederer
Albena Lederer
Broad diversity and heterogeneity are inherently showcased by both natural and synthetic macromolecular structures. The high application potential for such structures and their combinations calls for novel analytical approaches that allow for comprehensive characterization and a full understanding of their complex composition. This review gives an overview of recent advances in designing and fabricating bioconjugated and self‐assembled polymer structures, and introduces adequate characterization protocols for sufficient elucidation of their specific molecular properties. Possible pitfalls in their analysis are demonstrated, and potential alternatives are discussed. The primary focus is on addressing the highlights, and future prospects of applying field‐flow fractionation coupled and/or hyphenated to different detection methods as a powerful separation and analytical technique for bioconjugate and self‐assembled nanostructures.

27 November 2022 in Macromolecular Chemistry and Physics
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LELisa Ehrlich
Lisa Ehrlich
DPDoris Pospiech
Doris Pospiech
UMUpenyu Muza
Upenyu Muza
ALAlbena Lederer
Albena Lederer
JMJulia Muche
Julia Muche
Ulrich SchubertUlrich Schubert
Ulrich Schubert
Organic, solid‐state batteries require efficient solid electrolytes able to provide stable ion conduction. Here, solid electrolytes based on ionic liquid (IL) polymers with chloride counterions as electrolyte materials for batteries are presented. Acrylic monomers with imidazolium substituents with alkyl side groups that are linked by alkyl spacers to the acrylic group are employed. The IL monomers with chloride counterions are either converted by thermally initiated radical polymerization into linear homopolymers or incorporated into polymer networks by UV‐initiated copolymerization utilizing a bifunctional, non‐ionic cross‐linker. Both procedures successfully yielded the desired materials, which is confirmed by NMR spectroscopy (linear homopolymers) or Raman spectroscopy (IL networks). The ionic conductivities at room temperature are measured by Electrochemical Impedance Spectroscopy. The ionic conductivities of the linear homopolymers are in the range of 10−4 to 10−6 S cm−1, while those of the IL networks are about two orders of magnitude lower. They increase to 10−4 S cm−1 at 70 °C. The electrochemical stability is examined by Linear Sweep Voltammetry and is proven in the voltage range of −2 to +2 V. The results reveal that the materials represent promising electrolytes for potential solid‐state battery applications.

16 September 2024 in Macromolecular Chemistry and Physics
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Journal Article
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MSMichael‐Phillip Smith
Michael‐Phillip Smith
CCChané Calitz
Chané Calitz
UMUpenyu Muza
Upenyu Muza
ALAlbena Lederer
Albena Lederer
CECatharine Esterhuysen
Catharine Esterhuysen
BKBert Klumperman
Bert Klumperman
Poly(styrene‐co‐maleic anhydride) (SMAnh) is a copolymer system that is well known for its alternating tendency, which has been thoroughly investigated by many research groups over the decades and is widely used in industry. Investigations have focused almost entirely on thermally initiated systems. However, very few investigations have been conducted on light‐initiated radical copolymerization. In this study, the photoinitiated copolymerization of styrene and maleic anhydride is investigated without the use of an external radical source, such as the classical 2,2‐azobis(2‐methylpropionitrile) (AIBN), benzoyl peroxide (BPO), or any photoinitiators. The initiation of the polymerization is instead found to take place through an excited state biradical generated in situ from a photoexcited charge‐transfer complex (CTC) comprising the donor (styrene) and acceptor (maleic anhydride) monomers. The formation of the complex is found to be solvent dependent. Excitation of the complex results in copolymerization of monomers to afford high‐molecular‐weight (>105 g·mol−1) alternating copolymers.