Preparation, characterization, and optimization of primaquine-loaded solid lipid nanoparticles

NANOPARTICLE-BASED formulation of dihydroartemisinin-lumefantrine duo-drugs: Preclinical Evaluation and enhanced antimalarial efficacy in a mouse model

Artemisinin-based combinations (ACTs) are World Health Organization-recommended treatment for malaria. Artemether (A) and lumefantrine (LUM) were the first co-formulated ACT and first-line treatment for malaria globally, artemether is dihydroartemisinin's (DHA's) prodrug. Artemisinins and LUM face low aqueous solubility while artemisinin has low bioavailability and short half-life thus requiring continuous dosage to maintain adequate therapeutic drug-plasma concentration. This study aimed at improving ACTs limitations by nano-formulating DHA-LUM using solid lipid nanoparticles (SLNs) as nanocarrier. SLNs were prepared by modified solvent extraction method based on water-in-oil-in-water double emulsion. Mean particle size, polydispersity index and zeta potential were 308.4 nm, 0.29 and -16.0 mV respectively. Nanoencapsulation efficiencies and drug loading of DHA and LUM were 93.9%, 33.7%, 11.9%, and 24.10% respectively. Nanoparticles were spherically shaped and drugs followed Kors-Peppas release model, steadily released for over 72 h. DHA-LUM-SLNs were 31% more efficacious than conventional oral doses in clearing Plasmodium berghei from infected Swiss albino mice.

Nanotherapeutics against malaria: A decade of advancements in experimental models

Malaria, caused by different species of protists of the genus Plasmodium, remains among the most common causes of death due to parasitic diseases worldwide, mainly for children aged under 5. One of the main obstacles to malaria eradication is the speed with which the pathogen evolves resistance to the drug schemes developed against it. For this reason, it remains urgent to find innovative therapeutic strategies offering sufficient specificity against the parasite to minimize resistance evolution and drug side effects. In this context, nanotechnology-based approaches are now being explored for their use as antimalarial drug delivery platforms due to the wide range of advantages and tuneable properties that they offer. However, major challenges remain to be addressed to provide a cost-efficient and targeted therapeutic strategy contributing to malaria eradication. The present work contains a systematic review of nanotechnology-based antimalarial drug delivery systems generated during the last 10 years. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Transethosome: An ultra-deformable ethanolic vesicle for enhanced transdermal drug delivery

Drug delivery through the skin improves solubility, bioavailability, and unwanted systemic side effects of the drug. The selection of a suitable carrier is a challenging process. The conventional lipid vesicles have some limitations. They deliver the drug in the stratum corneum and have poor colloidal stability. Here comes the need for ultra-deformable lipid vesicles to provide the drug beyond the stratum corneum. Transethosomes are novel ultra-deformable vesicles that can deliver drugs into deeper tissues. The composition of transethosomes includes phospholipid, ethanol and surfactants. Each ingredient has a pivotal role in the properties of the carrier. This review covers the design, preparation method, characterisation, and characteristics of the novel vesicle. Also, we cover the impact of surfactants on vesicular properties and the skin permeation behaviour of novel vesicles.

Design of Chitosan-Coated, Quercetin-Loaded PLGA Nanoparticles for Enhanced PSMA-Specific Activity on LnCap Prostate Cancer Cells

Nanoparticles are designed to entrap drugs at a high concentration, escape clearance by the immune system, be selectively taken up by cancer cells, and release bioactives in a rate-modulated manner. In this study, quercetin-loaded PLGA nanoparticles were prepared and optimized to determine whether coating with chitosan would increase the cellular uptake of the nanoparticles and if the targeting ability of folic acid as a ligand can provide selective toxicity and enhanced uptake in model LnCap prostate cancer cells, which express high levels of the receptor prostate-specific membrane antigen (PSMA), compared to PC-3 cells, that have relatively low PSMA expression. A design of experiments approach was used to optimize the PLGA nanoparticles to have the maximum quercetin loading, optimal cationic charge, and folic acid coating. We examined the in vitro release of quercetin and comparative cytotoxicity and cellular uptake of the optimized PLGA nanoparticles and revealed that the targeted nano-system provided sustained, pH-dependent quercetin release, and higher cytotoxicity and cellular uptake, compared to the non-targeted nano-system on LnCap cells. There was no significant difference in the cytotoxicity or cellular uptake between the targeted and non-targeted nano-systems on PC-3 cells (featured by low levels of PSMA), pointing to a PSMA-specific mechanism of action of the targeted nano-system. The findings suggest that the nano-system can be used as an efficient nanocarrier for the targeted delivery and release of quercetin (and other similar chemotherapeutics) against prostate cancer cells.

