Sustained-release Delivery System Research Articles

Composite whey protein–cellulose nanocrystals at oil-water interface: Towards delaying lipid digestion

Lipid digestion is an interfacial process that is largely controlled by the adsorption of lipase + colipase + bile salts onto the surface of the emulsified lipid droplets. Therefore, engineering oil-in-water (O/W) interfaces that prevent competitive displacement by bile salts and/or delay the transportation of lipase to the hydrophobic lipid core can be effective strategies to delay lipolysis. In this study, we present such an interface using composite protein-particle system, consisting of whey protein isolate (WPI) (1 wt%) + cellulose nanocrystals (CNCs) (1–3 wt%). Droplet size, microscopy at various length scales (confocal, electron microscopy), ζ-potential and kinetics of fatty acid release were used to assess how the presence of CNCs impacted the microstructural stability of the emulsions in in vitro duodenal conditions (pH 6.8, 37 ○C). Adding CNCs at sufficiently high concentrations (3 wt%) significantly decreased the rate and degree of lipolysis as compared to that of protein-coated emulsion droplets. The principal cause of this altered lipolysis profile was the binding of bile salts by CNCs, which restricted both the interfacial displacement and solubilisation of lipid-digestion products by bile salts. The CNCs can be envisaged to be strongly bound to the protein-coated droplets by virtue of hydrogen bonding with the underlying protein. Furthermore, the ability of the CNCs in the continuous phase to bridge several protein-coated droplets reduced the overall surface area available for the lipolysis. Composite WPI + CNC interface holds promise in designing physiologically relevant emulsions to target satiety or delivery systems for sustained release of lipophilic components.

Preparation and characterization of β-cyclodextrin grafted N-maleoyl chitosan nanoparticles for drug delivery

β-cyclodextrin (CD) grafted N-maleoyl chitosan (CD-g-NMCS) with two different degrees of substitution (DS) of N-maleoyl (DS = 21.2% and 30.5%) were synthesized from maleic anhydride and chitosan bearing pendant cyclodextrin (CD-g-CS). CD-g-NMCS based nanoparticles were prepared via an ionic gelation method together with chitosan and CD-g-CS nanoparticles. The size and zeta potential of prepared CD-g-NMCS nanoparticles were 179.2~274.0 nm and 36.2~42.4 mV, respectively. In vitro stability test indicated that CD-g-NMCS nanoparticles were more stable in phosphate-buffered saline compared with chitosan nanoparticles. Moreover, a poorly water-soluble drug, ketoprofen (KTP), was selected as a model drug to study the obtained nanoparticle's potentials as drug delivery carriers. The drug loading efficiency of CD-g-NMCS20 nanoparticles were 14.8% for KTP. MTT assay showed that KTP loaded CD-g-NMCS nanoparticles were safe drug carriers. Notably, in vitro drug release studies showed that KTP was released in a sustained-release manner for the nanoparticles. The pharmacokinetic of drug loaded CD-g-NMCS20 nanoparticles were evaluated in rats after intravenous administration. The results of studies revealed that, compared with free KTP, KTP loaded CD-g-NMCS20 nanoparticles exhibited a significant increase in AUC0→24h and mean residence time by 6.6-fold and 2.9-fold, respectively. Therefore, CD-g-NMCS nanoparticles could be used as a novel promising nanoparticle-based drug delivery system for sustained release of poorly water-soluble drugs. The carboxylic acid groups of the CD-g-NMCS molecule provide convenient sites for further structural modifications including introduction of tissue- or disease- specific targeting groups.

Film Forming Emulgel: An Overview

Sustained release delivery system with features of both semisolid formulations And patches has been employed in the formulation of film forming emulgel. The concept of film forming formulation is very recent. Film forming formulations may be solutions, gel o emulsions. Film forming formulations are defined as non solid dosage forms that produce a substantial film in situ after application on the skin or any other body surface. Such a compositions can either be liquid or semisolids with a film forming polymers as basic materials for the matrix. He formed film is sufficiently substantial to provide a sustained drug release to the skin. Film forming emulgels are emulsions, either of the oil-in-water or water-in-oil type, which are gelled by mixing with a gelling agent. Film forming emulgel is stable one and better vehicle for hydrophobic or water insoluble drugs.

