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The synergistic effect of chemotherapy and ablation using high-intensity focused ultrasound (HIFU) is realized with a newly developed drug-delivery system. The system comprises an ultrathin silica shell surrounding a poly(lactic-co-glycolic acid) nanoemulsion core containing the drug (CPT) and a perfluorocarbon (PFOB). This nanosystem presents many advantages in drug delivery, such as excellent structural stability, high drug-loading capacity, and rapid HIFU-mediated drug release., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

It is increasingly recognized that use of stiff biodegradable polymers in connective tissue engineering has an inherent flaw. Although polymer stiffness has early benefit for mechanical strength of implants, such pseudoprosthetic material function inevitably stress shields embedded cells, switching off their synthetic/remodeling functions. This core conundrum represents a tension between early mechanical benefits of polymer stiffness against blocking of cell load-dependent matrix production. In effect, an ideal system would produce a gradual, transfer of load onto resident cells and their matrix. Toward this target, our "less is more" (LiM) hypothesis proposes that less stress shielding (polymer stiffness) will lead to more cell-dependent tissue formation. To test this we have designed a hybrid segregation solution in which the cells are segregated into a native (but weak) collagen-gel matrix while the external mechanical loading is taken by temporary, reinforcing polyglycolic acid (PGA) fibers, with gradual, load transfer as the polymer µ-fibers fracture. Dermal fibroblasts grew predictably in the hybrid construct and the fine, parallel PGA fibers fractured and fragmented due to hydrolysis, giving a fall of construct stiffness to near collagen-only levels, over 14 days. The same fiber fracture and fall in stiffness occurred over 14 days in constructs implanted in vivo. In this case a cell dependent, net enhancement of connective tissue stiffness could be identified in hybrid constructs, supporting the LiM hypothesis for cytomechanical control of matrix. This is the first demonstration of spatiotemporal load transfer as a customizable tool for improved, biomimetic connective tissue engineering., (© 2014 Wiley Periodicals, Inc.)

Aim: To quantify in vivo the biodistribution of poly(lactic-co-glycolic) acid (PLGA) and PLGA/chitosan nanoparticles (PLGA/Chi NPs) and assess if the positive charge of chitosan significantly enhances nanoparticle absorption in the GI tract., Material & Methods: PLGA and PLGA/Chi NPs covalently linked to tetramethylrhodamine-5-isothiocyanate (TRITC) were orally administered to F344 rats for 7 days, and the biodistribution of fluorescent NPs was analyzed in different organs., Results: The highest amount of particles (% total dose/g) was detected for both treatments in the spleen, followed by intestine and kidney, and then by liver, lung, heart and brain, with no significant difference between PLGA and PLGA/Chi NPs. , Conclusion: Only a small percentage of orally delivered NPs was detected in the analyzed organs. The positive charge conferred by chitosan was not sufficient to improve the absorption of the PLGA/Chi NPs over that of PLGA NPs.

Hypothesis: Artemisinin, a potential antileishmanial compound with poor bioavailability and stability has limited efficacy in visceral leishmaniasis. Encapsulating artemisinin into poly lactic-co glycolic nanoparticles may improve its effectiveness and reduce toxicity., Experiments: Artemisinin-loaded nanoparticles were prepared, optimized (using Box-Behnken design) and characterized by dynamic light scattering technique, Atomic force microscopy (AFM), Transmission electron microscopy (TEM) and Fourier Transform-Infra Red spectroscopy. Release kinetics of artemisinin from optimized nanoformulation was studied by dialysis method at pH 7.4 and 5.5. Cytotoxicity and antileishmanial activity of these nanoparticles was tested on murine macrophages by MTT assay and macrophage-infested Leishmania donovani amastigotes ex vivo, respectively., Findings: Artemisinin-loaded nanoparticles were 221±14nm in diameter, with polydispersity index, zeta potential, drug loading and entrapment efficiency of 0.1±0.015, -9.07±0.69mV, 28.03±1.14 and 68.48±1.97, respectively. AFM and TEM studies indicated that the particles were spherical in shape. These colloidal particles showed a sustained release pattern in vitro. Treatment with artemisinin-loaded nanoparticles significantly reduced the number of amastigotes per macrophage and percent infected macrophages ex vivo compared to free artemisinin. These nanoparticles were also non-toxic to macrophages compared to artemisinin alone., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We determined the efficacy and safety of chitosan (CS)-coated poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) as a delivery system for a vaccine to protect chickens against Newcastle disease virus (NDV). The newly constructed vaccine contained DNA (the F gene) of NDV. The Newcastle disease virus (NDV) F gene deoxyribonucleic acid (DNA) plasmid (pFDNA)-CS/PLGA-NPs were spherical (diameter =699.1 ± 5.21 nm [mean ± standard deviation]) and smooth, with an encapsulation efficiency of 98.1% and a Zeta potential of +6.35 mV. An in vitro release assay indicated that CS controlled the burst release of plasmid DNA, such that up to 67.4% of the entire quantity of plasmid DNA was steadily released from the pFDNA-CS/PLGA-NPs. An in vitro expression assay indicated that the expression of nanoparticles (NPs) was maintained in the NPs. In an immunization test with specific pathogen-free chickens, the pFDNA-CS/PLGA-NPs induced stronger cellular, humoral, and mucosal immune responses than the plasmid DNA vaccine alone. The pFDNA-CS/PLGA-NPs did not harm 293T cells in an in vitro assay and did not harm chickens in an in vivo assay. Overall, the results indicated that CS-coated PLGA NPs can serve as an efficient and safe mucosal immune delivery system for NDV DNA vaccine.

Polymeric nanoparticles (NPs) offer a promising approach for therapeutic intracellular delivery of proteins, conventionally hampered by short half-lives, instability and immunogenicity. Remarkably, NPs uptake occurs via endocytic internalization leading to NPs content's release within lysosomes. To overcome lysosomal degradation and achieve NPs and/or loaded proteins release into cytosol, we propose the formulation of hybrid NPs by adding 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as pH sensitive component in the formulation of poly-lactide-co-glycolide (PLGA) NPs. Hybrid NPs, featured by different DOPE/PLGA ratios, were characterized in terms of structure, stability and lipid organization within the polymeric matrix. Experiments on NIH cells and rat primary neuronal cultures highlighted the safety profile of hybrid NPs. Moreover, after internalization, NPs are able to transiently destabilize the integrity of lysosomes in which they are taken up, speeding their escape and favoring cytoplasmatic localization. Thus, these DOPE/PLGA-NPs configure themselves as promising carriers for intracellular protein delivery., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The aim of study was to formulate PLGA nanoparticles (NPs) of Gemcitabine HCl for enhanced oral bioavailability via absorption through M cells of Peyer's patches. Commercially, the drug is available as i.v. infusion due to its short half life (8-17 min), rapid metabolism and limited tumor uptake. The NPs were prepared by multiple solvent emulsification method. Optimized formulation had particle size of 166.4±2.42 nm, and entrapment of 56.48±3.63%. TEM image revealed discrete spherical structures of NPs. DSC and FTIR studies confirmed absence of interaction between drug and polymer. In vitro and ex vivo studies demonstrated sustained release from the NPs. The enhanced absorption and uptake of NPs in Caco-2 cells and in vivo absorption in intestinal tissue after oral delivery in rats was confirmed by confocal microscopy. Transport studies in Caco-2 cells confirmed 6.37-fold permeability for NPs. In vitro antiproliferative studies confirmed marked cytotoxicity of NPs on K562 leukemia cell lines. In vivo pharmacokinetic studies in rats showed 21.47-folds bioavailability enhancement from NPs. Hence, orally delivered Gemcitabine HCl loaded NPs have the potential for improving its bioavailability and avoiding side effects associated with iv infusions as well as enhancing patient compliance through "Chemotherapy at Home"., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The combination of two differently charged polypeptides, poly-L-lysine (PL) and poly-L-glutamate (PG), has shown excellent postsurgical antiadhesive properties. However, the high molecular, positively charged PL is toxic in high doses, proposed as lysis of red blood cells. This study aims to elucidate the in vivo toxicity and biodistribution of PL and complex bound PLPG comparing intravenous and intraperitoneal administration. Fifty-six Sprague-Dawley rats were used in a model with repeated blood samples within 30 min examining blood gases and blood smears. Similarly, FITC labelled PL were used to track bio distribution and clearance of PL, given as single dose and complex bound to PG after intravenous and intraperitoneal administration. Tissue for histology and immunohistochemistry was collected. Blood gases and blood smears as well as histology points to a toxic effect of high dose PL given intravenously but not after intraperitoneal administration. The toxic effect is exerted through endothelial disruption and subsequent bleeding in the lungs, provoking sanguineous lung edema. FITC-labelled PL experiments reveal a rapid clearance with differences between routes and complex binding. This study advocates a new theory of the toxic effects in vivo of high molecular PL. PLPG complex is safe to use as antiadhesive prevention based on this toxicity study given that PL is always intraperitoneally administered in combination with PG and that the dose is adequate.

