Preparation,characterization,and in vitro biological performance evaluation of PLGA electrospinning membranes doped with metformin-loaded hollow mesoporous silica nanoparticles / 实用口腔医学杂志

Objective:To prepare PLGA electrospinning membranes doped with hollow mesoporous silica nanoparticles loaded with metformin and investigate their biological properties.Methods:PLGA(Control group)and PLGA/HMSN/Met electrospun membranes(Experimental group)were prepared by electrospinning technology.The microscopic morphology of the 2 groups of electrospun mem-branes was observed by SEM.The hydrophilicity,elemental composition and in vitro drug release were detected by contact angle meas-urement,EDS,and drug release test,respectively.SEM and laser scanning confocal microscope(LSCM)were used to observe the growth of periodontal ligament stem cells(PDLSCs)on the 2 groups of electrospun membranes,and CCK-8 assay was used to detect the cell proliferation.Results:Both electrospun membranes had extracellular matrix(ECM)-like fiber structures.The PLGA/HMSN/Met electrospun membranes could slowly release Met for up to 35 days,and the hydrophilicity of PLGA membranes was improved by HMSN-Met doped.The composite electrospun membranes had good cell biocompatibility in vitro,and could promote cell proliferation.Conclu-sion:Modification of PLGA with HMSN-Met can improve the hydrophilicity of PLGA electrospun membranes,continuously release Met,and have good cell biocompatibility.

Effect of domestic porous tantalum modified by osteogenic induction factor slow-release system on function of MG63 cells / 中国组织工程研究

BACKGROUND:Previous research by the research team found that domestically produced porous tantalum is beneficial for early adhesion and proliferation of MG63 cells,and can be used as a scaffold material for bone tissue engineering. OBJECTIVE:To investigate the effect of domestic porous tantalum modified by osteogenic induction factor slow-release system on the adhesion,proliferation,and differentiation of MG63 cells. METHODS:Osteogenic induction factor slow-release system was constructed by adding 15%volume fraction of osteogenic factor solution to poly(lactic-co-glycolic-acid)gel.The passage 3 MG63 cells were inoculated on a porous tantalum surface(control group),porous tantalum surface coated with poly(lactic-co-glycolic-acid)copolymer gel(gel group),and porous tantalum surface coated with osteoblastic induction factor slow-release system(slow-release system group),and co-cultured for 5 days.The surface cytoskeleton of the material was observed by phalloidine staining.Cell proliferation was detected by flow cytometry.Western blot assay and RT-qPCR were used to detect the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 on the surface cells of the material. RESULTS AND CONCLUSION:(1)Phalloidine staining showed that MG63 cells adhered to and grew on the surface and inside of the three groups of porous tantalum,and the matrix secreted by the cells covered the surface of the material.(2)Flow cytometry showed that the cell proliferation in the slow-release system group was faster than that in the control group and the gel group(P<0.05).(3)Western blot assay and RT-qPCR showed that the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 in the slow-release system group were higher than those in the control group and gel group(P<0.05).(4)The results showed that the domestic porous tantalum modified by the osteogenic induction factor slow-release system was beneficial to the adhesion,proliferation,and differentiation of MG63 osteoblasts.

Preparation and preliminary evaluation of SARS-CoV-2 DNA vaccine based on PLGA nanoparticles / 药学学报

We constructed and optimized the plasmid DNA (pDNA) Opt-S encoding the gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, using poly (lactic-co-glycolic acid) copolymer (PLGA) as a delivery carrier for pDNA. PLGA-pDNA NPs were loaded by nanoprecipitation and its properties in vitro were preliminary evaluated. The results showed that the prepared PLGA-pDNA NPs were regular morphology, clear edges, with an average particle size of (184.2 ± 2.4) nm, polydisperse index (PDI) of 0.093 ± 0.013, zeta potential of (-68.10 ± 0.36) mV, and encapsulation rate of (98.92 ± 0.22)%. The PLGA-pDNA NPs were stable at -20 ℃ for 7 months and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The PLGA-pDNA NPs have low cytotoxicity and high safety. In addition, in vitro transfection experiments showed that the SARS-CoV-2 S gene could enter cells and be expressed. These results indicate that PLGA-pDNA NPs non-viral gene vector have simple preparation process and good performance, which are expected to provide a new idea for the research and development of SARS-CoV-2 vaccine.

