Alginate Nanoparticles Research Articles

Sodium alginate nanoparticles as a new transdermal vehicle of glucosamine sulfate for treatment of osteoarthritis

AbstractGlucosamine sulfate (GS) has been used orally for the treatment of osteoarthritis (OA). However, it may be susceptible to the liver first pass phenomenon, which greatly affects its bioavailability, in addition to its side effects on the gastrointestinal tract. Alginate nanoparticles (Alg NPs) were investigated as a new drug carrier for transdermal delivery of GS to improve its effectiveness and reduce side effects. GS-Alg NPs were characterized by encapsulation efficiency, NP yield, particle size and surface charge properties. The in vitro release studies of GS and the ex vivo permeability through rat skin were determined using a UV-Vis spectrophotometer. GS-Alg NPs are within the nanometer range of size. High negative surface charge values are obtained and indicate the high suspension stability of the prepared formulation. The in vitro release studies showed that GS is released from Alg NPs in a sustained and prolonged manner. The ex vivo permeability of GS through rat skin is enhanced significantly after encapsulation in the negatively charged Alg NPs. We successfully reported a highly stable nanoparticlulate system using Alg NPs that permits the encapsulation of GS for topical administration, overcoming the disadvantages of oral administration.

Influence of different classes of crosslinkers on alginate polyelectrolyte nanoparticle formation, thermodynamics and characteristics

Complexation of linear alginate polyanions with different classes of crosslinkers (divalent cations, polycations, positively charged surfactants) was investigated, to unravel their effects on nanoparticle formation. The goal was to define the crosslinker-to-alginate molar ratios at which nanoparticles are formed, and to reveal the underlying thermodynamics and molecular interactions using dynamic and electrophoretic light scattering, isothermal titration calorimetry, and infrared spectroscopy. Alginate nanoparticles were formed across a limited range of molar ratios that was specific for each crosslinker, and had different size and stability. Thermodynamic parameters of alginate complexation with crosslinkers showed that nanoparticle formation was in all cases entropy driven, together with a minor enthalpic contribution. The crosslinking mechanism was based on ionic interactions, with accompanying weaker interactions specific for each crosslinker, and involved characteristic macroscopic association constants (Ka1) for complexation of alginate (range, 104–109M−1). Additionally, the ionic strengths of the media influenced the characteristics and stabilities of the polyelectrolyte nanoparticles.

Removal of copper (II) from aqueous solutions by sodium alginate/hydroxy apatite hydrogel modified by Zeolite

The study presented in this article investigated the removal of copper ions from aqueous solutions by a synthetic hydrogel-forming adsorbent polymer based on sodium alginate (SA) and hydroxy apatite (HA) nanoparticles. The effect of adding Zeolite on the adsorption performance of this hydrogel was also investigated, and the optimum amount of Zeolite was determined by changing its quantity. The FTIR spectrum determined the structure of the synthesized adsorbent; non-continuous adsorption tests were performed to study the kinetics and thermodynamics of adsorption and also the recovery of the adsorbent. The degree of adsorption of the synthesized nanocomposite was compared with that of Zeolite, and the results showed that the maximum adsorption capacities of Zeolite and the nanocomposite for Cu ions were 29.7 and 75.8 mg/g, respectively. The kinetic studies indicated that the process of adsorption of Cu ions on both absorbents followed a pseudo second order kinetic equation. It took the Zeolite and the hydrogel 90 and 120 minutes, respectively, to reach equilibrium. The thermodynamic studies showed that Cu absorption by both adsorbents matched the Langmuir isotherm very well (R2=0.99). Since adsorbent recovery and its lifespan are of significant importance in absorption processes, recovery was carried out by hydrochloric acid (2% by weight). The repulsion coefficient of the recovered adsorbent and its efficiency in five recovery cycles were measured. The results of the tests indicated that the repulsion coefficient of Cu was 70-82.75 percent and the adsorption efficiency of Cu after 5 recovery cycles was 75 percent of the initial adsorbent.