A review of poly(lactic-co-glycolic) acid (PLGA) nanoparticle (NP) biodistribution was conducted with the intent of identifying particle behavior for drug delivery applications. Databases such as Science Direct and Web of Science were used to locate papers on biodistribution of intravenous (i.v.) and orally delivered PLGA NPs in mice and rats. The papers included in the review were limited to those that report biodistribution data in terms of % dose particles/g tissue in the liver, kidney, spleen, lung, heart and brain. Noted trends involved particle behavior based on individual organ, particle size, animal model, type of indicator (entrapped versus covalently linked) and method of delivery (oral or i.v.). The liver showed the highest uptake of particles in mice, and the lung showed the highest uptake in rats. Minimal amounts of particles were detected in both the heart and brain of rats and mice. In rats, the concentration of particles approached 0% dose/g or decreased significantly over 24 h after administration of a single dose of particles. Higher concentrations of smaller particles were evident in the liver, kidney and spleen. Orally delivered drugs showed little to no uptake within the 24 h analysis when compared with i.v. delivered NPs. Differences in particle concentrations between rats and mice were also observed as expected when expressed as % dose/g organ. Particles with covalently linked indicators showed lower concentrations in tissues than particles with physically entrapped indicators. Further research on oral delivery of PLGA NPs as well as distribution beyond 24 h is needed to fully understand particle behavior in vivo for successful application of NPs in drug delivery.

Objective: Alzheimer's disease (AD) is a progressive neurodegenerative disorder manifested by cognitive, memory deterioration and variety of neuropsychiatric symptoms. Donepezil is a reversible cholinesterase inhibitor used for the treatment of AD. The purpose of this work is to prepare a nanoparticulate drug delivery system of donepezil using poly(lactic-co-glycolic acid) (PLGA) for sustained release and efficient brain targeting., Materials and Methods: PLGA nanoparticles (NPs) were prepared by the solvent emulsification diffusion-evaporation technique and characterized for particle size, particle-size distribution, zeta potential, entrapment efficiency, drug loading and interaction studies and in vivo studies using gamma scintigraphy techniques., Results and Discussion: The size of drug-loaded NPs (drug polymer ratio 1:1) was found to be 89.67 ± 6.43 nm. The TEM and SEM images of the formulation suggested that particle size was within 20-100 nm and spherical in shape, smooth morphology and coating of Tween-80 on the NPs was clearly observed. The release behavior of donepezil exhibited a biphasic pattern characterized by an initial burst release followed by a slower and continuous sustained release. The biodistribution studies of donepezil-loaded PLGA NPs and drug solution via intravenous route revealed higher percentage of radioactivity per gram in the brain for the nanoparticulate formulation as compared with the drug solution (p < 0.05)., Conclusion: The high concentrations of donepezil uptake in brain due to coated NPs may help in a significant improvement for treating AD. But further, more extensive clinical studies are needed to check and confirm the efficacy of the prepared drug delivery system.

Background: The encapsulation of curcumin (Cur) in polylactic-co-glycolic acid (PLGA) nanoparticles (Cur- NPs) was designed to improve its solubility and stability. Conjugation of the Cur-NPs with anti-P-glycoprotein (P-gp) antibody (Cur-NPs-APgp) may increase their targeting to P-gp, which is highly expressed in multidrug- resistance (MDR) cancer cells. This study determined whether Cur-NPs-APgp could overcome MDR in a human cervical cancer model (KB-V1 cells) in vitro and in vivo., Materials and Methods: First, we determined the MDR- reversing property of Cur in P-gp-overexpressing KB-V1 cells in vitro and in vivo. Cur-NPs and Cur-NPs-APgp, in the range 150-180 nm, were constructed and subjected to an in vivo pharmacokinetic study compared with Cur. The in vitro and in vivo MDR-reversing properties of Cur-NPs and Cur-NPs-APgp were then investigated. Moreover, the stability of the NPs was determined in various solutions., Results: The combined treatment of paclitaxel (PTX) with Cur dramatically decreased cell viability and tumor growth compared to PTX treatment alone. After intravenous injection, Cur-NPs-APgp and Cur-NPs could be detected in the serum up to 60 and 120 min later, respectively, whereas Cur was not detected after 30 min. Pretreatment with Cur-NPs-APgp, but not with NPs or Cur-NPs, could enhance PTX sensitivity both in vitro and in vivo. The constructed NPs remained a consistent size, proving their stability in various solutions., Conclusions: Our functional Cur-NPs-APgp may be a suitable candidate for application in a drug delivery system for overcoming drug resistance. The further development of Cur-NPs-APgp may be beneficial to cancer patients by leading to its use as either as a MDR modulator or as an anticancer drug.

Aim: To study the effect of poly(d,l-lactic-co-glycolic acid) (PLGA) microparticles (MPs) preparation techniques on particle physical characterization with special emphasis on burst drug release., Methods: A basic drug clozapine was used in combination with acid-terminated PLGA. Two approaches for MP preparation were compared; the in situ forming microparticle (ISM) and the emulsion-solvent evaporation (ESE) methods using an experimental design. The MPs obtained were compared according to their physical characterization, burst release and T80%. An in vivo pharmacokinetic study with in vitro-in vivo correlation (IVIVC) was also performed for the selected formula., Results: Both methods were able to sustain drug release for three weeks. ISM produced more porous particles and was not effective as ESE for controlling burst release. A good IVIVC (R(2) = 0.9755) was attained when injecting the selected formula into rats., Conclusion: MPs prepared with ESE showed a minimum burst release and a level A IVIVC was obtained when administered to rats.

The chitosan scaffold, which has both of anticancer and antivascularization effects, was developed for using in local therapy of brain tumours. This is why, poly-lactic-co-glycolic acid (50:50) nanoparticles (~200 nm) including an anticancer drug, 5-fluorouracil (5-FU), were prepared by emulsion-solvent evaporation method. Then, these nanoparticles and antivascularization agent, bevacizumab, were loaded into the scaffold during manufacturing by freeze-drying and embedding after freeze-drying, respectively. The idea behind this system is to destroy tumour tissue by releasing 5-FU and to prevent the proliferation of tumour cells by releasing bevacizumab. In addition, 3D scaffold can support healthy tissue formation in the tumourigenic region. In vitro effectiveness of this system was investigated on T98G human glioblastoma cell line and human umbilical vein endothelial cells. The results show that the chitosan scaffold containing 100 µg 5-FU and 100 µg bevacizumab has a potential to prevent the tumour formation in vitro conditions.