Efeitos da nanopartícula de ácido poli lático-co-glicólico (PLGA) associada ao cloridrato de metformina na doença periodontal em ratos diabéticos / Effects of polylactic-co-glycolic acid (PLGA) nanoparticle associated with metformin hydrochloride on periodontal disease in diabetic rats

Existe uma associação entre diabetes e a periodontite, e a Metformina (MET) além de controlar os níveis glicêmicos, tem apresentado efeitos antiinflamatórios e na diminuição da perda óssea periodontal. Ao se veicular a MET a um sistema de nanopartículas pode-se apresentar a vantagem de aumento da eficácia terapêutica. Objetivos: esse estudo consistiu na avaliação dos efeitos antiinflamatórios, perda óssea e disponibilidade in vitro/in vivo de uma nanopartícula de ácido poli lático-co-glicólico (PLGA) associada à MET em um modelo de periodontite induzida por ligadura. Materiais e métodos: o PLGA carreado com diferentes doses da MET foi caracterizado pelo seu diâmetro médio, tamanho da partícula, índice de polidispensão e eficiência de aprisionamento. Foram utilizados ratos machos da linhagem Wistar, divididos aleatoriamente, em grupos controles e experimentais com diferentes doses de MET associadas ou não ao PLGA, os quais receberam diferentes tratamentos. Amostras de maxilas e tecidos gengivais foram utilizadas para avaliação de perda óssea e inflamação, por meio da microtomografia computadorizada, histopatológico, imunohistoquímica, análise de citocinas inflamatórias e expressão gênica de proteínas por RT-PCR quantitativo. Para o ensaio de liberação in vitro, utilizou-se o dispositivo de células de difusão vertical de Franz estáticas. Para a disponibilidade in vivo, as amostras de sangue foram coletadas em diferentes intervalos de tempo e analisadas por cromatografia líquida de alta eficiência acoplado a espectrometria de massas (HPLC-MS/MS). Resultados: o diâmetro médio das nanopartículas de PLGA carreadas com MET estava em um intervalo de 457,1 ± 48,9 nm (p <0,05) com um índice de polidispersidade de 0,285 (p <0,05), potencial Z de 8,16 ± 1,1 mV (p <0,01) e eficiência de aprisionamento (EE) de 66,7 ± 3,73. O tratamento com a MET 10 mg / kg + PLGA mostrou uma baixa concentração de células inflamatórias, fraca imunomarcação para RANKL, Catepsina K, OPG e osteocalcina. Diminuição dos níveis de IL-1ß e TNF-α (p <0,05), aumento da expressão gênica do AMPK (p <0,05) e diminuição do NF-κB p65, HMGB1 e TAK-1 (p <0,05). O 10 mg/kg MET + PLGA foi liberado no ensaio in vitro sugerindo um modelo cinético de difusão parabólica com um perfil de liberação que atinge 50% de seu conteúdo em 2h e permanece em liberação constante em torno de 60% até o final de 6h. O ensaio in vivo mostrou o volume aparente de distribuição Vz/F (10 mg/kg MET + PLGA, 46,31 mL/kg vs. 100 mg/kg MET + PLGA, 28,8 mL/kg) e o tempo médio de residência MRTinf (PLGA + MET 10 mg /kg, 37,66h vs. MET 100 mg/kg, 3,34h). Conclusão: o PLGA carreado com MET diminuiu a inflamação e a perda óssea na periodontite em ratos diabéticos. O 10 mg/kg MET + PLGA teve uma taxa de eliminação mais lenta em comparação com o MET 100 mg/kg. A formulação modifica os parâmetros farmacocinéticos, como volume de distribuição aparente e tempo médio de residência (AU).

