Co-delivery of simvastatin and microRNA-21 through liposome could accelerates the wound healing process.

The gene delivery approach, mainly microRNAs (miRNA) as key wound healing mediators, has recently received extensive attention. MicroRNA-21 (miR-21) has strongly impacted wound healing by affecting the inflammation and proliferation phases. Previous studies have also demonstrated the beneficial effect of simvastatin on wound healing. Therefore, we designed a dual-drug/gene delivery system using PEGylated liposomes that could simultaneously attain the co-encapsulation and co-delivery of miRNA and simvastatin (SIM) to explore the combined effect of this dual-drug delivery system on wound healing. The PEG-liposomes for simvastatin and miR-21 plasmid (miR-21-P/SIM/Liposomes) were prepared using the thin-film hydration method. The liposomes showed 85 % entrapment efficiency for SIM in the lipid bilayer and high physical entrapment of miR-21-P in the inner cavity. In vitro studies demonstrated no cytotoxicity for the carrier on normal human dermal fibroblast cells (NHDF) and 97 % cellular uptake over 2 h incubation. The scratch test revealed excellent cell proliferation and migration after treatment with miR-21-P/SIM/Liposomes. For the in vivo experiments, a full-thickness cutaneous wound model was used. The wound closure on day 8 was higher for Liposomal formulation containing miR-21-P promoting faster re-epithelialization. On day 12, all treated groups showed complete wound closure. However, following histological analysis, the miR-21-P/SIM/Liposomes revealed the best tissue regeneration, similar to normal functional skin, by reduced inflammation and increased re-epithelialization, collagen deposition and angiogenesis. In conclusion, the designed miR-21-P/SIM/Liposomes could significantly accelerate the process of wound healing, which provides a new strategy for the management of chronic wounds.

Transferrin decorated-nanostructured lipid carriers (NLCs) are a promising delivery system for rapamycin in Alzheimer's disease: An in vivo study.

Alzheimer's disease (AD), the most common neurodegenerative disorder, is characterized by progressive cognitive impairment and memory loss. The mammalian target of rapamycin (mTOR) signaling pathway could regulate learning and memory. The effect of rapamycin (Rapa) on mTOR activity could slow or prevent the progression of AD by affecting various essential cellular processes. Previously, we prepared transferrin (Tf) decorated-nanostructured lipid carriers (NLCs) for rapamycin (150 ± 9 nm) to protect the drug from chemical and enzymatic degradation and for brain targeted delivery of rapamycin. Herein, the effect of Tf-NLCs compared to untargeted anionic-NLCs and free rapamycin, were studied in amyloid beta (Aß) induced rat model of AD. Behavioral test revealed that the Rapa Tf-NLCs were able to significantly improve the impaired spatial memory induced by Aß. Histopathological studies of hippocampus also showed neural survival in Rapa Tf-NLCs treated group. The immunosuppressive, and delayed wound healing adverse effects in the rapamycin solution treated group were abolished by incorporating the drug into NLCs. The Aß induced oxidative stress was also reduced by Rapa Tf-NLCs. Molecular studies on the level of Aß, autophagy (LC3) and apoptotic (caspase-3) markers, and mTOR activity revealed that the Rapa Tf-NLCs decreased the Aß level and suppressed the toxic effects of Aß plaques by modulating the mTOR activity and autophagy, and decreasing the apoptosis level. As a conclusion, the designed Tf-NLCs could be an appropriate and a safe brain delivery system for rapamycin and make this drug more efficient in AD for improving memory and neuroprotection.

Trimethyl-Chitosan Coated Gold Nanoparticles Enhance Delivery, Cellular Uptake and Gene Silencing Effect of EGFR-siRNA in Breast Cancer Cells.