Preparation of Solid Lipid Nanoparticle-Ferrous Sulfate by Double Emulsion Method Based on Fat Rich in Monolaurin and Stearic Acid

Ferrous sulfate is one type of iron that is commonly used in iron supplementation and fortification in food products, but it has low stability and an unfavorable flavor, causing its use to be limited. Encapsulation in a solid lipid nanoparticle (SLN) system is one technology that offers stable active compound protection and a good delivery system; however, a solid lipid matrix should be selected which has good health effects, such as glycerol monolaurate or monolaurin. The purpose of this study was to obtain SLN-ferrous sulfate based on stearic acid and fat rich in monolaurin. SLN-Ferrous sulfate was synthesized at various concentrations of monolaurin-rich fat (20%; 30%; 40% w/w lipid) and various concentrations of ferrous sulfate (5%; 10%; 15% w/w lipid). The results showed that the use of monolaurin-rich fat 40% w/w lipid and 15% w/w ferrous sulfate produced the best characteristics with high entrapment efficiency and loading capacity of 0.06%. The Z-average value of SLN was 292.4 nm with a polydispersity index (PI) of 1.03. SLN-ferrous sulfate showed a spherical morphology, where the Fe trapped in the SLN was evenly dispersed in the lipid matrix to form a nanosphere system. Preparation of SLN-ferrous sulfate by double emulsion method based on stearic acid and fat rich in monolaurin effectively encapsulated ferrous sulfate with high entrapment efficiency and good physicochemical properties.

Optimization of the Conditions of Solid Lipid Nanoparticles (SLN) Synthesis

Solid lipid nanoparticles (SLNs) have been synthesized as potential drug delivery systems. They are classified as solid lipid nanocarriers that can successfully carry both hydrophilic and hydrophobic drugs. SLNs are based on a biocompatible lipid matrix that is enzymatically degraded into natural components found in the human body. Solid lipid nanoparticles are suitable for the incorporation of hydrophobic active ingredients such as curcumin. The study included the optimization of lipid nanoparticle composition, incorporation of the active compound (curcumin), a stability evaluation of the obtained nanocarriers and characterization of their lipid matrix. Through process optimization, a dispersion of solid lipid nanoparticles (solid lipid:surfactant—2:1.25 weight ratio) predisposed to the incorporation of curcumin was developed. The encapsulation efficiency of the active ingredient was determined to be 99.80%. In stability studies, it was found that the most suitable conditions for conducting high-pressure homogenization are 300 bar pressure, three cycles and a closed-loop system. This yields the required values of the physicochemical parameters (a particle size within a 200−450 nm range; a polydispersity index of <30%; and a zeta potential of about |±30 mV|). In this work, closed-loop high-pressure homogenization was used for the first time and compared to the currently preferred open-loop method.

Development of Sustained Release Baricitinib Loaded Lipid-Polymer Hybrid Nanoparticles with Improved Oral Bioavailability

Baricitinib (BTB) is an orally administered Janus kinase inhibitor, therapeutically used for the treatment of rheumatoid arthritis. Recently it has also been approved for the treatment of COVID-19 infection. In this study, four different BTB-loaded lipids (stearin)-polymer (Poly(d,l-lactide-co-glycolide)) hybrid nanoparticles (B-PLN1 to B-PLN4) were prepared by the single-step nanoprecipitation method. Next, they were characterised in terms of physicochemical properties such as particle size, zeta potential (ζP), polydispersity index (PDI), entrapment efficiency (EE) and drug loading (DL). Based on preliminary evaluation, the B-PLN4 was regarded as the optimised formulation with particle size (272 ± 7.6 nm), PDI (0.225), ζP (-36.5 ± 3.1 mV), %EE (71.6 ± 1.5%) and %DL (2.87 ± 0.42%). This formulation (B-PLN4) was further assessed concerning morphology, in vitro release, and in vivo pharmacokinetic studies in rats. The in vitro release profile exhibited a sustained release pattern well-fitted by the Korsmeyer-Peppas kinetic model (R2 = 0.879). The in vivo pharmacokinetic data showed an enhancement (2.92 times more) in bioavailability in comparison to the normal suspension of pure BTB. These data concluded that the formulated lipid-polymer hybrid nanoparticles could be a promising drug delivery option to enhance the bioavailability of BTB. Overall, this study provides a scientific basis for future studies on the entrapment efficiency of lipid-polymer hybrid systems as promising carriers for overcoming pharmacokinetic limitations.

Design expert assisted formulation, characterization and optimization of microemulsion based solid lipid nanoparticles of repaglinide

Repaglinide, a member of the meglitinide class of drugs, is a new anti-diabetic agent that is utilized as an oral hypoglycemic agent. Using glyceryl monostearate, cetyl palmitate, and tristearin as lipids and poloxamer 188 as a surfactant, repaglinide-loaded solid lipid nanoparticles were created. Solid lipid nanoparticles were prepared utilizing an o/w microemulsion technique, which included the lipids glyceryl monostearate and tristearin, as well as waxes such as cetyl palmitate and the surfactant poloxamer 188. The mean particle size of the solid lipid nanoparticles formed was around 339 nm, with an entrapment efficiency of 82.20%. In-vitro release studies continued to be conducted using the dialysis bag diffusion technique. Within 12 h, the cumulative drug release was 88.4%. The results indicate that repaglinide was released more slowly from solid lipid nanoparticles made from tristearin and glyceryl monostearate in an equal ratio. Tristearin found the controlled release and extreme entrapment from other lipid carriers like glyceryl monostearate and cetyl palmitate. Differential scanning calorimetry demonstrates that repaglinide is entangled in amorphous or molecular state within solid lipid nanoparticles. SEM microscopy revealed that the produced repaglinide solid lipid nanoparticles had a spherical shape. After one month of storage at 2-8 °C, short-term stability testing revealed no significant alteration.

