Exogenous and endogenous nitric oxide eluting polylactic acid-based nanofibrous scaffolds for enhancing angiogenesis of diabetic wounds.

Delayed wound healing is a major complication that diabetic patients suffer from due to high microbial infection susceptibility, high diabetic wound alkalinity, a low lymphangiogenesis rate, and a high inflammation rate, resulting in severe gangrene. Hence, this study aims to develop a multifunctional adhesive nanofibrous patch to promote the wound healing process. Phenytoin, sildenafil citrate, and/or nitric oxide-eluting nanoparticles were incorporated separately within the polylactic acid nanofibrous layer. Polylactic acid was fabricated in the form of highly porous nanofibrous matrices that resemble the natural structure of skin tissues in order to act as scaffolds that help cell migration and proliferation. A polylactic acid nanofibrous layer incorporating phenytoin was designed to stimulate fibroblast proliferation and inhibit inflammation. Another polylactic acid nanofibrous layer was loaded either with nitric oxide-eluting nanoparticles or sildenafil as a pro-angiogenic layer that can supply tissues with nitric oxide gas either exogenously or endogenously, respectively. The developed nanofibrous layers were in-vitro evaluated through different physicochemical, mechanical, and biological approaches. Finally, the efficiency of the prepared single multilayered patch was tested using an in-vivo alloxan-induced diabetic rats' model, which proved that the patches were able to release the incorporated cargos in a controlled manner, enhancing the wound healing process.

"Review of strategic methods for encapsulating essential oils into chitosan nanosystems and their applications".

Essential oils (EOs) are hydrophobic, concentrated extracts of botanical origin containing diverse bioactive molecules that have been used for their biomedical properties. On the other hand, the volatility, toxicity, and hydrophobicity limited their use in their pure form. Therefore, nano-encapsulation of EOs in a biodegradable polymeric platform showed a solution. Chitosan (CS) is a biodegradable polymer that has been intensively used for EOs encapsulation. Various approaches such as homogenization, probe sonication, electrospinning, and 3D printing have been utilized to integrate EOs in CS polymer. Different CS-based platforms were investigated for EOs encapsulation such as nanoparticles (NPs), nanofibers, films, nanoemulsions, 3D printed composites, and hydrogels. Biological applications of encapsulating EOs in CS include antioxidant, antimicrobial, and anticancer functions. This review explores the principles for nanoencapsulation strategies, and the available technologies are also reviewed, in addition to an in-depth overview of the current research and application of nano-encapsulated EOs.

Antimicrobial and anti-SARS-CoV-2 activities of smart daclatasvir-chitosan/gelatin nanoparticles-in-PLLA nanofibrous medical textiles; in vitro, and in vivo study.

This study aims at the development of electrospun polylactic acid nanofibers (PLLA NFs) incorporating smart daclatasvir-loaded chitosan gelatin nanoparticles to be used as medical textiles. First, smart nanoparticles were prepared through ionic gelation and optimized using Design Expert® software where daclatasvir (DAC), chitosan (CS), and gelatin (GL) amounts were selected to be the independent variables. DAC was used owing to its reported Anti-SARS-CoV-2 activity, CS was chosen due to its antimicrobial activity and GL was used owing to its sensitivity to be hydrolyzed upon exposure to Papain-like protease enzyme (PLpro). The optimum DAC-CS/TAN NPs possessed 109 nm size and 94.44 % entrapment efficiency in addition to sustained drug release for 14 days. Furthermore, upon exposure to PLpro, smart DAC-CS/GL NPs released the whole DAC amount within 3 h. Then, DAC-CS/GL NPs were incorporated within PLLA NFs through electrospinning. Swellability was found to increase gradually reflecting the controlled release of DAC from nanofibers within 3 weeks. Cell viability assessments using human fibroblasts showed that the developed nanofibers possess high biocompatibility. An in-vivo animal model for skin irritation was carried out for two weeks where visual inspection and histopathological investigations showed that neither edema nor erythema were observed.

Evaluating the protective role of trimetazidine versus nano-trimetazidine in amelioration of bilateral renal ischemia/reperfusion induced neuro-degeneration: Implications of ERK1/2, JNK and Galectin-3 /NF-κB/TNF-α/HMGB-1 signaling.

