Topical Nanoemulsions as Delivery Systems for Green Extracts of Pterocaulon balansae Aiming at the Treatment of Sporotrichosis.

Coumarins are benzopyrones found in several plant genera, including Pterocaulon (Asteraceae). These compounds represent an important source of new treatments, especially as antimicrobial and antifungal agents. In this study, two coumarin-rich extracts from Pterocaulon balansae using green technologies were obtained through aqueous maceration (AE) and supercritical fluid extraction (SFE). Such extracts were incorporated into nanoemulsions (NAE and NSFE) composed of a medium-chain triglyceride oil core stabilized by phospholipids. The nanoemulsions exhibited droplet sizes between 127 and 162 nm, pH above 5.0, and viscosity of approximately 1.0 cP, properties compatible with the topical route. The coumarins permeation/retention from formulations through ear porcine skin using Franz-type diffusion cells were evaluated. Whatever the extract, coumarins were distributed in skin layers, especially in the dermis in both intact and impaired (tape stripping) skin. In addition, a significant increase in coumarins that reached up to the receptor fluid was observed for impaired skin, with increases of approximately threefold for NAE and fourfold for NSFE. Finally, antifungal activity of nanoemulsions was evaluated according to minimum inhibitory concentrations, and the values were 250 µg/mL for all strains tested. The overall results demonstrated the feasibility of incorporating P. balansae extracts into nanoemulsions and showed a potential alternative for the treatment of sporotrichosis.

Regulatory Framework, Challenges, and Initial Strategic Planning for Advanced Therapy Products (PTAs) Development in Brazil.

Advanced Therapies are a class of innovative complex biological products used for therapeutic purposes, encompassing cell therapy, tissue engineering, and gene therapy products. These are promising therapeutic strategies for several complex diseases with low or non-existent therapeutic alternatives. The proper transposition of basic research in this area into medicinal products must comply with regulatory requirements. Here we review the main regulatory recommendations, emphasizing on the Brazilian regulation. The critical points are the manufacturing process, challenges in characterizing the product, development of non-clinical trials, lack of adequate animal models representative of the clinical situation, and absence of valid and measurable therapeutic endpoints. Based on that, we propose a framework for strategic planning of pre-clinical studies in this field. The detailed example involves producing a nonviral vector-based gene editing product, but the regulations and methods may be extrapolated for developing different types of advanced therapies.

Nasal administration of a temozolomide-loaded thermoresponsive nanoemulsion reduces tumor growth in a preclinical glioblastoma model.

Glioblastoma (GB) is the worst and most common primary brain tumor. Temozolomide (TMZ), an alkylating agent, is widely used for treating primary and recurrent high-grade gliomas. However, at least 50% of TMZ treated patients do not respond to TMZ and the development of chemoresistance is a major problem. Here, we designed a lipid nanoemulsion containing a thermoresponsive polymer (poloxamer 407) aiming to improve TMZ release into the brain via nasal delivery. Increasing amounts of poloxamer 407 were added to preformed nanoemulsions (250 nm-range) obtained by spontaneous emulsification. The influence of the polymer concentration (from 2.5% to 12.5%) and temperature on viscosity was clearly evidenced. Such effect was also noticed on the mucoadhesiveness of formulations, as well as TMZ release rate and retention/permeation through nasal porcine mucosa using Franz-type diffusion cells. From these results, a formulation containing 10% of poloxamer (NTMZ-P10) was selected for further experiments by nasal route. A significantly higher TMZ amount was observed in the brain of rats from NTMZ-P10 in comparison with controls. Finally, our results show that formulation reduced significantly tumor growth by three-fold: 103.88 ± 43.67 mm3 (for NTMZ-P10) and 303.28 ± 95.27 mm3 (control). Overall, these results suggest the potential of the thermoresponsive formulation, administered by the non-invasive nasal route, as a future effective glioblastoma treatment.

Gene editing strategies to treat lysosomal disorders: The example of mucopolysaccharidoses.

