Hansen, A. E. | bioRxiv Science

bioRxiv2023

Cancer Immunotherapy through Tissue Adhering Polymers

TLR 7/8 agonists are highly potent immunostimulators, though their clinical translation has been met with mixed success, due to their high toxicity as a result of an unregulated systemic immune activation. There is enormous potential to augment cancer immunotherapies with synthetic TLR 7/8 agonists, though a thorough control of pharmacokinetics and localization is needed for the general use of TLR 7/8 agonists in cancer immunotherapy. Herein, we control localization of TLR 7/8 agonists, by exploiting the extensive tissue retention of poly(acrylic acid-co-styrene). In a murine CT26 model, we find that covalently attaching TLR 7/8 agonists to the copolymer allows for retaining the drug in the tumor microenvironment for at least 15 weeks, after intratumoral injection, and results in a curative monotherapy. The copolymer itself is a new avenue for attaining prolonged tissue rentention for covalently attached drugs.

cancer biology↗

bioRxiv2019

Blue sky’s the limit? Somatic embryogenesis as a means of propagating recalcitrant blue spruce (Picea pungens) cultivar Hoopsii

The triple-blue cultivar of blue spruce (Picea pungens Hoopsii) is notably recalcitrant towards the realm of traditional vegetative propagation methods. Its ability to naturally proliferate is limited by ovule and embryo abortion during the growing season, leading to low viable seed yield. In this study, we established a protocol using somatic embryogenesis (SE) as a means of propagating this popular ornamental cultivar. We collected cones from Hoopsii trees at seven different timepoints throughout the growing season (mid-June to late July in Ottawa (Plant Hardiness Zone 5A)). Female megagametophytes were harvested following each collection and immature zygotic embryos were plated onto induction media. Early somatic embryos began developing from the embryonic tissue (ET) three to five weeks following induction. The highest ET initiation frequency occurred from embryos collected June 20-July 10, suggesting that developmental stage of the embryo was a significant factor in SE induction. The conversion of mature somatic embryos into plantlets (emblings) was completed in eight-ten weeks at a rate of 92.8%. In this study, we demonstrate that in vitro somatic embryogenesis using our optimized protocol is a fast and prolific method for the mass propagation of Hoopsii blue spruce. This is the first report on the production of somatic Hoopsii emblings.

plant biology↗