Skip to main content

Research Repository

Advanced Search

Chain-extension in hyperbranched polymers alters tissue distribution and cytotoxicity profiles in orthotopic models of triple negative breast cancers

Moloney, Cara; Mehradnia, Fatemeh; Cavanagh, Robert J.; Ibrahim, Asmaa; Pearce, Amanda K.; Ritchie, Alison A.; Clarke, Philip; Rahman, Ruman; Grabowska, Anna M.; Alexander, Cameron

Chain-extension in hyperbranched polymers alters tissue distribution and cytotoxicity profiles in orthotopic models of triple negative breast cancers Thumbnail


Authors

Fatemeh Mehradnia

Asmaa Ibrahim

Amanda K. Pearce

Alison A. Ritchie

Philip Clarke

Profile image of RUMAN RAHMAN

RUMAN RAHMAN RUMAN.RAHMAN@NOTTINGHAM.AC.UK
Professor of Molecular Neuro-Oncology

Anna M. Grabowska



Abstract

The therapeutic efficacy of nanomedicines is highly dependent on their access to target sites in the body, and this in turn is markedly affected by their size, shape and transport properties in tissue. Although there have been many studies in this area, the ability to design nanomaterials with optimal physicochemical properties for in vivo efficacy remains a significant challenge. In particular, it is often difficult to quantify the detailed effects of cancer drug delivery systems in vivo as tumour volume reduction, a commonly reported marker of efficacy, does not always correlate with cytotoxicity in tumour tissue. Here, we studied the behaviour in vivo of two specific poly(2-hydroxypropyl methacrylamide) (pHPMA) pro-drugs, with hyperbranched and chain-extended branched architectures, redox-responsive backbone components, and pH-sensitive linkers to the anti-cancer drug doxorubicin. Evaluation of the biodistribution of these polymers following systemic injection indicated differences in the circulation time and organ distribution of the two polymers, despite their very similar hydrodynamic radii (∼10 and 15 nm) and architectures. In addition, both polymers showed improved tumour accumulation in orthotopic triple-negative breast cancers in mice, and decreased accumulation in healthy tissue, as compared to free doxorubicin, even though neither polymer–doxorubicin pro-drug decreased overall tumour volume as much as the free drug under the dosing regimens selected. However, the results of histopathological examinations by haematoxylin and eosin, and TUNEL staining indicated a higher population of apoptotic cells in the tumours for both polymer pro-drug treatments, and in turn a lower population of apoptotic cells in the heart, liver and spleen, as compared to free doxorubicin treatment. These data suggest that the penetration of these polymer pro-drugs was enhanced in tumour tissue relative to free doxorubicin, and that the combination of size, architecture, bioresponsive backbone and drug linker degradation yielded greater efficacy for the polymers as measured by biomarkers than that of tumour volume. We suggest therefore that the effects of nanomedicines may be different at various length scales relative to small molecule free drugs, and that penetration into tumour tissue for some nanomedicines may not be as problematic as prior reports have suggested. Furthermore, the data indicate that dual-responsive crosslinked polymer-prodrugs in this study may be effective nanomedicines for breast cancer chemotherapy, and that endpoints beyond tumour volume reduction can be valuable in selecting candidates for pre-clinical trials.

Citation

Moloney, C., Mehradnia, F., Cavanagh, R. J., Ibrahim, A., Pearce, A. K., Ritchie, A. A., Clarke, P., Rahman, R., Grabowska, A. M., & Alexander, C. (2023). Chain-extension in hyperbranched polymers alters tissue distribution and cytotoxicity profiles in orthotopic models of triple negative breast cancers. Biomaterials Science, 11, 6545-6560. https://doi.org/10.1039/d3bm00609c

Journal Article Type Article
Acceptance Date Jul 30, 2023
Online Publication Date Aug 4, 2023
Publication Date Oct 7, 2023
Deposit Date Aug 16, 2023
Publicly Available Date Aug 21, 2023
Journal Biomaterials Science
Electronic ISSN 2047-4849
Publisher Royal Society of Chemistry
Peer Reviewed Peer Reviewed
Volume 11
Pages 6545-6560
DOI https://doi.org/10.1039/d3bm00609c
Keywords General Materials Science; Biomedical Engineering
Public URL https://nottingham-repository.worktribe.com/output/24074907
Publisher URL https://pubs.rsc.org/en/Content/ArticleLanding/2023/BM/D3BM00609C

Files





You might also like



Downloadable Citations