Lysosomal storage disorders are a group of progressive multisystemic hereditary diseases with a combined incidence of 1:4,800. Here we review the clinical and molecular characteristics of these diseases, with a special focus on Mucopolysaccharidoses, caused primarily by the lysosomal storage of glycosaminoglycans. Different gene editing techniques can be used to ameliorate their symptoms, using both viral and nonviral delivery methods. Whereas these are still being tested in animal models, early results of phase I/II clinical trials of gene therapy show how this technology may impact the future treatment of these diseases. Hurdles related to specific hard-to-reach organs, such as the central nervous system, heart, joints, and the eye must be tackled. Finally, the regulatory framework necessary to advance into clinical practice is also discussed.

Brain and visceral gene editing of mucopolysaccharidosis I mice by nasal delivery of the CRISPR/Cas9 system.

BACKGROUND: Mucopolysaccharidosis type I (MPS I) is an inherited disease caused by deficiency of the enzyme alpha-l-iduronidase (IDUA). MPS I affects several tissues, including the brain, leading to cognitive impairment in the severe form of the disease. Currently available treatments do not reach the brain. Therefore, in this study, we performed nasal administration (NA) of liposomal complexes carrying two plasmids encoding for the CRISPR/Cas9 system and for the IDUA gene targeting the ROSA26 locus, aiming at brain delivery in MPS I mice. METHODS: Liposomes were prepared by microfluidization, and the plasmids were complexed to the formulations by adsorption. Physicochemical characterization of the formulations and complexes, in vitro permeation, and mucoadhesion in porcine nasal mucosa (PNM) were assessed. We performed NA repeatedly for 30 days in young MPS I mice, which were euthanized at 6 months of age after performing behavioral tasks, and biochemical and molecular aspects were evaluated. RESULTS: Monodisperse mucoadhesive complexes around 110 nm, which are able to efficiently permeate the PNM. In animals, the treatment led to a modest increase in IDUA activity in the lung, heart, and brain areas, with reduction of glycosaminoglycan (GAG) levels in serum, urine, tissues, and brain cortex. Furthermore, treated mice showed improvement in behavioral tests, suggesting prevention of the cognitive damage. CONCLUSION: Nonviral gene editing performed through nasal route represents a potential therapeutic alternative for the somatic and neurologic symptoms of MPS I and possibly for other neurological disorders.

Biodistribution of Transplanted Hematopoietic Precursor Cells Injected Through Different Administration Routes in Newborn Mice.

Hematopoietic stem cell transplantation has been studied for several decades now, mostly as a treatment for malignancies and hematological diseases but also for genetic metabolic disorders. Since many diseases that could be potentially treated with this approach develop early in life, studies of cell transplantation in newborn mice are needed, especially for gene therapy protocols. However, the small size of pups restricts the possibilities for routes of administration, and those available are normally technically challenging. Our goal was to test different routes of administration of Lin- cells in 2-day-old mice: intraperitoneal, intravenous through temporal vein (TV), and intravenous through retro-orbital (RO) sinus. Routes were evaluated by their easiness of execution and their influence in the biodistribution of cells in the short (48 h) and medium (30 days) term. In either 48 h or 30 days, all three routes presented similar results, with cells going mostly to bone marrow, liver, and spleen in roughly the same number. RO injection resulted in quick distribution of cells to the brain, suggesting better performance than the others. Rate of failure was higher for the TV route, which was also the hardest to execute, whereas the other two were considered easier. In conclusion, TV was the hardest to perform and all routes seemed to demonstrate similar results for cell biodistribution. In particular, the RO injection results in quicker biodistribution of cells to the brain, which is particularly important in the study of genetic metabolic disorders with a neurological component.

Gene Therapy of Mucopolysaccharidosis Type I Mice: Repeated Administrations and Safety Assessment of pIDUA/Nanoemulsion Complexes.

