Polyglutamic acid-based Crosslinked Doxorubicin Nanogels as an Anti-Metastatic Treatment for Triple Negative Breast Cancer

PreprintTreatment of triple negative breast cancer (TNBC)-associated metastasis represents an unmet clinical need, and we lack effective therapeutics for a disease that exhibits high relapse rates and associates with poor patient outcomes. Advanced nanosized drug delivery systems may enhance the efficacy of first-line chemotherapeutics by altering drug pharmacokinetics and enhancing tumor/metastasis targeting to signif-icantly improve efficacy and safety. Herein, we propose the application of injectable poly-amino acid-based nanogels (NGs) as a versatile hydrophilic drug delivery platform for the treatment of TNBC lung metastasis. We prepared biocompatible and biodegradable cross-linked NGs from polyglutamic acid (PGA) loaded with the chemotherapeutic agent doxorubicin (DOX). Our optimized synthetic procedures generated NGs of ~100 nm in size and 25 wt% drug loading content that became rapidly internalized in TNBC cell lines and displayed IC50 values comparable to the free form of DOX. Importantly, PGA-DOX NGs significantly inhibited lung metastases and almost completely suppressed lymph node metastases in a spontaneously metastatic orthotopic mouse TNBC model. Overall, our newly developed PGA-DOX NGs represent a potentially effective therapeutic strategy for the treatment of TNBC metastases.A.S-H thanks MC IEF actions (Project 302717). We thank Dr. M. A. Molina for AFM experiments, Ser-vicio SEM Cordoba (Argentina), and Mario Soriano Navarro from the electron microscopy service for Cryo-TEM pictures at CIPF. The authors would also like to thank Dr. Stuart P. Atkinson for his collabo-ration in the revision of the manuscript. This work has been supported by the European Research Council (grant ERC-CoG-2014-648831 “MyNano”), by the Spanish Ministry of Science and Innovation (SAF2013-44848-R, SAF2016-80427-R, RTI2018-099227-B-I00), by a Marie Curie IEF (Project 302717), and the Bundesministerium für Bildung und Forschung (BMBF) through the NanoMatFutur award (13N12561). Part of the equipment employed in this work has been funded by Generalitat Valen-ciana and co-financed with FEDER funds (PO FEDER of Comunitat Valenciana 2014–2020

Effective nephroprotection against acute kidney injury with a star-shaped polyglutamate-curcuminoid conjugate

The lack of efective pharmacological treatments for acute kidney injury (AKI) remains a signifcant public health problem. Given the involvement of apoptosis and regulated necrosis in the initiation and progression of AKI, the inhibition of cell death may contribute to AKI prevention/recovery. Curcuminoids are a family of plant polyphenols that exhibit attractive biological properties that make them potentially suitable for AKI treatment. Now, in cultured tubular cells, we demonstrated that a crosslinked self-assembled star-shaped polyglutamate (PGA) conjugate of bisdemethoxycurcumin (StPGA-CL-BDMC) inhibits apoptosis and necroptosis induced by Tweak/TNFα/IFNγ alone or concomitant to caspase inhibition. St-PGA-CL-BDMC also reduced NF-κB activation and subsequent gene transcription. In vivo, St-PGA-CL-BDMC prevented renal cell loss and preserved renal function in mice with folic acid-induced AKI. Mechanistically, St-PGA-CL-BDMC inhibited AKI-induced apoptosis and expression of ferroptosis markers and also decreased the kidney expression of genes involved in tubular damage and infammation, while preserving the kidney expression of the protective factor, Klotho. Thus, due to renal accumulation and attractive pharmacological properties, the application of PGAbased therapeutics may improve nephroprotective properties of current AKI treatmentsTis work was supported by grants from the Instituto de Salud Carlos III, FEDER funds: PI16/02057, PI16/01900, PI18/01133, PI19/00815, ISCIII RETIC REDINREN RD16/0009; Sociedad Española de Nefrología; FRIAT; Comunidad de Madrid en Biomedicina B2017/BMD-3686 CIFRA2-CM; ERA-PerMed-JTC2018 (AC18/00071; DTS18/00032); Spanish Ministry of Economy and Competitiveness (Grant numbers SAF2013-44848-R, SAF2016-80427-R). Partly co-funded by FEDER (PO FEDER Valencian Community - 2014–2020

