Increased radical scavenging activity of thymoquinone and l-ascorbic acid dual encapsulated in palmitoyl-chitosan nanoparticles in a human normal lung fibroblast, MRC-5 due to synergistic antioxidative effects.

Less effective antioxidant supplementation in combating free radicals is often related to the lack of the formulation of carriers. The antioxidant may be one of the most powerful substances but is marred by poor uptake by cells when the carrier degraded and dissolved too rapidly. Nanoparticle (NP) systems are promising in overcoming the problem since they provide high surface area to enhance encapsulation and release efficiency. With the right selection of material, NP carriers could function as constructive antioxidant cargos. Generally, NPs carry only one active ingredient; this study, however, utilized chitosan nanoparticles (CNPs) and hydrophobically modified palmitoyl-chitosan nanoparticles (PCNPs) that were dual encapsulated with antioxidants of different polarities, namely, hydrophobic thymoquinone (TQ) and hydrophilic l-ascorbic acid (LAA) to evaluate their combination effects in scavenging free radicals. The antioxidants followed zero-order release kinetics with a controlled release manner for about 48 h. The interaction effects between TQ and LAA loaded in the NP systems were determined by classical isobologram (CI) values. The CI values were derived by a diphenyl picrylhydrazyl (DPPH) assay, a radical scavenging activity assay. Combined TQ and LAA had CI values of less than one, with a lower value in the PCNP system than in the CNP system. This indicates that the interaction between those antioxidants showed higher synergistic effects in PCNPs, which enhanced the DPPH radical scavenging activities. The antioxidative potential of compound(s) encapsulated in the PCNP carrier was further experimented by a reactive oxygen species (ROS) assay on a human normal lung fibroblast cell line (MRC-5) as lung is one of the organs with high accumulation of free radicals. About 48 h post treatment, the dual-loaded TQ and LAA in PCNPs showed the lowest ROS level in comparison to single-loaded antioxidants and bare antioxidant delivery. The hydrogen peroxide (H2O2) radical scavenging was influenced by both the controlled release property of the PCNP system and the synergy between TQ and LAA. In short, dual-loaded TQ and LAA in the hydrophobically modified PCNP had effectively depicted the capability of a single CS-based nanocarrier to hold more than one compound at a time to function as a potent radical scavenger.

Leveraging interactive voice response technology to mitigate COVID-19 risk in refugee settlements in Uganda: Lessons learned implementing "Dial-COVID" a toll-free mobile phone symptom surveillance and information dissemination tool.

BACKGROUND: Persons living in refugee settlements in sub-Saharan Africa may be at increased risk for COVID-19 and experience barriers to accessing COVID-19 information. We aimed to evaluate the implementation of "Dial-COVID" a multi-lingual, toll free, telephone platform that uses interactive voice response (IVR) to track COVID-19 symptoms/exposure and disseminate COVID-19 health information in refugee settlements in Uganda. We hypothesized that IVR could provide an alternative way to screen for COVID-19 and communicate public health information to humanitarian populations when physical access and testing capacity were limited. METHODS: The Dial-COVID IVR platform was created in ten languages and advertised by community health workers in refugee settlements for participants to call into toll free. In a recorded IVR symptom survey, participants were screened for COVID-19 symptoms/exposures and based on their responses, received tailored public health messages about COVID-19 risk mitigation in accordance with Uganda Ministry of Health guidelines. Here we report the challenges and lessons learned implementing this research during the pandemic. RESULTS: Between February 2021 and March 2022, 15,465 calls were received by the Dial-COVID platform from all 31 refugee settlements in Uganda through which 6,913 symptom surveys were completed and 10,411 public health messages were disseminated in all study languages. Uptake of Dial-COVID fluctuated with the national COVID-19 caseload and was impacted by phone ownership and connectivity in refugee settlements. Intensified advertising efforts promoted Dial-COVID uptake. Flexibility to adapt IVR messages was contingent on translation capacity. CONCLUSION: Refugees living in refugee settlements across Uganda accessed Dial-COVID to share and obtain COVID-19 information suggesting that IVR holds potential for rapid information dissemination and screening of humanitarian populations during future infectious disease outbreaks and may be a valuable tool for routine public health programs. IVR adaptation flexibility and reach are influenced by language constraints and by contextual factors related to platform access. REGISTRATION DETAILS: World Pandemic Research Network- 490652.