There is an association between diabetes and periodontitis, and Metformin (MET) in addition to controlling glycemic levels, has shown anti-inflammatory effects and decreased periodontal bone loss. By transferring MET to a nanoparticle system, the advantage of increasing therapeutic efficacy can be presented. Objectives: this study consisted of evaluating the antiinflammatory effects, bone loss and in vitro/in vivo availability of a polylactic-co-glycolic acid (PLGA) nanoparticle associated with MET in a ligature-induced periodontitis model. Materials and methods: PLGA loaded with different doses of MET was characterized by its mean diameter, particle size, polydispension index and entrapment efficiency. Male Wistar rats were used, randomly divided into control and experimental groups with different doses of MET associated or not with PLGA, which received different treatments. Samples of jaws and gingival tissues were used to assess bone loss and inflammation, using computed microtomography, histopathology, immunohistochemistry, analysis of inflammatory cytokines and gene expression of proteins by quantitative RT-PCR. For the in vitro release assay, the static Franz vertical diffusion cell device was used. For in vivo availability, blood samples were collected at different time intervals and analyzed by high performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Results: the mean diameter of MET-loaded PLGA nanoparticles was in the range of 457.1 ± 48.9 nm (p <0.05) with a polydispersity index of 0.285 (p <0.05), Z potential of 8.16 ± 1.1 mV (p <0.01) and trapping efficiency (EE) of 66.7 ± 3.73. Treatment with MET 10 mg/kg + PLGA showed a low concentration of inflammatory cells, weak immunostaining for RANKL, Cathepsin K, OPG and osteocalcin. Decreased IL-1ß and TNF-α levels (p <0.05), increased AMPK gene expression (p <0.05) and decreased NF-κB p65, HMGB1 and TAK-1 (p <0. 05). The 10 mg/kg MET + PLGA was released in the in vitro assay suggesting a kinetic model of parabolic diffusion with a release profile that reaches 50% of its content in 2h and remains in constant release around 60% until the end of 6h . The in vivo assay showed the apparent volume of distribution Vz/F (10 mg/kg MET + PLGA, 46.31 mL/kg vs. 100 mg/kg MET + PLGA, 28.8 mL/kg) and the mean MRTinf residency (PLGA + MET 10 mg/kg, 37.66h vs. MET 100 mg/kg, 3.34h). Conclusion: MET-loaded PLGA decreased inflammation and bone loss in periodontitis in diabetic rats. 10 mg/kg MET + PLGA had a slower rate of elimination compared to 100 mg/kg MET. The formulation modifies pharmacokinetic parameters such as apparent volume of distribution and mean residence time (AU).

Accelerated stability test of sustained-release thienorphine loaded microspheres for injection / 药学学报

In order to meet the clinical needs of long-acting sustained-release thienorphine, injectable thienorphine loaded microspheres were developed, and the accelerated stability study was carried out to explore the suitable storage and transportation conditions of the microspheres. Using poly(lactic-co-glycolic acid) (PLGA) as carrier material, 3 batches of microspheres were prepared in pilot scale with emulsion solvent evaporation method. By investigating the in vitro release of thienorphine loaded microspheres at 37, 45, 52, and 60 ℃, and applying the Arrhenius equation, the linear relationship between the release rate constant (lgk) and the temperature (1/T) was established to obtain the equation: lgk = -8.073/T + 24.35 (R2 = 0.985 3), which showed that the release of microspheres at high temperature can be used to predict the release in vitro at 37 ℃, and 52.0 ± 0.5 ℃ was selected as the accelerated release condition in vitro. The quality research methods were established to investigate the changes of critical quality attributes such as microsphere morphology, drug loading, particle size and distribution, polymer molecular weight, and the related substances under accelerated conditions. The difference factor f1 and similarity factor f2 were used to assess the similarity of release behavior under accelerated conditions. The results showed that under the accelerated experimental conditions of 25 ± 2 ℃ and relative humidity (RH) 60% ± 5%, the critical quality attributes of injectable thienorphine loaded microspheres had no significant change in 6 months, suggesting that the long-term storage condition could be 5 ± 3 ℃.

The Evaluation of Bone Regeneration Following Socket Preservation with Concentrated Growth Factor (CGF) and Poly Lactic-Co-Glycolic Acid (PLGA) Scaffold in Rabbits

ABSTRACT@#Various grafting materials are utilised to facilitate regeneration. There is currently a paradigm shift towards applying poly lactic-co-glycolic acid (PLGA), which is regarded as an excellent scaffold for tissue engineering. Concentrated growth factor (CGF) has also been reported to promote wound healing. Nevertheless, the role of PLGA microspheres as a substitute for bone graft material with CGF in bone regeneration remains unclear. This study was designed to evaluate the effect of CGF with PLGA on bone formation and the expression of alkaline phosphatase (ALP) following socket preservation. PLGA microspheres were prepared using double solvent evaporation method and observed under scanning electron microscopy (SEM). A 6 mL of rabbit’s blood was collected from the marginal ear vein and centrifuged to obtain CGF. Blood was also collected for ALP assessment from 24 New Zealand White (NZW) male rabbits subjected to the first upper left premolar extraction. Sockets were filled with CGF, PLGA, CGF+PLGA or left empty and observed with microscopic computed tomography (micro-CT) at four weeks and eight weeks. The SEM image revealed a spherical shape with interconnected pores on the surface of the PLGA particles. Repeated measures ANOVA were used to evaluate the effect of time and treatment (p < 0.05) with significant differences in bone width, height, volume, volume fraction and expression of ALP was observed with CGF+PLGA. Both CGF and PLGA have the potential as the alternative grafting materials and this study could serve as an ideal benchmark for future investigations on the role of CGF+PLGA in bone regeneration enhancement.

