Poly(vinyl alcohol) physical hydrogel nanoparticles, not polymer solutions, exert inhibition of nitric oxide synthesis in cultured macrophages.

Hydrogel nanoparticles (HNP) are an emerging tool of biomedicine with unique materials characteristics, scope, and utility. These hydrated, soft colloidal carriers can penetrate through voids with dimensions narrower than the size of the particle, provide stabilization for fragile biological cargo and allow diffusion and exchange of solutes with external phase. However, techniques to assemble HNP are few; solitary examples exist of biocompatible polymers being formulated into HNP; and knowledge on the biomedical properties of HNP remains rather cursory. In this work, we investigate assembly of HNP based on a polymer with decades of prominence in the biomedical field, poly(vinyl alcohol), PVA. We develop a novel method for production of PVA HNP through nanoprecipitation-based assembly of polymer nanoparticles and subsequent physical hydrogelation of the polymer. Polymer nanoparticles and HNP were visualized using scanning electron microscopy and fluorescence imaging, and characterized using dynamic light scattering and zeta potential measurements. Interaction of PVA HNP with mammalian cells was investigated using flow cytometry, viability screening, and measurements of nitric oxide production by cultured macrophages. The latter analyses revealed that PVA administered as a polymer solution or in the form of HNP resulted in no measurable increase in production of the inflammation marker. Unexpectedly, PVA HNP exerted a pronounced inhibition of NO synthesis by stimulated macrophages, that is, had an anti-inflammatory activity. This effect was accomplished with a negligible change in the cell viability and was not observed when PVA was administered as a polymer solution. To the best of our knowledge, this is the first observation of inhibition of NO synthesis in macrophages by administered nanoparticles and specifically hydrogel nanoparticles. Taken together, our results present PVA HNP as promising colloidal hydrogel nanocarriers for biomedical applications, specifically drug delivery and assembly of intracellular biosensors

Doravirine plus lamivudine two-drug regimen as maintenance antiretroviral therapy in people living with HIV: a French observational study

International audienceBackground: Two-drug regimens based on integrase strand transfer inhibitors (INSTIs) and boosted PIs have entered recommended ART. However, INSTIs and boosted PIs may not be suitable for all patients. We aimed to report our experience with doravirine/lamivudine as maintenance therapy in people living with HIV (PLWH) followed in French HIV settings.Methods: This observational study enrolled all adults who initiated doravirine/lamivudine between 1 September 2019 and 31 October 2021, in French HIV centres participating in the Dat'AIDS cohort. The primary outcome was the rate of virological success (plasma HIV-RNA < 50 copies/mL) at Week (W)48. Secondary outcomes included: rate of treatment discontinuation for non-virological reasons, evolution of CD4 count and CD4/CD8 ratio over follow-up.Results: Fifty patients were included, with 34 (68%) men; median age: 58 years (IQR 51-62), ART duration: 20 years (13-23), duration of virological suppression: 14 years (8-19), CD4 count: 784 cells/mm3 (636-889). Prior to switching, all had plasma HIV-RNA < 50 copies/mL. All but three were naive to doravirine, and 36 (72%) came from a three-drug regimen. Median follow-up was 79 weeks (IQR 60-96). Virological success rate at W48 was 98.0% (95% CI 89.4-99.9). One virological failure occurred at W18 (HIV-RNA = 101 copies/mL) in a patient who briefly discontinued doravirine/lamivudine due to intense nightmares; there was no resistance at baseline and no resistance emergence. There were three strategy discontinuations for adverse events (digestive disorders: n = 2; insomnia: n = 1). There was no significant change in CD4/CD8 ratio, while CD4 T cell count significantly increased.Conclusions: These preliminary findings suggest that doravirine/lamivudine regimens can maintain high levels of viral suppression in highly ART-experienced PLWH with long-term viral suppression, and good CD4+ T cell count