Evaluating the Efficacy of Polyglycolic Acid-Loading Tetrandrine Nanoparticles in the Treatment of Dry Eye.

INTRODUCTION: Dry eye disease (DED) is a multifactor-induced disease accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. Traditional anti-inflammation agent corticosteroids applied in DED treatment could result in high intraocular pressure, especially in long-term treatment. Therefore, we explored a nano drug that aimed to block the formation pathway of DED which had anti-inflammatory, sustained release, and good biocompatibility characteristics in this study. METHODS: We prepared a novel nanomedicine (Tet-ATS@PLGA) by the thin film dispersion-hydration ultrasonic method and detected its nanostructure, particle size, and zeta potential. Flow cytometry was used to detect the cell survival rate of each group after 24 h of drug treatment on inflammed Statens Seruminstitut Rabbit Corneal (SIRC) cells. Observed and recorded corneal epithelial staining, tear film rupture time, and Schirmer test to detect tear secretion on the ocular surface of rabbits. The corneal epithelial thickness, morphology, and number of bulbar conjunctival goblet cells were recorded by H&E staining. Finally, we detected the expression of VEGF, IL-1ß, PGE2, and TNF-α by cellular immunofluorescence staining and enzyme-linked immunosorbent assay (ELISA). RESULTS: The encapsulation efficiency and drug loading of Tet-ATS@PLGA were 79.85% and 32.47%, respectively. At eye surface temperature, Tet can easily release from Tet-ATS@PLGA while that it was difficult to release at storage temperature and room temperature. After 2 weeks medication, Tet-ATS@PLGA can effectively improve the tear film rupture time and tear secretion time in a DED model (p <0.05). Compared with the normal group (62.34 ± 4.86 mm), the thickness of corneal epithelium in ATS (29.47 ± 3.21 mm), Tet-ATS (46.23 ± 2.87 mm), and Tet-ATS@PLGA (55.76 ± 3.95 mm) gradually increased. Furthermore, the flow cytometry indicated that Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory SIRC cells, and the cellular immunofluorescence and ELISA experiments showed that the expression intensity of inflammatory factors such as VEGF, IL-1ß, PGE2, and TNF-α decreased in this process. Interestingly, Tet also had the effect of reducing intraocular pressure. CONCLUSION: Tet-ATS@PLGA can effectively promote the apoptosis of inflammatory corneal epithelial cells, thus inhibiting the expression of inflammatory factors to block the formation of DED and improve the secretion of tear on the ocular surface.

In vitro and in vivo evaluation of DC-targeting PLGA nanoparticles encapsulating heparanase CD4+ and CD8+ T-cell epitopes for cancer immunotherapy.

Heparanase has been identified as a universal tumor-associated antigen, but heparanase epitope peptides are difficult to recognize. Therefore, it is necessary to explore novel strategies to ensure efficient delivery to antigen-presenting cells. Here, we established a novel immunotherapy model targeting antigens to dendritic cell (DC) receptors using a combination of heparanase CD4+ and CD8+ T-cell epitope peptides to achieve an efficient cytotoxic T-cell response, which was associated with strong activation of DCs. First, pegylated poly(lactic-coglycolic acid) (PLGA) nanoparticles (NPs) were used to encapsulate a combined heparanase CD4+ and CD8+ T-cell epitope alone or in combination with Toll-like receptor 3 and 7 ligands as a model antigen to enhance immunogenicity. The ligands were then targeted to DC cell-surface molecules using a DEC-205 antibody. The binding and internalization of these PLGA NPs and the activation of DCs, the T-cell response and the tumor-killing effect were assessed. The results showed that PLGA NPs encapsulating epitope peptides (mHpa399 + mHpa519) could be targeted to and internalized by DCs more efficiently, stimulating higher levels of IL-12 production, T-cell proliferation and IFN-γ production by T cells in vitro. Moreover, vaccination with DEC-205-targeted PLGA NPs encapsulating combined epitope peptides exhibited higher tumor-killing efficacy both in vitro and in vivo. In conclusion, delivery of PLGA NP vaccines targeting DEC-205 based on heparanase CD4+ and CD8+ T-cell epitopes are suitable immunogens for antitumor immunotherapy and have promising potential for clinical applications.