Sustained Release of Brimonidine from a New Composite Drug Delivery System for Treatment of Glaucoma.

A novel layered double hydroxide (LDH) nanoparticle/thermogel composite drug delivery system (DDS) for sustained release of brimonidine (Bri) has been designed, prepared, and characterized in this study for treatment of severe glaucoma. Brimonidine is first loaded onto LDH (Bri@LDH) nanoparticles, which are then dispersed in the thermogel consisting of plenty of micelles based on poly(dl-lactic acid-co-coglycolic acid)-polyethylene glycol-poly(dl-lactic acid-co-coglycolic acid) (PLGA-PEG-PLGA) copolymer. The Bri@LDH/Thermogel DDS containing 125.0 μg/g of brimonidine has been found to sustainably release the drug for up to 144 h, significantly extending the drug release period compared to that from Bri@LDH nanoparticles. The Bri@LDH/Thermogel DDS is not cytotoxic to human corneal epithelial cells and shows good biocompatibility. In vivo drug release from the special contact lens made of Bri@LDH/Thermogel DDS has been sustained for at least 7 days, which more effectively modulates the relief of intraocular pressure (IOP). Thus, the Bri@LDH/Thermogel DDS is a promising drug delivery alternative that can be used for treatment of severe glaucoma.

Liposomal delivery of ferrous chlorophyllin: A novel third generation photosensitizer for in vitro PDT of melanoma

BackgroundCutaneous melanoma (CM) has substantially increased among Caucasian populations in the past few decades. This increased the number of CM deaths throughout the world. Pigmentation of melanoma reduces the efficacy of photodynamic therapy (PDT). Third generation photosensitizers (PSs) are characterized by improved targeting to the diseased tissue and reduced systemic side effects. This study is directed towards synthesis and characterization of liposomes encapsulating sodium ferrous chlorophyllin (Fe-CHL) and assessing its efficacy as a PS in PDT of melanoma. MethodsPhenylthiourea (PTU) was used as a melanin synthesis inhibitor. PDT has been applied on de-pigmented melanoma cells using liposomes-encapsulated Fe-CHL. Cell death mechanisms after PDT were evaluated. ResultsTreatment of melanoma cells with 200μM of PTU for 48h provided 49.9% melanin inhibition without significant cytotoxicity. Transmission electron microscope (TEM) results proved an increase in the cellular uptake of liposomes by increasing incubation period from 6 to 24h via endocytosis with preferential accumulation in the mitochondria and the nucleus. Following de-pigmentation, PDT was applied resulting in LC50 of 18.20 and 1.77μM after 24 and 48h incubation with liposomes-encapsulated Fe-CHL respectively and exposure to 56.2J/cm2 monochromatic red laser of wavelength of 652nm. Mechanism of cell death of Fe-CHL mediated PDT was found to be a combination of both apoptosis and necrosis. ConclusionsLiposomes could be efficiently employed as a potential sustained release delivery system in the Fe-CHL-mediated PDT of de-pigmented melanoma.