Multifunctional polymeric nano- and microparticles are engineered as theranostic carriers and their selective size-dependent cellular uptake is demonstrated. It is found that effective uptake and accumulation of nanoparticles occurs in both normal and cancer cells, whereas, that of microparticles occurs in cancer cells but not in normal cells, allowing cancer cells to be specifically targeted for local drug delivery., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Superparamagnetic iron oxide nanoparticles (SPIONs) show a great promise for a wide specter of bioapplications, due to their characteristic magnetic properties exhibited only in the presence of magnetic field. Their advantages in the fields of magnetic drug targeting and imaging are well established and their safety is assumed, since iron oxide nanoparticles have already been approved for in vivo application, however, according to many literature reports the bare metal oxide nanoparticles may cause toxic effects on treated cells. Therefore, it is reasonable to prevent the direct interactions between metal oxide core and surrounding environment. In the current research ricinoleic acid coated maghemite nanoparticles were successfully synthesized, characterized and incorporated in the polymeric matrix, resulting in nanosized magnetic polymeric particles. The carrier system was shown to exhibit superparamagnetic properties and was therefore responsive towards external magnetic field. Bioevaluation using T47-D breast cancer cells confirmed internalization of magnetic polymeric nanoparticles (MNPs) and their intracellular localization in various subcellular compartments, depending on presence/absence of external magnetic field. However, the number of internalized MNPs observed by fluorescent and transmission electron microscopy was relatively low, making such way of targeting effective only for delivery of highly potent drugs. The scanning electron microscopy of treated cells revealed that MNPs influenced the cell adhesion, when external magnetic field was applied, and that treatment resulted in damaged apical plasma membrane right after exposure to the magnetic carrier. On the other hand, MNPs showed only reversibly reduced cellular metabolic activity in concentrations up to 200 μg/ml and, in the tested concentration the cell cycle distribution was within the normal range, indicating safety of the established magnetic carrier system for the treated cells., (Copyright © 2013 Elsevier B.V. All rights reserved.)

To develop a long-acting injectable thienorphine biodegradable poly (d, l-lactide-co-glycolide) (PLGA) microsphere for the therapy of opioid addiction, the effects of formulation parameters on encapsulation efficiency and release behavior were studied. The thienorphine loaded PLGA microspheres were prepared by o/w solvent evaporation method and characterized by HPLC, SEM, laser particle size analysis, residual solvent content and sterility testing. The microspheres were sterilized by gamma irradiation (2.5 kGy). The results indicated that the morphology of the thienorphine PLGA microspheres presented a spherical shape with smooth surface, the particle size was distributed from 30.19 ± 1.17 to 59.15 ± 0.67 μm and the drug encapsulation efficiency was influenced by drug/polymer ratio, homogeneous rotation speed, PVA concentration in the water phase and the polymer concentration in the oil phase. These changes were also reflected in drug release. The plasma drug concentration vs. time profiles were relatively smooth for about 25 days after injection of the thienorphine loaded PLGA microspheres to beagle dogs. In vitro and in vivo correlation was established.

The aim of the present study was to develop and characterize metformin HCl-loaded nanoparticle formulations. Nanoparticles were prepared by the nanoprecipitation method using both a single polymer (Eudragit(®)RSPO) and a polymer mixture (Eudragit/PLGA). The mean particle size ranged from 268.8 to 288 nm and the nanoparticle surface was positively charged (9.72 to 10.1 mV). The highest encapsulation efficiency was observed when Eudragit®RSPO was used. All formulations showed highly reproducible drug release profiles and the in vitro drug release in phosphate buffer (pH = 6.8) ranged from 92 to 100% in 12 h. These results suggest that Eudragit(®)RSPO or Eudragit/PLGA nanoparticles might represent a promising sustained-release oral formulation for metformin HCl, reducing the necessity of repeated administrations of high doses to maintain effective plasma concentrations, and thus, increasing patient compliance and reducing the incidence of side-effects.

Although treatment of pulmonary tuberculosis with respirable microspheres (MS) with an incorporated antituberculosis drug is expected to be highly effective, this treatment seems to achieve a much lesser effect than expected in the case of killing Mycobacterium tuberculosis residing in the lungs. To elucidate the reason for this weaker effect, we examined the distribution and accumulation of respirable MS consisting of poly(lactic-co-glycolic) acid (PLGA) in rat lungs. For this, we delivered the PLGA MS containing fluorescent coumarin 6 or an antituberculosis agent, rifampicin (RFP), by insufflation via the trachea and then determined the pulmonary distribution by counting the number of the MS in lung cryosections observed under a microscope. In addition, the uptake of MS by alveolar macrophage (AMφ) was determined by immunostaining for Mφ cell marker CD68 and RFP content in the cells. Approximately half of the fluorescent PLGA MS reached the alveoli without entrapment by trachea and primary bronchi and were then ingested by the AMφ cells up to 24h after insufflation. RFP in a form of PLGA MS was markedly transported into AMφ at an amount 10 times greater than that for the free RFP powder. However, a large proportion of RFP was eliminated from the lungs by 6h after insufflation., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The intracellular delivery of Doxorubicin (Dox) from poly(lactide-co-glycolide) (PLGA) nanoparticles stabilised with bovine serum albumin, in HepG2 cells, is studied via flow cytometry, fluorescence lifetime imaging microscopy (FLIM), confocal Raman microscopy (CRM) and cell viability studies. Flow cytometry shows that the initial uptake of PLGA and Dox follow the same kinetics. However, following 8 h of incubation, the fluorescence intensity and cellular uptake of Dox decreases, while in the case of PLGA both parameters remain constant. FLIM shows the presence of a single-lifetime species, with a lifetime of 1.15 ns when measured inside the cells. Cell viability decreases by approximately 20% when incubated for 24 h with PLGA loaded with Dox, with a particle concentration of 100 µg · mL(-1). At the single-cell level, CRM shows changes in the bands from DNA and proteins in the cell nucleus when incubated with PLGA loaded with Dox., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Potency and activity of SR13668 in cancer prevention have been proven in several in vitro and in vivo cancer models. However, the compound is highly hydrophobic and its limited oral bioavailability has hindered its clinical translation. In this study, we encapsulated SR13668 into polymeric nanoparticles to increase compound aqueous solubility and therefore bioavailability. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (100-200 nm) encapsulating SR13668 with narrow size distribution and high drug loading were generated by a continuous and scalable process of flash nanoprecipitation integrated with spray dry. A single gavage dose of SR13668-PLGA nanoparticles at 2.8 mg/kg was administered in eight beagle dogs. Drug levels in animal whole blood and plasma were measured over 24 hours. Enhanced bioavailability of SR13668 using nanoparticles compared with formulations of Labrasol® and neat drug in 0.5% methylcellulose is reported. This is the first attempt to study pharmacokinetics of SR13668 in large animals with orally administrated nanoparticle suspension.

Purpose: Itraconazole (ITZ) is a synthetic triazole antifungal agent, which is widely used for treatment and prevention of fungal infections. The purpose of this study is to develop ITZ-loaded poly(lactic-co-glycolic acid) (PLGA) nanospheres (PLGA-ITZ-NS) as a new sustained-release formulation for intravenous ITZ administration., Materials and Methods: PLGA-ITZ-NS were prepared by a nanoprecipitation method and optimized by modifying the surfactant poloxamer 188 concentration and PLGA:ITZ ratio. Their physicochemical properties, including size, zeta potential, external morphology and encapsulation efficiency, were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and high performance liquid chromatography (HPLC). The effect of the different selected lyoprotectants with various concentrations on NS particles size and surface charge were also assessed. Rapid and sensitive HPLC and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed to determine ITZ concentrations in formulation and in rat plasma, respectively. Pharmacokinetics of the optimum PLGA-ITZ-NS formulation was compared with the former commercial Sporanox® injection formulation using rats as the animal model. Noncompartmental pharmacokinetic parameters were obtained by WinNonlin® software., Results: Optimal PLGA-ITZ-NS had a mean particle size of about 200 nm with a high homogeneity (polydispersity index ≈0.2), favorable zeta potential (approximately -20 to -30 mV) and encapsulation efficiency (72%). In addition, 2% w/v sucrose was selected as a lyoprotectant for NS freeze-drying. The newly developed LC-MS/MS assay was validated and found to be accurate and precise. The in vivo study showed that the NS formulation has a similar systemic bioavailability to Sporanox® while providing a sustained plasma level (> 100 ng/mL) for up to 24 hours after intravenous administration., Conclusion: Our newly developed PLGA-ITZ-NS has shown great sustained release and comparable bioavailability with Sporanox®, therefore having the potential to be an alternative injectable formulation of ITZ.

