First human study in treatment of unresectable liver metastases from colorectal cancer with irinotecan-loaded beads (DEBIRI)

The objective of this pilot clinical study was to assess the safety, technical feasibility, pharmacokinetic (PK) profile and tumour response of DC Bead™ with irinotecan (DEBIRI™) delivered by intra-arterial embolisation for the treatment of metastatic colorectal cancer. Eleven patients with unresectable liver metastases from CRC, tumour burden <30% of liver volume, adequate haematological, liver and renal function, performance status of <2 were included in this study. Patients received up to 4 sessions of TACE with DEBIRI at 3-week intervals. Feasibility of the procedure, safety and tumour response were assessed after each cycle. PK was measured after the first cycle. Patients were followed up to 24 weeks. Only mild to moderate adverse events were observed. DEBIRI is a technically feasibile procedure; no technical complications were observed. Average Cmax for irinotecan and SN-38 was 194 ng/ml and 16.7 ng/ml, respectively, with average t½ of 4.6 h and 12.4 h following administration of DEBIRI. Best overall response during the study showed disease control in 9 patients (2 patients with partial response and 7 with stable disease, overall response rate of 18%). Our study shows that transarterial chemoembolisation with irinotecan-loaded DC beads (DEBIRI) is safe, technically feasible and effective with a good PK profile

Valency engineering of monomeric enzymes for self-assembling biocatalytic hydrogels

All-enzyme hydrogels are efficient reagents for continuous flow biocatalysis. These materials can be obtained by self-assembly of two oligomeric enzymes, modified with the complementary SpyTag and SpyCatcher units. To facilitate access to the large proportion of biocatalytically relevant monomeric enzymes, we demonstrate that the tagging valency of the monomeric (S)-stereoselective ketoreductase Gre2p from Saccharomyces cerevisiae can be designed to assemble stable, active hydrogels with the cofactor-regenerating glucose 1-dehydrogenase GDH from Bacillus subtilis. Mounted in microfluidic reactors, these gels revealed high conversion rates and stereoselectivity in the reduction of prochiral methylketones under continuous flow for more than 8 days. The sequential use as well as parallelization by ‘numbering up’ of the flow reactor modules demonstrate that this approach is suitable for syntheses on the semipreparative scale

An Immobilised Silicon‐Carbon Bond‐Forming Enzyme for Anaerobic Flow Biocatalysis

The recent development of tailored cytochrome enzymes has enabled “new-to-nature” reactivities, such as the biocatalytic formation of carbon-silicon bonds using the cytochrome c from Rhodothermus marinus. To maximise the potential of this remarkable biocatalyst by increasing its turnover numbers (TON) and to enable its reusability in continuous processes, we report the use of the SpyTag/SpyCatcher bioconjugation system to immobilise this enzyme. We successfully modified the enzyme with a SpyTag without significant effects on its catalytic activity. Even after immobilization on microparticles the enzyme retained 60 % activity. When the immobilized enzyme was used in sequential batch or continuous flow to produce an organosilicon, we observed up to 6-fold higher turnover numbers over a total period of 10 days compared to the free enzyme reaction, however we observed a drop in stereoselectivity under these conditions. This is the first report on the successful immobilisation of a carbon-silicon bond forming enzyme for the continuous, biocatalytic production of organosilicons

Self-immobilizing Biocatalysts for fluidic Reaction Cascades

The industrial implementation of whole-cells and enzymes in flow biocatalysis microreactors is essential for the emergence of a biobased circular economy. Major challenges concern the efficient immobilization of delicate enzymes inside miniaturized reactors without compromising their catalytic activity. We describe the design and application of four different immobilization techniques including self-immobilizing whole-cells and purified enzymes on magnetic microbeads, as well as reactor modules manufactured by 3D printing of bioinks containing thermostable enzymes. To increase the volumetric activity of our microreactors we furthermore developed and applied self-assembling all-enzyme hydrogels with cofactor-regenerating capabilities. The resulting reactor formats have excellent operational stability times of > 14 days and maximum space-time yields of > 450 g product/L-1day-1 paving the way for mild and effective immobilization techniques of biocatalysts in microfluidic systems