Antibacterial and osteogenic properties of vancomycin/PLGA-coated porous magnesium alloy scaffolds / 中华创伤骨科杂志

Objective:To evaluate the physicochemical properties, degradation and drug release behaviour, cytocompatibility and bacteriostatic properties in vitro of porous magnesium alloy scaffolds containing vancomycin/poly(lactic-co-glycolic acid) (PLGA). Methods:Porous magnesium scaffolds (Mg-2Zn-0.3Ca) were prepared using the template replication technique. The MgF 2 surface layer was obtained by high temperature fluorination. The vancomycin/PLGA porous magnesium alloy drug-loaded scaffolds were obtained by homogeneous lifting after submersion in a dichloromethane solution of PLGA containing vancomycin hydrochloride. According to the products at each stage of the preparation (scaffolds of magnesium alloy, magnesium fluoride alloy, PLGA coated magnesium fluoride alloy, and vancomycin/PLGA magnesium fluoride alloy), they were divided into an Mg group, an MgF 2 group, a PLGA group, and a vancomycin/PLGA group. Immediately after preparation, the material science characterization, degradation rate, drug release rate, antibacterial properties, hemocompatibility, and cell proliferation and differentiation ability of the scaffolds were measured and evaluated. Results:Vancomycin-loaded magnesium alloy scaffolds were successfully prepared with an average porosity of 66.39%. Their degradation rate [(0.540±0.102) mm/year] was significantly lower than that of the Mg ones [(10.048±0.297) mm/year] ( P<0.05). Their pH of degradation in Hank equilibrium salt solution was close to the physiological pH. Their release of vancomycin was fast in the first 48 h and gradually slowed down after 48 h. Their cumulative drug concentration reached a maximum of 43 mg/L at d 11; their vancomycin was still released slowly after d 11. The antimicrobial rate in the vancomycin/PLGA group (97.89%±0.28%) was significantly higher than that in the Mg group (74.92%±2.20%), the MgF 2 group (78.46%±2.59%) and the PLGA group (61.08%±4.21%) ( P<0.05). Their hemolysis rate (0.55%) was much lower than the requirement of ISO 10993-4 (5%). The extract liquid from them promoted the proliferation of rat bone marrow mesenchymal stem cells (BMSCs), showing a gradually increased proliferation rate from d1 (104.80%±5.13%) to d3 (112.36%±2.07%) and d7 (127.79%±4.61%). The calcium nodules in BMSCs were significantly increased at d 14, with an OD value of absorbance of 1.189±0.020, significantly higher than that in the Mg group (0.803±0.020), the MgF 2 group (0.878±0.028) and the PLGA group (0.887±0.026) ( P<0.05). Conclusion:Vancomycin/PLGA-loaded porous magnesium alloy scaffolds exhibit good material properties, antibacterial properties, biocompatibility and osteogenic properties in vitro.

Preparation of magnetic lidocaine microsphere and effects on sciatic nerve block in rabbits / 中华麻醉学杂志