Magnetic Nanoparticles Used in Oncology

Recently, magnetic nanoparticles (MNPs) have more and more often been used in experimental studies on cancer treatments, which have become one of the biggest challenges in medical research. The main goal of this research is to treat and to cure advanced or metastatic cancer with minimal side effects through nanotechnology. Drug delivery approaches take into account the fact that MNPs can be bonded to chemotherapeutical drugs, nucleic acids, synthetized antibodies or radionuclide substances. MNPs can be guided, and different treatment therapies can be applied, under the influence of an external magnetic field. This paper reviews the main MNPs’ synthesis methods, functionalization with different materials and highlight the applications in cancer therapy. In this review, we describe cancer cell monitorization based on different types of magnetic nanoparticles, chemotherapy, immunotherapy, magnetic hyperthermia, gene therapy and ferroptosis. Examples of applied treatments on murine models or humans are analyzed, and glioblastoma cancer therapy is detailed in the review. MNPs have an important contribution to diagnostics, investigation, and therapy in the so called theranostics domain. The main conclusion of this paper is that MNPs are very useful in different cancer therapies, with limited side effects, and they can increase the life expectancy of patients with cancer drug resistance.

Chitosan-Coated PLGA Nanoparticles Encapsulating Triamcinolone Acetonide as a Potential Candidate for Sustained Ocular Drug Delivery

The current treatment for the acquired retinal vasculopathies involves lifelong repeated intravitreal injections of either anti-vascular endothelial growth factor (VEGF) therapy or modulation of inflammation with steroids. Consequently, any treatment modification that decreases this treatment burden for patients and doctors alike would be a welcome intervention. To that end, this research aims to develop a topically applied nanoparticulate system encapsulating a corticosteroid for extended drug release. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) supports the controlled release of the encapsulated drug, while surface modification of these NPs with chitosan might prolong the mucoadhesion ability leading to improved bioavailability of the drug. Triamcinolone acetonide (TA)-loaded chitosan-coated PLGA NPs were fabricated using the oil-in-water emulsion technique. The optimized surface-modified NPs obtained using Box-Behnken response surface statistical design were reproducible with a particle diameter of 334 ± 67.95 to 386 ± 15.14 nm and PDI between 0.09 and 0.15. These NPs encapsulated 55-57% of TA and displayed a controlled release of the drug reaching a plateau in 27 h. Fourier-transform infrared spectroscopic (FTIR) analysis demonstrated characteristic peaks for chitosan (C-H, CONH2 and C-O at 2935, 1631 and 1087 cm-1, respectively) in chitosan-coated PLGA NPs. This result data, coupled with positive zeta potential values (ranged between +26 and +33 mV), suggests the successful coating of chitosan onto PLGA NPs. Upon coating of the NPs, the thermal stability of the drug, polymer, surfactant and PLGA NPs have been enhanced. The characteristics of the surface-modified NPs supports their use as potential candidates for topical ocular drug delivery for acquired retinal vasculopathies.

Primaquine Loaded Solid Lipid Nanoparticles (SLN), Nanostructured Lipid Carriers (NLC), and Nanoemulsion (NE): Effect of Lipid Matrix and Surfactant on Drug Entrapment, in vitro Release, and ex vivo Hemolysis

Primaquine (PQ), an 8-aminoquinoline antimalarial drug, has been widely used for the eradication of hypnozoites from the liver and, therefore, recognized as the radical cure of malaria. However, the clinical applications of PQ are restricted to patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to severe dose-related hemolytic side effects. Nanoparticle carriers have shown great potential in achieving higher PQ concentrations in the target site, thereby reducing dose-related systemic toxicity caused by non-specific exposure. This work aims to develop, compare, and evaluate three PQ-loaded lipid-based drug carriers including solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nano-emulsions (NE). The optimized PQ-SLN, PQ-NLC, and PQ-NE had a particle size of 250 nm, a PDI range of 0.1 to 0.3, a zeta potential of - 30 mV, and entrapment efficiency of ~ 90%. All lipid formulations showed sustained release in both simulated gastric and intestinal fluids over 6 h. Four empirical models - including zero-order, Higuchi, Korsmeyer-Peppas, and Hixson-Crowell models - were tested to understand the drug release mechanisms of PQ-SLN, PQ-NLC, and PQ-NE. The model fitness was found to be the highest in the Korsmeyer-Peppas model for all the PQ-loaded lipid formulations (R²: 0.88-0.94). No significant changes were observed in the entrapment efficiency, particle size, and PDI of lipid formulations throughout 1 month of storage at 4 °C and 25 °C. PQ-SLN and PQ-NLC can be further lyophilized with cryoprotectants to improve long-term stability. Finally, the treatment of erythrocytes with PQ-SLN, PQ-NLC, and PQ-NE reduced erythrocyte hemolysis by approximately 4.5-fold compared to the free drug solution.