A Phenolic Acid Decarboxylase-Based All-Enzyme Hydrogel for Flow Reactor Technology

Carrier-free enzyme immobilization techniques are an important development in the field of efficient and streamlined continuous synthetic processes using microreactors. Here, the use of monolithic, self-assembling all-enzyme hydrogels is expanded to phenolic acid decarboxylases. This provides access to the continuous flow production of p-hydroxystyrene from p-coumaric acid for more than 10 h with conversions ≥98% and space time yields of 57.7 g·(d·L)−1. Furthermore, modulation of the degree of crosslinking in the hydrogels resulted in a defined variation of the rheological behavior in terms of elasticity and mesh size of the corresponding materials. This work is addressing the demand of sustainable strategies for defunctionalization of renewable feedstocks

Transarterielle Chemoembolisation (TACE) mit Irinotecan beladenen DC BEAD Microspheres zur Behandlung inoperabler Lebermetastasen bei Patienten mit kolorektalem Karzinom : Ergebnisse einer klinischen Phase-I/II-Prüfung

Das kolorektale Karzinom gehört weltweit zu den häufigsten Krebserkrankungen. Die Leber ist der am häufigsten betroffene Ort für extralymphatische Metastasen. 35-60% der Patienten entwickeln Metastasen in der Leber (4). In 17% bis 25% der Fälle werden bereits bei der Diagnose des Primärtumors synchrone Lebermetastasen festgestellt (5). Etwa 80-85% der Lebermetastasen befinden sich in einem primär irresektablen Zustand (7). Somit ist bei einem großen Teil der Patienten der Goldstandard, dass heißt die Resektion, schon zum Zeitpunkt der Diagnose nicht mehr anwendbar. Da Lebermetastasen die Haupttodesursache beim kolorektalen Karzinom darstellen, versucht man, neben der systemischen Chemotherapie neue Verfahren für deren gezielte Behandlung zu entwickeln. In der hier vorliegenden monozentrischen Phase I-II Studie wurde die Sicherheit und Wirksamkeit Irinotecan beladener DC Beads Microspheres bei der Behandlung von inoperablen Lebermetastasen des kolorektalen Karzinoms mittels transarterieller Chemoembolisation (TACE) untersucht. Bei den DC Beads (Firma Biocompatibles UK Limited) handelt es sich um Hydrogel-Mikrosphären aus einem mit Sulfonatgruppen modifizierten Polyvinylalkohol. Sie können Irinotecan über einen Ionen-Austauschmechanismus aufnehmen und wieder abgeben. Es wurden 10 Patienten mit insgesamt 38 Chemoembolisationen behandelt und dabei Einzeldosen zwischen 21 mg und 143 mg Irinotecan appliziert. Hierbei traten ausschließlich Nebenwirkungen auf, die im Rahmen einer Chemoembolisation zu erwarten waren. Es wurden keine für Irinotecan typischen Nebenwirkungen wie Diarrhoe und Neutropenie beobachtet. Im Vergleich zu ähnlichen Studien, waren die Nebenwirkungen durchschnittlich seltener und schwächer. Das Tumoransprechen wurde gemäß der RECIST-Kriterien ausgwertet. Zum Studienende (objective response rate) hatten 2 Patienten einen Partial Response, 2 Patienten Stable disease und 6 Patienten Progressive Disease. Betrachtet man das beste in der Studie aufgetretene Ansprechen (best overall response), so gab es 2 Patienten mit Partial Response und 8 Patienten mit Stable Disease. Es wurde somit ein Ansprechen von 20% erreicht. Zwischen den CEA-Werten und dem endgültigen Studienausgang (objective response rate) nach RECIST gab es eine weitgehende Übereinstimmung. Bei vier Patienten konnte durch die Studienbehandlung ein Downstaging erreicht werden, wodurch eine laserinduzierte Thermotherapie (LITT) mit besserer Prognose möglich wurde. Die pharmakokinetische Untersuchung zeigte nach der Chemoembolisation mit Irinotecan beladenen DC Beads im Vergleich zur intravenösen Gabe von Irinotecan eine niedrigere Plasmakonzentration an Irinotecan aber eine höhere für den aktiven Metaboliten SN-38. Auch bei der Bewertung der Durchführbarkeit der Chemoembolisation traten im Umgang mit den DC Beads keine Komplikationen auf. Es konnte in dieser Studie gezeigt werden, dass Chemoembolisationen mit Irinotecan beladenen DC Beads technisch problemfrei, sicher und mit guter Wirksamkeit durchführbar sind. Auf Grund der guten Ergebnisse sollte die Studienbehandlung in weiteren Untersuchungen mit einem größeren Patientenkollektiv überprüft werden, um so statistisch signifikantere Daten zu erhalten.Colorectal Cancer is one of the most common malignancies in mankind with the liver as the most frequent site of extralymphatic metastatic disease. 