BACKGROUND: Mucopolysaccharidosis type I (MPS I) is an inherited disorder caused by α-L-iduronidase (IDUA) deficiency. The available treatments are not effective in improving all signs and symptoms of the disease. OBJECTIVE: In the present study, we evaluated the transfection efficiency of repeated intravenous administrations of cationic nanoemulsions associated with the plasmid pIDUA (containing IDUA gene). METHODS: Cationic nanoemulsions were composed of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(amino[polyethylene glycol]- 2000) (DSPE-PEG), 1,2-dioleoyl-sn-glycero-3-trimethylammonium propane (DOTAP), medium- chain triglycerides, glycerol, and water and were prepared by high-pressure homogenization and were repeatedly administered to MPS I mice for IDUA production and gene expression. RESULTS: A significant increase in IDUA expression was observed in all organs analyzed, and IDUA activity tended to increase with repeated administrations when compared to our previous report when mice received a single administration of the same dose. In addition, GAGs were partially cleared from organs, as assessed through biochemical and histological analyzes. There was no presence of inflammatory infiltrate, necrosis, or signs of an increase in apoptosis. Furthermore, immunohistochemistry for CD68 showed a reduced presence of macrophage cells in treated than in untreated MPS I mice. CONCLUSION: These sets of results suggest that repeated administrations can improve transfection efficiency of cationic complexes without a significant increase in toxicity in the MPS I murine model.

Optimization of Coumarins Extraction from Pterocaulon balansae by Box-Behnken Design and Anti-Trichomonas vaginalis Activity.

Trichomonas vaginalis causes trichomoniasis, a nonviral sexually transmitted infection with a high prevalence worldwide. Oral metronidazole is the drug of choice for the treatment of this disease, although high levels of T. vaginalis resistance to this agent are well documented in the literature. This study describes the anti-T. vaginalis activity of an optimized coumarin-rich extract from Pterocaulon balansae. Optimization was performed to maximize extraction of total coumarins by means of a 3-level Box-Behnken design, evaluating the effect of three factors: extraction time, plant : solvent ratio, and ethanol concentration. Optimum conditions were found to be 5 h extraction time and a plant : solvent ratio of 1% (w/v) and 60% (v/v) ethanol, which resulted in approximately 30 mg of total coumarins/g of dry plant. The coumarin-enriched extract exhibited a minimum inhibitory concentration of 30 µg/mL and an IC50 of 3.2 µg/mL against T. vaginalis, a low cytotoxicity, and a high selectivity index (18 for vaginal epithelial cells and 16 for erythrocytes). The coumarins permeation/retention profile through porcine vaginal mucosa was evaluated in Franz-type diffusion cells. After 8 h of kinetics, coumarins were detected in the tissue (4.93 µg/g) without detecting them in the receptor compartment. A significant increase of coumarins in the mucosa layers (8.18 µg/g) and receptor compartment (0.26 µg/g) was detected when a T. vaginalis suspension (2 × 105 trophozoites/mL) was previously added onto the mucosa. No alterations were visualized in the stratified squamous non-keratinized epithelium of the porcine vaginal mucosa after contact with the extract. Overall, these results suggest that the P. balansae coumarin-rich extract may have potential as a treatment for trichomoniasis.

In vitro protective effect of topical nanoemulgels containing Brazilian red propolis benzophenones against UV-induced skin damage.

The overexposure of the skin to ultraviolet (UV) radiation may lead to oxidative stress, resulting in severe damage. The prevention of skin injuries through the topical application of natural compounds rich in antioxidants, such as propolis extracts, has shown promising results. In Brazil, the "red propolis" extract has stood out due to its complex constitution, based mainly on polyprenylated benzophenones (BZP). However, although the use of red propolis extracts has been shown to be encouraging, their addition in topical formulations is limited by the low solubility of BZP. For this reason, this study aimed to develop topical nanoemulgels containing Brazilian red propolis (BRP) extract to increase the potential of topical application, and the evaluation of skin protection against UVA/UVB radiation damage by means of protein carbonylation, protein thiol content and TBARS assays. The nanoemulgels were obtained by adding gelling polymer to nanoemulsions that were previously prepared by spontaneous emulsification. In this sense, a nanoemulgel containing BRP extract-loaded nanoemulsions (H-NE) and a nanoemulgel containing BRP extract-loaded nanoemulsions with DOTAP (H-NE/DT) were prepared. The physicochemical characterization of nanoemulgels showed monodisperse populations of 200-300 nm. The H-NE zeta potential was -38 mV, while that of H-NE/DT was +36 mV. BZP content in the formulations was around 0.86 mg g-1. These parameters remained stable for 90 days under cold storage. H/NE and H-NE/DT presented a non-Newtonian pseudoplastic rheological behavior. Permeation/retention studies, through porcine ear skin, showed the highest BZP retention (18.11 µg cm-2 after 8 h) for H-NE/DT, which also demonstrated, in an in vitro study, the highest ability to protect skin against oxidative damage after UVA/UVB radiation exposure. The results concerning the antioxidant activity revealed that formulations containing the BRP n-hexane extract were the most promising in combating oxidative stress, probable due to the presence of polyprenylated BZP. Altogether, the outcomes of this study suggest that nanoemulgels have suitable characteristics for topical application, and may be an alternative for the prevention of oxidative skin damage caused by UVA/UVB radiation.