Objective:To develop a novel sustained-release local anesthetic microspheres and evaluate the effects on sciatic nerve block in rabbits.Methods:The magnetic lidocaine microspheres were prepared by W 1/O/W 2 compound emulsion method, investigating their external morphology, measuring the magnetic response characteristics by the VSM and draw the hysteresis loop.The encapsulation efficiency and drug-loading rate were calculated, and the cumulative release curves in vitro were drawn.Fifteen healthy rabbits (half male and half female), aged 5-6 months, weighing 3.0-3.5 kg, were selected for sciatic nerve block and divided into 3 groups ( n=5 each) using a random number table method: magnetic response lidocaine microspheres group (PL group), normal saline control group (C group) and lidocaine group (L group). Magnetic response lidocaine microsphere buffer 2 ml, normal saline 2 ml and 2% lidocaine 2 ml were injected around the rabbit sciatic nerve through a catheter in PL, C and L groups, respectively.The applied magnetic field was withdrawn at 60 h after injection.Before injection (T 0) and at 30 min and 2 , 8, 16, 24, 48, 60, 62 and 64 h after injection (T 1-9), the compound action potentials and conduction velocities of bilateral sciatic nerve trunks were measured, and block was assessed using toe reflex score and modified Tarlov score. Results:The magnetic lidocaine microspheres were brown in color and observed as monodisperse, regular spheres with a diameter of (9±3) μm, an encapsulation rate of 46.18%, a drug loading of 6.02%, and a superparamagnetic release rate of 97% in vitro at 60 h. The hysteresis loop passed through the origin and no hysteresis occurred with the absence of an external magnetic field.Compared with C group, the action potentials and conduction velocities of the sciatic nerve, toe reflex score and modified Tarlov score were significantly decreased at T 1-T 8 in PL group ( P<0.05). Compared with L group, the action potentials and conduction velocities of the sciatic nerve were significantly increased at T 1, the action potential was decreased at T 2-T 8, the conduction velocity was decreased at T 3-T 8, the toe reflex score was increased at T 1 and decreased at T 3-T 8, and the modified Tarlov score was increased at T 1 and T 2 and decreased at T 3-T 8 in PL group ( P<0.05). Conclusions:Magnetic response lidocaine microsphere is successfully developed with good magnetic responsiveness and release and can prolong the sciatic nerve block time in rabbits.

Preparation and properties of injectable minocycline hydrochloride microsphere depot / 中国药科大学学报

@#To prepare a minocycline hydrochloride microsphere depot and evaluate its release performance and physicochemical properties, poly (lactic-co-glycolic acid) (PLGA) was used as raw material, the minocycline hydrochloride microspheres were prepared by electrospray, and the morphology and size distribution of the microspheres were characterized by polarizing microscopy and scanning electron microscopy (SEM). The microspheres were then mixed with sucrose acetate isobutyrate (SAIB) depot at a ratio of 1:10 to form a minocycline hydrochloride microsphere depot, and its release performance and porosity changes were evaluated. The results showed that the microspheres had smooth surface and the diameter was (5.294 ± 1.222) μm. After the microspheres were added into SAIB depot, the burst release of minocycline hydrochloride significantly decreased from 60% to 3.27% at the first day, and then the release lasted for 42 days . Additionally, the porosity of the depot increased rapidly from (12.53 ± 0.43)% to (32.53 ± 0.43)% during days 0-15, and increased slowly from (32.53 ± 0.43)% to (33.81 ± 0.54)% during days 15-45. The minocycline hydrochloride microsphere depot prepared in this study is expected to be an effective way for the application of minocycline hydrochloride for its good release performance and simple preparation process.

Application of poly(lactic-co-glycolic acid) in the treatment of pulp diseases / 口腔疾病防治

@#The development of materials science is of great significance to the treatment of dental pulp diseases. Poly lactic acid glycolic acid (PLGA) copolymer is an organic macromolecule compound that is widely used in the preparation of biomedical materials. In recent years, PLGA, as a drug/molecular loaded system and tissue regeneration scaffold, has shown prospects for application in the treatment of dental pulp diseases. This paper will review the application of PLGA in the treatment of dental pulp diseases and provide a basis for its further development and utilization. The results of the literature review show that PLGA is a drug/molecular delivery system that is mainly used in the improvement of pulp capping materials, root canal disinfectant and apexification materials. PLGA-improved pulp capping agents can prolong the action time of the drug and reduce toxicity. The modified root canal disinfectant can realize the sustained release of drug, make the drug penetrate deeper into the subtle structure, and contact more widely with the pathogenic bacteria. The modified apexification materials can provide more convenient administration methods for apexifixment. As a scaffold for tissue engineering, PLGA is mainly used in the study of pulp regeneration. The optimization of PLGA physical properties and action environment can provide a more suitable microenvironment for seed cells to proliferate and differentiate. How to utilize the advantages of PLGA to develop a more suitable material for endodontic application needs further study.