TrkA inhibitor promotes motor functional regeneration of recurrent laryngeal nerve by suppression of sensory nerve regeneration.

Recurrent laryngeal nerve (RLN) injury, in which hoarseness and dysphagia arise as a result of impaired vocal fold movement, is a serious complication. Misdirected regeneration is an issue for functional regeneration. In this study, we demonstrated the effect of TrkA inhibitors, which blocks the NGF-TrkA pathway that acts on the sensory/automatic nerves thus preventing misdirected regeneration among motor and sensory nerves, and thereby promoting the regeneration of motor neurons to achieve functional recovery. RLN axotomy rat models were used in this study, in which cut ends of the nerve were bridged with polyglycolic acid-collagen tube with and without TrkA inhibitor (TrkAi) infiltration. Our study revealed significant improvement in motor nerve fiber regeneration and function, in assessment of vocal fold movement, myelinated nerve regeneration, compound muscle action potential, and prevention of laryngeal muscle atrophy. Retrograde labeling demonstrated fewer labeled neurons in the vagus ganglion, which confirmed reduced misdirected regeneration among motor and sensory fibers, and a change in distribution of the labeled neurons in the nucleus ambiguus. Our study demonstrated that TrkAi have a strong potential for clinical application in the treatment of RLN injury.

Low power laser irradiation and human adipose-derived stem cell treatments promote bone regeneration in critical-sized calvarial defects in rats.

Both stem cell therapy and physical treatments have been shown to be beneficial in accelerating bone healing. However, the efficacy of combined treatment with stem cells and physical stimuli for large bone defects remains uncertain. The aim of this study was to evaluate the bone regeneration effects of low-power laser irradiation (LPLI) and human adipose-derived stem cell (ADSC) treatments during fracture repair using a comparative rat calvarial defect model. We evaluated the viability of human ADSCs, which were cultured on a porous PLGA scaffold using an MTS assay. The critical-sized calvarial bone defect rats were divided into 4 groups: control group, LPLI group, ADSC group, and ADSC+LPLI group. Bone formation was evaluated using micro-CT. New bone formation areas and osteogenic factor expression levels were then examined by histomorphological analysis and immunohistochemical staining. Our data showed that PLGA had no cytotoxic effect on human ADSCs. Micro-CT analyses revealed that both the LPLI and ADSC groups showed improved calvarial bone defect healing compared to the control group. In addition, the ADSC+LPLI group showed significantly increased bone volume at 16 weeks after surgery. The area of new bone formation ranked as follows: control group < LPLI group < ADSC group < ADSC+LPLI group. There were significant differences between the groups. In addition, both ADSC and ADSC+LPLI groups showed strong signals of vWF expression. ADSC and LPLI treatments improved fracture repair in critical-sized calvarial defects in rats. Importantly, the combined treatment of ADSCs and LPLI further enhances the bone healing process.

Etoposide-Loaded Poly(Lactic-co-Glycolic Acid) Intravitreal Implants: In Vitro and In Vivo Evaluation.

Etoposide-loaded poly(lactic-co-glycolic acid) implants were developed for intravitreal application. Implants were prepared by a solvent-casting method and characterized in terms of content uniformity, morphology, drug-polymer interaction, stability, and sterility. In vitro drug release was investigated and the implant degradation was monitored by the percent of mass loss. Implants were inserted into the vitreous cavity of rabbits' eye and the in vivo etoposide release profile was determined. Clinical examination and the Hen Egg Test-Chorioallantoic Membrane (HET-CAM) method were performed to evaluate the implant tolerance. The original chemical structure of the etoposide was preserved after incorporation in the polymeric matrix, which the drug was dispersed uniformly. In vitro, implants promoted sustained release of the drug and approximately 57% of the etoposide was released in 50 days. In vivo, devices released approximately 63% of the loaded drug in 42 days. Ophthalmic examination and HET-CAM assay revealed no evidence of toxic effects of implants. These results tend to show that etoposide-loaded implants could be potentially useful as an intraocular etoposide delivery system in the future.