Encapsulation of zidovudine in PF-68 coated alginate conjugate nanoparticles for anti-HIV drug delivery

Retroviral drug delivery faces many challenges due to its low bioavailability, short half life and hydrophobicity. In this study, the anti viral drug zidovudine (AZT) was encapsulated inside the amide functionalised alginate nanoparticles (AZT-GAAD NPs) using emulsion solvent evaporation method. The amide derivative of alginate was prepared by coupling reaction with d,l glutamic acid using carbodiimide activation chemistry. The stabilizer, PF-68 was integrated during the preparation of nanoparticles. The alginate nanoparticles were prepared via chemical cross linking. The novelty of this work imparts the absence of chemical cross-linking for the preparation of nanoparticles.The resulting nanoparticles had spherical shape with an average size of 432±11.9nm as confirmed by TEM images. The nanoparticles had a loading efficacy of 29.5±3.2% obtained by dialysis method. The release of AZT in PBS(pH-7.4) was studied and a slow and sustained release of AZT was observed. The nanoparticles were found to be biocompatible and in vitro cellular internalization studies indicated significantly higher internalization efficiency. All these results suggested that (AZT-GAAD NPs) can function as a promising delivery vectors for efficient antiviral drug delivery.

An Inexpensive, Point-of-Care Urine Test for Bladder Cancer in Patients Undergoing Hematuria Evaluation.

Although hematuria (blood in urine) is the most common symptom of bladder cancer, 70-98% of hematuria cases are benign. These hematuria patients unnecessarily undergo costly, invasive, and expensive evaluation for bladder cancer. Therefore, there remains a need for noninvasive office-based tests that can rapidly and reliably rule out bladder cancer in patients undergoing hematuria evaluation. Herein, a clinical assay for matrix metalloproteinases ("Ammps") is presented, which generates a visual signal based on the collagenase activity (in urine of patients) on the Ammps substrates. Ammps substrates are generated by crosslinking gelatin with Fe(II) chelated alginate nanoparticles, which precipitate in urine samples. The cleavage of gelatin-conjugated alginate (Fe(II)) nanoparticles by collagenases generates free-floating alginate (Fe(II)) nanoparticles that participate in Fenton's reaction to generate a visual signal. In a pilot study of 88 patients, Ammps had 100% sensitivity, 85% specificity, and a negative predictive value (NPV) of 100% for diagnosing bladder cancer. This high NPV can be useful in ruling out bladder cancer in patients referred for hematuria evaluation.

Autophagy promotes degradation of polyethyleneimine-alginate nanoparticles in endothelial progenitor cells.

Polyethyleneimine (PEI)–alginate (Alg) nanoparticle (NP) is a safe and effective vector for delivery of siRNA or DNA. Recent studies suggest that autophagy is related to cytotoxicity of PEI NPs. However, contribution of autophagy to degradation of PEI–Alg NPs remains unknown. CD34+VEGFR-3+ endothelial progenitor cells isolated from rat bone marrow were treated with 25 kDa branched PEI modified by Alg. After treatment with the NPs, morphological changes and distribution of the NPs in the cells were examined with scanning and transmission electron microscopies. Cytotoxicity of the NPs was analyzed by reactive oxygen species (ROS) production, lactate dehydrogenase leakage and induction of apoptosis. The level of autophagy was assessed with expression of Beclin-1 and LC3 and formation of autophagic structures and amphisomes. Colocalization of LC3-positive puncta and the NPs was determined by LC3–GFP tracing. Cytotoxicity of PEI NPs was reduced greatly after modification with Alg. PEI–Alg NPs were distributed in mitochondria, rough endoplasmic reticula and nuclei as well as cytoplasm. After phagocytosis of the NPs, expression of Beclin-1 mRNA and LC3 protein was upregulated, and the number of LC3-positive puncta, autophagic structures and amphisomes increased significantly. The number of lysosomes also increased obviously. There were LC3-positive puncta in nuclei, and some puncta were colocalized with the NPs. These results demonstrate that the activated autophagy promotes degradation of PEI–Alg NPs via multiple pathways.