Luteolin-loading of Her-2-poly (lactic-co-glycolic acid) nanoparticles and proliferative inhibition of gastric cancer cells via targeted regulation of forkhead box protein O1

Background: Developing the natural medicine that allow for the specific targeting cytotoxicity is a very important research area in the development of anti-tumor drugs. Aims and Objectives: This study was conducted to determine the targeted inhibitory effects of luteolin-loaded Her-2-poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) on gastric cancer cells and to delineate the mechanism underlying the inhibition of tumors by luteolin. Materials and Methods: Luteolin-loaded Her-2-PLGA NPs (Her-2-NPs) were prepared, physically and chemically characterized, and their effects on gastric cancer cells were investigated. The rate of NP uptake by cells and the cell morphology were observed using confocal microscopy; the rates of cell proliferation and apoptosis were identified using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay and flow cytometry, respectively; and the mRNA and protein expression levels of forkhead box protein O1 (FOXO1) were determined using quantitative polymerase chain reaction and Western blotting, respectively. Results: Compared with nontargeted microspheres, Her-2-NPs led to significantly enhanced uptake of luteolin by SGC-7901 cells. Luteolin-loaded Her-2-NPs also significantly inhibited the proliferation of gastric cancer cells, weakened their migratory ability, and increased both the mRNA and protein expression levels of FOXO1. Conclusion: Luteolin-loading of Her-2-NPs could potentially be used as a novel anti-cancer drugs for targeted cancer therapy.

Encapsulation of Ginseng inside Poly(lactic-co-glycolic acid)/ Polyaniline Microcaspsules

@#Introduction: : Ginseng is a type of traditional medicine that has been used for thousand years to treat various diseases and has been proven effective in treating cardiovascular diseases. Incorporation of polyaniline (PANI) which is a type of conductive polymer together with ginseng into poly(lactic-co-glycolic acid) (PLGA) microcapsules is necessary for the treatment of cardiovascular diseases as the polymer will control drug release and the electroconductivity of PANI is beneficial on myocardium cells. Methods: Therefore, this project involved the encapsulation of ginseng inside PLGA/PANI microcapsules. The encapsulation of ginseng inside the microcapsules was verified through the identification of chemical composition of ginseng, PLGA and PANI using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Results: The results of scanning electron microscope (SEM) showed the formation of microspheres where the microcapsule size was decreased from 3.14±1.87 μm to 1.98±1.30 μm as the concentration of PANI increased. The distribution of microcapsules size was more homogeneous in the high concentration of PANI as been determined through the histogram analysis. In addition, the fluorescence analysis demonstrated the efficiency of ginseng encapsulation inside PLGA/PANI microcapsules through the appearance of stained ginseng inside the microcapsules. Conclusion: As a conclusion, the ginseng was successfully encapsulated within PLGA/PANI microcapsules that will be beneficial in drug delivery application, specifically in the cardiovascular area.

Osteogenesis of bone marrow mesenchymal stem cells on hydroxyapatite/icariin/poly(Lactic-co-glycolic acid) scaffolds / 中国组织工程研究

BACKGROUND: Bone tissue engineering has provided a novel ideal for treating bone defects in clinic. This study is the first to combine traditional Chinese medicine with the nanostructures of tissue-engineered scaffolds in order to explore and construct a new bone tissue substitute material for the treatment of bone defects. OBJECTIVE: To investigate the osteogenic activity of icariin (ICA)/hydroxyapatite (HA)/poly(lactic-co-glycolic acid) (PLGA) composite scaffolds. METHODS: A HA/PLGA composite scaffold was prepared by physical blending of HA and PLGA, and was then soaked in ICA solution of different concentrations to obtain the HA/ICA/PLGA scaffold. Rabbit bone marrow mesenchymal stem cells were used to evaluate the cell adhesion, proliferation, osteogenesis and cytotoxicity of the composite scaffold. The cell adhesion, proliferation and cytotoxicity were detected by MTT method. The activities of alkaline phosphatase and osteocalcin were detected by ELISA. The expression levels of osteogenic genes and proteins were detected by fluorescence quantitative PCR and western blot assay, respectively. RESULTS AND CONCLUSION: Adding appropriate amount of HA into PLGA could improve the mechanical strength of the scaffold, and 10% HA had the best effect with tensile strength of (1.67±0.37) MPa, and compression modulus of (4.17±1.62) MPa, and nanostructure would be formed on the surface of the scaffold. The nanostructure could promote the adhesion of bone marrow mesenchymal stem cells on the surface of the scaffold. ICA did not affect the proliferation of bone marrow mesenchymal stem cells on the composite scaffold. However, the HA/PLGA composite scaffold soaked in 1.00 µmol/L ICA aqueous solution had the optimal osteogenic differentiation function, and the expression levels of alkaline phosphatase, osteocalcin, osteogenic related genes and proteins (Runx-2 and COL I) were increased. The ICA/HA/PLGA scaffold had no cytotoxicity. These results suggest that HA (10%)/ICA (1.00 µmol/L)/PLGA scaffold has good mechanical properties, osteogenesis and biocompatibility, which has the potential to be a favorable scaffold for bone tissue engineering.