As a potential bioactive material, β-calcium silicate (β-CS) has attracted particular attention in the field of bone regeneration. In this study, porous β-CS/Poly-D,L-Lactide-Glycolide (PDLGA) composite scaffolds were developed with the goals of controlling the degradation rate and improving the mechanical and biological properties. The compressive strength and toughness were significantly enhanced by PDLGA modification of porous β-CS ceramic scaffolds. The effects of the ionic extract from β-CS/PDLGA composite scaffolds on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (rBMSCs), proliferation of human umbilical vein endothelial cells (HUVECs) and the related mechanisms were investigated. It was shown that bioactive ions from β-CS/PDLGA scaffolds could enhance cell viability, alkaline phosphatase (ALP) activity, calcium mineral deposition, and mRNA expression levels of osteoblast-related genes of rBMSCs without addition of extra osteogenic reagents. The activation in AMP-activated protein kinase (AMPK), extracellular signal-related kinases (ERK) 1/2 and RUNX-2 were observed in rBMSCs cultured in the extract of β-CS/PDLGA, and these effects could be blocked by AMPK inhibitor Compound C. The extracts of β-CS/PDLGA composites stimulated HUVECs proliferation that was associated with phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) as well as an increase in nitric oxide (NO) production and secretion of vascular endothelial growth factor (VEGF). The inductions were abolished by the addition of phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. The composite scaffolds were implanted in critical sized rabbit femur defects (6 × 10 mm) for 4, 12 and 20 weeks with β-tricalcium phosphate (β-TCP) as controls. Sequential histological evaluations and radiographs revealed that β-CS/PDLGA dramatically stimulated new bone formation and angiogenesis. The biodegradation rate of the β-CS/PDLGA scaffolds was lower than that of β-TCP at each time point examined, and matched the new bone formation rates. These data suggest that β-CS/PDLGA could promote bone regeneration in vivo, which might be ascribed to the enhanced osteogenic differentiation of mesenchymal stem cells (MSCs) and increased angiogenic activity of endothelial cells (ECs)., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: 5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs)., Methods: A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined., Results: The mean particle size of spherical ALA PLGA NPs was 65.6 nm±26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8%±7.2% and ALA loading capacity was 0.62%±0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration., Conclusion: PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma.

Purpose: To compare the outcome of 2 bioabsorbable screws for tibial interference fixation in anterior cruciate ligament reconstruction with reference to rate of absorption, osteoconductive properties, and clinical outcome., Methods: Patients undergoing primary anterior cruciate ligament reconstruction with hamstring autograft in a single unit were invited to participate in this study. Patients were randomized to receive either the Calaxo screw (Smith & Nephew, Andover, MA) or Milagro screw (DePuy Mitek, Raynham, MA) for tibial fixation. Patients were reviewed with subjective and objective evaluation by use of the International Knee Documentation Committee form, Lysholm score, KT-1000 arthrometry (MEDmetric, San Diego, CA), and clinical examination. Magnetic resonance imaging was performed at 1 year and computed tomography scanning at 1 week and at 6, 12, and 24 months., Results: Sixty patients agreed to participate in the study, with 32 patients randomized to the Calaxo screw and 28 to the Milagro screw for tibial fixation. There was no significant difference in subjective or objective clinical outcome between the 2 groups. At 24 months, 88% of Calaxo screws showed complete screw resorption compared with 0% of Milagro screws (P < .001). Tibial cysts were present in 88% of the Calaxo group and 7% of the Milagro group (P = .001). At 24 months, the mean volume of new bone formation for the Calaxo group was 21% of original screw volume. Ossification of the Milagro screw was unable to be accurately assessed as a result of incomplete screw resorption., Conclusions: Both screws showed similar favorable objective and subjective outcomes at 2 years. The Calaxo screw resorbed completely over a period of 6 months and was associated with a high incidence of intra-tunnel cyst formation. The Milagro screw increased in volume over a period of 6 months, followed by a gradual resorption, which was still ongoing at 2 years. Both screws were associated with tunnel widening, and neither showed evidence of significant tunnel ossification. We conclude that, despite satisfactory clinical outcomes, the addition of "osteoconductive" materials to bioabsorbable screws is not associated with bone formation at the screw site at 2 years., Level of Evidence: Level I, randomized controlled trial., (Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Thrombotic disease is a leading cause of death and disability worldwide. The development of magnetic resonance molecular imaging provides potential promise for early disease diagnosis. In this study, we explore the preparation and characterization of gadolinium (Gd)-loaded poly (lactic-co-glycolic acid) (PLGA) particles surface modified with the Arg-Gly-Asp-Ser (RGDS) peptide for the detection of thrombus. PLGA was employed as the carrier-delivery system, and a double emulsion solvent-evaporation method (water in oil in water) was used to prepare PLGA particles encapsulating the magnetic resonance contrast agent Gd diethylenetriaminepentaacetic acid (DTPA). To synthesize the Gd-PLGA/chitosan (CS)-RGDS particles, carbodiimide-mediated amide bond formation was used to graft the RGDS peptide to CS to form a CS-RGDS film that coated the surface of the PLGA particles. Blank PLGA, Gd-PLGA, and Gd-PLGA/CS particles were fabricated using the same water in oil in water method. Our results indicated that the RGDS peptide successfully coated the surface of the Gd-PLGA/CS-RGDS particles. The particles had a regular shape, smooth surface, relatively uniform size, and did not aggregate. The high electron density of the Gd-loaded particles and a translucent film around the particles coated with the CS and CS-RGDS films could be observed by transmission electron microscopy. In vitro experiments demonstrated that the Gd-PLGA/CS-RGDS particles could target thrombi and could be imaged using a clinical magnetic resonance scanner. Compared with the Gd-DTPA solution, the longitudinal relaxation time of the Gd-loaded particles was slightly longer, and as the Gd-load concentration increased, the longitudinal relaxation time values decreased. These results suggest the potential of the Gd-PLGA/CS-RGDS particles for the sensitive and specific detection of thrombus at the molecular level.

Liposomes and polymers are widely used drug carriers for controlled release since they offer many advantages like increased treatment effectiveness, reduced toxicity and are of biodegradable nature. In this work, anticancer drug-loaded PLGA-lecithin-PEG nanoparticles (NPs) were synthesized and were functionalized with AS1411 anti-nucleolin aptamers for site-specific targeting against tumor cells which over expresses nucleolin receptors. The particles were characterized by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The drug-loading efficiency, encapsulation efficiency and in vitro drug release studies were conducted using UV spectroscopy. Cytotoxicity studies were carried out in two different cancer cell lines, MCF-7 and GI-1 cells and two different normal cells, L929 cells and HMEC cells. Confocal microscopy and flowcytometry confirmed the cellular uptake of particles and targeted drug delivery. The morphology analysis of the NPs proved that the particles were smooth and spherical in shape with a size ranging from 60 to 110 nm. Drug-loading studies indicated that under the same drug loading, the aptamer-targeted NPs show enhanced cancer killing effect compared to the corresponding non-targeted NPs. In addition, the PLGA-lecithin-PEG NPs exhibited high encapsulation efficiency and superior sustained drug release than the drug loaded in plain PLGA NPs. The results confirmed that AS1411 aptamer-PLGA-lecithin-PEG NPs are potential carrier candidates for differential targeted drug delivery., (Copyright © 2012 Wiley Periodicals, Inc.)