Molybdenum cluster loaded PLGA nanoparticles: An innovative theranostic approach for the treatment of ovarian cancer.

We evaluate poly (d,l-lactide-co-glycolide) (PLGA) nanoparticles embedding inorganic molybdenum octahedral cluster for photodynamic therapy of cancer (PDT). Tetrabutyl ammonium salt of Mo6Br14 cluster unit, (TBA)2Mo6Br14, presents promising photosensitization activity in the destruction of targeted cancer cells. Stable cluster loaded nanoparticles (CNPs) were prepared by solvent displacement method showing spherical shapes, zeta potential values around -30 mV, polydispersity index lower than 0.2 and sizes around 100 nm. FT-IR and DSC analysis revealed the lack of strong chemical interaction between the cluster and the polymer within the nanoparticles. In vitro release study showed that (TBA)2Mo6Br14 was totally dissolved in 20 min, while CNPs were able to control the release of encapsulated cluster. In vitro cellular viability studies conducted on A2780 ovarian cancer cell line treated up to 72 h with cluster or CNPs did not show any sign of toxicity in concentrations up to 20 µg/ml. This concentration was selected for photo-activation test on A2780 cells and CNPs were able to generate oxygen singlet resulting in a decrease of the cellular viability up to 50%, respectively compared to non-activated conditions. This work presents (TBA)2Mo6Br14 as a novel photosensitizer for PDT and suggests PLGA nanoparticles as an efficient delivery system intended for tumor targeting.

Preparation and characterization of surface-modified PLGA-polymeric nanoparticles used to target treatment of intestinal cancer.

Docetaxel (DTX), a cytotoxic taxane, is a poor water-soluble drug and exhibits less oral bioavailability. Current research investigates the effective transport, for DTX-loaded chitosan (CS)-coated-poly-lactide-co-glycolide (PLGA)-nanoparticles (NPs) (DTX-CS-PLGA-NPs) and DTX-PLGA-NPs as well as a novel third-generation P-gp inhibitor i.e. GF120918 (Elacridar), across intestinal epithelium with its successive uptake by the tumour cells in an in vitro model. The prepared NPs showed a spherical shape particle size i.e. <123.96 nm with polydispersity index (PDI) of <0.290 whereas for CS-coated NPs, the zeta potential was converted from negative to positive value along with a small modification in particle size distribution. The entrapment efficiency observed for DTX-CS-PLGA-NPs was 74.77%, whereas the in vitro release profile revealed an initial rapid DTX release followed by a sustained release pattern. For apparent permeability, DTX-CS-PLGA-NPs and DTX-PLGA-NPs along with GF120918 showed a five-fold (p < .01) and 2.2-fold enhancement, respectively, as observed in rat ileum permeation study. Similarly, for pharmacokinetic (PK) studies, higher oral bioavailability was observed from DTX-CS-PLGA-NPs (5.11-folds) and DTX-PLGA-NPs (3.29-folds) as compared with DTX-suspension (DTX-S). Cell uptake studies on A549 cells as performed for DTX-CS-PLGA-NPs and DTX-PLGA-NPs loaded with rhodamine 123 dye, exhibited enhanced uptake as compared with plain dye solution. The enhanced uptake for DTX-CS-PLGA-NPs and DTX-PLGA-NPs formulations in the presence of GF120918 was confirmed further with the help of confocal laser scanning microscopic images (CLSM). The potential of the third-generation novel P-gp inhibitor (GF120918) investigated for the effective delivery of DTX as well as investigation of permeability and uptake studies whereby a strong potential of GF120918 for effective oral delivery was established.

Distribution of PLGA-modified nanoparticles in 3D cell culture models of hypo-vascularized tumor tissue.