Targeting Solid Lipid Nanoparticles with Anisamide for Docetaxel Delivery to Prostate Cancer: Preparation, Optimization, and In-vitro Evaluation

The purpose of the current study was to prepare and characterize the targeted solid lipid nanoparticles (SLNs) containing docetaxel (DTX) for prostate cancer treatment. The goal has been achieved by locating anisamide (Anis) ligand on the surface of SLNs, which can interact with the overexpressed sigma receptor on the prostate cancer cells. DTX loaded SLNs were prepared by high shear homogenization and ultra-sonication method and optimized by applying experimental design. The average particle size and the entrapment efficiency of the optimum DTX-SLN were 174 ± 9.1 nm and 83 ± 3.34%, respectively. The results of differential scanning calorimetry showed that DTX had been dispersed as amorphous in the nanocarriers. Scanning electron microscopy (SEM) images confirmed the nanoscale size and spherical shape of the nanoparticles. The cytotoxicity studies have demonstrated that IC₅₀ of free drug, DTX-SLN and DTX-SLN-Anis was 0.25 ± 0.01, 0.23 ± 0.02, 0.12 ± 0.01 nM on PC3 cell line and 20.9 ± 3.89, 18.74 ± 7.43, and 14.68 ± 5.70 nM on HEK293 cell line, respectively. Targeted DTX-SLN-Anis was acted more effectively on prostate cancer cells in comparison to DTX-SLN and free drug. The results of this study have depicted that the anti-cancer drug loaded in targeted SLNs can be a promising way for cancer treatment. In addition, performing in-vivo studies will be complementary to these findings.

Interactions of primaquine and chloroquine with PEGylated phosphatidylcholine liposomes

This study aimed to analyze the interaction of primaquine (PQ), chloroquine (CQ), and liposomes to support the design of optimal liposomal delivery for hepatic stage malaria infectious disease. The liposomes were composed of hydrogenated soybean phosphatidylcholine, cholesterol, and distearoyl-sn-glycero-3-phosphoethanolamine-N-(methoxy[polyethyleneglycol]-2000), prepared by thin film method, then evaluated for physicochemical and spectrospic characteristics. The calcein release was further evaluated to determine the effect of drug co-loading on liposomal membrane integrity. The results showed that loading PQ and CQ into liposomes produced changes in the infrared spectra of the diester phosphate and carbonyl ester located in the polar part of the phospholipid, in addition to the alkyl group (CH₂) in the nonpolar portion. Moreover, the thermogram revealed the loss of the endothermic peak of liposomes dually loaded with PQ and CQ at 186.6 °C, which is identical to that of the phospholipid. However, no crystallinity changes were detected through powder X-ray diffraction analysis. Moreover, PQ, with either single or dual loading, produced the higher calcein release profiles from the liposomes than that of CQ. The dual loading of PQ and CQ tends to interact with the polar head group of the phosphatidylcholine bilayer membrane resulted in an increase in water permeability of the liposomes.

Azacarbazole n-3 and n-6 polyunsaturated fatty acids ethyl esters nanoemulsion with enhanced efficacy against Plasmodium falciparum

Alternative therapies are necessary for the treatment of malaria due to emerging drug resistance. However, many promising antimalarial compounds have poor water solubility and suffer from the lack of suitable delivery systems, which seriously limits their activity. To address this problem, we synthesized a series of azacarbazoles that were evaluated for antimalarial activity against D10 (chloroquine-sensitive) and W2 (chloroquine-resistant) strains of P. falciparum. The most active compound, 9H-3-azacarbazole (3), was encapsulated in a novel o/w nanoemulsion consisting of ethyl esters of polyunsaturated fatty acids n-3 and n-6 obtained from flax oil as the oil phase, Smix (Tween 80 and Transcutol HP) and water. This formulation was further analyzed using transmission electron microscopy, dynamic light scattering and in vitro and in vivo studies. It was shown that droplets of the 3-loaded nanosystem were spherical, with satisfactory stability, without cytotoxicity towards fibroblasts and intestinal cell lines at concentrations corresponding to twice the IC50 for P. falciparum. Moreover, the nanoemulsion with this type of oil phase was internalized by Caco-2 cells. Additionally, pharmacokinetics demonstrated rapid absorption of compound 3 (tmax = 5.0 min) after intragastric administration of 3-encapsulated nanoemulsion at a dose of 0.02 mg/kg in mice, with penetration of compound 3 to deep compartments. The 3-encapsulated nanoemulsion was found to be 2.8 and 4.2 times more effective in inhibiting the D10 and W2 strains of the parasite, respectively, compared to non-encapsulated 3. Our findings support a role for novel o/w nanoemulsions as delivery vehicles for antimalarial drugs.

Formulation and Characterization of Phytostanol Ester Solid Lipid Nanoparticles for the Management of Hypercholesterolemia: An ex vivo Study

BACKGROUND

Phytostanols are naturally occurring compounds that reduce blood cholesterol levels significantly. However, their aqueous insolubility poses formulation challenges.