Purpose: To establish the biodistribution profile of the PLGA nanoparticles with dual surface modifications of PEG and folic acid (FA) in mice xenografted with MDA-MB-231 human breast cancer cells with high expression of folate receptor (FR); and to illustrate that the modified nanoparticles can target the loaded indocyanine green (ICG) to the tumor with high FR expression., Methods: ICG-loaded nanoparticles were prepared with PLGA (non-modified nanoparticles, NM-NP) or mPEG-PLGA and FA-PLGA (dual modified nanoparticles, DM-NP). Biodistribution of the ICG-loaded nanoparticles (1.25 mg/kg) after i.v. injection was investigated on athymic mice transplanted with MDA-MB-231 tumor., Results: ICG concentration in plasma from the DM-NP group was significantly (p<0.05) higher than the NM-NP group from 90 min to the end of the study (12 h). After 4 h, the drug concentration in the tumor tissue from the DM-NP started to be significantly (p<0.05) higher than the NM-NP until 12 h. Compared to the NM-NP, the DM-NP increased the AUC(0-12 h) in plasma by 245% and the AUC(0-12 h) in tumor by 194%, while decreased the AUC(0-12 h) in liver by 13%., Conclusion: The accumulation of DM-NP into the tumor was significantly higher than NM-NP due to the long circulation and FR-mediated uptake., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Introduction: Inflammation plays a key role in the progression of intervertebral disc degeneration, a condition strongly implicated as a cause of lower back pain. The objective of this study was to investigate the therapeutic potential of poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with interleukin-1 receptor antagonist (IL-1ra) for sustained attenuation of interleukin-1 beta (IL-1β) mediated degradative changes in the nucleus pulposus (NP), using an in vitro model., Methods: IL-1ra was encapsulated in PLGA microspheres and release kinetics were determined over 35 days. NP agarose constructs were cultured to functional maturity and treated with combinations of IL-1β and media conditioned with IL-1ra released from microspheres at intervals for up to 20 days. Construct mechanical properties, glycosaminoglycan content, nitrite production and mRNA expression of catabolic mediators were compared to properties for untreated constructs using unpaired Student's t-tests., Results: IL-1ra release kinetics were characterized by an initial burst release reducing to a linear release over the first 10 days. IL-1ra released from microspheres attenuated the degradative effects of IL-1β as defined by mechanical properties, glycosaminoglycans (GAG) content, nitric oxide production and mRNA expression of inflammatory mediators for 7 days, and continued to limit functional degradation for up to 20 days., Conclusions: In this study, we successfully demonstrated that IL-1ra microspheres can attenuate the degradative effects of IL-1β on the NP for extended periods. This therapeutic strategy may be appropriate for treating early-stage, cytokine-mediated disc degeneration. Ongoing studies are focusing on testing IL-1ra microspheres in an in vivo model of disc degeneration, as a prelude to clinical translation.

We prepared a complex drug delivery system consisted of rifampicin-poly(lactic-co-glycolic acid) (PLGA) microspheres in combination with sodium alginate in situ gel. The microspheres were obtained by using a solvent evaporation method, the mean diameter was 1.748 μm and the span of particle distribution was 0.78. The combination delivery system was obtained by adding microspheres to sodium alginate solution followed by physically mixing. In an in vitro study of drug release monitored for 11 days, the release of rifampicin from combination delivery system was slower than microspheres. The cumulative release percent of rifampicin from combination delivery system was 91.83 ± 1.26%, which was lower than 97.36 ± 3.41% of rifampicin released from microspheres. An in vivo fluorescence imaging study suggests that the gel adhered to lungs within 24h, and microspheres stayed in lungs at least for 504 h (21 days). In vivo drug release study indicates that the maximum local rifampicin concentration in lungs was 48.60 ± 15.67 μg mL(-1) 5h after administration. After 21 days, the local rifampicin concentration was 0.81±0.14μgmL(-1), which was above the minimum inhibitory concentration of rifampicin. The combination delivery system significantly prolonged RFP release compared to microspheres, from which RFP released could only be detected for 10 days. This approach to control the release of rifampicin using PLGA microspheres/in situ gel combination delivery system in conjunction with interventional technology is useful for improving anti-tuberculosis treatment effectiveness for patients., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Purpose: Nanomedicines represent an alternative for the treatment of aggressive glioblastoma tumors. Behaviour of PLGA-nanoparticles (NPs) was here investigated as a function of their protein adsorption characteristics at the different biological interfaces they are expected to face in order to reach brain cancer cells., Methods: NPs were studied for size, zeta potential, blood half-life, in vitro endocytic behavior and in vivo accumulation within healthy rat brain and brain tumors., Results: While slightly modifying size (80 to 90 nm) and zeta potential (-44 to -32 mV) protein coating of PLGA-NPs by bovine serum albumin (BSA) or transferrin (Tf) greatly prolonged their blood half-life when intravenously injected in rats and mice. In contrast with THP-1 monocytes, differentiated THP-1 macrophages, F98 glioma cells and astrocytes internalized BSA- and Tf-NPs in vitro. Increase of Tf-NP uptake by F98 cells through caveolae- and clathrin-mediated pathways supports specific interaction between Tf and overexpressed Tf-receptor. Finally, in vivo targeting of healthy brain was found higher with Tf-NPs than with BSA-NPs while both NPs entered massively within brain-developed tumors., Conclusion: Taken together, those data evidence that Tf-NPs represent an interesting nanomedicine to deliver anticancer drugs to glioma cells through systemic or locoregional strategies at early and late tumor stages.

Lymph node (LN) examination plays a critical role in the staging and treatment of several kinds of cancer such as lesions of the breast. However current strategies have limitations. This study aimed to develop a novel imaging agent, a polymeric ultrasonographic contrast agent carrying Sudan black (SB), for ultrasonographic imaging of the regional LNs before surgery and to directly localize the LNs during surgery. The poly(lactide-co-glycolide) (PLGA) ultrasonographic microbubbles carrying Sudan black B (SB) (SB-PLGA microbubbles) were prepared by the double emulsion method. The SB-PLGA microbubbles had a diameter of 1.5 ± 0.5 μm and the SB encapsulation efficiency was (86.2 ± 1.56%). Results from MTT assays suggested that these bubbles have little cytotoxicity to mouse macrophages after incubation. Confocal laser scanning microscopy showed that the PLGA microbubbles carrying the fluorescent dye rhodamine 6G were taken up by macrophages after 2-hour incubation. In addition, these SB-PLGA microbubbles were able to enhance ultrasonographic contrast of 12 popliteal LNs of 6 rabbits. Furthermore, the LNs were easily identifiable by the naked eye during surgery because of the blue color of the SB-PLGA microbubbles inside the LNs. By cryosectioning and hematoxylin and eosin (H&E) staining of LN tissue, our results showed that these SB-PLGA microbubbles were internalized inside the macrophages of the LNs. To conclude, the SB-PLGA microbubbles could be a suitable imaging agent for preoperative and intraoperative localization of LNs as well as for a preoperative ultrasonographically guided core needle biopsy of suspicious sentinel lymph nodes (SLNs) in cancer patients, hence enhancing treatment outcome., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Alpha 1-antitrypsin (α1AT) belongs to the superfamily of serpins and inhibits different proteases. α1AT protects the lung from cellular inflammatory enzymes. In the absence of α1AT, the degradation of lung tissue results to pulmonary complications. The pulmonary route is a potent noninvasive route for systemic and local delivery. The aerosolized α1AT not only affects locally its main site of action but also avoids remaining in circulation for a long period of time in peripheral blood. Poly (D, L lactide-co glycolide) (PLGA) is a biodegradable and biocompatible polymer approved for sustained controlled release of peptides and proteins. The aim of this work was to prepare a wide range of particle size as a carrier of protein-loaded nanoparticles to deposit in different parts of the respiratory system especially in the deep lung. Various lactide to glycolide ratio of the copolymer was used to obtain different release profile of the drug which covers extended and rapid drug release in one formulation., Results: Nonaqueous and double emulsion techniques were applied for the synthesis of nanoparticles. Nanoparticles were characterized in terms of surface morphology, size distribution, powder X-ray diffraction (XRD), encapsulation efficiency, in vitro drug release, FTIR spectroscopy and differential scanning calorimetry (DSC). To evaluate the nanoparticles cytotoxicity, cell cytotoxicity test was carried out on the Cor L105 human epithelial lung cancer cell line. Nanoparticles were spherical with an average size in the range of 100 nm to 1μ. The encapsulation efficiency was found to be higher when the double emulsion technique was applied. XRD and DSC results indicated that α1AT encapsulated in the nanoparticles existed in an amorphous or disordered-crystalline status in the polymer matrix. The lactic acid to glycolic acid ratio affects the release profile of α1AT. Hence, PLGA with a 50:50 ratios exhibited the ability to release %60 of the drug within 8, but the polymer with a ratio of 75:25 had a continuous and longer release profile. Cytotoxicity studies showed that nanoparticles do not affect cell growth and were not toxic to cells., Conclusion: In summary, α1AT-loaded nanoparticles may be considered as a novel formulation for efficient treatment of many pulmonary diseases.