Chitosan-coated rosmarinic acid nanoemulsion nasal administration protects against LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats.

Rosmarinic acid (RA) lipid-nanotechnology-based delivery systems associate with mucoadhesive biopolymers for nasal administration has arisen as a new promising neuroprotective therapy for neurodegenerative disorders (ND). We have previously demonstrated the glioprotective effect of chitosan-coated RA nanoemulsions (RA CNE) against lipopolysaccharide (LPS)-induced damage in rat astrocyte primary culture. Here, we further investigate the protective effect of RA CNE nasal administration on LPS-induced memory deficit, neuroinflammation, and oxidative stress in Wistar rats, since these in vivo studies were crucial to understand the impact of developed delivery systems in the RA neuroprotective effects. The animals were treated through nasal route with RA CNE (2 mg·mL-1), free RA (2 mg·mL-1), blank CNE, and saline (control and LPS groups) administrations (n.a., 100 µL per nostril) twice a day (7 a.m./7 p.m.) for six days. On the sixth day, the animals received the last treatments and LPS was intraperitoneally (i.p.) administrated (250 µg·kg-1). Overall results, proved for the first time that the RA CNE nasal administration elicits a neuroprotective effect against LPS-induced damage, which was associated with increased 1.6 times recognition index, decreased 5.0 and 1.9 times in GFAP+ cell count and CD11b expression, respectively, as well as increased 1.7 times SH in cerebellum and decreased 3.9 times TBARS levels in cerebral cortex in comparison with LPS group. RA CNE treatment also facilitates RA bioavailability in the brain, confirmed by RA quantification. Free RA also demonstrates a protective effect in some studied parameters, although no RA was quantified in the brain.

Neonatal nonviral gene editing with the CRISPR/Cas9 system improves some cardiovascular, respiratory, and bone disease features of the mucopolysaccharidosis I phenotype in mice.

Mucopolysaccharidosis type I (MPS I) is caused by deficiency of alpha-L-iduronidase (IDUA), leading to multisystemic accumulation of glycosaminoglycans (GAG). Untreated MPS I patients may die in the first decades of life, mostly due to cardiovascular and respiratory complications. We previously reported that the treatment of newborn MPS I mice with intravenous administration of lipossomal CRISPR/Cas9 complexes carrying the murine Idua gene aiming at the ROSA26 locus resulted in long-lasting IDUA activity and GAG reduction in various tissues. Following this, the present study reports the effects of gene editing in cardiovascular, respiratory, bone, and neurologic functions in MPS I mice. Bone morphology, specifically the width of zygomatic and femoral bones, showed partial improvement. Although heart valves were still thickened, cardiac mass and aortic elastin breaks were reduced, with normalization of aortic diameter. Pulmonary resistance was normalized, suggesting improvement in respiratory function. In contrast, behavioral abnormalities and neuroinflammation still persisted, suggesting deterioration of the neurological functions. The set of results shows that gene editing performed in newborn animals improved some manifestations of the MPS I disorder in bone, respiratory, and cardiovascular systems. However, further studies will be imperative to find better delivery strategies to reach "hard-to-treat" tissues to ensure better systemic and neurological effects.

An overview of the neuroprotective potential of rosmarinic acid and its association with nanotechnology-based delivery systems: A novel approach to treating neurodegenerative disorders.