PROCESS AND PARAMETERS AFFECTING DRUG RELEASE PERFORMANCE OF PREPARED CROSS-LINKED ALGINATE HYDROGEL BEADS FOR EZETIMIBE

<p><strong>Objective: </strong>The objective of this study was to formulate an oral sustained release delivery system of ezetimibe mucoadhesive beads by ionic gelation technique based on sodium alginate used as a hydrophilic carrier in combination with carbopol 934P which acts as a rate modifier.</p><p><strong>Methods: </strong>Microbeads of ezetimibe were prepared using an easy method of ionotropic gelation by little modification while in addition of drug. The prepared beads were characterised for mean particle size, entrapment efficiency, swelling capacity, and <em>in vitro</em> release. They were also subjected to various studies such as Fourier Transform Infrared Spectrophotometer (FTIR) Spectroscopy for drug polymer reaction, Scanning Electron Microscopy for surface morphology, and Differential Scanning Calorimetric Analysis to determine the physical state of the drug in the beads.</p><p><strong>Results</strong>:<strong> </strong>The microspheres of ezetimibe were formulated successfully. The addition of drug concentration gives higher drug loading and higher conc. of Alcl<sub>+3</sub> yields small diameter beads and lower drug entrapment. Analysis of the release profiles showed that the data corresponds to zero order release and the diffusion-controlled mechanism as suggested by Higuchi concept.</p><p><strong>Conclusion</strong>:<strong> </strong>It can be concluded that beads produced by the sequential method had higher drug entrapment. Beads produced by simultaneous yields larger beads in diameter. The concept was cleared that drug release was dependent upon the quantity of polymer and increase in conc. of. aluminium chloride retarded the drug release in the sequential method. Prepared beads enhance the dissolution of ezetimibe and the oral bioavailability and also reduce the fluctuations in the oral bioavailability.</p>

Hydrogels based on copolymers of 2‐hydroxyethylmethacrylate and 2‐hydroxyethylacrylate as a delivery system for proteins: Interactions with lysozyme

ABSTRACTHydrogels have attracted considerable attention due to numerous applications, in particular as contact lenses and carriers for sustained drug delivery. The aim of the present work is to characterize the interactions of copolymer hydrogels consisted of 2‐hydroxyethylmethacrylate (HEMA) and 2‐hydroxyethylacrylate (HEA) with a small protein (lysozyme) and to assess the potential applications of these hydrogels as a drug delivery system for sustained release of protein‐based therapeutics. Physicochemical properties of protein‐loaded hydrogels, as well as lysozyme in vitro loading and release and the conformation of the protein released from hydrogels were studied. The effect of copolymer composition on the protein deposition on hydrogels and protein aggregation in the presence of hydrogels was also assessed. The results show that introduction of HEA into the copolymeric hydrogels enhances their suitability as a delivery system for proteins. Copolymerisation of HEMA and HEA allows controlling the physicochemical properties of hydrogels and the protein release rate. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44768.

Sustained-Release Delivery System of a Slow Hydrogen Sulfide Donor, GYY 4137, for Potential Application in Glaucoma.

Hydrogen sulfide (H2S) targets both underlying factors in glaucoma pathogenesis by reducing elevated intraocular pressure (IOP) and providing retinal neuroprotection, whereas the current clinical approaches targets only reducing IOP. Therefore, H2S could be a potential superior candidate for glaucoma pharmacotherapy. However, H2S could be toxic in a concentration greater than 200μM and its donors are unstable in water. Therefore, this study investigated the preparation and characterization of a non-aqueous in situ gelling sustained-release delivery system for H2S donors. The delivery system was prepared by dissolving GYY 4137, a H2S donor, in poly lactide-co-glycolide polymer (PLGA) (Resomer® RG 502H) solution prepared by dissolving polymer in a mixture of benzyl alcohol and benzyl benzoate in a ratio of 7:3, respectively. The GYY 4137 formulation was characterized for syringeability/injectability, change in pH and tonicity, moisture content, GYY 4137 degradation, and toxicity using rheometer, pH and osmometer, Karl Fisher titrimeter, NMR spectrometer, and Y79 retinoblastoma cells, respectively. The formulation was easily syringeable and injectable as evidenced by rheological data (plastic flow pattern with 43.89 ± 3.21cP viscosity and 1.12 ± 0.15Pa yield value). The pH, tonicity, and moisture content values were within acceptable range. NMR spectroscopy indicated presence of 4-methoxyphenylphosphonic acid (GYY 4137 degradation product). The GYY 4137 formulation did not show any significant (p < 0.05) toxicity except the solvent mixture. A sustained release of H2S was observed up to 72h. The in situ gel forming PLGA-based system can be manipulated to achieve sustained release of H2S from its donor GYY 4137.

