Effects of caloric overload before caloric restriction in the murine heart.

The beneficial effects of caloric restriction (CR) against cardiac aging and for prevention of cardiovascular diseases are numerous. However, to our knowledge, there is no scientific evidence about how a high-calorie diet (HCD) background influences the mechanisms underlying CR in whole heart tissue (WHT) in experimental murine models. In the current study, CR-treated mice with different alimentary backgrounds were subjected to transthoracic echocardiographic measurements. WHT was then analyzed to determine cardiac energetics, telomerase activity, the expression of energy-sensing networks, tissue-specific adiponectin, and cardiac precursor/cardiac stem cell markers. Animals with a balanced diet consumption before CR presented marked cardiac remodeling with improved ejection fraction (EF) and fractional shortening (FS), enhanced OXPHOS complex I, III, and IV, and CKMT2 enzymatic activity. Mice fed an HCD before CR presented moderate changes in cardiac geometry with diminished EF and FS values, but improved OXPHOS complex IV and CKMT2 activity. Differences in cardiac remodeling, left ventricular systolic/diastolic performance, and mitochondrial energetics, found in the CR-treated mice with contrasting alimentary backgrounds, were corroborated by inconsistencies in the expression of mitochondrial-biogenesis-related markers and associated regulatory networks. In particular, disruption of eNOS and AMPK -PGC-1α-mTOR-related axes. The impact of a past habit of caloric overload on the effects of CR in the WHT is a scarcely explored subject that requires deeper study in combination with analyses of other tissues and organs at higher levels of organization within the organ system. Such research will eventually lead to the development of preventative and therapeutic strategies to promote health and longevity.

Development and Evaluation of Curcumin Encapsulated Self-assembled Nanoparticles as Potential Remedial Treatment for PCOS in a Female Rat Model.

PURPOSE: Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies affecting women of reproductive age and leads to metabolic disorders and infertility. The present study was conducted to investigate the therapeutic effects of curcumin (Cur) encapsulated arginine (Arg) and N-acetyl histidine (NAcHis) modified chitosan (Arg-CS-NAcHis/Cur) nanoparticles (NPs). METHODS: In this study, amphiphilic chitosan (CS) conjugate was developed by modification with hydrophilic arginine (Arg) and hydrophobic N-acetyl histidine (NAcHis) group (Arg-CS-NAcHis). The synthesized conjugate was well characterized by FTIR and NMR studies. Self-assembled nanoparticles based on the synthesized conjugate were developed by simple sonication method and characterized for the physicochemical properties of zeta potential, particle size and drug encapsulation. Next, in vitro drug release, cytotoxicity, and cellular uptake studies of the NPs were evaluated. Finally, the developed nanoparticles were examined for their therapeutic potential against estradiol valerate (EV) induced PCOS rats by evaluating hormone level changes and ovarian morphology. RESULTS: The results showed that zeta potential of the nanoparticles was 39.8±2.52 mV and the average size was 200 nm. The in vitro drug release profile showed sustained release pattern. Cytotoxicity and cellular uptake studies also showed preferential effectiveness than free curcumin. Both the biochemical and histopathological studies showed positive effects in reverting the symptoms of PCOS rats to normalcy. CONCLUSION: Curcumin encapsulated arginine and N-acetyl histidine modified chitosan (Arg-CS-NAcHis/Cur) nanoparticles have been successfully developed. The present study suggested that treatment of the nanoparticles might reverse many of the PCOS symptoms. Therefore, these nanoparticles might be used as promising new candidate for delivery of curcumin to treat PCOS.

The consequences of a high-calorie diet background before calorie restriction on skeletal muscles in a mouse model.

The beneficial effects of calorie restriction (CR) are numerous. However, there is no scientific evidence about how a high-calorie diet (HCD) background influences the mechanisms underlying CR on skeletal muscles in an experimental mouse model. Herein we present empirical evidence showing significant interactions between HCD (4 months) and CR (3 months). Pectoralis major and quadriceps femoris vastus medialis, in the experimental and control groups, displayed metabolic and physiologic heterogeneity and remarkable plasticity, according to the dietary interventions. HCD-CR not only altered genetic activation patterns of satellite SC markers but also boosted the expression of myogenic regulatory factors and key activators of mitochondrial biogenesis, which in turn were also associated with metabolic fiber transition. Our data prompt us to theorize that the effects of CR may vary according to the physiologic, metabolic, and genetic peculiarities of the skeletal muscle described here and that INTM/IM lipid infiltration and tissue-specific fuel-energy status (demand/supply) both hold dependent-interacting roles with other key anti-aging mechanisms triggered by CR. Systematic integration of an HCD with CR appears to bring potential benefits for skeletal muscle function and energy metabolism. However, at this stage of our research, an optimal balance between the two dietary conditions, where anti-aging effects can be accomplished, is under intensive investigation in combination with other tissues and organs at different levels of organization within the organ system.

Development of novel pH-sensitive thiolated chitosan/PMLA nanoparticles for amoxicillin delivery to treat Helicobacter pylori.