BACKGROUND: Advanced stage cancer treatments are often invasive and painful-typically comprised of surgery, chemotherapy, and/or radiation treatment. Low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies. To address these transport challenges, nanoparticles (NPs) are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. Here, we evaluate stealth polyethylene-glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies in 3D cell culture representing hypo-vascularized tissue. RESULTS: Smaller, more regularly-shaped avascular tissue was generated using the hanging drop (HD) method, while more irregularly-shaped masses were formed with the liquid overlay (LO) technique. To compare NP distribution differences within the same type of tissue as a function of different cancer types, we selected HeLa, cervical epithelial adenocarcinoma cells; CaSki, cervical epidermoid carcinoma cells; and SiHa, grade II cervical squamous cell carcinoma cells. In HD tumors, enhanced distribution relative to unmodified NPs was measured for MPG and PEG NPs in HeLa, and for all modified NPs in SiHa spheroids. In LO tumors, the greatest distribution was observed for MPG and MPG/PEG NPs in HeLa, and for PEG and MPG/PEG NPs in SiHa spheroids. CONCLUSIONS: Pre-clinical evaluation of PLGA-modified NP distribution into hypo-vascularized tumor tissue may benefit from considering tissue morphology in addition to cancer type.

Ciprofloxacin-loaded PLGA nanoparticles against cystic fibrosis P. aeruginosa lung infections.

Current pulmonary treatments against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lung suffer from deactivation of the drug and immobilization in thick and viscous biofilm/mucus blend, along with the general antibiotic resistance. Administration of nanoparticles (NPs) with high antibiotic load capable of penetrating the tight mesh of biofilm/mucus can be an advent to overcome the treatment bottlenecks. Biodegradable and biocompatible polymer nanoparticles efficiently loaded with ciprofloxacin complex offer a solution for emerging treatment strategies. NPs were prepared under controlled conditions by utilizing MicroJet Reactor (MJR) to yield a particle size of 190.4±28.6nm with 0.089 PDI. Encapsulation efficiency of the drug was 79% resulting in a loading of 14%. Release was determined to be controlled and medium-independent in PBS, PBS+0.2% Tween 80 and simulated lung fluid. Cytotoxicity assays with Calu-3 cells and CF bronchial epithelial cells (CFBE41o-) indicated that complex-loaded PLGA NPs were non-toxic at concentrations ≫ MICcipro against lab strains of the bacteria. Antibacterial activity tests revealed enhanced activity when applied as nanoparticles. NPs' colloidal stability in mucus was proven. Notably, a decrease in mucus turbidity was observed upon incubation with NPs. Herewith, ciprofloxacin complex-loaded PLGA NPs are introduced as promising pulmonary nano drug delivery systems against P.aeruginosa infections in CF lung.

Laser irradiated fluorescent perfluorocarbon microparticles in 2-D and 3-D breast cancer cell models.

Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work.

Development of a Sustainable Release System for a Ranibizumab Biosimilar Using Poly(lactic-co-glycolic acid) Biodegradable Polymer-Based Microparticles as a Platform.

Ranibizumab is a humanized monoclonal antibody fragment against vascular endothelial growth factor (VEGF)-A and is widely used to treat age-related macular degeneration (AMD) caused by angiogenesis. Ranibizumab has a short half-life in the eye due to its low molecular weight and susceptibility to proteolysis. Monthly intravitreal injection of a large amount of ranibizumab formulation is a burden for both patients and medical staff. We therefore sought to develop a sustainable release system for treating the eye with ranibizumab using a drug carrier. A ranibizumab biosimilar (RB) was incorporated into microparticles of poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer. Ranibizumab was sustainably released from PLGA microparticles (80+% after 3 weeks). Assay of tube formation by endothelial cells indicated that RB released from PLGA microparticles inhibited VEGF-induced tube formation and this tendency was confirmed by a cell proliferation assay. These results indicate that RB-loaded PLGA microparticles are useful for sustainable RB release and suggest the utility of intraocular sustainable release systems for delivering RB site-specifically to AMD patients.

PLGA nanoparticles for the oral delivery of nuciferine: preparation, physicochemical characterization and in vitro/in vivo studies.