Development and In Vitro Evaluation of Liposomes Using Soy Lecithin to Encapsulate Paclitaxel

The formulation of a potential delivery system based on liposomes (Lips) formulated from soy lecithin (SL) for paclitaxel (PTX) was achieved (PTX-Lips). At first, PTX-Lips were prepared by thin film method using SL and cholesterol and then were characterized for their physiochemical properties (particle size, polydispersity index, zeta potential, and morphology). The results indicated that PTX-Lips were spherical in shape with a dynamic light scattering (DLS) particle size of 131 ± 30.5 nm. Besides, PTX was efficiently encapsulated in Lips, 94.5 ± 3.2% for drug loading efficiency, and slowly released up to 96 h, compared with free PTX. More importantly, cell proliferation kit I (MTT) assay data showed that Lips were biocompatible nanocarriers, and in addition the incorporation of PTX into Lips has been proven successful in reducing the toxicity of PTX. As a result, development of Lips using SL may offer a stable delivery system and promising properties for loading and sustained release of PTX in cancer therapy.

In vitro study on the osteogenesis enhancement effect of BMP-2 incorporated biomimetic apatite coating on titanium surfaces.

To fabricate a sustained-release delivery system of bone morphogenetic protein (BMP-2) on titanium surface, explore the effect of BMP-2 concentration on the loading/release behavior of BMP-2 and evaluate the cell compatibility of the system in vitro, pure titanium specimens were immersed into supersaturated calcium phosphate solutions (SCP) containing 4 different concentrations of BMP-2: 0, 50, 100, 200 and 400 ng/mL. Biomimetic calcium phosphate coating was formed on titanium surface and BMP-2 was incorporated into the coating through co-deposition. The release profile of BMP-2 suggested that BMP-2 were delivered sustainably up to 20 days. CCK-8 and ALP assay showed that 200 group and 400 ng/mL BMP-2 group have significant effect on promoting MC3T3-E1 cell proliferation and differentiation. The BMP-2 incorporated into the hybrid coating released in a sustained manner and significantly promoted the proliferation and differentiation of MC3T3-E1 on the titanium surface.

ABACAVIR LOADED NANOPARTICLES: PREPARATION, PHYSICOCHEMICAL CHARACTERIZATION AND IN VITRO EVALUATION

Objectives: Abacavir is a nucleoside analog reverse transcriptase inhibitor (NRTI), antiretroviral drug; it is used in treatment of AIDS. The present study deals with the formulation and evaluation of Abacavir nanoparticles. Methods: Abacavir nanoparticles were formulated by solvent displacement method using Eudragit RL-100, chitosan and Poloxamer-188. Nanoparticles were characterized by determining its particle size, drug entrapment efficiency, particle morphological character and in-vitro drug release. Results: Particle size range of nanoparticles was in the range of 121.4-140.6 nm. Zeta potential of formulations was determined, and it was found in range of 16.5-20.45 mv. The in-vitro release of nanoparticles were carried out which exhibited a sustained release of Abacavir from nanoparticles up to 10 hrs. Conclusion: The study concludes that nanoparticles can be a promising drug delivery system for sustained release of Abacavir in terms of increased bioavailability. Peer Review History: Article received on- 15 November Revised on- 10 December Accepted on- 15 December, Available online 15 January 2017 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 4.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Kingsley C Anukam, University of Benin, Nigeria, kanukam@gmail.com Dr. Iman Muhammad Higazy, National Research Center, Egypt, imane.higazy@hotmail.com Similar Articles: NANOSPONGES: A NEW ERA OF VERSATILE DRUG DELIVERY SYSTEM

Preparation and evaluation of a thermosensitive liposomal hydrogel for sustained delivery of danofloxacin using mesoporous silica nanoparticles