AIM

To formulate and characterize solid lipid nanoparticle carriers for phytostanol esters to enhance the bioavailability of phytostanols.

METHODS

Phytostanol ester solid lipid nanoparticles were formulated by the microemulsion method. They were characterized for particle size distribution, polydispersity index, shape, surface charge, entrapment efficiency, stability, chemical structure, and thermal properties. The uptake of the formulation by cell lines, HepG2 and HT-29, and its effect on cell viability were evaluated.

RESULTS

The formulation of solid lipid nanoparticles was successfully optimised by varying the type of lipids and their concentration relative to that of surfactants in the present study. The optimised formulation had an average diameter of (171 ± 9) nm, a negative surface charge of (-23.0 ± 0.8) mV and was generally spherical in shape. We report high levels of drug entrapment at (89 ± 5)% in amorphous form, drug loading of (9.1 ± 0.5)%, nanoparticle yield of (67 ± 4)% and drug excipient compatibility. The biological safety and uptake of the formulations were demonstrated on hepatic and intestinal cell lines.

CONCLUSION

Phytostanol ester solid lipid nanoparticles were successfully formulated and characterized. The formulation has the potential to provide an innovative drug delivery system for phytostanols which reduce cholesterol and have a potentially ideal safety profile. This can contribute to better management of one of the main risk factors of cardiovascular diseases.

Co-transfection with BMP2 and FGF2 via chitosan nanoparticles potentiates osteogenesis in human adipose-derived stromal cells in vitro

OBJECTIVE

To investigate if co-transfection of human bone morphogenetic protein 2 (BMP-2, BMP2) and human fibroblast growth factor 2 (FGF2, FGF2) via chitosan nanoparticles promotes osteogenesis in human adipose tissue-derived stem cells (ADSCs) in vitro.

MATERIALS AND METHODS

Recombinant BMP2 and/or FGF2 expression vectors were constructed and packaged into chitosan nanoparticles. The chitosan nanoparticles were characterized by atomic force microscopy. Gene and protein expression levels of BMP-2 and FGF2 in ADSCs in vitro were evaluated by real-time polymerase chain reaction (PCR), western blot, and enzyme-linked immunosorbent assay. Osteocalcin (OCN) and bone sialoprotein (BSP) gene expression were also evaluated by real-time PCR to assess osteogenesis.

RESULTS

The prepared chitosan nanoparticles were spherical with a relatively homogenous size distribution. The BMP2 and FGF2 vectors were successfully transfected into ADSCs. BMP-2 and FGF2 mRNA and protein levels were significantly up-regulated in the co-transfection group compared with the control group. OCN and BSP mRNA levels were also significantly increased in the co-transfection group compared with cells transfected with BMP2 or FGF2 alone, suggesting that co-transfection significantly enhanced osteogenesis.

CONCLUSIONS

Co-transfection of human ADSCs with BMP2/FGF2 via chitosan nanoparticles efficiently promotes the osteogenic properties of ADSCs in vitro.

Formulation and evaluation of rutin-loaded solid lipid nanoparticles for the treatment of brain tumor

The primary requirement for curing cancer is the delivery of essential drug load at the cancer microenvironment with therapeutic efficacy. Considering this, the present study aims to formulate "Rutin"-encapsulated solid lipid nanoparticles (SLNs) for effective brain delivery across the blood-brain barrier (BBB). Rutin-loaded SLNs were fabricated by oil-in-water microemulsion technique and were characterized for their physicochemical properties. The in vivo biodistribution study of rutin-loaded SLNs was studied using Rattus norvegicus rats. Subsequently, in silico molecular docking and dynamic calculations were performed to examine the binding affinity as well as stability of rutin at the active site of target protein "epidermal growth factor receptor (EGFR)." Formulated rutin-loaded SLNs were predominantly spherical in shape with an average particle diameter of 100 nm. Additionally, the biocompatibility and stability have been proved in vitro. The presence and biodistribution of rutin in vivo after 54 h of injection were observed as 15.23 ± 0.32% in the brain, 8.68 ± 0.63% in the heart, 4.78 ± 0.28% in the kidney, 5.04 ± 0.37% in the liver, 0.92 ± 0.04% in the lung, and 11.52 ± 0.65% in the spleen, respectively. Molecular docking results revealed the higher binding energy of - 150.973 kJ/mol of rutin with EGFR. Molecular dynamic simulation studies demonstrated that rutin with EGFR receptor complex was highly stable at 30 ns. The observed results exemplified that the formulated rutin-loaded SLNs were stable in circulation for a period up to 5 days. Thus, rutin-encapsulated SLN formulations can be used as a promising vector to target tumors across BBB. Graphical abstract.