35% to 60% of patients with colorectal cancer develop liver metastases (4). Approximately 17% to 25% of patients will have synchronous liver metastases at the time of diagnosis (5). 80 to 85% of colorectal liver metastases are primarily unresectable (7). Therefore the Gold standard of surgical resection cannot be used in the majority of patients. Liver metastases are the main cause of death in patients with colorectal cancer. Therefore new alternative treatment options should be developed beside systemic chemotherapy to especially target metastasis of the liver. The present monocentric phase I-II study was designed to assess the safety and tumour response of irinotecan drug-eluting DC Bead delivered by intra-arterial embolisation for the treatment of metastatic colorectal cancer to the liver. DC Bead (Biocompatibles UK, Limited) is an embolic microsphere product based on a polyvinyl alcohol hydrogel that has been modified with sulfonate groups. DC Beads are able to uptake and release irinotecan by an ionic exchange mechanism. Ten patients were treated with a total of 38 chemoembolisations using single dosage between 21mg to 143mg Irinotecan. We found only mild to moderate adverse events, which are expected to be seen after chemoembolisation procedure. There were no irinotecan related toxicities like delayed diarrhoea or neutropenia. In comparison to other studies, adverse events were less frequent and generally milder. Local Tumor response was assessed according to the RECIST-criteria. Objective response showed 2 patients with partial response, 2 with stable disease and 6 with progressive disease. The best overall response during the study showed 2 patients with partial response and 8 patients with stable disease. This equates an overall response of 20%. A high correlation was found between CEA level and the objective response rates measured by RECIST. Due to the study procedure four patients experienced a downstaging and were found to be eligible to laser-induced thermotherapy with a potential better prognosis. The pharmacokinetic analysis showed lower systemic levels of irinotecan and higher levels of the active metabolite SN-38 after chemoembolisation with irinotecan loaded DC Bead compared to intravenous administration. Our study shows, that Chemoembolisation with irinotecan loaded DC Beads is feasible, active and well tolerated. Because of these positive and promising results, the study population should be increased to get statistically more significant data

A Phenolic Acid Decarboxylase-Based All-Enzyme Hydrogel for Flow Reactor Technology

Carrier-free enzyme immobilization techniques are an important development in the field of efficient and streamlined continuous synthetic processes using microreactors. Here, the use of monolithic, self-assembling all-enzyme hydrogels is expanded to phenolic acid decarboxylases. This provides access to the continuous flow production of p-hydroxystyrene from p-coumaric acid for more than 10 h with conversions &ge;98% and space time yields of 57.7 g&middot;(d&middot;L)&minus;1. Furthermore, modulation of the degree of crosslinking in the hydrogels resulted in a defined variation of the rheological behavior in terms of elasticity and mesh size of the corresponding materials. This work is addressing the demand of sustainable strategies for defunctionalization of renewable feedstocks