BACKGROUND: Renal ischemia/reperfusion (I/R) is a primary culprit of acute kidney injury. Neurodegeneration can result from I/R, but the mechanisms are still challenging. We studied the implications of bilateral renal I/R on brain and potential involvement of the oxidative stress (OS) driven extracellular signal-regulated kinase1/2, c-Jun N-terminal kinase (ERK1/2, JNK) and Galectin-3 (Gal-3)/nuclear factor Kappa B (NF-қB)/tumor necrosis factor-alpha (TNF-α), high mobility group box-1 (HMGB-1), and caspase-3 paths upregulation. We tested the impact of Nano-trimetazidine (Nano-TMZ) on these pathways being a target of its neuroprotective effects. METHODS: Study groups; Sham, I/R, TMZ+I/R, and Nano-TMZ+I/R. Kidney functions, cognition, hippocampal OS markers, Gal-3, NF-қB, p65 and HMGB-1 gene expression, TNF-α level, t-JNK/p-JNK and t-ERK/p-ERK proteins, caspase-3, glial fibrillary acidic protein (GFAP) and ionized calcium binding protein-1 (Iba-1) were assessed. RESULTS: Nano-TMZ averted renal I/R-induced hippocampal impairment by virtue of its anti: oxidative, inflammatory, and apoptotic properties. CONCLUSION: Nano-TMZ is more than anti-ischemic.

Propranolol-Loaded Trehalosome as Antiproliferative Agent for Treating Skin Cancer: Optimization, Cytotoxicity, and In Silico Studies.

This study aims at preparing propranolol-loaded trehalosomes (a trehalose-coated liposome) to be used as an antiproliferative agent for treating skin cancer. A factorial design was used to select the optimum formula, where trehalose, lecithin, and Tween 80 levels were studied. A total of 24 runs were prepared and characterized according to size, charge, entrapment efficiency, and release after 3 h to select the optimum formula. The optimized formula was investigated using TEM, DSC, and FTIR. Cell studies were carried out against the human melanoma cell line to measure cytotoxicity, apoptosis/necrosis, and cell cycle arrest. In silico studies were conducted to understand the interaction between propranolol and the influential receptors in melanoma. The results showed the selected formula consisted of trehalose (175 mg), lecithin (164 mg), and Tween 80 (200 mg) with a size of 245 nm, a charge of -9 mV, an EE% of 68%, and a Q3 of 62%. Moreover, the selected formula has good cytotoxicity compared to the free drug due to the synergistic effect of the drug and the designed carrier. IC50 of free propranolol and the encapsulation of propranolol were 17.48 µg/mL and 7.26 µg/mL, respectively. Also, propranolol and the encapsulation of propranolol were found to significantly increase early and late apoptosis, in addition to inducing G1 phase cell cycle arrest. An in silico virtual study demonstrated that the highest influential receptors in melanoma were the vitamin D receptor, CRH-R1, VEGFR 1, and c-Kit, which matches the results of experimental apoptotic and cell cycle analysis. In conclusion, the selected formula has good cytotoxicity compared to the free drug due to the synergistic effect of the drug and the designed carrier, which make it a good candidate as an antiproliferative agent for treating skin cancer.

SARS-CoV-2 Papain-like Protease Responsive ZnO/Daclatasvir-Loaded Chitosan/Gelatin Nanofibers as Smart Antimicrobial Medical Textiles: In Silico, In Vitro and Cell Studies.

A significant number of deaths are reported annually worldwide due to microbial and viral infections. The development of protective medical textiles for patients and healthcare professionals has attracted many researchers' attention. Therefore, this study aims to develop smart drug-eluting nanofibrous matrices to be used as a basic material for medical textile fabrication. First, chitosan/gelatin nanofibers were selected as the basic material owing to the wide antimicrobial activity of chitosan and the capability of gelatin to be hydrolyzed in the abundance of the papain-like protease (PLpro) enzyme secreted by SARS-CoV-2. Daclatasvir (DAC), an NS5A inhibitor, was selected as the model drug based on in silico studies where it showed high anti-SARS-CoV-2 potential compared to FDA-approved references. Due to their reported antimicrobial and antiviral activities, ZnO NPs were successfully prepared and incorporated with daclatasvir in chitosan/gelatin nanofibrous matrices through electrospinning. Afterward, an in vitro release study in a simulated buffer revealed the controlled release of DAC over 21 days from the nanofibers compared to only 6 h for free DAC. On the other hand, the abundance of PLpro induced the complete release of DAC from the nanofibers in only 4-8 h. Finally, the nanofibers demonstrated a wide antimicrobial activity against S. aureus, E. coli, and C. albicans.