In spite of good research in drug delivery, bone targeting remains largely unexplored. Even some of the bone diseases are seldom cured just because of poor distribution of drug at the bone site. Zoledronate (ZOL) having strong affinity towards bone and its utility in bone metastasis management makes it perfect ligand for bone targeting. Recent studies revealed that ZOL in combination with docetaxel showed significant synergism in the management of bone metastasis. From the results, it is clear that ZOL-conjugated PLGA nanoparticles (NPs) showed more cellular uptake than pegylated PLGA NPs with change in cellular uptake route. In vitro studies on MCF-7 and BO2 cell line revealed that ZOL anchored PLGA-PEG NPs showed enhanced cell cytotoxicity, increase in cell cycle arrest and more apoptotic activity. PLGA-PEG-ZOL NPs found to block mevalonate pathway and increase accumulation of apoptotic metabolites such as ApppI. In vivo animal studies using technetium-99m radiolabeling showed prolong blood circulation half-life, reduced liver uptake and significantly higher retention of ZOL tagged NPs at the bone site with enhanced tumor retention. Here, we can conclude that the targeting ability of ZOL enhanced by strong affinity to bone, enhanced endocytosis of ZOL anchored PLGA-PEG NPs., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The surface of nanoparticles is often functionalised with polymeric surfactants, in order to increase systemic circulation time. This has been investigated mainly for intravenously administered nanoparticles. This study aims to elucidate the effect of surface coating with various concentrations of polymeric surfactants (PEG and Pluronics F127) on the in vitro protein binding as well as the tissue biodistribution, post oral administration, of PLGA nanoparticles. The in vitro protein binding varied depending on the polymeric surfactant used. However, in vivo, 1% PEG and 1% Pluronics F127 coated particles presented similar biodistribution profiles in various tissues over seven days. Furthermore, the percentage of PEG and Pluronics coated particles detected in plasma was higher than that of uncoated PLGA particles, indicating that systemic circulation time can also be increased with oral formulations. The difference in the in vitro protein binding as a result of the different poloxamers used versus similar in vivo profiles of these particles indicates that in vitro observations for nanoparticles cannot represent or be correlated to the in vivo behaviour of the nanoparticles. Our results therefore suggest that more studies have to be conducted for oral formulations to give a better understanding of the kinetics of the particles., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Solanum tuberosum lectin (STL) conjugated poly (DL-lactic-co- glycolic acid) (PLGA) nanoparticle (STL-NP) was constructed in this paper as a novel biodegradable nose-to-brain drug delivery system. The in vitro uptake study showed markedly enhanced endocytosis of STL-NP compared to unmodified PLGA nanoparticles (NP) in Calu-3 cells and significant inhibition of uptake in the presence of inhibitor sugar (chitin hydrolysate). Following intranasal administration, coumarin-6 carried by STL-NP was rapidly absorbed into blood and brain. The AUC((0→12 h)) of coumarin-6 in blood, olfactory bulb, cerebrum and cerebellum were about 0.77-, 1.48-, 1.89- and 1.45-fold of those of NP, respectively (p < 0.05). STL-NP demonstrated 1.89-2.45 times (p < 0.01) higher brain targeting efficiency in different brain tissues than unmodified NP. Enhanced accumulation of STL-NP in the brain was also observed by near infrared fluorescence probe image following intranasal administration. The fluorescence signal of STL-NP appeared in olfactory bulb, cerebrum and brainstem early at 0.25 h. The signal in olfactory bulb decreased gradually after 2 h, while the obvious signal in brainstem, cerebrum and cerebellum lasted for more than 8 h. The STL-NP safety experiments showed mild cytotoxicity and negligible cilia irritation. These intriguing in vitro and in vivo results suggest that STL-NP might serve as a promising brain drug delivery system.

PLGA nanoparticles loaded with monensin (carboxylic ionophore) were prepared by emulsion solvent evaporation method using PLGA of molecular weight (Mw.) 19000 and 110000 Da. The nanoparticles were characterized by applying dynamic light scattering (DLS), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and Fourier transformed infrared spectroscopy (FTIR). Negatively charged and spherical smooth surfaced nanoparticles of size range between 147-167 nm were obtained. The nanoparticles of monensin-PLGA showed no chemical interaction between monensin and the polymer molecules. The release kinetics in vitro studies exhibited biphasic release profile characterized by an initial fast release followed by a slower release. The antimalarial efficacy of monensin-PLGA nanoparticles was also examined. Monensin loaded in nanoparticles was 10-fold more effective in inhibiting the growth of P. falciparum in vitro as compared to free monensin. The antimalarial efficacy of monensin-PLGA nanoparticles was significantly dependent on the Mw. of the polymer.

Although few experimental studies have been handled so far to exploit the potential of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) in the production of dry powders for antibiotic inhalation, there has been no comprehensive study on the role played by NP composition. In this work, we try to shed light on this aspect by designing and developing a pulmonary delivery system for antibiotics, such as tobramycin (Tb), based on PLGA NPs embedded in an inert microcarrier made of lactose, referred to as nano-embedded micro-particles (NEM). At nanosize level, helper hydrophilic polymers were used to impart the desired surface, bulk and release properties to PLGA NPs prepared by a modified emulsion-solvent diffusion technique. Results showed that poly(vinyl alcohol) (PVA) and chitosan (CS) are essential to optimise the size and modulate the surface properties of Tb-loaded PLGA NPs, whereas the use of alginate (Alg) allows efficient Tb entrapment within NPs and its release up to one month. Optimized formulations display good in vitro antimicrobial activity against P. aeruginosa planktonic cells. Furthermore, spray-drying of the NPs with lactose yielded NEM with peculiar but promising flow and aerosolization properties, while preserving the peculiar NP features. Nonetheless, in vivo biodistribution studies showed that PVA-modified Alg/PLGA NPs reached the deep lung, while CS-modified NPs were found in great amounts in the upper airways, lining lung epithelial surfaces. In conclusion, PLGA NP composition appears to play a crucial role in determining not only the technological features of NPs but, once processed in the form of NEM, also their in vitro/in vivo deposition pattern., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Biodistribution of nanoparticles is dependent on their physicochemical properties (such as size, surface charge, and surface hydrophilicity). Clear and systematic understanding of nanoparticle properties' effects on their in vivo performance is of fundamental significance in nanoparticle design, development and optimization for medical applications, and toxicity evaluation. In the present study, a physiologically based pharmacokinetic model was utilized to interpret the effects of nanoparticle properties on previously published biodistribution data. Biodistribution data for five poly(lactic-co-glycolic) acid (PLGA) nanoparticle formulations prepared with varied content of monomethoxypoly (ethyleneglycol) (mPEG) (PLGA, PLGA-mPEG256, PLGA-mPEG153, PLGA-mPEG51, PLGA-mPEG34) were collected in mice after intravenous injection. A physiologically based pharmacokinetic model was developed and evaluated to simulate the mass-time profiles of nanoparticle distribution in tissues. In anticipation that the biodistribution of new nanoparticle formulations could be predicted from the physiologically based pharmacokinetic model, multivariate regression analysis was performed to build the relationship between nanoparticle properties (size, zeta potential, and number of PEG molecules per unit surface area) and biodistribution parameters. Based on these relationships, characterized physicochemical properties of PLGA-mPEG495 nanoparticles (a sixth formulation) were used to calculate (predict) biodistribution profiles. For all five initial formulations, the developed model adequately simulates the experimental data indicating that the model is suitable for description of PLGA-mPEG nanoparticle biodistribution. Further, the predicted biodistribution profiles of PLGA-mPEG495 were close to experimental data, reflecting properly developed property-biodistribution relationships.

Aim: To characterize the pharmacokinetic and pharmacodynamic profiles of the recombinant human erythropoietin (rhEPO)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres in rats., Methods: The rhEPO-loaded microspheres were prepared using a solid-in-oil-in-water emulsion method. Pharmacokinetics and pharmacodynamics of the rhEPO-loaded microspheres were evaluated in male Sprague-Dawley rats. The serum rhEPO level was determined with ELISA. The level of anti-rhEPO antibody in the serum was measured to assess the immunogenicity of rhEPO released from the microspheres., Results: rhEPO was almost completely released from the PLGA microspheres in vitro, following zero-order release kinetics over approximately 30 d. After intramuscular injection (10,000 or 30,000 IU rhEPO/kg) in the rats, the serum rhEPO concentration reached maximum levels on d 1, then decreased gradually and was maintained at nearly steady levels for approximately 4 weeks. Furthermore, the release of rhEPO from the PLGA microspheres was found to be controlled mainly by a dissolution/diffusion mechanism. A good linear correlation (R(2)=0.98) was obtained between the in vitro and in vivo release data. A single intramuscular injection of the rhEPO-loaded PLGA microspheres (10,000 or 30,000 IU rhEPO/kg) in the rats resulted in elevated hemoglobin and red blood cell concentrations for more than 28 d. Moreover, the immunogenicity of rhEPO released from the PLGA microspheres was comparable with that of the unencapsulated rhEPO., Conclusion: The results prove the feasibility of using the PLGA-based microspheres to deliver rhEPO for approximately 1 month.

