Phytoglycogen Encapsulation of Lanthanide-Based Nanoparticles as an Optical Imaging Platform with Therapeutic Potential

Lanthanide-based upconverting nanoparticles (UCNPs) are largely sought-after for biomedical applications ranging from bioimaging to therapy. A straightforward strategy is proposed here using the naturally sourced polymer phytoglycogen to coencapsulate UCNPs with hydrophobic photosensitizers as an optical imaging platform and light-induced therapeutic agents. The resulting multifunctional sub-micrometer-sized luminescent beads are shown to be cytocompatible as carrier materials, which encourages the assessment of their potential in biomedical applications. The loading of UCNPs of various elemental compositions enables multicolor hyperspectral imaging of the UCNP-loaded beads, endowing these materials with the potential to serve as luminescent tags for multiplexed imaging or simultaneous detection of different moieties under near-infrared (NIR) excitation. Coencapsulation of UCNPs and Rose Bengal opens the door for potential application of these microcarriers for collagen crosslinking. Alternatively, coloading UCNPs with Chlorin e6 enables NIR-light triggered generation of reactive oxygen species. Overall, the developed encapsulation methodology offers a straightforward and noncytotoxic strategy yielding water-dispersible UCNPs while preserving their bright and color-tunable upconversion emission that would allow them to fulfill their potential as multifunctional platforms for biomedical applications.

Honest olfactory ornamentation in a female-dominant primate

Sexual selection theory predicts that potential mates or competitors signal their quality to conspecifics. Whereas evidence of honest visual or vocal signals in males abounds, evidence of honest signalling via scent or by females is scarce. We previously showed that scent marks in male lemurs seasonally encode information about individual heterozygosity - a reliable predictor of immunocompetence and survivorship. As female lemurs dominate males, compete over resources, and produce sexually differentiated scent marks that likely evolved via direct selection, here we tested whether females also advertise genetic quality via olfactory cues. During the breeding season specifically, individual heterozygosity correlated negatively with the diversity of fatty acids (FAs) expressed in labial secretions and positively with the diversity of heavy FA esters. As odour-gene relationships predictive of health and survivorship emerged during a period critical to mate choice and female competition, we posit that genital scent marks function as honest olfactory ornaments in females.