Evaluation of in vitro and in vivo immunostimulatory activities of poly (lactic-co-glycolic acid) nanoparticles loaded with soluble and autoclaved Leishmania infantum antigens: A novel vaccine candidate against visceral leishmaniasis

Objective: To prepare and characterize poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.

Evaluation of in vitro and in vivo immunostimulatory activities of poly (lactic-co-glycolic acid) nanoparticles loaded with soluble and autoclaved Leishmania infantum antigens: A novel vaccine candidate against visceral leishmaniasis

Objective: To prepare and characterize poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.

Preparation of Juglone-loaded PLGA Nanoparticles and Its Anti-tumor Effect on Melanoma A375 Cells in Vitro / 中国实验方剂学杂志

Objective: To prepare Juglone-loaded poly lactic-co-glycolic acid nanoparticles (Jug-PLGA-NPs), and investigate their physicochemical properties, release characteristics in vitro and anti-tumor activities on A375 melanoma cells in vitro. Method: Jug-PLGA-NPs were prepared by emulsification-solvent evaporation method. Then the particle size, encapsulation efficiency, drug loading rate and in vitro release characteristics were investigated. Fluorescence microscopy was used to observe the uptake of PLGA-NPs in vitro. The distribution of PLGA-NPs in BALB/c nude mice after tail vein injection was observed by the small living animal imaging system. Their inhibition effect on proliferation of A375 cells was detected by thiazolyl blue tetrazolium bromide (MTT) assay. Apoptosis rate and cell cycle detection were performed by flow cytometry. Western blot was used to determine the protein kinase B (Akt), phosphorylated Akt (p-Akt) and cyclinD1. Result: The average particle size of the prepared Jug-PLGA-NPs was (149.6±21.5) nm, entrapment rate of (68.39±2.51)%, and drug-loading rate of (5.07±0.98)%, showing good sustained-release characteristics. PLGA-NPs showed good penetration and targeting properties in cellular uptake in vitro and in vivo imaging. Different concentrations of Jug-PLGA-NPs could significantly inhibit the proliferation and promote apoptosis of A375 cells in a time and concentration dependent manner (P1 expression (P0/G1 phase (PConclusion: The Jug-PLGA-NPs are easy to prepare and have good sustained-release characteristics, tumor targeting and anti-tumor ability, providing a new pharmaceutical dosage form for the future clinical application of Jug.

RGD peptide-modified phase-change nanoparticles combining with low-intensity focused ultrasound for targeting and imaging experiments of gastric cancer in vivo and vitro / 中华超声影像学杂志

Objective To prepare RGD peptide modified perfluorohexane ( PFH ) polymer nanoparticles RGD-PFH-NPs and investigate its basic characteristics ,targeting ability and combine with low-intensity focused ultrasound ( LIFU ) for ultrasonic imaging in vivo and vitro . Methods Targeted nanoparticles RGD-PFH-NPs were prepared by double emulsifying method and carbodiimide method . Their morphology and distribution were observed . The particle size ,zeta potential and connection probability were measured . The phase-changed properties and the LIFU-induced imaging ability in contrast-enhanced ultrasound mode of RGD-PFH-NPs were investigated in vivo and vitro . The tagetability of nanoparticles to human gastric cancer cell line MGC803 and tumor-bearing nude mouse were observed through targeting group and non-targeting group . Results The prepared sample was milky white suspension liquid . The RGD-PFH-NPs were spherical uniform size ,good dispersion when observed through the optical microscope and transmission electron microscopy . The particle size was ( 259 .3 ± 42 .6) nm and the Zeta potential was ( -17 .6+5 .4) mV . The connection probability of RGD peptide was 89 .13％ . With 70℃ water bath and LIFU stimulation RGD-PFH-NPs can remarkably change phase and show good imaging performance in both conventional ultrasound and contrast-enhanced ultrasound mode in vivo and vitro . The connection probability to MGC803 cells in targeting group ( RGD-PFH-NPs ) and the non-targeting group( PFH-NPs)were 82 .59％ and 2 .96％ . The accumulation of nanoparticles in the RGD-PFH-NPs group in tumor tissues was significantly higher than that in the non-targeted PFH-NPs group( P) . Conclusions The constructed nanoparticles RGD-PFH-NPs ,providing contrast-enhanced ultrasonic imaging and excellent targeting ability to human gastric cancer cells MGC803 and gastric cancer tissue ,is expected to become a new type of gastric cancer targeted ultrasound contrast agent .