Neurodegenerative disorders (ND) are characterized by slow and progressive neuronal dysfunction induced by the degeneration of neuronal cells in the central nervous system (CNS). Recently, the neuroprotective effects of natural compounds with anti-inflammatory and antioxidant activities has been clearly demonstrated. This appears to be an attractive therapeutic approach for ND, particularly regarding the use of polyphenols. In this review, we present an overview of the neuroprotective potential of rosmarinic acid (RA) and discuss the use of nanotechnology as a novel approach to treating ND. RA presents a variety of biological important activities, i.e. the modulation of pro-inflammatory cytokine expression, prevention of neurodegeneration and damage reduction. However, its poor bioavailability represents a limitation in terms of pharmacodynamics. In this sense, nanotechnology-based carriers could allow for the administration of higher but still safe amounts of RA, aiming for CNS delivery. Nasal administration could be a pleasant route for delivery to the CNS, as this represents a direct route to the CNS. With these advantages, RA-loaded nanotechnology-based therapy through the nasal route could be promising approach for the treatment of ND.

In vivo genome editing of mucopolysaccharidosis I mice using the CRISPR/Cas9 system.

Mucopolysaccharidosis type I (MPS I) is a multisystemic disorder caused by the deficiency of alpha-L-iduronidase (IDUA) that leads to intracellular accumulation of glycosaminoglycans (GAG). In the present study we aimed to use cationic liposomes carrying the CRISPR/Cas9 plasmid and a donor vector for in vitro and in vivo MPS I gene editing, and compare to treatment with naked plasmids. The liposomal formulation was prepared by microfluidization. Complexes were obtained by the addition of DNA at +4/-1 charge ratio. The overall results showed complexes of about 110 nm, with positive zeta potential of +30 mV. The incubation of the complexes with fibroblasts from MPS I patients led to a significant increase in IDUA activity and reduction of lysosomal abnormalities. Hydrodynamic injection of the liposomal complex in newborn MPS I mice led to a significant increase in serum IDUA levels for up to six months. The biodistribution of complexes after hydrodynamic injection was markedly detected in the lungs and heart, corroborating the results of increased IDUA activity and decreased GAG storage especially in these tissues, while the group that received the naked plasmids presented increased enzyme activity especially in the liver. Furthermore, animals treated with the liposomal formulation presented improvement in cardiovascular parameters, one of the main causes of death observed in MPS I patients. We conclude that the IDUA production in multiple organs had a significant beneficial effect on the characteristics of MPS I disease, which may bring hope to gene therapy of Hurler patients.

Nasal Administration of Cationic Nanoemulsions as Nucleic Acids Delivery Systems Aiming at Mucopolysaccharidosis Type I Gene Therapy.

PURPOSE: This study demonstrates the nasal administration (NA) of nanoemulsions complexed with the plasmid encoding for IDUA protein (pIDUA) as an attempt to reach the brain aiming at MPS I gene therapy. METHODS: Formulations composed of DOPE, DOTAP, MCT (NE), and DSPE-PEG (NE-PEG) were prepared by high-pressure homogenization, and assessed in vitro on human fibroblasts from MPS I patients and in vivo on MPS I mice for IDUA production and gene expression. RESULTS: The physicochemical results showed that the presence of DSPE-PEG in the formulations led to smaller and more stable droplets even when submitted to dilution in simulated nasal medium (SNM). In vitro assays showed that pIDUA/NE-PEG complexes were internalized by cells, and led to a 5% significant increase in IDUA activity, besides promoting a two-fold increase in IDUA expression. The NA of pIDUA/NE-PEG complexes to MPS I mice demonstrated the ability to reach the brain, promoting increased IDUA activity and expression in this tissue, as well as in kidney and spleen tissues after treatment. An increase in serum IL-6 was observed after treatment, although with no signs of tissue inflammatory infiltrate according to histopathology and CD68 assessments. CONCLUSIONS: These findings demonstrated that pIDUA/NE-PEG complexes could efficiently increase IDUA activity in vitro and in vivo after NA, and represent a potential treatment for the neurological impairment present in MPS I patients.

Skin Permeation and Oxidative Protection Effect of Soybean Isoflavones from Topical Nanoemulsions-a Comparative Study of Extracts and Pure Compounds.