High throughput fiber reactor process for organic nanoparticle production: Poly(N‐isopropylacrylamide), polyacrylamide, and alginate

ABSTRACTThe goal of the present research was to scale microfluidic technology to a high throughput system using a fiber reactor platform. The nanoparticles studied are used in nanomedicine as drug delivery devices or “cages.” This process complements new research into skid‐based pharmaceutical production. Alginate nanoparticles were successfully generated in this process ranging in size from 23 to 151 nm with 424 g/day throughput. Polyacrylamide (PAm) nanoparticles were also formed and crosslinked with sizes ranging from 79 to 117 nm with 662 g/day throughput. Poly(N‐isopropylacrylamide) (PNIPAm) nanoparticles with a size range of 12 to 63 nm and 650 g/day were produced as well. Both one‐ and two‐phase flows were demonstrated. The effects of changes in various process parameters on the formed nanoparticle morphology are documented. Tunable process control is demonstrated to reliably manipulate the PNIPAm nanoparticle lower critical solution temperature. Process temperature affected the mean diameter and size dispersity of all the nanoparticles. This was postulated to be due to a shearing effect arising from carrier viscosity changes. Flow rate affected the average particle diameter by 10%–30%, and temperature could be used to tune the NP diameter by 50% across a moderate process temperature range of 5 to 25 °C. The PDI was very responsive to process temperature as well, decreasing by almost 50% across the same temperature range. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45524.

Efficient Removal of Methylene Blue Using a Hybrid Organic–Inorganic Hydrogel Nanocomposite Adsorbent Based on Sodium Alginate–Silicone Dioxide

In this work, we reported synthesis, structure characterization and methylene blue (MB) adsorption of a novel organic–inorganic hydrogel nanocomposite adsorbent (HNA) based on sodium alginate (NaAlg) and silicone dioxide nanoparticles (SiO2-NPs). The HNAs were prepared using grafting of acrylic acid (AA) onto NaAlg by using ammonium persulfate as a free radical initiator and methylene bisacrylamide as a crosslinker in the presence of SiO2-NPs, which synthesized in situ from the base-catalyzed hydrolysis of tetraethylorthosilicate (TEOS). The structure of HNAs were characterized by FTIR, SEM, EDX, TEM, XRD, UV–Vis and TGA techniques and a proposed mechanism for preparation of adsorbents was also suggested. The swelling capacity of HNAs was examined in buffer solutions with pH ranged 1.0–14.0. The nanocomposites exhibited a pH-responsiveness character so that a swelling-deswelling pulsatile behavior was recorded at pHs 2.0 and 9.0. The swelling kinetics of HNA was also preliminary investigated. Moreover, the effects of agitation time, pH, initial dye concentration, adsorbent dose, TEOS content, AA concentration and temperature were optimized with respect to dye adsorption capacity of HNAs in detail. Furthermore, the kinetic and adsorption isotherm of MB dye onto HNAs were investigated in detail. The HNAs also showed excellent regeneration capacity after five consecutive cycles of dye adsorption–desorption. In general, the results indicated that the synthesized adsorbents with biodegradability and biocompability properties can be used in wastewater treatment via dye adsorption.

Exemestane loaded alginate nanoparticles for cancer treatment: Formulation and in vitro evaluation

Alginate, a biopolymer is most useful for anticancer drug delivery, because of it is biocompatible, nontoxic, biodegradable and exploiting ligand-receptor interaction. Breast cancer is spreading very fast due to the changing food habits and environmental causes. Exemestane (EXE) an oral chemotherapeutic drug was used to treat breast cancer, while loading EXE in alginate nanoparticles, the side effects which was faced during administration are expected to be reduced and control the release of exemestane. Thus, in the present study, an anticancer drug EXE was loaded into the Alginate nanoparticles (ALG-NPs) through simple controlled gelation method and evaluated in vitro to study the performance of ALG-NPs in delivering the anticancer drug EXE. The unloaded and loaded formulation was characterized by FT-IR, XRD and SEM studies. The encapsulation of Exemestane was confirmed using FTIR and XRD analysis results. The surface morphology, shape and size of the formulation was studied using SEM analysis and result reveals that the size was in nano size range with rough surface morphology. Encapsulation of EXE was studied by using UV–vis spectrophotometer. In vitro drug release studies implies that ALG-NPs acts as a novel drug delivery system for the effective controlled delivery for cancer treatment.