Background: Sustained release delivery system can reduce the dosage frequency and maintain the therapeutic level of drugs for a longer time. Biodegradable, biocompatible and thermosensitive chitosan-beta-glycerophosphate (C-GP) solutions can solidify at body temperature and maintain their physical integrity for a longer duration. OBJECTIVES: To develop a novel delivery system based on the integration of liposomes in hydrogel using mesoporous silica nanoparticles (MSNs) for sustained release of danofloxacin in farm animals. METHODS: The MSNs were prepared using N-cetyltrimethylammonium bromide and tetraethylortho silica. The liposomes were prepared by thin film hydration method. C-GP solution containing danofloxacin-loaded MSN liposomes underwent different in-vitro tests, including evaluation of the entrapment efficiency, gelation time, morphology, drug release pattern as well as antimicrobial activities against S. aureus and E. coli. RESULTS: The mean pore size of MSNs was 2.8 nm and the mean MSN entrapment efficiency was 45%. Kinetics of danofloxacin release from liposomal hydrogel followed the Higuchi’s model. This formulation was capable of sustaining the danofloxacin release for more than 96 h. The FTIR studies showed that there were no interactions between danofloxacin and hydrogel excipients. Scanning electron microscopy (SEM) showed that the formed gel had a continuous texture, while the swelled gel in the phosphate buffer had a porous structure. Microbiological tests revealed a high antibacterial activity for lipomosal hydrogel of danofloxacin-loaded MSN comparable with danofloxacin solution. CONCLUSIONS: The liposomal hydrogel solidified at body temperature, effectively sustained the release of danofloxacin and showed in vitro antibacterial effects.

A review of materials used as carrier agents in pesticide formulations

Development of environmentally-friendly pesticides for sustainable agriculture is a key focus in the agrochemical industry. Identifying novel active ingredients and improving the delivery system of a pesticide are the main challenges in developing new pesticides. Strategies for the control of delivery systems for slow and sustained release of agrochemicals are of great interest to environmental scientists. In this context, the selection of materials to be used as carrier agents in pesticide formulations is crucial. In recent years, the efficacy of several materials for agrochemical formulations has been evaluated by researchers. These materials have unique properties, such as being biodegradable and biocompatible, and having low toxicity and involving a simple preparation process. This review summarises recent applications of various materials in pesticide formulations. The application of the materials can effectively encapsulate or bind the pesticide’s active ingredients in the material’s matrix with a sustained release profile and slow mobility in soil. This review also discusses some issues and concerns that are faced in formulating pesticide products.

Preparation and In Vitro Evaluation of Resealed Erythrocytes as A New Trend in Treatment of Asthma

Carrier erythrocytes are emerging as one of the most promising biological drug delivery systems investigated in recent decades. Beside its biocompatibility, biodegradability and ability to circulate throughout the body, it has the ability to perform extended release system of the drug for a long period. The ultimate goal of this study is to introduce a new carrier system for Salbutamol, maintaining suitable blood levels for a long time, as atrial to resolve the problems of nocturnal asthma medication Therefore in this work we study the effect of time, temperature as well as concentration on the loading of salbutamol in human erythrocytes to be used as systemic sustained release delivery system for this drug. After the loading process is performed the carrier erythrocytes were physically and cellulary characterized. Also, the in vitro release of salbutamol from carrier erythrocytes was studied over time interval. From the results it was found that, human erythrocytes have been successfully loaded with salbutamol using endocytosis method either at 25 Co or at 37 Co . The highest loaded amount was 3.5 mg/ml and 6.5 mg/ml respectively. Moreover, the percent of cells recovery is 90.7± 1.64%. Hematological parameters and osmotic fragility behavior of salbutamol loaded erythrocytes were similar that of native erythrocytes. Scanning electron microscopy demonstrated that the salbutamol loaded cells has moderate change in the morphology. Salbutamol releasing from carrier cell was 43% after 36 hours in phosphate buffer saline. The releasing pattern of the drug from loaded erythrocytes showed initial burst release in the first hour followed by a very slow release, obeying zero order kinetics. It concluded that salbutamol is successfully entrapped into erythrocytes with acceptable loading parameters and moderate morphological changes, this suggesting that erythrocytes can be used as prolonged release carrier for salbutamol.