Efficient drug and gene delivery to liver fibrosis: rationale, recent advances, and perspectives

Liver fibrosis results from chronic damages together with an accumulation of extracellular matrix, and no specific medical therapy is approved for that until now. Due to liver metabolic capacity for drugs, the fragility of drugs, and the presence of insurmountable physiological obstacles in the way of targeting, the development of efficient drug delivery systems for anti-fibrotics seems vital. We have explored articles with a different perspective on liver fibrosis over the two decades, then collected and summarized the information by providing corresponding in vitro and in vivo cases. We have discussed the mechanism of hepatic fibrogenesis with different ways of fibrosis induction in animals. Furthermore, the critical chemical and herbal anti-fibrotics, biological molecules such as micro-RNAs, siRNAs, and growth factors, which can affect cell division and differentiation, are mentioned. Likewise, drug and gene delivery and therapeutic systems on in vitro and in vivo models are summarized in the data tables. This review article enlightens recent advances in emerging drugs and nanocarriers and represents perspectives on targeting strategies employed in liver fibrosis treatment.

Solid Lipid Nanoparticles Enhanced the Neuroprotective Role of Curcumin against Epilepsy through Activation of Bcl-2 Family and P38 MAPK Pathways

Oxidative stress of neurons caused by a series of complex neuropathological processes will induce certain neurodegenerative disorders including epilepsy. Curcumin (Cur) is an effective natural antioxidant compound; however, the poor bioavailability obstructs its neural protective applications. In this study, Cur is encapsulated in solid lipid nanoparticles (SLNs) for better neuroprotective efficacy. In vitro study certified that Cur-SLNs functioned obviously better against neuronal apoptosis than Cur, by significantly decreasing the level of free radical and reversing mitochondrial function through the activation of the Bcl-2 family. In vivo experiments showed that SLNs transported Cur through the blood-brain barrier (BBB). The behavioral performance of epileptic mice was improved by Cur-SLNs, with more NeuN but less TUNEL positive cells observed in hippocampus. The in vivo mechanism was also explored. Cur-SLNs reduced neuronal apoptosis through Bcl2 family and P38 MAPK pathways. Overall, Cur-SLNs have better protective effects toward oxidative stress in neurons than free Cur both in vitro and in vivo, which suggests they may be a promising agent against neurodegenerative disorders including epilepsy.

Climatic Conditions: Conventional and Nanotechnology-Based Methods for the Control of Mosquito Vectors Causing Human Health Issues

Climate variability is highly impacting on mosquito-borne diseases causing malaria and dengue fever across the globe. Seasonal variability change in temperature and rainfall patterns are impacting on human health. Mosquitoes cause diseases like dengue fever, yellow fever, malaria, Chikungunya, West Nile and Japanese encephalitis. According to estimations by health organizations, annually one million human deaths are caused by vector-borne diseases, and dengue fever has increased about 30-fold over the past 50 years. Similarly, over 200 million cases of malaria are being reported annually. Mosquito-borne diseases are sensitive to temperature, humidity and seasonal variability. Both conventional (environmental, chemical, mechanical, biological etc.) and nanotechnology-based (Liposomes, nano-suspensions and polymer-based nanoparticles) approaches are used for the eradication of Malaria and dengue fever. Now green approaches are used to eradicate mosquitoes to save human health without harming the environment. In this review, the impact of climatic conditions on mosquito-borne diseases along with conventional and nanotechnology-based approaches used for controlling malaria and dengue fever have been discussed. Important recommendations have been made for people to stay healthy.

Cloning and expression of L-asparaginase from Bacillus tequilensis PV9W and therapeutic efficacy of Solid Lipid Particle formulations against cancer

L-asparaginase, a therapeutic involved in cancer therapy, from Bacillus tequilensis PV9W (ansA gene) was cloned and over expressed in Escherichia coli BL21 (DE3), achieved the aim of maximizing the yield of the recombinant enzyme (6.02 ± 1.77 IU/mL) within 12 h. The native L-asparaginase of B. tequilensis PV9W was encapsulated using solid lipid particles by hot lipid emulsion method, which is reported for first time in this study. Subsequently, the lipid encapsulated L-asparaginase (LPE) was characterized by SEM, UV-Vis spectroscopy, FT-IR, SDS-PAGE and its thermo stability was also analyzed by TGA. Further characterization of LPE revealed that enzyme was highly stable for 25 days when stored at 25 °C, showed high pH (9) tolerance and longer trypsin half-life (120 min). In addition, the cytotoxic ability of LPE on HeLa cells was highly enhanced compared to the native L-asparaginase from Bacillus tequilensis PV9W. Moreover, better kinetic velocity and lower Km values of LPE aided to detect L-asparagine in cell extracts by Differential Pulse Voltammetry (DPV) method. The LPE preparation also showed least immunogenic reaction when tested on normal macrophage cell lines. This LPE preparation might thus pave way for efficient drug delivery and enhancing the stability of L-asparaginase for its therapeutic applications.

