Introduction: Coronavirus 2019 disease , caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered the worst pandemic disease of the current millennium. In some cases, it causes severe neurological complications, such as encephalitis and Guilain-Barré syndrome. Therapeutic strategies that clearly inhibit the effects of this virus in the brain still need to be achieved. Therefore, polymeric nanoparticles (PNPs) have been shown to be a promising material in the biomedical area due to the targeted administration of therapeutics (e.g. antivirals) for specific areas of the body such as the brain. So, this work describes development of encapsulated polycaprolactone (PCL) nanoparticles against SARS-CoV-2 on infected brain cells.Objective: Synthesize PCL-carrier nanoparticles against the SARS-CoV-2 virus and evaluate their biological activities.Methodology: 1) Synthesis: The PNPs suspensions were obtained by the unique method of emulsion and solvent evaporation, using a 4:1 ratio of polymer and drug, which was selected in previous studies. The organic solvent was then removed by vacuum evaporation and the PNPs were washed by the ultrafiltration method. 2) Characterization: The mean diameter and zeta potential of the nanoparticles were determined by Dynamic Light Scattering method using Zetasizer TM Nano ZS 90 equipment. The amount of free antiviral was estimated by UV-visible spectroscopy and the encapsulation efficiency (EE%) was calculated by subtraction the amount of free drug released from the total of the inserted drug. Biologic function was evaluated in vitro by using Vero E6 cells. Results:The average size of PNPs was estimated as 173.3 ± 0.08 nm with a polydispersivity index (PDI) of 0.07 suggesting a narrow size distribution and high homogeneity. In addition, zeta potential was slightly negative due to dissociation of the PCL functional groups on the particle surface. The concentration of the free drug releasing, calculated as encapsulation efficiency was estimated as 69.0%. Also, in vitro assay showed to be non toxic and able to inhibit viral replication by 40%. Conclusion:The production of PNPs by the single emulsion and solvent evaporation method was efficient for the production of carrier particles with nanometric scale. The sample showed size within desired range which would allow targeting to the brain. In addition, the encapsulation efficiency showed that high level of the drug remains encapsulated. Therefore, we were able to obtain compatible nanoparticles for use in the brain in which preliminary in vitro tests proved to be non-toxic and able to inhibit viral replication even at low doses of antiviral.

Introduction: Neurological manifestations have been observed in patients affected by coronavirus 19 disease since the emergence of the pandemic. Although questions remain about the frequency and severity of this condition and regarding which factors may predispose to the neurological condition, therapeutic strategies to inhibit this action of the coronavirus are necessary. Polymeric nanoparticles (PNPs) have been shown to be interesting carriers, presenting adequate characteristics of stability, biodegradability and low toxicity. The functionalization of PNPs with cell penetrate peptides (CPPs) is a targeting strategy, that enables to translocate by the plasma membrane and facilitates the antiviral release. CPPs are small, highly cationic peptide chains acting as drug delivery agents to target cells. In this work, the optimal condition of functionalization of PNPs with CPP will be evaluated, which will potentially lead PNPs containing the antiviral through the central nervous system for the neurocovid treatment.Objective: Functionalization and characterization of PNPs with CPPs obtained by enzimatic hydrolysis, purification and activation.Methodology: CPPs were obtained by enzymatic hydrolysis in buffered medium (pH 6.8). The nonhydrolyzed peptide and remained enzyme were removed by ultrafiltration. Hydrolysis efficiency was evaluated by fluorescence spectroscopy using extrinsic Bis-ANS probe. CPPs were purified by affinity chromatography with ultraviolet (UV) detection and the molecular mass was estimated by SEC. CPPs were activated by reaction with the succinimidyl-3-(2-pyridyldithio)-propionate reagent and subsequent reduction with excess dithiothreitol. Its concentration was determined by visible absorption spectrophotometry after colorimetric reaction with Ellman's reagent. The PNPs were functionalized by the direct reaction with CPPs, under agitation for 16-20h. The precipitate was resuspended in water. Functionalization efficiency was assessed by determining the mean diameter and zeta potential obtained by the dynamic light scattering technique and comparing of the spectroscopy data in the infrared region of funcionalizated and non-functionalized PNPs.Results: After determining the optimal hydrolysis condition, obtained CPPs were evaluated by the emission intensity decrease in the fluorescence spectrum as a function of the incubation time with the enzyme, The results confirmed the efficiency of hydrolysis. Chromatographic profile of the purification was similar to that described in the literature and allowed to select one of the five peaks observed. After activation, the concentration of CPPs were estimated in 0.28mg/mL with an average molecular mass of 1380Da. The efficiency of functionalization of antiviral PNPs with the activated CPPs was evaluated by the mean diameter, zeta potential and IR spectra for non-functionalized PNPs compared to those obtained after functionalization. The results suggests that reaction conditions employed were efficient to obtain PNPs linked to CPPs. Conclusion:The reaction co...