Design, development, in-vitro and in-vivo evaluation of polylactic acid-based multifunctional nanofibrous patches for efficient healing of diabetic wounds.

Impaired healing of diabetic ulcers is one of the major complications of diabetic patients due to high susceptibility to microbial infections, impaired lymphianogenesis, edema, and consequently impairing proper healing. This could even lead to much worse complications that include severe gangrene, trauma and finally limb amputation. Therefore, this study aims to develop a multilayered durable nanofibrous wound patch loaded with three promising drugs (phenytoin, sildenafil citrate and simvastatin) each in a separate layer to target a different wound healing phase. Polylactic acid was used for the preparation of the nanofibrous matrix of the wound patch, where each drug was incorporated in a separate layer during the preparation process. Drugs release profiles were studied over 3 weeks. Results showed that both phenytoin and simvastatin were released within 14 days while sildenafil continued till 21 days. Both physicochemical and mechanical characteristics of the patches were fully assessed as well as their biodegradability, swellability, breathability and porosity. Results showed that incorporation of drugs preserved the physicochemical and mechanical properties as well as porosity of the developed nanofibers. In addition, patches were evaluated for their biocompatibility and cell adhesion capability before being tested through in-vivo diabetic wound rat model induced by alloxan for three weeks. In vivo results showed that the patches were successful in inducing proper wound healing in diabetic rat model with overcoming the above-mentioned obstacles within 3 weeks. This was confirmed through assessing wound closure as well as from histopathological studies that showed complete healing with proper cell regeneration and arrangement without forming scars.

Investigating the bone regeneration activity of PVA nanofibers scaffolds loaded with simvastatin/chitosan nanoparticles in an induced bone defect rabbit model.

This study aims at preparing electrospun PVA NFs incorporating simvastatin/chitosan nanoparticles (SIM CS NPs) as a controlled drug eluting scaffold for bone regeneration. Optimization was performed by Design Expert® software through establishing two factor, three level factorial design, where the independent variables were the applied voltage, flow rate and PVA solution/SIM CS NPs ratio. Formulation variables values for the optimized formula were 18KV, 0.5 mL/h, and 3:1 respectively. NFs diameter and mesh pore size were chosen as the dependent variables. The optimized NFs were evaluated morphologically, chemically, and physically. Additionally, in-vitro SIM release from the scaffolds was investigated along 24 days. Optimum NFs possessed 136 nm diameter size and 6.5 nm porosity. Also, they showed sustained SIM release for 24 days to achieve the desired goal in bone regeneration. The optimized NFs were implanted within induced bone defects in rabbits. In-vivo assessments were performed through cone beam computed tomography 3D images, bone density measurements, histological analysis and bone morphogenetic protein 2 (BMP 2) level. The obtained results proved the high potential of the optimized NFs in promoting bone regeneration compared to untreated group, non-medicated NFs group, free SIM group and NFs loaded with SIM group after 6 weeks of implantation.

Antimicrobial and Wound-Healing Activities of Graphene-Reinforced Electrospun Chitosan/Gelatin Nanofibrous Nanocomposite Scaffolds.

This study aims at preparing electrospun chitosan/gelatin nanofiber scaffolds reinforced with different amounts of graphene nanosheets to be used as antibacterial and wound-healing scaffolds. Full characterization was carried out for the different fabricated scaffolds before being assessed for their antimicrobial activity against Escherichia coli and Staphylococcus aureus, cytotoxicity, and cell migration capacity. Raman and transmission electron microscopies confirmed the successful reinforcement of nanofibers with graphene nanosheets. Scanning electron microscopy and porosity revealed that nanofibers reinforced with 0.15% graphene nanosheets produced the least diameter (106 ± 30 nm) and the highest porosity (90%), in addition to their good biodegradability and swellability. However, the excessive increase in graphene nanosheet amount produced beaded nanofibers with decreased porosity, swellability, and biodegradability. Interestingly, nanofibers reinforced with 0.15% graphene nanosheets showed E. coli and S. aureus growth inhibition percents of 50 and 80%, respectively. The cell viability assay showed no cytotoxicity on human fibroblasts when cultured with either unreinforced or reinforced nanofibers. The cell migration was higher in the case of reinforced nanofibers when compared to the unreinforced nanofibers after 24 and 48 h, which is substantially associated with the great effect of the graphene nanosheets on the cell migration capability. Unreinforced and reinforced nanofibers showed cell migration results up to 93.69 and 97%, respectively, after 48 h.