Nanodelivery systems and stabilized solid-drug nanoparticles for orally administered medicine: current landscape

The use of nanoparticles as a means of targeted delivery of therapeutics and imaging agents could greatly enhance the transport of biologically active contents to specific target tissues, while avoiding or reducing potentially undesired side effects. Generally speaking, the oral route of administration is associated with good patient compliance, as it is convenient, economical, noninvasive, and does not require special training. Here, we review the progress of the utilization of nanodelivery-system carriers or stabilized solid-drug nanoparticles following oral administration, with particular attention on toxicological data. Mechanisms of cytotoxicity are discussed and the problem of extrapolating knowledge to human scenarios highlighted. Additionally, issues associated with administration of drugs via the oral route are underlined, while strategies utilized to overcome these are highlighted. This review aims to offer a balanced overview of strategies currently being used in the application of nanosize constructs for oral medical applications.

Nanomedicines for Malaria Chemotherapy: Encapsulation vs. Polymer Therapeutics

Malaria is one of the oldest infectious diseases that afflict humans and its history extends back for millennia. It was once prevalent throughout the globe but today it is mainly endemic to tropical regions like sub-Saharan Africa and South-east Asia. Ironically, treatment for malaria has existed for centuries yet it still exerts an enormous death toll. This contradiction is attributed in part to the rapid development of resistance by the malaria parasite to chemotherapeutic drugs. In turn, resistance has been fuelled by poor patient compliance to the relatively toxic antimalarial drugs. While drug toxicity and poor pharmacological potentials have been addressed or ameliorated with various nanomedicine drug delivery systems in diseases like cancer, no clinically significant success story has been reported for malaria. There have been several reviews on the application of nanomedicine technologies, especially drug encapsulation, to malaria treatment. Here we extend the scope of the collation of the nanomedicine research literature to polymer therapeutics technology. We first discuss the history of the disease and how a flurry of scientific breakthroughs in the latter part of the nineteenth century provided scientific understanding of the disease. This is followed by a review of the disease biology and the major antimalarial chemotherapy. The achievements of nanomedicine in cancer and other infectious diseases are discussed to draw parallels with malaria. A review of the current state of the research into malaria nanomedicines, both encapsulation and polymer therapeutics polymer-drug conjugation technologies, is covered and we conclude with a consideration of the opportunities and challenges offered by both technologies.

The Next Generation Scientist program: capacity-building for future scientific leaders in low- and middle-income countries

BACKGROUND

Scientific and professional development opportunities for early career scientists in low- and middle- income countries (LMICs) are limited and not consistent. There is a disproportionately low number of biomedical and clinical researchers in LMIC's relative to their high burden of disease, a disparity that is aggravated by emigration of up to 70% of scientists from their countries of birth for education and employment elsewhere. To help address this need, a novel University-accredited, immersive fellowship program was established by a large public-academic-private network. We sought to describe the program and summarize progress and lessons learned over its first 7-years.

METHODS

Hallmarks of the program are a structured learning curriculum and bespoke research activities tailored to the needs of each fellow. Research projects expose the scientists to state-of-the-art methodologies and leading experts in their fields while also ensuring that learnings are implementable within their home infrastructure. Fellows run seminars on drug discovery and development that reinforce themes of scientific leadership and teamwork together with practical modules on addressing healthcare challenges within their local systems. Industry mentors achieve mutual learning to better understand healthcare needs in traditionally underserved settings. We evaluated the impact of the program through an online survey of participants and by assessing research output.

RESULTS

More than 140 scientists and clinicians from 25 countries participated over the 7-year period. Evaluation revealed strong evidence of knowledge and skills transfer, and beneficial self-reported impact on fellow's research output and career trajectories. Examples of program impact included completion of post-graduate qualifications; establishment and implementation of good laboratory- and clinical- practice mechanisms; and becoming lead investigators in local programs. There was a high retention of fellows in their home countries (> 75%) and an enduring professional network among the fellows and their mentors.

CONCLUSIONS

Our experience demonstrates an example for how multi-sectoral partners can contribute to scientific and professional development of researchers in LMICs and supports the idea that capacity-building efforts should be tailored to the specific needs of beneficiaries to be maximally effective. Lessons learned may be applied to the design and conduct of other programs to strengthen science ecosystems in LMICs.

In vitro evaluation of chloroquine-loaded and heparin surface-functionalized solid lipid nanoparticles

Background

Use of chloroquine, an otherwise safe and relatively affordable anti-malarial drug, was discontinued due to widespread prevalence of resistant parasites. Many entrant anti-malarial drugs for treatment of chloroquine resistant malaria raises the concerns of cost and safety among other challenges. Innovative ways of circumventing chloroquine resistance is of paramount importance. Such may include nanoparticulate delivery strategies and targeting. This study evaluated physicochemical properties and in vitro antiplasmodial activity of chloroquine encapsulated heparin functionalized solid lipid nanoparticles (CQ-Hep-SLNs) and non-heparin functionalized SLNs (CQ-SLN) against Plasmodium falciparum.

Methods

The modified double-emulsion solvent evaporation technique was used to prepare the nanoparticles. HPLC/UV was used to determine the in vitro drug release. The semi-automated micro-dilution technique was adapted in assessing the in vitro antiplasmodial activity to give drug concentration capable of inhibiting 50% of the P. falciparum (IC₅₀), as a function of antiplasmodial efficacy.