Soybean isoflavone-rich extracts have been considered as promising skin antiaging products due to their antioxidant activity. This study investigates the effect of soybean isoflavone forms on porcine ear skin permeation/retention from topical nanoemulsions and their potential in protecting skin against oxidative damage caused by UVA/UVB light. Soybean non-hydrolyzed (SNHE) and hydrolyzed (SHE) extracts, mainly composed of genistin and genistein, were produced. Nanoemulsions containing SNHE (NESNHE) and SHE (NESHE) were prepared by spontaneous emulsification procedure and yielded monodispersed nanoemulsions. A delay of isoflavone release was observed after extracts incorporation into nanoemulsions when compared to a propyleneglycol dispersion of pure compounds. An increase of isoflavone skin retention from nanoemulsions was also achieved. However, from extracts, a higher amount of genistin (NESNHE) and a lower amount of genistein (NESHE) were detected in the skin in comparison to pure isoflavones. Finally, the protection of porcine ear skin by formulations against UVA/UVB oxidative stress was evaluated. Extract-loaded nanoemulsions offered better skin protection than pure isoflavones. Skin lipids were similarly protected by NESHE and NESNHE, whereas skin proteins were more protected by NESNHE. Overall, nanoemulsions containing isoflavone-rich soybean extracts may be considered a better topical formulation aiming skin protection from UVA/UVB oxidative damage.

Box-Behnken design optimization of mucoadhesive chitosan-coated nanoemulsions for rosmarinic acid nasal delivery-In vitro studies.

Mucoadhesive chitosan-coated nanoemulsions for rosmarinic acid (RA) nasal delivery were optimized. The optimum ratio between the formulation components that led to minimum droplet size and PDI, and maximal ζ-potential and RA content was obtained using Box-Behnken design (BBD). Optimized conditions were 8.5% oil phase (w/v), 3:10 lecithin to oil phase ratio (w/w), and 0.1% chitosan final concentration (w/v). Physicochemical characterization, mucoadhesion measurement, in vitro release and permeation/retention were performed. Optimized chitosan-coated RA nanoemulsions presented adequate physicochemical characteristics, high mucoadhesive potential, prolonged drug release, and long-lasting permeation time with a higher RA penetration/retention through porcine nasal mucosa. Cell viability and death by necrosis in fibroblasts cells were also evaluated to investigate the formulations safety. Formulations did not induce cytotoxicity following 24 h (3.125-50 µM) or 48 h (3.125-25 µM) of treatments. Overall results demonstrated that optimized chitosan-coated nanoemulsion showed to be a suitable carrier for RA nasal delivery aiming neuroprotective therapies.

Intra-articular nonviral gene therapy in mucopolysaccharidosis I mice.

Mucopolysaccharidosis type I (MPS I) is caused by the lysosomal accumulation of glycosaminoglycans (GAGs) due to the deficiency of the enzyme alpha-L-iduronidase (IDUA). Currently available treatments may improve several clinical manifestations, but they have limited effects on joint disease, resulting in persistent orthopedic complications and impaired mobility. Thus, this study aimed to perform an intra-articular administration of cationic nanoemulsions complexed with the plasmid encoding for the IDUA protein (pIDUA) targeting MPS I gene therapy for the synovial joints. Formulations composed of DOPE, DOTAP, MCT (NE), and DSPE-PEG (NE-PEG) were prepared by high-pressure homogenization, and the pIDUA plasmid was associated by adsorption onto the surface of nanoemulsions (pIDUA/NE or pIDUA/NE-PEG). The physicochemical characterization showed that the presence of DSPE-PEG in pIDUA/NE-PEG formulations led to small and highly stable droplets even when incubated with simulated synovial fluid (SSF), when compared to the non-pegylated complexes (pIDUA/NE). Uptake by fibroblast-like synoviocytes (FLS) was demonstrated, and high cell viability (70%) in addition with increased IDUA activity (2.5% of normal) were observed after incubation with pIDUA/NE-PEG. The intra-articular injection of pIDUA/NE-PEG complexes in MPS I mice showed that the complexes were localized in the joints, were able to transfect synovial cells, and thus promoted an increase in IDUA activity and expression in the synovial fluid, with no significant activity in other tissues (kidney, liver, lung, and spleen). The overall results demonstrated a contained, safe, tolerable, and effective in situ approach of nonviral intra-articular gene therapy targeting the reduction or prevention of the debilitating orthopedic complications of MPS I disorder.

Gene editing of MPS I human fibroblasts by co-delivery of a CRISPR/Cas9 plasmid and a donor oligonucleotide using nanoemulsions as nonviral carriers.