The cysteine conjugated chitosan/PMLA multifunctional nanoparticles were synthesized as targeted Nano-drug delivery system to eradicate Helicobacter pylori. Helicobacter pylori specifically express urea transport protein on its membrane to carrying urea to the cytoplasm urease to supply ammonia that protects bacteria in the acid environment of the stomach. The clinical suitability of topical antimicrobial agents is required to get rid of Helicobacter pylori inside the inflamed basal region. In this work, cysteine conjugated chitosan derivative, Cys-CS for their mucoadhesive and anticoagulant properties was designed and synthesized, for the preparation of multifunctional nanoparticles. The technique turned into optimized to prepare Cys-CS/PMLA nanoparticles for encapsulation of amoxicillin. The results showed that amoxicillin-Cys-CS/PMLA nanoparticles exhibit favorable pH-sensitive properties that could procrastinate the release of amoxicillin at gastric acid and allow the drug to deliver and target to Helicobacter pylori at its survival region efficiently. In comparison with unmodified amoxicillin-chitosan/PMLA nanoparticles, effective inhibition of Helicobacter pylori growth was observed for amoxicillin-Cys-CS/PMLA nanoparticles. These results indicate that the multifunctional amoxicillin-loaded nanoparticles have great potential for the effective treatment of Helicobacter pylori infection. They can also be used as pharmacologically powerful nanocarriers for oral targeted delivery of different therapeutic drugs to treat Helicobacter pylori.

Synthesis and evaluation of pH-sensitive, self-assembled chitosan-based nanoparticles as efficient doxorubicin carriers.

A novel pH-responsive polymer based on amphiphilic N-acetyl histidine and arginine-grafted chitosan was synthesized using N-acetyl histidine as hydrophobic segment and arginine as hydrophilic segment by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-mediated coupling reactions as anticancer drug delivery system for doxorubicin. The structure of the synthesized polymer was confirmed by Fourier transform infrared and 1H nuclear magnetic resonance analysis. Due to self-association behavior, N-acetyl histidine and arginine-grafted chitosan structured nanoparticles with in size range of 204 nm. N-acetyl histidine and arginine-grafted chitosan with different substitution degree of N-acetyl histidine were initially prepared and characterized. The critical micelle concentration decreased with increasing substitution degree of N-acetyl histidine. Furthermore, N-acetyl histidine and arginine-grafted chitosan nanoparticles exhibited an acidic pH-triggered aggregation and disassembling nature. The doxorubicin-encapsulated nanoparticles based on synthesized conjugate ( N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles) showed a sustained drug release pattern, which could be hastened under acidic pH conditions but delayed with increasing substitution degree of N-acetyl histidine. Anticancer effects demonstrated that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles could suppress both sensitive and resistant human breast tumor cell line (MCF-7) efficiently in a dose- and time-dependent pattern. Confocal microscopy results evidenced increased cellular uptake and enhanced retention of the synthesized nanoparticles in drug-resistant cells demonstrating better efficacy of nanoparticles over native doxorubicin. These results suggest that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles might be promising carriers for delivery of hydrophobic drug doxorubicin against drug-resistant tumors.

Isolation, Characterization and Evaluation of Collagen from Jellyfish Rhopilema esculentum Kishinouye for Use in Hemostatic Applications.

Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM). Collagen sponges exhibited higher water absorption rates than medical gauze and EDC/NHS cross-linking method could improve the stability of the collagen sponges. Compared with medical gauze groups, the blood clotting indexes (BCIs) of collagen sponges were significantly decreased (P < 0.05) and the concentration of collagen also had an influence on the hemostatic property (P < 0.05). Collagen sponges had an improved hemostatic ability compared to the gauze control in tail amputation rat models. Hemostatic mechanism studies showed that hemocytes and platelets could adhere and aggregate on the surface of collagen sponge. All properties make jellyfish collagen sponge to be a suitable candidate used as hemostatic material and for wound healing applications.

Preparation and characterization of polyelectrolyte complex nanoparticles based on poly (malic acid), chitosan. A pH-dependent delivery system.

The main objective of this work was to develop polyelectrolyte complex (PEC) nanoparticles based on poly (malic acid), chitosan (PMLA/CS) as pH-dependent delivery systems. The results indicated that the PMLA/CS Nps were successfully prepared. The prepared PMLA/CS Nps showed spherical morphology with a mean diameter of 212.81 nm and negative surface charge of -24.60 mV, and revealing significant pH-sensitive properties as the mass ratio of PMLA to CS was 5:5. The prepared PMLA/CS Nps were characterized by FT-IR, TEM and DLS. The prepared PMLA/CS Nps remained stable over a temperature range of 4-53 °C. Doxorubicin (Dox) as a model drug was loaded on the nanoparticles through the physical adsorption method. The high drug loading efficiency (16.9%) and the sustained release patterns in acidic media were observed, and the release accelerated in alkaline solutions. MTT based cytotoxic analysis also depicted the non-toxic nature of PMLA/CS Nps, while Dox-PMLA/CS Nps showed dose-dependent cytotoxicity towards MDA-MB-231 cells. Hence, the nanoparticles could be potentially applied as pH sensitive drug vehicles for controlled release.