This article reports a promising approach to enhance the oral delivery of nuciferine (NUC), improve its aqueous solubility and bioavailability, and allow its controlled release as well as inhibiting lipid accumulation. NUC-loaded poly lactic-co-glycolic acid nanoparticles (NUC-PLGA-NPs) were prepared according to a solid/oil/water (s/o/w) emulsion technique due to the water-insolubility of NUC. PLGA exhibited excellent loading capacity for NUC with adjustable dosing ratios. The drug loading and encapsulation efficiency of optimized formulation were 8.89 ± 0.71 and 88.54 ± 7.08%, respectively. NUC-PLGA-NPs exhibited a spherical morphology with average size of 150.83 ± 5.72 nm and negative charge of -22.73 ± 1.63 mV, which are suitable for oral administration. A sustained NUC released from NUC-PLGA-NPs with an initial exponential release owing to the surface associated drug followed by a slower release of NUC, which was entrapped in the core. In addition, ∼77 ± 6.67% was released in simulating intestinal juice, while only about 45.95 ± 5.2% in simulating gastric juice. NUC-PLGA-NPs are more efficient against oleic acid (OA)-induced hepatic steatosis in HepG2 cells when compared to naked NUC (n-NUC, *p < 0.05). The oral bioavailability of NUC-PLGA-NPs group was significantly higher (**p < 0.01) and a significantly decreased serum levels of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), as well as a higher concentration of high-density lipoprotein cholesterol (HDL-C) was observed, compared with that of n-NUC treated group. These findings suggest that NUC-PLGA-NPs hold great promise for sustained and controlled drug delivery with improved bioavailability to alleviating lipogenesis.

Exploring polyvinylpyrrolidone in the engineering of large porous PLGA microparticles via single emulsion method with tunable sustained release in the lung: In vitro and in vivo characterization.

Sustained pulmonary drug delivery is regarded as an effective strategy for local treatment of chronic lung diseases. Despite of the progress made so far, there remains a need for respirable drug loaded porous microparticles, where porosity of the microparticles can be readily engineered during the preparation process, with tunable sustained drug release upon lung deposition. In this work, polyvinyl pyrrolidone (PVP) was used as a novel porogen to engineer PLGA-based large porous particles (LPPs) using single emulsion method, with fine tuning of the porosity, sustained drug release both in vitro and in vivo. Using cinaciguat as the model drug, influence of PVP content and PLGA type on the properties of the LPPs was characterized, including geometric particle size, drug encapsulation efficiency, tap density, theoretical and experimental aerodynamic particle size, specific surface area, morphology, and in vitro drug release. Solid state of cinaciguat in the LPPs was studied based on DSC and X-ray analysis. LPPs retention in the rat lung was carried out using bronchoalveolar lavage fluid method. Raw 264.7 macrophage cells were used for LPPs uptake study. Pharmacodynamic study was performed in mini-pigs in a well-established model of pulmonary arterial hypertension (thromboxane challenge). It was demonstrated that porosity of the LPPs is tunable via porogen content variation. Cinaciguat can be released from the LPP in a controlled manner for over 168h. Significant reduction of macrophage phagocytosis was presented for LPPs. Furthermore, LPPs was found to have extended retention time (~36h) in the rat lung and accordingly, sustained pharmacodynamics effect was achieved in mini-pig model. Taken together, our results demonstrated that this simple PLGA based LPPs engineering using single emulsion method with PVP as porogen may find extensive application for the pulmonary delivery of hydrophobic drugs to realize tunable sustained effect with good safety profile.

Electrochemical manipulation of cell populations supported by biodegradable polymeric nanosheets for cell transplantation therapy.

We describe an electrochemical method of harvesting cells cultured on a biodegradable polymeric nanosheet (cell/nanosheet construct), which is stabilized on a self-assembled monolayer (SAM) of thiol molecules. A poly(lactic-co-glycolic acid) (PLGA) nanosheet was attached by hydrophobic interactions onto the surface of a SAM of l-cysteine coated onto a gold electrode. Retinal pigment epithelial cell lines (RPE-J cells) were cultured on the nanosheet to form a monolayer. An AA-size dry battery was used to apply a negative electrical potential, causing reductive desorption of the SAM from the gold surface. Within one minute of application of the voltage, the cell/nanosheet of several mm in diameter was successfully detached without the loss of cell viability in a gentle stream of the electrolyte solution. The use of a porous electrode shortened the detachment time due to the more efficient permeation of the electrolyte solution to the electrode surface. Cell transplantation following the harvesting process was demonstrated by the local delivery of RPE-J cell/nanosheet constructs into the subretinal space of rat eyes through a capillary needle. This nanosheet-based approach that allows the on-demand harvesting of cell/nanosheet constructs and their subsequent transplantation in a minimally-invasive manner could play an important role in cell transplantation therapy.