Release behaviour of amoxicillin from chitosan coated liposomes derived from eggs

A delivery system consisting of chitosan coated liposomes was tested for its ability to deliver drugs over a period of time. Amoxicillin was used as the drug of choice and was entrapped in liposomes made of egg yolk lecithin and coated with chitosan with the aid of Tween 80 and sodium tripolyphosphate. These nanoparticles were monitored for the release of the drug in vitro . The activity of the released amoxicillin was measured against Staphylococcus aureus (NCTC-6571 strain) in BHI broth medium. The percentage of drug released with time was measured by HPLC. The nanoparticles showed sustained release of amoxicillin over a period of 24 hours. Approximately 80 % of the encapsulated drug was released in the first 10 hours. A sufficient drug release to kill the bacteria was obtained in 4 hours and a steady increase in drug concentration was observed up to 8 hours of testing. This study has enabled the model formulation of a sustained release delivery system for amoxicillin in vitro capable of delivering the drug over a period of 8 hours, which may enable drug activity such that the number of times of administration is reduced.

Preparation and evaluation of a phospholipid-based injectable gel for the long term delivery of leuprolide acetate

A phospholipid-based injectable gel was developed for the sustained delivery of leuprolide acetate (LA). The gel system was prepared using biocompatible materials (SPME), including soya phosphatidyl choline (SPC), medium chain triglyceride (MCT) and ethanol. The system displayed a sol state with low viscosity in vitro and underwent in situ gelation in vivo after subcutaneous injection. An in vitro release study was performed using a dialysis setup with different release media containing different percentages of ethanol. The stability of LA in the SPME system was investigated under different temperatures and in the presence of various antioxidants. In vivo studies in male rats were performed to elucidate the pharmacokinetic profiles and pharmacodynamic efficacy. A sustained release of LA for 28 days was observed without obvious initial burst in vivo. The pharmacodynamic study showed that once-a-month injection of LA-loaded SPME (SPME-LA) led to comparable suppression effects on the serum testosterone level as observed in LA solution except for the onset time. These findings demonstrate excellent potential for this novel SPME system as a sustained release delivery system for LA.

Reprint of “Soy glycinin as food-grade Pickering stabilizers: Part. III. Fabrication of gel-like emulsions and their potential as sustained-release delivery systems for β-carotene”

Formulation of food-grade Pickering emulsions has attracted growing attention in the food and drug fields, due to their promising potential as novel delivery systems for lipophilic bioactive ingredients. The present work reported that a kind of gel-like Pickering emulsions stabilized by heat (at 100 °C)-treated soy glycinin (SG; a major globulin in soy proteins), fabricated by modulating protein concentration (c) and/or oil fraction (ϕ), can perform as sustained release delivery systems for β-carotene. Rheological measurements and microstructural observations indicated that increasing c and/or ϕ resulted in a progressive strengthening of gel-like network in the emulsions stabilized by heated SG, which was closely related to a high percentage of proteins adsorbed at the interface, or entrapped within the network. In contrast, no distinct gel formation was observed for the emulsions stabilized by unheated SG. In vitro intestinal digestion experiments showed that for the emulsions (stabilized by unheated or heated SG) without distinct gel formation, the release behavior of β-carotene was mainly determined by droplet size, while in the case of gel-like emulsions by heated SG, the gel-like network formation greatly slowed down the β-carotene release (irrespective of the applied c and/or ϕ). All the test emulsions did not suffer a distinct degradation of β-carotene over the whole digestion process. The findings are of great interest for the development of novel sustained delivery systems for lipophilic components, based on Pickering emulsions stabilized by a kind of protein-based particle stabilizers.

Expression analysis of Sox9 genes during annual reproductive cycles in gonads and after nanodelivery of LHRH in Clarias batrachus