Multilayer micro-dispersing system as oral carriers for co-delivery of doxorubicin hydrochloride and P-gp inhibitor.

The primary constraints for efficient oral delivery of anticancer drugs include the efflux pump function of the multidrug transporter P-glycoprotein (P-gp) for anticancer drugs and the barriers to drug absorption in gastrointestinal (GI) tract. To improve bypassing P-gp drug efflux pumps and oral bioavailability of doxorubicin hydrochloride (DOX), Multilayer micro-dispersing system (MMS) was constructed by co-immobilization of DOX loaded chitosan/carboxymethyl chitosan nanogels (DOX:CS/CMCS-NGs), along with quercetin (Qu) in the core of multilayer sodium alginate beads (DOX:NGs/Qu-M-ALG-Beads). The obtained DOX:NGs/Qu-M-ALG-Beads possessed layer-by-layer structure and porous core with many nanoscale particles. The swelling characteristic and drug release results indicated that DOX:NGs/Qu-M-ALG-Beads exhibited favorable gastric acid tolerance and targeting release of intact DOX:CS/CMCS-NGs and Qu in small intestine. After oral administration of DOX:NGs/Qu-M-ALG-Beads in rats, DOX was effectively delivered into systemic circulation due to P-gp inhibitory properties of Qu. The absolute bioavailability reached 55.75%, about 18.65 folds higher than oral DOX. Tissue distribution results showed that the liver exhibited the highest DOX level, followed by kidney, heart, lung, and spleen. These results implied that DOX:NGs/Qu-M-ALG-Beads had great potential to be applied as dual drug delivery for oral chemotherapy.

Self-assembled nanoparticles based on amphiphilic chitosan derivative and arginine for oral curcumin delivery.

Curcumin (Cur) is a striking anticancer agent, but its low aqueous solubility, poor absorption, hasty metabolism, and elimination limit its oral bioavailability and consequently hinder its development as a drug. To redress these limitations, amphiphilic chitosan (CS) conjugate with improved mucoadhesion and solubility over a wider pH range was developed by modification with hydrophobic acrylonitrile (AN) and hydrophilic arginine (Arg); the synthesized conjugate (AN-CS-Arg), which was well characterized by Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy. Results of critical aggregation concentration revealed that the AN-CS-Arg conjugate had low critical aggregation concentration and was prone to form self-assembled nanoparticles (NPs) in aqueous medium. Cur-encapsulated AN-CS-Arg NPs (AN-CS-Arg/Cur NPs) were developed by a simple sonication method and characterized for the physicochemical parameters such as zeta potential, particle size, and drug encapsulation. The results showed that zeta potential of the prepared NPs was 40.1±2.81 mV and the average size was ~218 nm. A considerable improvement in the aqueous solubility of Cur was observed after encapsulation into AN-CS-Arg/Cur NPs. With the increase in Cur concentration, loading efficiency increased but encapsulation efficiency decreased. The in vitro release profile exhibited sustained release pattern from the AN-CS-Arg/Cur NPs in typical biological buffers. The ex vivo mucoadhesion study revealed that AN-CS-Arg/Cur NPs had greater mucoadhesion than the control CS NPs. Compared with free Cur solution, AN-CS-Arg/Cur NPs showed stronger dose-dependent cytotoxicity against HT-29 cells. In addition, it was observed that cell uptake of AN-CS-Arg/Cur NPs was much higher compared with free Cur. Furthermore, the in vivo pharmacokinetic results in rats demonstrated that the AN-CS-Arg/Cur NPs could remarkably improve the oral bioavailability of Cur. Therefore, the developed AN-CS-Arg/Cur NPs might be a promising nano-candidate for oral delivery of Cur.

Nanoparticles based on oleate alginate ester as curcumin delivery system.

Hydrophobic alginate derivative was prepared by the modification of alginate with methyl oleate. The synthesized oleate alginate ester (OAE) conjugate was characterized by FTIR and (1)HNMR analysis. Results of critical aggregation concentration (CAC) revealed that OAE conjugate had low CAC and was prone to form self-assembled nanoparticles in aqueous medium. Curcumin loaded OAE nanoparticles (Cur-OAE Nps) were developed by a simple sonication method and the physicochemical parameters of the nanoparticles such as zeta potential, size distribution and drug encapsulation were characterized. The results showed that zeta potential of the prepared nanoparticles was -55.4±0.91 mV and the average size was about 200 nm. A significant enhancement in aqueous solubility and stability of curcumin were observed after encapsulation into OAE nanoparticles. With the increase of curcumin concentration, loading efficiency increased but encapsulation efficiency decreased. The in vitro release profile exhibited significant sustained release pattern with initial burst release followed by a slower release over a period of one week. Cytotoxicity assay against MCF-7cells showed that Cur-OAE Nps had slow and continuous cytotoxic effect. Furthermore, in vitro cell uptake study revealed that cell uptake of curcumin from OAE nanoparticles was sustained and both were time and concentration dependent. Therefore, the developed Cur-OAE Nps might be promising candidates for curcumin delivery to cancer cells.