Targeting Alzheimer's disease with multimodal polypeptide-based nanoconjugates

Alzheimer’s disease (AD), the most prevalent form of dementia, remains incurable mainly due to our failings in the search for effective pharmacological strategies. Here, we describe the development of targeted multimodal polypeptide-based nanoconjugates as potential AD treatments. Treatment with polypeptide nanoconjugates bearing propargylamine moieties and bisdemethoxycurcumin or genistein afforded neuroprotection and displayed neurotrophic effects, as evidenced by an increase in dendritic density of pyramidal neurons in organotypic hippocampal culture. The additional conjugation of the Angiopep-2 targeting moiety enhanced nanoconjugate passage through the blood-brain barrier and modulated brain distribution with nanoconjugate accumulation in neurogenic areas, including the olfactory bulb. Nanoconjugate treatment effectively reduced neurotoxic β amyloid aggregate levels and rescued impairments to olfactory memory and object recognition in APP/PS1 transgenic AD model mice. Overall, this study provides a description of a targeted multimodal polyglutamate-based nanoconjugate with neuroprotective and neurotrophic potential for AD treatment

Peptide-Based Polymer Therapeutics

Polypeptides are envisaged to achieve a major impact on a number of different relevant areas such as biomedicine and biotechnology. Acquired knowledge and the increasing interest on amino acids, peptides and proteins is establishing a large panel of these biopolymers whose physical, chemical and biological properties are ruled by their controlled sequences and composition. Polymer therapeutics has helped to establish these polypeptide-based constructs as polymeric nanomedicines for different applications, such as disease treatment and diagnostics. Herein, we provide an overview of the advantages of these systems and the main methodologies for their synthesis, highlighting the different polypeptide architectures and the current research towards clinical applications

One-pot synthesis of oxidation-sensitive supramolecular gels and vesicles

Polypeptide-based nanoparticles offer unique advantages from a nanomedicine perspective such as biocompatibility, biodegradability and stimuli-responsive properties to (patho)physiological conditions. Conventionally, self-assembled polypeptide nanostructures are prepared by first synthesizing their constituent amphiphilic polypeptides followed by post-polymerization self-assembly. Herein, we describe the one-pot synthesis of oxidation-sensitive supramolecular micelles and vesicles. This was achieved by polymerization-induced self-assembly (PISA) of the N-carboxyanhydride (NCA) precursor of methionine using polyethylene oxide as stabilizing and hydrophilic block in dimethyl sulfoxide (DMSO). By adjusting the hydrophobic block length and concentration we obtained a range of morphologies from spherical to worm-like micelles, to vesicles. Remarkably, the secondary structure of polypeptides greatly influenced the final morphology of the assemblies. Surprisingly, worm-like micellar morphologies were obtained for a wide range of methionine block lengths and solid contents, with spherical micelles restricted to very short hydrophobic lengths. Worm-like micelles further assembled into oxidation-sensitive, self-standing gels in the reaction pot. Both vesicles and worm-like micelles obtained using this method demonstrated to degrade under controlled oxidant conditions which would expand their biomedical applications such as in sustained drug release or as cellular scaffolds in tissue engineering

Well-Defined Star-Shaped Polyglutamates with Improved Pharmacokinetic Profiles As Excellent Candidates for Biomedical Applications

There is a need to develop new and innovative polymer carriers to be used as drug delivery systems and/or imaging agents owing to the fact that there is no universal polymeric system that can be used in the treatment of all diseases. Additionally, limitations with existing systems, such as a lack of biodegradability and biocompatibility, inevitably lead to side effects and poor patient compliance. New polymer therapeutics based on amino acids are excellent candidates for drug delivery, as they do not suffer from these limitations. This article reports on a simple yet powerful methodology for the synthesis of 3-arm star-shaped polyglutamic acid with well-defined structures, precise molecular weights (MW), and low polydispersity (<i>Đ</i> = <1.3). These were synthesized by ring-opening polymerization (ROP) of <i>N</i>-carboxyanhydrides (NCA) in a divergent method from novel multifunctional initiators. Herein, their exhaustive physicochemical characterization is presented. Furthermore, preliminary in vitro evaluation in selected cell models, and exhaustive in vivo biodistribution and pharmacokinetics, highlighted the advantages of these branched systems when compared with their linear counterparts in terms of cell uptake enhancement and prolonged plasma half-life