| Summary: |
Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease, marked by a gradual degeneration of muscular neuron (MNs) that control voluntary muscle movement in the central nervous system (CNS).
This degeneration has been related with high levels of reactive oxygen species (ROS) in CNS, which ultimately lead to oxidative stress (OS). The data collected so far showed the interplay of several oxidative mechanisms, based on glutamatergic over-stimulation of the glutamate receptors, monoaminoxidase-B (MAO-B) upregulation, lipid peroxidation and dysregulation of iron metabolism, which leads to process of ferroptosis.
Currently, the therapy available is mainly used to extend the patient's life expectancy and to ameliorate symptomatology relief, being based on the administration of the anti-glutamatergic agent riluzole (RLZ), the antioxidant edaravone, or sodium phenylbutyrate/taurursodiol, which acts blocking cell death pathways in mitochondria and in the endoplasmic reticulum. Despite that, several drawbacks, such as the difficulty of RLZ and edaravone to be accumulated in CNS and the side effects associated with sodium phenylbutyrate/taurursodiol administration, are responsible for the lack of efficacy of the current ALS therapy. Because of that, it is emergent to explore new strategies to improve at least the patient's life.
One of the approaches it is the use of co-adjuvant drugs, like iron chelators (deferoxamine-DFO) to revert ferroptosis process present in ALS or other type of neuroprotective drugs, such as rasagiline (RAS), which is also a MAO-B inhibitor.
In alternative, the design of biocompatible polymeric nanoparticles (NPs), capable of selectively transport and deliver drugs in the CNS can also have a significant clinical impact in the treatment of ALS. Additionally, by coupling stimuli-responsive units into NPs' backbone it is possible to modulate their shape, solubility, swelling and di  |
Summary
Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease, marked by a gradual degeneration of muscular neuron (MNs) that control voluntary muscle movement in the central nervous system (CNS).
This degeneration has been related with high levels of reactive oxygen species (ROS) in CNS, which ultimately lead to oxidative stress (OS). The data collected so far showed the interplay of several oxidative mechanisms, based on glutamatergic over-stimulation of the glutamate receptors, monoaminoxidase-B (MAO-B) upregulation, lipid peroxidation and dysregulation of iron metabolism, which leads to process of ferroptosis.
Currently, the therapy available is mainly used to extend the patient's life expectancy and to ameliorate symptomatology relief, being based on the administration of the anti-glutamatergic agent riluzole (RLZ), the antioxidant edaravone, or sodium phenylbutyrate/taurursodiol, which acts blocking cell death pathways in mitochondria and in the endoplasmic reticulum. Despite that, several drawbacks, such as the difficulty of RLZ and edaravone to be accumulated in CNS and the side effects associated with sodium phenylbutyrate/taurursodiol administration, are responsible for the lack of efficacy of the current ALS therapy. Because of that, it is emergent to explore new strategies to improve at least the patient's life.
One of the approaches it is the use of co-adjuvant drugs, like iron chelators (deferoxamine-DFO) to revert ferroptosis process present in ALS or other type of neuroprotective drugs, such as rasagiline (RAS), which is also a MAO-B inhibitor.
In alternative, the design of biocompatible polymeric nanoparticles (NPs), capable of selectively transport and deliver drugs in the CNS can also have a significant clinical impact in the treatment of ALS. Additionally, by coupling stimuli-responsive units into NPs' backbone it is possible to modulate their shape, solubility, swelling and dissociation in response to a stimulus, resulting in the release of the incorporated species, which has great potential in the fields of controlled drug delivery. Recently, a specific biological stimulus that is gaining importance is caused by an oxidative environment due to the presence of ROS. The use of polymeric backbone with ROS-sensitive (ROSens) groups allows the self-assembly of narrow sized NPs under physiological conditions, but under oxidative conditions these moieties are oxidized or cleavable and NPs are degraded in biocompatible residues, releasing their cargo.
With this in mind, this project pursuits the development of a dual drug-loaded platform based on ROSens NPs decorated with DFO suitable for intranasal administration. This type of administration has been reported as reliable method for delivering drugs directly to CNS.
For that, we intend to encapsulate two drugs with different but synergic therapeutic effects, such as RLZ and RAS (RR), in ROSens NPs composed by the new thioether-based block P(NAM-b-NAT) copolymer, being their surface decorated with DFO as a possible third therapeutic agent. We also aim to develop a novel in vitro co-culture model with RPMI 2650 cell line and human neuroblastoma cells expressing the G93A SOD1 mutation (SH-SY5Y SOD1G93A). With this co-culture model, we intent to mimic a possible intranasal administration of RR-loaded ROSens NPs decorated with DFO (RR@ROSens-DFO).
A small library of RR@ROSens-DFO will be prepared by varying the molecular weight ratio between NAM/NAT and using different percentage of drug initial feeding. The structural, morphological and physicochemical characterization will be performed to ensure that suitable hydrodynamic size, surface charge and oxidative degradation of NPs' backbone is achieved. The storage stability RR@ROSens-DFO will be assessed as well as their interaction with nasal mucous using mucines. The amount of RLZ and RAS released from RR@ROSens-DFO under physiological and oxidative conditions will be determined by ultra-high performance liquid chromatography.
The cytotoxicity profile of RR@ROSens-DFO will be determined in RPMI 2650 and SH-SY5Y SOD1G93A cell lines. Thus, the protective effects of RR@ROSens-DFO against ALS-related oxidative events will be determined in SH-SY5Y SOD1G93A cells and permeability in RPMI 2650. In the end a co-culture model using both cell lines will be used to evaluate both parameters of RR@ROSens-DFO as an attempt to mimic a possible intranasal administration.
This proposal appears as a novel ALS therapy approach since combines ROSens carriers, multiple synergic drug delivery (RAS-RLZ-DFO) and intranasal administration, which, as far as we know, it was never attempted. Furthermore, the co-culture proposed here is quite a novelty. If successful, this type of proposal could be used to solve pharmacokinetic constraints of other drugs or drug candidates and looked as a therapeutic solution for ALS or other neurodegenerative diseases, currently without effective treatment. |