Nitric Oxide Releasing Hydrogel Nanoparticles Decreases Epithelial Cell Injuries Associated With Airway Reopening.

Acute respiratory distress syndrome (ARDS) is an acute inflammatory lung condition. It is characterized by disruption of gas exchange inside the alveoli, accumulation of protein edema, and an increase in lung stiffness. One major cause of ARDS is a lung infection, such as SARS-COV-2 infection. Lungs of ARDS patients need to be mechanically ventilated for airway reopening. Consequently, ventilation might damage delicate lung tissue leading to excess edema, known as ventilator-induced lung injury (VILI). Mortality of COVID-19 patients under VILI seems to be higher than non-COVID patients, necessitating effective preventative therapies. VILI occurs when small air bubbles form in the alveoli, injuring epithelial cells (EPC) due to shear stress. Nitric oxide (NO) inhalation was suggested as a therapy for ARDS, however, it was shown that it is not effective because of the extremely short half-life of NO. In this study, NO-releasing nanoparticles were produced and tested in an in vitro model, representing airways in the deep lung. Cellular injuries were quantified via fluorescent live/dead assay. Atomic force microscopy (AFM) was used to assess cell morphology. qRT-PCR was performed to assess the expression of inflammatory markers, specifically IL6 and CCL2. ELISA was performed to assess IL6 and confirm qRT-PCR results at the protein level. Finally, ROS levels were assessed in all groups. Here, we show that NO delivery via nanoparticles enhanced EPC survival and recovery, AFM measurements revealed that NO exposure affect cell morphology, while qRT-PCR demonstrated a significant downregulation in IL6 and CCL2 expression when treating the cells to NO both before and after shear exposure. ELISA results for IL6 confirmed qRT-PCR data. ROS experiment results support our findings from previous experiments. These findings demonstrate that NO-releasing nanoparticles can be used as an effective delivery approach of NO to deep lung to prevent/reduce ARDS associated inflammation and cell injuries. This information is particularly useful to treat severe ARDS due to COVID-19 infection. These nanoparticles will be useful when clinically administrated to COVID-19 patients to reduce the symptoms originating from lung distress.

Phenytoin/sildenafil loaded poly(lactic acid) bilayer nanofibrous scaffolds for efficient orthopedics regeneration.

Autologous and synthetic bone grafts showed some limitations during their usage in bone tissue regeneration. This is attributed to several drawbacks such as difficulty of finding a donor in addition to the autoimmune rejection. This study aims to fabricate a well-designed biocompatible double-layered structure of highly porous poly(lactic acid)-based electrospun nanofibers (NFs) as scaffolds for bone tissue regeneration. Poly(lactic acid) was chosen to fabricate the main matrix of the NFs scaffold as it is one of the FDA approved and highly recommended biopolymers for biomedical applications owing to its high biodegradability and biocompatibility Each layer is loaded with a different drug (Phenytoin and Sildenafil) to stimulate bone healing process. The solvents and the parameters of electrospinning were manipulated to produce highly porous structures in order to enhance the in-situ biodegradability of the NFs mats as well as the drug release rate. The produced NFs mats were fully characterized morphologically (SEM), chemically (FTIR), physically (DSC) and physicochemically (biodegradability, swellability, porosity and water vapor permeability) as well as studying the drug release profiles of both drugs. Cytotoxicity of the fabricated NFs was tested using fibroblast cells to detect their biocompatibility. Cell adhesion and proliferation were examined using SEM before using the NFs as scaffolds in mice animal model. The efficiency of the developed NFs scaffolds in healing bone fractures was assessed after 14 and 28 days through visual inspection, SEM investigation and bone mineral density assessment. Finally, sections from the bone fracture sites were isolated for histopathological examination. The study revealed the efficiency of the drugs-loaded NFs in enhancing cell adherence, cell proliferation, angiogenesis formation and finally tissue restoration of bone fractures.

Noninvasive biodegradable nanoparticles-in-nanofibers single-dose ocular insert: in vitro, ex vivo and in vivo evaluation.