Mucopolysaccharidosis type I (MPS I) is an inherited disease caused by the deficiency of alpha-L-iduronidase (IDUA). This study shows the use of nanoemulsions co-complexed with the plasmid of CRISPR/Cas9 system and a donor oligonucleotide aiming at MPS I gene editing in vitro. Nanoemulsions composed of MCT, DOPE, DOTAP, DSPE-PEG, and water were prepared by high-pressure homogenization. The DNA was complexed by adsorption (NA) or encapsulation (NE) of preformed DNA/DOTAP complexes with nanoemulsions at +4/-1 charge ratio. The incubation in pure DMEM or supplemented with serum showed that the complexation with DNA was stable after 1 h of incubation, but the complexes tended to release the adsorbed DNA after 24 h of incubation, while the encapsulated DNA remained complexed in the oil core of the nanoemulsions even 48 h after incubation with DMEM. The treatment of MPS I patient's fibroblasts homozygous for the p.Trp402∗ mutation led to a significant increase in IDUA activity at 2, 15, and 30 days when compared to MPS I untreated fibroblasts. Flow cytometry and confocal microscopy demonstrated that there was a reduction in the area of lysosomes to values similar to normal, an indicator of correction of the cellular phenotype. These results show that the nanoemulsions co-complexed with the CRISPR/Cas9 system and a donor oligonucleotide could effectively transfect MPS I p.Trp402∗ patient's fibroblasts, as well as enable the production of IDUA, and represent a potential new treatment option for MPS I.

Optimization of alginate microcapsules containing cells overexpressing α-l-iduronidase using Box-Behnken design.

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disease caused by deficiency of α-l-iduronidase (IDUA), which results in the lysosomal accumulation of glycosaminoglycans (GAG) leading to widespread clinical manifestations. The microencapsulation of IDUA overexpressing recombinant cells has been considered as a promising strategy for the treatment of MPS I. This study aimed at the optimization of alginate microcapsules containing recombinant BHK (Baby Hamster Kidney) cells (rBHK) overexpressing IDUA produced by electrostatic extrusion technique. The alginate microcapsule (MC-A) optimization study was carried out by means of an experimental Box-Behnken Design that allowed the simultaneous evaluation of the influence of voltage (kV), alginate/cell suspension flow (mL/h), and alginate concentration (%) on size and IDUA activity. The optimal conditions of voltage (10kV), flow (25mL/h), and alginate concentration (1.3%) made possible to obtain the smallest microcapsules showing the highest IDUA activity. After optimization, the microcapsules were sequentially coated with PLL and alginate (MC-APA) to increase their stability. MC-A and MC-APA presented monodisperse populations (span<1.22) with an average diameter of less than 350µm. The coating increased the mechanical stability of MC-APA by about 6-fold and modulated the permeability to the enzyme. Surface analyzes of MC-APA showed the presence of PLL bands, suggesting that the last alginate layer appears to have only partially coated the PLL. After 30days of subcutaneous implantation of the MC-APA microcapsules containing rBHK cells in a MPS I murine model, a significant increase in IDUA activity was observed in the skin near the implant. Histological analysis revealed an inflammatory infiltrate at the application site, which did not prevent the release of the enzyme under the conditions evaluated. Taken together, the overall results demonstrate the feasibility of MC-APA as a potential alternative for local treatment of MPS I.

Cationic nanoemulsions as nucleic acids delivery systems.

Since the first clinical studies, knowledge in the field of gene therapy has advanced significantly, and these advances led to the development and subsequent approval of the first gene medicines. Although viral vectors-based products offer efficient gene expression, problems related to their safety and immune response have limited their clinical use. Thus, design and optimization of nonviral vectors is presented as a promising strategy in this scenario. Nonviral systems are nanotechnology-based products composed of polymers or lipids, which are usually biodegradable and biocompatible. Cationic liposomes are the most studied nonviral carriers and knowledge about these systems has greatly evolved, especially in understanding the role of phospholipids and cationic lipids. However, the search for efficient delivery systems aiming at gene therapy remains a challenge. In this context, cationic nanoemulsions have proved to be an interesting approach, as their ability to protect and efficiently deliver nucleic acids for diverse therapeutic applications has been demonstrated. This review focused on cationic nanoemulsions designed for gene therapy, providing an overview on their composition, physicochemical properties, and their efficacy on biological response in vitro and in vivo.