Curcumin, a natural polyphenolic pigment present in the spice turmeric (Curcuma longa), is known to possess a pleiotropic activity such as antioxidant, anti-inflammatory, and anti-amyloid-β activities. However, these benefits of curcumin are limited by its poor aqueous solubility and oral bioavailability. In the present study, a polymer-based nanoparticle approach has been utilized to deliver drugs to neuronal cells. Curcumin was encapsulated in biodegradable poly (lactide-co-glycolide) (PLGA) based-nanoparticulate formulation (Nps-Cur). Dynamic laser light scattering and transmission electronic microscopy analysis indicated a particle diameter ranging from 80 to 120 nm. The entrapment efficiency was 31% with 15% drug-loading. In vitro release kinetics of curcumin from Nps-Cur revealed a biphasic pattern with an initial exponential phase followed by a slow release phase. Cellular internalization of Nps-Cur was confirmed by fluorescence and confocal microscopy with a wide distribution of the fluorescence in the cytoplasm and within the nucleus. The prepared nanoformulation was characterized for cellular toxicity and biological activity. Cytotoxicity assays showed that void PLGA-nanoparticles (Nps) and curcumin-loaded PLGA nanoparticles (Nps-Cur) were nontoxic to human neuroblastoma SK-N-SH cells. Moreover, Nps-Cur was able to protect SK-N-SH cells against H2O2 and prevent the elevation of reactive oxygen species and the consumption of glutathione induced by H2O2. Interestingly, Nps-Cur was also able to prevent the induction of the redox-sensitive transcription factor Nrf2 in the presence of H2O2. Taken together, these results suggest that Nps-Cur could be a promising drug delivery strategy to protect neurons against oxidative damage as observed in Alzheimer's disease.

To improve poor water solubility of cyclosporine A (CsA), hydroxypropyl-beta-cyclodextrin (HPβCD) was incorporated into the nanoparticle formulation. Solid complexes of CsA with HPβCD in different ratios were prepared by the kneading method. CsA containing alone or in combination with HPβCD in poly-lactide-co-glycolide (P-CsA or P-CsA-HPβCD) nanoparticles were prepared by the emulsification solvent evaporation method. The mean size of CsA-loaded NPs was found to be approximately 220 nm. The solubility of CsA was significantly improved and the phase solubility diagram of CsA-HPβCD systems showed an A(L) type phase. Nanoparticles showed high CsA encapsulation efficiency (88%) and production yield (89%). Release rate was increased by the presence of HPβCD and total cumulative release ranged from 75% to 96% in 24 h. In vitro cytotoxicity study assay resulted in a low toxicity for all types of nanoparticles. After 6 h incubation period, the cellular uptake was found at 33% and 32% for P-CsA and P-HPβCD-CsA nanoparticles, respectively.

Purpose: To develop a novel brain drug delivery system based on self-assembled poly(ethyleneglycol)-poly (D,L-lactic-co-glycolic acid) (PEG-PLGA) polymersomes conjugated with lactoferrin (Lf-POS). The brain delivery properties of Lf-POS were investigated and optimized., Method: Three formulations of Lf-POS, with different densities of lactoferrin on the surface of polymersomes, were prepared and characterized. The brain delivery properties in mice were investigated using 6-coumarin as a fluorescent probe loaded in Lf-POS (6-coumarin-Lf-POS). A neuroprotective peptide, S14G-humanin, was incorporated into Lf-POS (SHN-Lf-POS); a protective effect on the hippocampuses of rats treated by Amyloid-β(25-35) was investigated by immunohistochemical analysis., Results: The results of brain delivery in mice demonstrated that the optimized number of lactoferrin conjugated per polymersome was 101. This obtains the greatest blood-brain barrier (BBB) permeability surface area(PS) product and percentage of injected dose per gram brain (%ID/g brain). Immunohistochemistry revealed the SHN-Lf-POS had a protective effect on neurons of rats by attenuating the expression of Bax and caspase-3 positive cells. Meanwhile, the activity of choline acetyltransferase (ChAT) had been increased compared with negative controls., Conclusion: These results suggest that lactoferrin functionalized self-assembled PEG-PLGA polymersomes could be a promising brain-targeting peptide drug delivery system via intravenous administration.

The aim of this research was to increase the oral bioavailability of daidzein by the formulations of poly(lactic-co-glycolic) acid (PLGA) nanoparticles loaded with daidzein. Amongst the various traditional and novel techniques of preparing daidzein-loaded PLGA nanoparticles, daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles were selected. The average drug entrapment efficiency, particle size, and zeta potential of daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles were 81.9% ± 5%, 309.2 ± 14.0 nm, -32.14 ± 2.53 mV and 83.2% ± 7.2%, 323.2 ± 4.8 nm, -18.73 ± 1.68 mV, respectively. The morphological characterization of nanoparticles was observed with scanning electron microscopy by stereological method and the physicochemical state of nanoparticles was valued by differential scanning calorimetry. The in vitro drug-release profile of both nanoparticle formulations fitted the Weibull dynamic equation. Pharmacokinetic studies demonstrated that after oral administration of daidzein-loaded phospholipid complexes PLGA nanoparticles and daidzein-loaded cyclodextrin inclusion complexes PLGA nanoparticles to rats at a dose of 10 mg/kg, relative bioavailability was enhanced about 5.57- and 8.85-fold, respectively, compared to daidzein suspension as control. These results describe an effective strategy for oral delivery of daidzein-loaded PLGA nanoparticles and might provide a fresh approach to enhancing the bioavailability of drugs with poor lipophilic and poor hydrophilic properties.

Human immunodeficiency viruses (HIV) hide themselves in macrophages at the early stage of infection. Delivering drug in a sustained manner from polymeric nanoparticles in those cells could control the disease effectively. The study was intended to develop poly(d,l-lactic-co-glycolic acid)-based nanoparticles containing didanosine and to observe their uptake by macrophages in vitro. Various physicochemical evaluations related to nanoparticles, such as drug-excipient interaction, surface morphology, particle size, zeta potential, polydispersity index, drug loading, in vitro drug release and nanoparticle-uptake by macrophages in vitro were determined. Homogenising speeds and drug-polymer ratio varied drug loading and polydispersity index of nanoparticles, providing sustained drug release. Dimethyl sulphoxide/polyethylene glycol improved drug loading predominantly. Nanoparticle-uptake by macrophages was concentration dependent. Experimental nanoparticles successfully transported didanosine to macrophages in vitro, suggesting reduction of dose, thus minimising toxicity and side effects. Developed nanoparticle may control HIV infection effectively at an early stage.