Transcription factor Sox9 plays a crucial role in determining the fate of several cell types and is a primary factor in regulation of gonadal development. Present study reports full-length cDNA sequence of Sox9a gene and partial coding sequence (cds) of Sox9b (two duplicate orthologs of Sox9 gene) from Clarias batrachus. The coding region of Sox9a gene encoded a peptide of 460 amino acids. The partial cds of Sox9b with the length of 558bp was amplified that codes for 186 amino acids. Quantitative Real-time PCR (qRT-PCR) analysis revealed that Sox9a and Sox9b mRNA expression was significantly higher in gonads and brain tissues. Furthermore Sox9a and Sox9b mRNA expression levels were high during preparatory and pre-spawning phases and decreased gradually with onset of spawning and post-spawning phases of reproductive cycles in gonads. Chitosan nanoconjugated sLHRH (CsLHRH) of particle size 133.0nm and zeta potential of 34.3mV were synthesized and evaluated against naked sLHRH (salmon luteinizing hormone-releasing hormone). The entrapment efficiency of CsLHRH was 63%. CsLHRH nanoparticles increased the expression level of Sox9 transcripts in gonads and steroid hormonal levels in blood of male and female. Thus, our findings clearly indicate that Sox9 genes play essential role during seasonal variation of gonads. Besides, the current study reports that sustained release delivery-system will be helpful for proper gonadal development of fish. To the best of our knowledge, till date no study has been reported on nanodelivery of sLHRH and their effect on reproductive gene expression in fish.

Molecular characterization of kisspeptin gene and effect of nano–encapsulted kisspeptin-10 on reproductive maturation in Catla catla

Kisspeptin, a member of the RF-amide–related peptide family, has emerged recently as an essential gatekeeper of various reproductive processes via its ability to activate kisspeptin receptors at puberty. In this study, the kiss1 gene and its receptor kiss1rb were cloned and characterized from the brain of Catla catla. Further, the effects of kissppetin-10 (K-10) and chitosan–encapsulated K-10 nanoparticles (CK-10) on gene expression were assessed. The full-length complementary DNA sequence of kiss1 is 754 bp with an open reading frame of 351 bp that encodes a putative protein of 116 amino acids. The kiss1rb complementary DNA is 1,280 bp long and contains a 5′-untranslated region of 30 bp, 3′-untranslated region of 149 bp, and an open reading frame (open reading frame) of 1,101 bp. The expression patterns of kiss1 and kiss1rb messenger RNA (mRNA) in basal tissues revealed that they are mainly expressed in the brain, pituitary gland, and gonads. CK-10 nanoparticles with a particle size of 125 nm and a zeta potential of 36.45 mV were synthesized and compared with K-10. Chitosan nanoparticles showed 60% entrapment efficiency for K-10. The mRNA expression of reproductive genes (GnRH, LH, and FSH) in fish injected with K-10 declined after 6 h, whereas those injected with CK-10 showed controlled and a sustained surge of mRNA expression of these genes with a peak at 12 h. Histologic examination of ovaries indicated a pronounced effect of CK-10 on maturation and gonadal development. The study reports that this sustained release delivery system will help in increasing the half-life of K-10 and other therapeutic protein drugs in the biological system. Besides, the nanoformulation developed in the present study may be useful for developing therapies against various reproductive dysfunctions in vertebrates.

Soy glycinin as food-grade Pickering stabilizers: Part. III. Fabrication of gel-like emulsions and their potential as sustained-release delivery systems for β-carotene

Formulation of food-grade Pickering emulsions has attracted growing attention in the food and drug fields, due to their promising potential as novel delivery systems for lipophilic bioactive ingredients. The present work reported that a kind of gel-like Pickering emulsions stabilized by heat (at 100 °C)-treated soy glycinin (SG; a major globulin in soy proteins), fabricated by modulating protein concentration (c) and/or oil fraction (ϕ), can perform as sustained release delivery systems for β-carotene. Rheological measurements and microstructural observations indicated that increasing c and/or ϕ resulted in a progressive strengthening of gel-like network in the emulsions stabilized by heated SG, which was closely related to a high percentage of proteins adsorbed at the interface, or entrapped within the network. In contrast, no distinct gel formation was observed for the emulsions stabilized by unheated SG. In vitro intestinal digestion experiments showed that for the emulsions (stabilized by unheated or heated SG) without distinct gel formation, the release behavior of β-carotene was mainly determined by droplet size, while in the case of gel-like emulsions by heated SG, the gel-like network formation greatly slowed down the β-carotene release (irrespective of the applied c and/or ϕ). All the test emulsions did not suffer a distinct degradation of β-carotene over the whole digestion process. The findings are of great interest for the development of novel sustained delivery systems for lipophilic components, based on Pickering emulsions stabilized by a kind of protein-based particle stabilizers.