Preparation and characterization of PLGA-ß-CD polymeric nanoparticles containing methotrexate and evaluation of their effects on T47D cell line.

Among all cancers that affect women, breast cancer has most mortality rate. It is essential to attain more safe and efficient anticancer drugs. Recent advances in medical nanotechnology and biotechnology have caused in novel improvements in breast and other cancer drug delivery. Methotrexate is an anticancer drug that prevents the dihydrofolate reductase enzyme, which inhibits in the formation of DNA, RNA and proteins which have poor water-solubility. For enhancing the solubility and stability of drugs in delivery systems, we used methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles. The PLGA- beta-cyclodextrin nanoparticles were synthesized by a double emulsion method and characterized with FT-IR and SEM. T47D breast cancer cell lines were treated with equal concentrations of methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles and free methotrexate. MTT assay confirmed that methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles enhanced cytotoxicity and drug delivery in T47D breast cancer cells. These results indicate that encapsulated drugs could be effective in controlled drug release for a sustained period would serve the purpose for long-term treatment of many diseases such as breast cancer.

PLGA-soya lecithin based micelles for enhanced delivery of methotrexate: Cellular uptake, cytotoxic and pharmacokinetic evidences.

Biocompatible and biodegradable polymers like PLGA have revolutionized the drug delivery approaches. However, poor drug loading and substantially high lipophilicity, pave a path for further tailing of this promising agent. In this regard, PLGA was feathered with biocompatible phospholipid and polymeric micelles were developed for delivery of Methotrexate (MTX) to cancer cells. The nanocarriers (114.6nm±5.5nm) enhanced the cytotoxicity of MTX by 2.13 folds on MDA-MB-231 cells. Confocal laser scanning microscopy confirmed the increased intracellular delivery. The carrier decreased the protein binding potential and enhanced the bioavailable fraction of MTX. Pharmacokinetic studies vouched substantial enhancement in AUC and bioresidence time, promising an ideal carrier to effectively deliver the drug to the site of action. The developed nanocarriers offer potential to deliver the drug in the interiors of cancer cells in an effective manner for improved therapeutic action.

Targeting tumor highly-expressed LAT1 transporter with amino acid-modified nanoparticles: Toward a novel active targeting strategy in breast cancer therapy.

Designing active targeting nanocarriers with increased cellular accumulation of chemotherapeutic agents is a promising strategy in cancer therapy. Herein, we report a novel active targeting strategy based on the large amino acid transporter 1 (LAT1) overexpressed in a variety of cancers. Glutamate was conjugated to polyoxyethylene stearate as a targeting ligand to achieve LAT1-targeting PLGA nanoparticles. The targeting efficiency of nanoparticles was investigated in HeLa and MCF-7 cells. Significant increase in cellular uptake and cytotoxicity was observed in LAT1-targeting nanoparticles compared to the unmodified ones. More interestingly, the internalized LAT1 together with targeting nanoparticles could recycle back to the cell membrane within 3 h, guaranteeing sufficient transporters on cell membrane for continuous cellular uptake. The LAT1 targeting nanoparticles exhibited better tumor accumulation and antitumor effects. These results suggested that the overexpressed LAT1 on cancer cells holds a great potential to be a high-efficiency target for the rational design of active-targeting nanosystems.

Improved Bone Regeneration With Multiporous PLGA Scaffold and BMP-2-Transduced Human Adipose-Derived Stem Cells by Cell-Permeable Peptide.