Nano-encapsulation of chicken immunoglobulin (IgY) in sodium alginate nanoparticles: In vitro characterization

Controlled delivery of therapeutic agents by alginate nanoparticles became an attractive issue in the gastric organ. Some therapeutic agents such as proteins could not tolerate in severe condition in the gastrointestinal tract. In the present study, four concentrations of a specific IgY as a prophylactic agent against E. coli O157: H7 was entrapped in 0.2% w/v sodium alginate nanoparticles by ionic gelation method. Depending on the IgY concentration entrapment efficacy was 28.31–99.84%. The physicochemical and structural characteristics of free and IgY-loaded Alg NPs revealed that the individual particles exhibited a spherical shape with a diameter of 45–85 nm, and a negatively charged surface with a zeta potential value of 26–36 mV. In vitro release study showed a high significant difference of released amounts of IgY at 10% and 99.84% in simulated gastric fluid (pH 1.2) and simulated intestine fluid (pH 6.8), respectively. Also, the quality and activity of released IgY from Alg NPs not changed. The cytotoxicity of different concentrations of Alg NPs on the Vero cells was measured. Our results indicated that Alg NPs prepared from 0.2%w/v stock solution could be appropriate candidates for efficient and safe delivery of IgY through the gastrointestinal tract.

Hybrid 3D printing and electrodeposition approach for controllable 3D alginate hydrogel formation

Calcium alginate hydrogels are widely used as biocompatible materials in a substantial number of biomedical applications. This paper reports on a hybrid 3D printing and electrodeposition approach for forming 3D calcium alginate hydrogels in a controllable manner. Firstly, a specific 3D hydrogel printing system is developed by integrating a customized ejection syringe with a conventional 3D printer. Then, a mixed solution of sodium alginate and CaCO3 nanoparticles is filled into the syringe and can be continuously ejected out of the syringe nozzle onto a conductive substrate. When applying a DC voltage (∼5 V) between the substrate (anode) and the nozzle (cathode), the Ca2+ released from the CaCO3 particles can crosslink the alginate to form calcium alginate hydrogel on the substrate. To elucidate the gel formation mechanism and better control the gel growth, we can further establish and verify a gel growth model by considering several key parameters, i.e., applied voltage and deposition time. The experimental results indicate that the alginate hydrogel of various 3D structures can be formed by controlling the movement of the 3D printer. A cell viability test is conducted and shows that the encapsulated cells in the gel can maintain a high survival rate (∼99% right after gel formation). This research establishes a reliable method for the controllable formation of 3D calcium alginate hydrogel, exhibiting great potential for use in basic biology and applied biomedical engineering.

Novel dendritic structure of alginate hybrid nanoparticles for effective anti-viral drug delivery

Lipid-polymer hybrid nanoparticles have recently gathered much attention as nanoplatforms for drug delivery applications due to their unique structural properties. In this study zidovudine (AZT) loaded hybrid nanoparticles of alginate (ALG) and stearic acid- poly ethylene glycol (SA-PEG) were synthesized. The structural characterization of drug loaded hybrid nanoparticles were studied using FT-IR spectroscopy, DLS and TEM analysis. These hybrid nanoparticles showed dendritic morphology and it can be used as an efficient carrier for zidovudine. In this drug loaded hybrid system of Alginate –Stearicacid/Poly (ethyleneglycol) Nanoparticles (ASNPs), AZT and alginate form the core wherein SA-PEG forms the external shell. We observed a dendritic morphology with internal voids and channels formed by the core molecule and the external shell forms the closed pack surface groups. The optimized formulation achieved a sub micron size of 407.67±19.18nm with drug encapsulation of 83.18±1.22%, and surface potential of −42.53mV, and has significant stability for six months. Haemolysis and aggregation studies revealed that there were no lysis and aggregation in WBC, RBC and platelets. In-vitro cytotoxicity and cellular uptake of the nanoparticles in Glioma, Neuro2a and Hela cells showed that ASNPs are non toxic. The results indicate that the synthesized hybrid nanoparticles represent a potential carrier for zidovudine, thus possibly increasing zidovudine’s efficiency as an anti-HIV drug.