Results

Prepared nanoparticles were below 500 nm in size with % drug loading (%DL) between 21 and 25% and encapsulation efficiency (%EE) of 78–90%. The drug-loaded SLN exhibited a biphasic drug release profile at pH 7.4, with an initial burst release during the first 24 h followed by sustained release in both formulations. Nanoformulated CQ-SLN (4.72 ± 0.14 ng/mL) and CQ-Hep-SLN (2.41 ± 0.27 ng/mL), showed enhanced in vitro antiplasmodial activities against chloroquine sensitive (D6) strain of P. falciparum, albeit with no activity against the chloroquine resistant W2 strain, compared to free CQ standard (5.81 ± 0.18 ng/mL).

Conclusions

These findings suggest that the nanoformulated drugs displayed enhanced anti-malarial activities against chloroquine sensitive (D6) strains of P. falciparum compared to the free CQ standard. There is some form of potential dual synergistic effect of CQ-loaded heparinized solid lipid nanoparticles (Hep-SLN), meaning that combining heparin and CQ in SLNs has beneficial effects, including potential for specific targeting of parasitized red blood cells as afforded by heparin. Thus, the study has produced SLNs nanoparticles that have superior in vitro activities than CQ on CQ-sensitive parasites.

Comparative Study of Glyceryl Behenate or Polyoxyethylene 40 Stearate-Based Lipid Carriers for Trans-Resveratrol Delivery: Development, Characterization and Evaluation of the In Vitro Tyrosinase Inhibition

Trans-resveratrol (RSV) is a natural compound with several properties, such as the ability to inhibit the tyrosinase enzyme, with potential application as a skin-lightning agent and for the treatment of skin disorders associated with hyperpigmentation and melanogenesis. However, the drug faces several drawbacks which altogether limit its therapeutic application. Thus, drug loading into nanocarriers emerge as an alternative to circumvent these problems. Herein, nanostructured lipid carriers (NLCs) have been employed for RSV encapsulation, with comparison of two different lipids, glyceryl behenate (more hydrophobic), and polyoxyethylene 40 (PEG 40) stearate. PEG 40 stearate-containing NLCs presented smaller particle size and polydispersity compared with glyceryl behenate, attributed to better emulsification and nanoparticle formation, resulting in higher RSV encapsulation efficiency. Drug was loaded in both carriers as a molecular dispersion. Furthermore, the formulations had very low RSV release, which occurred due to the crystallinity degree of lipid matrix, in accordance with the DSC data. Moreover, RSV cytotoxicity against L-929 cells was not increased when loaded into nanocarriers. Interestingly, RSV-loaded formulation prepared with PEG-40 stearate resulted on greater tyrosinase inhibition than RSV solution and formulation containing glyceryl behenate, equivalent to 1.31 and 1.83 times higher, respectively, demonstrating that the incorporation of RSV into NLC allowed an enhanced tyrosinase inhibitory activity. Overall, the results obtained herein evidence potential for future in vivo evaluation of RSV-loaded NLCs.

In Situ Hydrogel Formulation for Intra-Articular Application of Diclofenac Sodium-Loaded Polymeric Nanoparticles

Objectives

The world's population is getting older and the number of people suffering from arthritis is a major problem according to World Health Organization's data. In this respect, the need for more efficient treatment for arthritis becomes an urgent issue. In this research, nanoparticle bearing in situ gelling hydrogel formulation was developed for prolonged local delivery of diclofenac sodium (DS).

Materials and Methods

Emulsion-solvent evaporation technique was used for the preparation of nanoparticles. Particle size, encapsulation efficiency, morphology, and drug release profile of DS loaded biodegradable nanoparticles as well as gel viscosity and gelation time of in situ gelling hydrogel formulations were optimized to increase the time interval between each dose application for enhanced patience compliance.

Results

The spherical nanoparticles with a mean particle diameter of 168 nm was obtained and confirmed by both transmission electron microscope and atomic force microscope. Different types of surfactants were tested in the first emulsification step of nanoparticle production process and Arlacel^®-C significantly increased the encapsulation efficiency to 89.7%. Thirty days prolonged in vitro release of DS was achieved by using the combined formulation of polymeric nanoparticles and in situ hydrogel prepared by using poloxomer 407 and chitosan.

Conclusion

Local administration of DS with this novel delivery system could be considered of having potential to minimize side effects associated with decreased amount of drug in dosage form compared to conventional oral dose.

Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics

Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of −31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w/v) was screened as a cryoprotectant. Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffraction studies confirmed that the drug was encapsulated into SLNs in an amorphous form. The lyophilized powder was stable at both refrigeration (4°C) and ambient temperature (25°C) for 3 months, and the MTT assay demonstrated that the SLNs were nontoxic. The cellular uptake of fluorescein isothiocyanate-labeled SLNs in A549 cells was highly time dependent over a period of 3 hours, while the pharmacokinetic study in Sprague Dawley rats showed that the relative bioavailability of NRG-SLNs was 2.53-fold greater than that of NRG suspension after pulmonary administration. This study shows that SLNs offer a promising pulmonary delivery system to increase the bioavailability of the poorly water-soluble drug NRG.