AIM: This study involves, for the first time, the development of mucoadhesive biodegradable polymeric-multilayered nanoparticles-in-nanofibers (NPs-in-NFs) matrix as an innovative single-dose noninvasive ocular-insert that could substitute conventional ocular dosage-forms. MATERIALS & METHODS: Azithromycin-loaded poly(lactic-co-glycolic acid) copolymer/pluronic NPs were developed then incorporated into electrospun polyvinylpyrrolidone NFs, and tested for their efficient treatment of ocular bacterial infection. RESULTS: Release and permeation studies proved the ability of the insert to control drug release over 10 days. CONCLUSION: The incorporation of NPs into NFs achieved several other benefits like increasing ocular residence and contact time with conjunctival tissue, accurate dose delivery, sustaining drug release with constant rate, reducing frequency of administration, improving bioavailability along with decreasing incidence of visual and systemic side effects.

Energetic and electronic computation of the two-hydrogen atom donation process in catecholic and non-catecholic anthocyanidins.

Antioxidant activity of anthocyanidins is greatly affected by the 3-hydroxyl group and/or a catecholic moiety. The two-hydrogen atom donation process is frequently used to explain the high antioxidant activity of polyphenolic compounds leading to the formation of stable diketones e.g. 1,2-quinones. Thermodynamic parameters, HOMO and spin density were computed to identify the favoured path, either through the 3-hydroxyl group or through the catecholic moiety in a series of catecholic and non-catecholic 3-oxy- (and deoxy)-anthocyanidins. DFT calculations showed that the donation process in non-catecholic anthocyanidins depended on the substituents on ring B. Anthocyanidins with 3',5'-diOMe groups showed donation through 3,4'-OH or, otherwise, through 3,5-OH groups. Catecholic 3-oxyanthocyanidins, on the other hand, showed donation through the 3,4'-OH path rather than the catecholic path (4',3'-path). The 3,4'-path was favoured by the formation of planar 3-radicals in the first step and the stabilization of 4'-radicals in the second step by H-bonding with the 3'-OH group.

Single-Dose Electrospun Nanoparticles-in-Nanofibers Wound Dressings with Enhanced Epithelialization, Collagen Deposition, and Granulation Properties.

Phenytoin (Ph), an antiepileptic drug, was reported to exhibit high wound healing activity. However, its limited solubility, bioavailability, and inefficient distribution during topical administration limit its use. Therefore, this study aims to develop new single-dose electrospun nanoparticles-in-nanofibers (NPs-in-NFs) wound dressings that allow a well-controlled release of Ph. These NPs-in-NFs systems are based on enhanced chitosan (CS)/poly(ethylene oxide) (PEO) electrospun nanofibers (NFs) incorporating optimized Ph-loaded nanocarriers. First, a study was conducted to investigate Ph loading efficiency into polymeric nanocarriers of different types; pluronic nanomicelles and poly(lactic-co-glycolic) acids nanoparticles (PLGA NPs). The drug release profile from the nanocarriers was further optimized via lecithin coating. Second, different electrospinning parameters were manipulated to fabricate beads-free homogeneous NFs with optimized polymer ratios. Plain and Ph-loaded nanocarriers were characterized using Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and scanning electron microscopy (SEM). Both entrapment efficiency of Ph (EE%) and its release profile in phosphate buffer saline (PBS; pH 5.5), simulating the wound environment, were studied. Biodegradability, swelling, vapor permeability, and porosity of the developed Ph-loaded NPs-in-NFs wound dressings were investigated. Morphology of the NPs-in-NFs was also studied using SEM and confocal laser microscopy (CLSM). Besides, the release profiles of Ph from the optimized NPs-in-NFs were assessed. The newly developed wound dressings were evaluated in vitro for their cytotoxicity using human fibroblasts and in vivo using a wound healing mice model. Nanocarriers with particle size ranging from 100 to 180 nm were successfully prepared. All nanocarriers attained a high drug entrapment efficiency exceeding 94% and showed promising sustained release profiles compared to free Ph. Results also demonstrated that NFs incorporating the optimized lecithin-coated Ph-loaded PLGA NPs could be the most promising candidate for efficient wound healing. These NPs-in-NFs systems conferred a well-controlled and sustained release of Ph over 9 days. Moreover, they showed the best re-epithelization and healing quality during the in vivo study with minimal inflammatory and necrotic cells formation.