Pickering emulsions stabilized by hydrophobically modified alginate nanoparticles: Preparation and pH-responsive performance in vitro

ABSTRACTpH-responsive Pickering emulsions were prepared, taking the hydrophobic modified calcium alginate nanoparticles (MCA) of pH sensitivity as emulsifiers. The MCAs were obtained via gelation between Ca2+ in emulsion and alginate sodium that reacted with diacetone acrylamide since alginate sodium was too hydrophilic to be used as a stabilizer. The effect of MCA characteristics, Ca2+ content, and pH on the preparation and property of emulsion was evaluated. Then, the released behaviors of MCA-stabilized emulsion loading oil-soluble drug of curcumin were investigated in vitro. The results demonstrated that Pickering emulsions released curcumin intestine-specifically (37% in 4 hours with a pH of 6.8), compared with the one in the gastric fluid (3% in 4 hours with a pH of 1.5), proving that MCA had similar pH sensitivity to alginates and probably as the promising candidate in oral drug controllable release.

Processing-size correlations in the preparation of magnetic alginate microspheres through emulsification and ionic crosslinking

Magnetic alginate microspheres are biocompatible due to their alginate matrix, and motion-controllable by applied magnetic fields due to their magnetic character. Therefore, they have the potential of being used as vessels to a broad variety of materials, including drugs and therapeutic agents, facilitating entry to biological systems in a relatively non-invasive manner. Here, magnetic alginate microspheres were prepared through an emulsification and ionic cross-linking process, where a mixture of alginate and iron oxide magnetic nanoparticles was initially dispersed in a continuous phase, followed by gelation of this dispersed phase into microspheres by cross-linking the dispersion with calcium ions. The resulting magnetic alginate microspheres were found to be superparamagnetic and to respond to applied magnetic fields by chain formation. The effect of shear rate, alginate concentration, and magnetic nanoparticle concentration on microsphere size was investigated with the aim to control the size of microspheres with respect to process and formulation parameters. Two of these parameters, shear rate and alginate concentration, were used to correlate experimental results with a theoretical model for the case where the dispersed phase is more viscous than the continuous phase.

Antibacterial-nanocomposite bone filler based on silver nanoparticles and polysaccharides.

Injectable bone fillers represent an attractive strategy for the treatment of bone defects. These injectable materials should be biocompatible, capable of supporting cell growth and possibly able to exert antibacterial effects. In this work, nanocomposite microbeads based on alginate, chitlac, hydroxyapatite and silver nanoparticles were prepared and characterized. The dried microbeads displayed a rapid swelling in contact with simulated body fluid and maintained their integrity for more than 30 days. The evaluation of silver leakage from the microbeads showed that the antibacterial metal is slowly released in saline solution, with less than 6% of silver released after 1 week. Antibacterial tests proved that the microbeads displayed bactericidal effects toward Staphylococcus aureus, Pseudomonas aeruginosa and Staphylococcus epidermidis, and were also able to damage pre-formed bacterial biofilms. On the other hand, the microbeads did not exert any cytotoxic effect towards osteoblast-like cells. After characterization of the microbeads bioactivity, a possible means to embed them in a fluid medium was explored in order to obtain an injectable paste. Upon suspension of the particles in alginate solution or alginate/hyaluronic acid mixtures, a homogenous and time-stable paste was obtained. Mechanical tests enabled to quantify the extrusion forces from surgical syringes, pointing out the proper injectability of the material. This novel antibacterial bone filler appears as a promising material for the treatment of bone defects, in particular when possible infections could compromise the bone-healing process. Copyright © 2016 John Wiley & Sons, Ltd.

