Ana Perez Lopez

University of Edinburgh | UoE · Institute of Genetics and Molecular Medicine

Several studies have reported the successful use of bio-orthogonal catalyst nanoparticles (NPs) for cancer therapy. However, the delivery of the catalysts to the target tissues in vivo remains an unsolved challenge. The combination of catalytic NPs with extracellular vesicles (EVs) has been proposed as a promising approach to improve the delivery o...

Crosslinking mass spectrometry provides pivotal information on the structure and interaction of proteins. MS-cleavable crosslinkers are regarded as a cornerstone for the analysis of complex mixtures. Yet they fragment under similar conditions as peptides, leading to mixed fragmentation spectra of the crosslinker and peptide. This hampers selecting...

Artificial metalloenzymes (ArMs) enrich bioorthogonal chemistry with new-to-nature reactions while limiting metal deactivation and toxicity. This enables biomedical applications such as activating therapeutics in situ. However, while combination therapies are becoming widespread anticancer treatments, dual catalysis by ArMs has not yet been shown....

Bioorthogonal metallocatalysis has opened up a xenobiotic route to perform nonenzymatic catalytic transformations in living settings. Despite their promising features, most metals are deactivated inside cells by a myriad of reactive biomolecules, including biogenic thiols, thereby limiting the catalytic functioning of these abiotic reagents. Here w...

5-Fluorouracil (5-FU) is an antineoplastic antimetabolite that is widely administered to cancer patients by bolus injection, especially to those suffering from colorectal and pancreatic cancer. Because of its suboptimal route of administration and dose-limiting toxicities, diverse 5-FU prodrugs have been developed to confer oral bioavailability and...

The recent incorporation of Au chemistry in the bioorthogonal toolbox has opened up new opportunities to deliver biologically independent reactions in living environments. Herein we report that the O-propargylation of the hydroxamate group of the potent HDAC inhibitor panobinostat leads to a vast reduction of its anticancer properties (>500-fold)....

The use of exosomes as selective delivery vehicles of therapeutic agents, such as drugs or hyperthermia-capable nanoparticles, is being intensely investigated on account of their preferential tropism toward their parental cells. However, the methods used to introduce a therapeutic load inside exosomes often involve disruption of their membrane, whi...

The promising potential of bioorthogonal catalysis in biomedicine is inspiring incremental efforts to design strategies that regulate drug activity in living systems. To achieve this, it is not only essential to develop customized inactive prodrugs and biocompatible metal catalysts, but also the right physical environment for them to interact and e...

The transformational impact of bioorthogonal chemistries has inspired new strategies for the in vivo synthesis of bioactive agents through non-natural means. Among these, Pd catalysts have played a prominent role in the growing subfield of bioorthogonal catalysis by producing xenobiotics and uncaging biomolecules in living systems. However, deliver...

Novel palladium (Pd)-loaded titanium (Ti) devices with high biocompatibility and catalytic activity were prepared using a range of fabrication methods such as powder metallurgy (i.e. sintering with and without space-holder), sputtering, pulsed laser deposition and supersonic cluster beam deposition. The surface of the Ti-[Pd] devices were physico-c...

Systemic side effects limit the efficacy of chemotherapy regimens. To reduce toxicity, a metabolically stable prodrug of SN‐38 (irinotecan's active metabolite) has been designed to be exclusively activated by Pd‐functionalized microdevices that can be implanted into tumors. It is also shown the first concomitant uncaging of two drugs used in clinic...

SN‐38, the active metabolite of irinotecan, is released upon liver hydrolysis to mediate potent antitumor activity. Systemic exposure to SN‐38, however, also leads to serious side effects. To reduce systemic toxicity by controlling where and when SN‐38 is generated, a new prodrug was specifically designed to be metabolically stable and undergo rapi...

Chemical proteomics approaches are widely used to identify molecular targets of existing or novel drugs. This manu-script describes the development of a straightforward approach to conjugate azide-labelled drugs via click chemistry to alkyne-tagged cell-penetrating fluorescent nanoparticles as a novel tool to study target engagement and/or identifi...

The incorporation of transition metal catalysts to the bioorthogonal toolbox has opened the possibility of producing supra-stoichiometric amounts of xenobiotics in living systems in a non-enzymatic fashion. For medical use, such metals could be embedded in implantable devices (i.e. heterogeneous catalyst) to “synthesize” drugs in desired locations...

Herein we report a straightforward method for the scalable preparation of Pd nanoparticles (Pd-NPs) with reduced inherent cytotoxicity and high photothermal conversion capacity. These Pd-NPs are rapidly taken up by cells and able to kill labelled cancer cells upon short exposure to near infrared (NIR) light. Following cell treatment with Pd-NPs, ab...