OBJECTIVE: Currently, much work has focused on the engineering of bone using adipose-derived stem cells (ADSCs), which differentiate into osteogenic cells. This study was conducted to assess the bone-regenerating capacity of ADSCs with genetic modification. MATERIALS AND METHODS: ADSCs were cultured and transduced with recombinant adenovirus-expressing bone morphogenetic protein-2 (rAd/BMP-2). Two 5-mm full-thickness bone defects were created on the parietal bones of 24 rats. The defects were left empty (n = 12), restored with a scaffold alone (n = 12), transplanted with ADSCs in osteogenic media (n = 12), or transplanted with rAd/BMP-2-transduced ADSCs (n = 12). Six defects from each group were assessed by histologic observation, histomorphometric analysis, and microcomputed tomography (micro-CT) imaging at 4 and 8 weeks after transplantation. RESULTS: Increased new bone formation was observed in the rAd/BMP-2-transduced ADSC groups, compared with the other groups. On micro-CT, significant differences were noted in bone volume-to-tissue volume ratios between rAd/BMP-2-transduced ADSCs group and the other groups at both time points (P < 0.05). CONCLUSION: The result demonstrates that transferring BMP-2 promotes the osteogenic differentiation of ADSCs and enhances bone regeneration. Under limitation of this study, genetic modification of ADSCs with BMP-2 could be adopted in clinical application.

Magnetic core-shell hybrid nanoparticles for receptor targeted anti-cancer therapy and magnetic resonance imaging.

Hybrid nanoparticles with magnetic poly (lactide-co-glycolide) (PLGA) nanoparticle 'core', surface modified with folate-chitosan (fol-cht) conjugate 'shell' are evaluated as simultaneous anti-cancer therapeutic and MRI contrast agent. The fol-cht conjugate is prepared using carbodiimide crosslinking chemistry at an optimized folate to amine (chitosan) molar ratio for further coating on PLGA nanoparticles loaded with docetaxel and well packed super paramagnetic iron oxide nanoparticles (SPIONs). Apart from possessing a targeting moiety, the coating provides a physical barrier to avoid undesired burst release of drug and also imparts sensitivity to acidic pH, due to protonated amine group dependent decondensation of the coating and subsequent drug release. The biocompatible hybrid nanoparticles provide receptor targeted docetaxel and SPION delivery for anti-cancer therapy and magnetic resonance (MR) imaging respectively, as tested in both folate receptor positive and negative cancer cells. Enhancement in nanoparticle uptake by folate receptor positive oral cancer cells caused significant increase in docetaxel mediated cytotoxicity. While polymeric encapsulation and fol-cht coating negatively affects the magnetic property of iron oxide nanoparticles, their aggregation in the core, shortened the overall T2 relaxation time thereby enhancing the nanoparticle relaxivity to provide better in vitro MR imaging.

Formulation and evaluation of targeted nanoparticles for breast cancer theranostic system.

Theranostic polymeric NPs developed for both cancer diagnosis and cancer therapy. This multifunctional polymeric vehicle was prepared by a single emulsion evaporation method, using carboxyl-terminated PLGA. LHRH as a targeting moiety, was conjugated to the surface of polymeric carrier by applying polyethylene glycol. The results indicated that the diameter of NPs was ~185.4±4.6nm as defined by DLS. The entrapment efficacy of docetaxel, silibinin, and SPIONs was 84.6±4.1%, 80.6±2.7%, and 77.9±4.3%, respectively. The NPs showed a triphasic in-vitro drug release pattern. MTT assay was done on two cell lines, MCF-7 and SKOV-3. Enhanced cellular uptake ability of the targeted NPs to MCF-7 was evaluated in-vitro by confocal laser scanning microscopy. The results indicated that compared to non-targeted NPs, the LHRH targeted NPs had significant efficacy at IC50 concentration. The effect of the NPs on VEGF expression in MCF-7 and SKOV-3 cells was investigated by Real-Time PCR method. VEGF mRNA level expression in MCF-7 cell line reduced by 83% in comparison to control cell line. The designed NPs can be used as promising multifunctional platform for detection and targeted drug delivery in breast cancer.