Mucopenetrating nanoparticles for enhancement of oral bioavailability of furosemide: In vitro and in vivo evaluation/sub-acute toxicity study

The aim of this study was to formulate and evaluate chitosan (CS)/alginate (ALG) nanoparticles (NPs) loaded with furosemide (FSM) in an attempt to enhance its release, permeability and bioavailability. Non-everted gut sac method was used to evaluate the ex vivo permeation of FSM from its suspension and the selected CS/ALG NPs formulation. The pharmacokinetic parameters of FSM subsequent to oral administration of the selected formulation were assessed in rats. In vivo subacute toxicity study of the prepared blank and FSM loaded formulations was evaluated in rats.The selected optimized formulation (F3) showed optimum particle size (PS), polydispersity index (PDI), zeta potential (ZP) and acceptable percentage entrapment efficiency (%EE) of 253.8nm±4.6, 0.25±0.03, −35mV±1 and 96%±1, respectively. The release profile of FSM from the selected formulation was characterized by initial burst effect in 0.1N HCl. Scanning electron microscope (SEM) demonstrated a smooth surface and spherical shape for the lyophilized optimized NPs.Selected CS/ALG NPs (F3) presented a significant enhancement (p≤0.01) in permeation parameters of FSM as well as in Tmax, Cmax, AUC0-24 and AUC0-∞. Subacute toxicity study results revealed that the selected formulation was safe and nontoxic. The histopathological inspection of the stomach and small intestine tissues of the loaded NPs (F3) and blank groups reflected no obvious signs of cellular toxicity or inflammatory reaction.CS/ALG NPs loaded with FSM enhanced both drug release and mucus-penetrating ability leading to an overall increase in FSM bioavailability. In addition, the in vivo subacute toxicity study results indicated the safety of the prepared NPs for oral drug delivery.

Carrageenan-stabilized chitosan alginate nanoparticles loaded with ethionamide for the treatment of tuberculosis

The objective of this work was to prepare ethionamide-loaded, cross linker free, chitosan alginate nanoparticles stabilized with varying amounts of carrageenan using simple inotropic gelation. The nanoparticles formulation was manipulated to optimize drug loading and release. Three different formulations containing different percentages of carrageenan (0%, 42%, and 59%) were evaluated for particles size, zeta potential, entrapment, and release. Results showed that carrageenan enhanced the stability of the nanoparticles to the formulation process and enhanced the entrapment of ethionamide in the nanoparticles (0.36 μg/mg for 0% carrageenan formulation vs 3.1 μg/mg for 59% carrageenan formulation). Moreover, nanoparticles exhibited controlled release over 96 h and the release was reduced with increasing the carrageenan content. The nanoparticles size for all formulations was found to in the range of 300 nm. These results were found concurring in size with the results obtained from TEM. Furthermore, the DSC and FTIR evaluation of the ethionamide in the freeze-dried nanoparticle preparation showed no chemical interaction between ethionamide nanocrystals and the excipients. Additionally, the ethionamide loaded nanoparticles showed significant antimycobacterial activity against H37RA mycobacterium strain using resazurin microtiter assay (REMA). Thus, it can inferred from these results that our nanoparticle formulations have a great potential in the treatment of tuberculosis.