Bioorthogonal uncaging of a structurally diverse selection of cytotoxic precursors is achieved by heterogeneous gold catalysis, allowing safe activation of therapeutics by nonbiological chemical stimuli. In their Communication (DOI: 10.1002/anie.201705609), J. Santamaría and A. Unciti-Broceta et al. report gold-catalyzed bioorthogonal uncaging of c...

Die bioorthogonale Aktivierung strukturell diverser Vorstufen für zytotoxische Wirkstoffe gelingt durch Gold-Heterogenkatalyse. In ihrer Zuschrift (DOI: 10.1002/ange.201705609) berichten J. Santamaría und A. Unciti-Broceta et al. über die chemische Aktivierung zugelassener Tumortherapeutika in Krebszellkulturen und die erste Aktivierung einer bioor...

Recent advances in bioorthogonal catalysis are increasing our capacity to manipulate the fate of molecules in complex biological systems. Herein we report a novel bioorthogonal uncaging strategy that is triggered by heterogeneous gold catalysis and facilitates the activation of a structurally-diverse range of therapeutics in cancer cell culture. Fu...

Recent advances in bioorthogonal catalysis are increasing our capacity to manipulate the fate of molecules in complex biological systems. Herein we report a novel bioorthogonal uncaging strategy that is triggered by heterogeneous gold catalysis and facilitates the activation of a structurally-diverse range of therapeutics in cancer cell culture. Fu...

Reactive oxygen species play numerous roles in a number of pathological processes. Monitoring H2O2 is a powerful tool for imaging and therapy of diseases wherein oxidative stress is involved. In particular, we report a specific application of functional microspheres as sensors of H2O2. Reactive oxygen species responsive delivery systems were develo...

The in situ detection of caspase-3 activity has applications in the imaging and monitoring of multiple pathologies, notably cancer. A series of cell penetrating FRET-based fluorogenic substrates were designed and synthesised for the detection of caspase-3 in live cells. A variety of modifications of the classical caspase-3 and caspase-7 substrate s...

MALDI-TOF MS spectra of substrate 12. (PDF)

MALDI-TOF MS spectra of 26. (PDF)

Cell viability. (PDF)

MALDI-TOF MS spectra of substrate 25. (PDF)

Solid phase synthesis of the fluorogenic substrates 1–24. (PDF)

MALDI-TOF MS spectra of substrate 11. (PDF)

MALDI-TOF MS spectra of 27. (PDF)

Quantification of caspase-3 in apoptotic cells by flow cytometry. (PDF)

MALDI-TOF MS spectra of substrate 14. (PDF)

Analysis of substrate 27 with caspase-3 and caspase-7. (PDF)

Substrate 27 selectively labels apoptotic cells. (PDF)

MALDI-TOF MS and HPLC analysis of substrates 1–27. (PDF)

Peptidomimetics, such as oligo-N-alkylglycines (peptoids), are attractive alternatives to traditional cationic cell-penetrating peptides (such as R9) due to their robust proteolytic stability and reduced cellular toxicity. Here, monomeric N-alkylglycines, incorporating amino-functionalised hexyl or triethyleneglycol (TEG) side chains, were synthesi...

The in situ immediate detection of the presence of bacteria in the distal human lung is of significant clinical utility. Herein we describe the development and optimization of a bacterial binding fragment (UBI29–41) of the antimicrobial peptide, ubiquicidin (UBI), conjugated to an environmentally sensitive fluorophore to enable rapid live bacterial...

11 FRET-based fluorogenic substrates were constructed using the pentapeptide template Asp-Glu-X2-Asp-X1', and evaluated with caspase-3, caspase-7 and cathepsin B. The sequence Asp-Glu-Pro-Asp-Ser was able to selectively quantify caspase-3 activity in vitro without notable caspase-7 and cathepsin B cross-reactivity, while exhibiting low μM KM values...

Octaarginine has been described as a molecular transporter. We report a useful synthesis of orthogonally protected L-octaarginine by using a method based on a microencapsulated palladium catalyst. Known palladium-based methods for allyl ester deprotection have been modified to facilitate purification of the unprotected intermediates. This improveme...

A novel multifunctional probe to monitor intracellular enzymatic activity in living cells is successfully developed. Their use as accurate intracellular sensors by conjugation of an internal control (that gives an extra feature to both evaluate cellular-uptake efficiency and track probes over time) is reported. In particular, a specific application...

A novel strategy for the efficient and safe delivery of thiolated therapeutic cargoes into mammalian cells has been developed. For this purpose, polymeric microspheres have been successfully functionalised to become a sulfhydryl reactive delivery system. SEM, DLS and zeta potential analysis were used to characterise these modified nanoparticles. Th...