Purpose: Despite the promising therapeutic effects of gene silencing with small interfering RNAs (siRNAs), the challenges associated with delivery of siRNAs to the tumor cells in vivo, has greatly limited its clinical application. To overcome these challenges, we employed gold nanoparticles modified with trimethyl chitosan (TMC) as an effective delivery carrier to improve the stability and cellular uptake of siRNAs against epidermal growth factor receptor (EGFR) that is implicated in breast cancer. Methods: AuNPs were prepared by the simple aqueous reduction of chloroauric acid (HAuCl4) with ascorbic acid and coated with synthesized TMC. EGFR-siRNA was then complexed with the AuNPs-TMC via electrostatic interaction to make AuNPs-TMC/EGFR-siRNA with a w/w ratio of 10:1. Nanoparticles were assessed for physicochemical characteristics and in vitro cellular behavior on MCF-7 breast cancer cell line. Results: Spherical and positively charged AuNPs-TMC (67 nm, +45 mV) were successfully complexed with EGFR-siRNA (82 nm, +11 mV) which were able to retard the gene migration completely. Confocal microscopy and flow cytometry analysis demonstrated complete cellular uptake of Cy5 labeled AuNPs-TMC in the MCF-7 cells after 4 h incubation. MTT test after 48 h incubation showed that the AuNPs-TMC were safe but when combined with EGFR-siRNA exert significant cytotoxicity while the cell viability was about 50%. These nanocomplexes also showed a high gene expression knockdown (86%) of EGFR and also a high apoptosis rate (Q2 + Q3 = 18.5%) after 24 h incubation. Conclusion: This study suggests that the simply synthesized AuNPs-TMC are novel, effective, and promising nanocarriers for siRNA delivery, and AuNPs-TMC/EGFR-siRNA appears to be a potential therapeutic agent for breast cancer treatment.

Brain targeted delivery of rapamycin using transferrin decorated nanostructured lipid carriers.

Introduction: Recent studies showed that rapamycin, as a mammalian target of rapamycin (mTOR) inhibitor, could have beneficial therapeutic effects for the central nervous system (CNS) related diseases. However, the immunosuppressive effect of rapamycin as an adverse effect, the low water solubility, and the rapid in vivo degradation along with the blood-brain barrier-related challenges restricted the clinical use of this drug for brain diseases. To overcome these drawbacks, a transferrin (Tf) decorated nanostructured lipid carrier (NLC) containing rapamycin was designed and developed. Methods: Rapamycin-loaded cationic and bare NLCs were prepared using solvent diffusion and sonication method and well characterized. The optimum cationic NLCs were physically decorated with Tf. For in vitro study, the MTT assay and intracellular uptake of nanoparticles on U-87 MG glioblastoma cells were assessed. The animal biodistribution of nanoparticles was evaluated by fluorescent optical imaging. Finally, the in vivo effect of NLCs on the immune system was also studied. Results: Spherical NLCs with small particle sizes ranging from 120 to 150 nm and high entrapment efficiency of more than 90%, showed ≥80% cell viability. More importantly, Tf-decorated NLCs in comparison with bare NLCs, showed a significantly higher cellular uptake (97% vs 60%) after 2 hours incubation and further an appropriate brain accumulation with lower uptake in untargeted tissue in mice. Surprisingly, rapamycin-loaded NLCs exhibited no immunosuppressive effect. Conclusion: Our findings proposed that the designed Tf-decorated NLCs could be considered as a safe and efficient carrier for targeted brain delivery of rapamycin which may have an important value in the clinic for the treatment of neurological disorders.

Correction: Brain targeted delivery of rapamycin using transferrin decorated nanostructured lipid carriers.

[This corrects the article DOI: 10.34172/bi.2021.23389.].

Nanostructured lipid carriers containing rapamycin for prevention of corneal fibroblasts proliferation and haze propagation after burn injuries: In vitro and in vivo.

Chemical burns are a major cause of corneal haze and blindness. Corticosteroids are commonly used after corneal burns to attenuate the severity of the inflammation-related fibrosis. While research efforts have been aimed toward application of novel therapeutics. In the current study, a novel drug delivery system based nanostructured lipid carriers (NLCs) were designed to treat corneal alkaline burn injury. Rapamycin, a potent inhibitor of mammalian target of rapamycin pathway, was loaded in NLCs (rapa-NLCs), and the NLCs were characterized. Cell viability assay, cellular uptake of NLCs, and in vitro evaluation of the fibrotic/angiogenic genes suppression by rapa-NLCs were carried out on human isolated corneal fibroblasts. Immunohistochemistry (IHC) assays were also performed after treatment of murine model of corneal alkaline burn with rapa-NLCs. According to the results, rapamycin was efficiently loaded in NLCs. NLCs could enhance coumarin-6 fibroblast uptake by 1.5 times. Rapa-NLCs efficiently downregulated platelet-derived growth factor and transforming growth factor beta genes in vitro. Furthermore, proliferation of fibroblasts, a major cause of corneal haze after injury, reduced. IHC staining of treated cornea with alpha-smooth muscle actin and CD34 + antibodies showed efficient prevention of myofibroblasts differentiation and angiogenesis, respectively. In conclusion, ocular delivery of rapamycin using NLCs after corneal injury may be considered as a promising antifibrotic/angiogenic treatment approach to preserve patient eyesight.