Dual responsive polymeric bionanocomposite gel beads for controlled drug release systems

ABSTRACTScientists are searching potential solutions for cancer treatments as well as ways to avoid the side effects of anti‐cancer agents, via targeted drug delivery. The aim of this research is to propose dual responsive beads based on sodium alginate (SA), methylcellulose (MC), and magnetic iron oxide nanoparticles (MIONs) for controlled release of 5‐Fluorouracil (5‐FU) as model drug. The beads were prepared by the dual crosslinking of SA and MC in the presence of MIONs. The structural, thermal, morphological, magnetic characteristics as well as the release profile of 5‐FU were studied. The characterization results showed that the drug molecules and MIONs were well dispersed in the polymeric matrix. The cumulative release percentage was ca. 80% at pH = 4.2 and 40% at pH = 7.2 after 6 h. Thus, the sensitivity of beads on the pH value was verified. Moreover, the release profile exhibited reduction with an increase in the concentration of MIONs under an external magnetic field. The obtained results confirmed the dual sensitive release of 5‐FU (i.e., PH/magnetic) that can be used for the targeted and controlled drug delivery systems. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45143.

Ultrasmall silver nanoparticles loaded in alginate–hyaluronic acid hybrid hydrogels for treating infected wounds

ABSTRACTNowadays, silver nanoparticles are in the limelight to control infection during wound healing process, and a vast variety of antimicrobial dressings based on colloidal silver have been marketed to fight wound invasion of pathogen bacteria, which represents one of the main adverse effects limiting the repair process. Here we propose a biofunctional hydrogel based on alginate (ALG) and hyaluronic acid (HA) embedding ultrasmall silver nanoparticles (usSN, <1 nm) as antimicrobial component. The hydrogels were fabricated in different size by a straightforward internal gelation method using CaCO3 and glucono-δ-lactone. To follow usSN release from the hydrogels in aqueous media, catalytic activity of usSN-loaded hydrogels was evaluated. Results suggested that catalytic activity was low in intact hydrogels and high when hydrogels dissolved, which suggests that usSN firmly interact with polymer chains and are available in the medium depending on the extent of hydrogel degradation. HA-containing hydrogels showed faster dissolution in simulated physiological conditions and higher antibiofouling properties as compared to hydrogels made only of ALG. Free usSN were not toxic toward human mesenchymal stem cells (Ad-MSCs), previously isolated from subcutaneous adipose tissue biopsies, up to 50 µg/mL. At this concentration, viability of Ad-MSCs was unaffected whereas their motility was significantly higher as compared to control (p<0.01) for both free usSN and hydrogel integrating. Antimicrobial activity on clinical isolates of both Gram-positive and Gram-negative bacteria demonstrated that usSN at 50 µg/mL were able to kill all the bacteria tested after 24 and 48 h of contact time. In the case of hydrogels, a matrix effect was found and bacterial killing was significant only at 24 h and dependent on bacterial strain, being Gram-negative bacteria more susceptible. These results clearly indicate that usSN interaction with polymer network and exposure time can strongly affect usSN antimicrobial profile in the hydrogel and, in turn, timing of hydrogel change at injured site in a clinical setting. On the whole, ALG/HA hydrogels integrating usSN can be considered a suitable option to fabricate biofunctional dressings for hospitalized patients and worth of further in vivo investigation.

Synthesis characterization and biological evaluation of alginate nanoparticle for the targeted delivery of curcumin

Cancer continues to be a serious disaster to mankind. Chemotherapy is an efficient and effective treatment against cancer. Lack of selectivity is the main challenge faced by chemotherapy. In present study we used folic acid (FA) as a targeting ligand, which selectively targets the cancer cell lines with over expressed folate receptors (FR). We grafted polyethylene glycol (PEG) to polyethylene imine (PEI) to form PEG-b-PEI (mPPS), which is then coupled with FA to form FA- PEG-b-PEI (PPF) which is then assembled with curcumin (CUR) loaded alginate nanoparticle (AlgNP). The carrier is well characterized using FTIR, XRD, SEM and DLS. At optimum conditions DLE of 68.3% and DEE of 92.4% have been achieved and a drug release percentage higher than 80% is also obtained. The cell viability of CUR loaded carrier is found to be less than 40%. In vitro cytotoxicity studies and fluorescence images of HeLa and H9c2 cell lines confirm the selective destruction of tumor cell lines.