Olanzapine (OZ) is a second-generation or atypical antipsychotic which selectively binds to central dopamine D₂ and serotonin (5-HT(2c)) receptors. It has poor bioavailability due to hepatic first-pass metabolism and low permeability into the brain due to efflux by P-glycoproteins. The present investigation aimed to prepare a nanoparticulate drug delivery system of OZ using poly(lactic-co-glycolic acid) (PLGA) for direct nose-to-brain delivery to provide brain targeting and sustained release. PLGA nanoparticles (NP) were prepared by the nanoprecipitation technique and characterized by entrapment efficiency, particle size, zeta potential, modulated temperature differential scanning calorimetry (MTDSC) and X-ray diffraction (XRD) studies. The NP were evaluated for in vitro release, ex vivo diffusion, toxicity and pharmacokinetic studies. The NP were 91.2±5.2 nm in diameter and had entrapment efficiency 68.91±2.31%. MTDSC studies indicated broadening of the drug peak and a shift in the polymer peak, possibly due to physical interaction or H-bonding between the carbonyl groups of PLGA and the NH groups of OZ, and also due to the plasticization effect of OZ on PLGA. XRD studies indicated a decrease in the crystallinity of OZ or amorphization. In vitro drug release showed a biphasic pattern with initial burst release and, later, sustained release (43.26±0.156% after 120 h), following the Fickian diffusion-based release mechanism. Ex vivo diffusion through sheep nasal mucosa showed 13.21±1.59% of drug diffusion in 210 min from NP. Histopathological study of sheep nasal mucosa showed no significant adverse effect of OZ-loaded NP. In vivo pharmacokinetic studies showed 6.35 and 10.86 times higher uptake of intranasally delivered NP than OZ solution delivered through intravenous (IV) and intranasal (IN) route, respectively. These results proved that OZ could be transported directly to the brain after IN delivery of PLGA NP, enhanced drug concentration in the brain and would therefore be effective in improving the treatment of central nervous system disorders., (Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

It has been proposed that localized and controlled delivery of alendronate and tetracycline to periodontal pocket fluids via guided tissue regeneration (GTR) membranes may be a valuable adjunctive treatment for advanced periodontitis. The objectives of this work were to develop a co-loaded, controlled release tetracycline and alendronate nanocomposite plasticized poly(lactic-co-glycolic acid) (PLGA) film that would form a suitable matrix supporting osteoblast proliferation and differentiation. Alendronate release was successfully controlled, with complete suppression of the burst phase of release by intercalation of alendronate anions in magnesium/aluminum layered double hydroxide (LDH) clay nanoparticles and dispersed in the PLGA film matrix. Tetracycline, loaded as free drug into the film together with alendronate-LDH clay complex released more rapidly than alendronate, but showed evidence of intercalation in the LDH clay particles. The dual drug loaded nanocomposite films were biocompatible with osteoblasts and after 5 week incubations, significant increase in alkaline phosphatase activity and bone nodule formation were observed., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Objective: • To determine if hyaluronic acid (HA) can be incorporated into porcine small intestinal submucosa (SIS) through poly (lactide-co-glycolide-acid) (PLGA) nanoparticles to improve the consistency of the naturally derived biomaterial and promote bladder tissue regeneration., Methods: • Beagle dogs were subjected to 40% partial cystectomy followed by bladder augmentation with commercial SIS or HA-PLGA-modified SIS. • Urodynamic testing was performed before and after augmentation to assess bladder volume. • A scoring system was created to evaluate gross and histological presentations of regenerative bladders., Results: • All dogs showed full-thickness bladder regeneration. • Histological assessment showed improved smooth muscle regeneration in the HA-PLGA-modified SIS group. • For both groups of dogs, urodynamics and graft measurements showed an approximate 40% reduction in bladder capacity and graft size from pre-augmentation to post-regeneration measurements. • Application of the scoring system and statistical analysis failed to show a significant difference between the groups., Conclusions: • SIS can be modified through the addition of HA-PLGA nanoparticles. The modified grafts showed evidence of improved smooth muscle regeneration on histological assessment, although this difference was not evident on a novel grading scale. • The volume loss and graft shrinkage experienced are consistent with previous models of SIS bladder regeneration at the 10-week time point. • Additional research into the delivery of HA and the long-term benefits of HA on bladder regeneration is needed to determine the full benefit of HA-PLGA-modified SIS. In addition, a more objective biochemical characterization will be needed to evaluate the quality of regeneration., (© 2010 THE AUTHORS. BJU INTERNATIONAL © 2010 BJU INTERNATIONAL.)

Several naturally occurring coumarin compounds, including scopoletin (7 hydroxy-6 methoxycoumarin), of plant origin have been reported to have anti-cancer potentials. A related but chemically synthesized coumarin, 4-methyl-7-hydroxy coumarin (SC), was also shown to have similar anti-cancer potentials. In the present study, to test if nano-encapsulated SC could be a more potent anti-cancer agent, we encapsulated SC with poly lactide-co-glycolide acid (PLGA) nanoparticles (Nano Coumarin; NC) and tested its potentials with a variety of protocols. NC demonstrated greater efficiency of drug uptake and showed anti-cancer potentials in melanoma cell line A375, as revealed from scanning electronic and atomic force microscopies. To test its possible interaction with target DNA, the combined data of circular dichroism spectra (CD) and melting temperature profile (T(m)) of calf thymus DNA treated with NC were analyzed. Results indicated a concentration dependent interaction of NC with calf thymus DNA, bringing in effective change in structure and conformation, and forming a new complex that increased its stability. Particle size and morphology of NC determined through polydispersity index and zeta potential using dynamic light scattering qualified NC to be a more potent anti-cancer agent than SC. Further, SC and NC showed negligible cytotoxic effects on normal skin cells and peripheral blood mononuclear cells of mice. Distribution assay of PLGA nanoparticles in different tissues like brain, heart, kidneys, liver, lungs, and spleen in mice revealed the presence of nanoparticles in different tissues including brain, indicating that the particles could cross the blood brain barrier, significant information for drug design., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Nanoscaled devices have great potential for drug delivery applications due to their small size. In the present study, we report for the first time the preparation and evaluation of antitumor efficacy of 5-fluorouracil (5-FU)-entrapped poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles with dependence on the lactide/glycolide combination of PLGA. 5-FU-loaded PLGA nanoparticles with two different monomer combinations, 50-50 and 90-10 were synthesized using a modified double emulsion method, and their biological evaluation was done in glioma (U87MG) and breast adenocarcinoma (MCF7) cell lines. 5-FU-entrapped PLGA 50-50 nanoparticles showed smaller size with a high encapsulation efficiency of 66%, which was equivalent to that of PLGA 90-10 nanoparticles. Physicochemical characterization of nanoparticles using differential scanning calorimetry and X-ray diffraction suggested the presence of 5-FU in molecular dispersion form. In vitro release studies showed the prolonged and sustained release of 5-FU from nanoparticles with both the PLGA combinations, where PLGA 50-50 nanoparticles showed faster release. Nanoparticles with PLGA 50-50 combination exhibited better cytotoxicity than free drug in a dose- and time-dependent manner against both the tumor cell lines. The enhanced efficiency of PLGA 50-50 nanoparticles to induce apoptosis was indicated by acridine orange/ethidium bromide staining. Cell cycle perturbations studied using flow cytometer showed better S-phase arrest by nanoparticles in comparison with free 5-FU. All the results indicate that PLGA 50-50 nanoparticles possess better antitumor efficacy than PLGA 90-10 nanoparticles and free 5-FU. Since, studies have shown that long-term exposure of ailing tissues to moderate drug concentrations is more favorable than regular administration of higher concentration of the drug; our results clearly indicate the potential of 5-FU-loaded PLGA nanoparticles with dependence on carrier combination as controlled release formulation to multiplex the therapeutic effect of cancer chemotherapy.

Background: Polymeric micelles using amphiphilic macromolecules are promising vehicles for antitumor targeting. In this study, we prepared anticancer agent-incorporated polymeric micelles using novel block copolymer., Methods: We synthesized a block copolymer composed of dextran and poly (DL-lactide-co-glycolide) (DexbLG) for antitumor drug delivery. Doxorubicin was selected as the anticancer drug, and was incorporated into polymeric micelles by dialysis. Polymeric micelles were observed by transmission electron microscopy to be spherical and smaller than 100 nm, with a narrow size distribution. The particle size of doxorubicin-incorporated polymeric micelles increased with increasing drug content. Higher initial drug feeding also increased the drug content., Results: During the drug-release study, an initial burst release of doxorubicin was observed for 10 hours, and doxorubicin was continuously released over 4 days. To investigate the in vitro anticancer effects of the polymeric micelles, doxorubicin-resistant HuCC-T1 cells were treated with a very high concentration of doxorubicin. In an antiproliferation study, the polymeric micelles showed higher cytotoxicity to doxorubicin-resistant HuCC-T1 cells than free doxorubicin, indicating that the polymeric micelles were effectively engulfed by tumor cells, while free doxorubicin hardly penetrated the tumor cell membrane. On confocal laser scanning microscopy, free doxorubicin expressed very weak fluorescence intensity, while the polymeric micelles expressed strong red fluorescence. Furthermore, in flow cytometric analysis, fluorescence intensity of polymeric micelles was almost twice as high than with free doxorubicin., Conclusion: DexbLG polymeric micelles incorporating doxorubicin are promising vehicles for antitumor drug targeting.