Comparative study of in vitro release and mucoadhesivity of gastric compacts composed of multiple unit system/bilayered discs using direct compression of metformin hydrochloride.

INTRODUCTION: Metformin is an oral anti-diabetic drug in the biguanide class. The goal of this study was to develop gastric-retentive MH discs in order to prolong the retention of drug in gastric mucosa. METHODS: Two groups of metformin hydrochloride (MH) mucoadhesive gastroretentive discs were prepared: (a) bilayered discs prepared by direct compression of powders containing polymers as Carbopol 934P (CP, mucoadhesive polymer) and ethylcellulose (EC, rotardant polymer), (b) multiple unit system (microparticle) discs prepared by the emulsification, solvent evaporation, and compression technique from microparticles using polymers CP and EC. Gastric-mucoadhesive compacts were evaluated by investigating their release pattern, swelling capacity, mucoadhesion property, surface pH, and in vitro gastro-retentive time. Discs formulation was subjected to disintegration and dissolution tests by placing in 0.1 M hydrochloric acid for 8 h. RESULTS: The production yield showed F2 microparticles of 98.80%, mean particle size of 933.25 µm and loading efficiency of 98.44%. The results showed that prepared microparticle discs had slower release than bilayered discs (p>0.05). The bilayered discs exhibited very good percentage of mucoadhesion. The results also showed a significant higher retention of mucoadhesive bilayered discs in upper gastrointestinal tract (F´1, 1:2 ratio of CP:EC). Histopathological studies revealed no gastric mucosal damage. CONCLUSION: Mucoadhesive multiple unit system/bilayered discs interact with mucus of gastrointestinal tract and are considered to be localized or trapped at the adhesive site by retaining a dosage form at the site of action as well as improving in the intimacy of contact with underlying absorptive membrane to achieve a better therapeutic performance of anti-diabetic drug.

Formulation and Evaluation of In-vitro Characterization of Gastic-Mucoadhesive Microparticles/Discs Containing Metformin Hydrochloride.

The present study involves preparation and evaluation of gastric-mucoadhesive microparticles with Metformin Hydrochloride as model drug for prolongation of gastric residence time. The microparticles were prepared by the emulsification solvent evaporation technique using polymers of Carbomer 934p (CP) and Ethylcellulose (EC). The microparticles were prepared by emulsion solvent evaporation method (O1/O2). Disc formulations were prepared by direct compression technique from microparticles. In the current study, gastric-mucoadhesive microparticles with different polymers ratios (CP:EC) were prepared and were characterized by encapsulation efficiency, particle size, flowability, mucoadhesive property and drug release studies. The best polymers ratio was 1:3 (F2) with Carbomer 934p (as mucoadhesive polymer) and ethylcellulose (as retardant polymer), respectively. The production yield microparticles F2 showed 98.80%, mean particle size 933.25 µm and loading efficiency %98.44. The results were found that microparticle discs prepared had slower release than microparticles (p > o.o5). The microparticles exhibited very good percentage of mucoadhesion and flowability properties. The release of drug was prolonged to 8 h (71.65-82.22%) when incorporated into mucoadhesive microparticles. The poor bioavailability of metformine is attributed to short retention of its dosage form at the absorption sites (in upper gastrointestinal tract). The results of mucoadhesion study showed better retention of metformine microparticles (8 h) in duodenal and jejunum regions of intestine (F1, 1:2 ratio of CP:EC). Therefore, it may be concluded that drug loaded gastric-mucoadhesive microparticles are a suitable delivery system for metformin hydrochloride, and may be used for effective management of NIDDM (Non Insulin Dependent Diabetes Mellitus).