Preparation of icariin/gelatin nanocomposite-PLGA sustained release system and its optimization of technology / 吉林大学学报(医学版)

Objective: To prepare the sustained release system of icariin (ICA) @ gelatin nanoparticles (GNPs)-polyactic-co-glycolic acid (PLGA) (ICA @ GNPs-PLGA), and to optimize the conditions. Methods: ICA@GNPs-PLGA sustained release system was prepared using two-step desolvation method and S/O/W emulsion solvent-evaporation technique. The effects of different conditions, such as the PLGA: GNPs mass ratio and the total quality of ICA added on the entrapment efficiency (EE) of ICA® GNPs-PLGA composite microspheres were detected to optimize the preparation process. The surface morphology of GNPs and ICA @ GNPs-PLGA composite microspheres were observed by SEM. The EE and the release results of ICA@GNPs-PLGA in the sample were determined with HPLC Results: The prepared composite microspheres and nanocomplex were were white powder. The SEM results showed that the composite microspheres and nanocomplexs were spherical, the surfaces were smoothy, and the particle size distribution range was 4-12 μm and 150-200 nm, respectively, relatively uniform At a GNPs mass fraction of 6 mg, the critical concentration of PLGA in DCM ranged within 0.5%-1.0%. At a GNPs mass fraction of 12 mg, the critical concentration of PLGA in DCM ranged within 1.0%-2.0%. However, at a critical PLGA mass fraction lower than 0.25%, no fully formed composite microspheres were observed. Within the critical concentration, the average EE of ICA@ GNPs-PLGA microspheres was higher than (62.00 ± 1.25)%. In addition, the EE of ICA in the microspheres was negatively correlated with the quality of ICA added. The accumulative release rate was less than in 24 h and it was 65.21% in 40 d. Conclusion: The ICA@GNPs-PLGA microspheres with homogeneous particle size distribution, high EE, low initial burst and without agglomeration can be acquired under the optimized conditions.

Preparation of bacterial outer membrane vesicle coated nanoparticle loaded with drug and evaluation of its nasal immune effect in mice / 上海交通大学学报（医学版）

Objective: To prepare a bacterial outer membrane vesicle (OMV) coated poly (lactic-co-glycolic acid) copolymer (PLGA) nanoparticle loaded with ovalbumin (OVA) and evaluate its intranasal immune effect in mice. Methods: OMV was prepared by ultrafiltration concentration method. OVA loaded PLGA nanoparticle (NP) was prepared by emulsion-solvent evaporation method. OMV coated PLGA nanoparticle (OMV-PLGA NP) loaded with OVA was prepared by extrusion method and characterized. BALB/c mice were intranasally immunized and specific sIgA levels in nasal wash, jejunum and fecal pellet were determined by ELISA. Results: Size of OVA loaded OMV-PLGA NP was (234.4±22.9) nm. The shell-core structure of OVA loaded OMV-PLGA NP was proved by transmission electron microscope. After 14 d of administration, sIgA antibody levels in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group were the highest in all treated groups. Compared with the group treated with OMV and OVA, OVA-specific sIgA antibody level in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was increased 1.6, 2.1 and 1.7 times, respectively. Compared with the group treated with OMV and OVA, OMV-specific sIgA antibody level in nasal wash, jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was all increased 1.5 times. Conclusion: This novel nanoparticle drug delivery system can simultaneously delivery OVA and OMV to antigen presenting cells, resulting in stronger mucosal immune response in mice.

Study on Preparation of Curcumin-PLGA Nanoparticles Thermosensitive in-situ Gel and Its Pharmacokinetics in Aqueous Humor of Rabbits / 中国药房

OBJECTIVE: To prepare curcumin (CUR) -Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (CUR-PLGA) thermosensitive in-situ gel (CUR-PLGA-GEL), and to study pharmacokinetic characteristics of it in aqueous humor of rabbits.METHODS: CUR-PLGA was prepared with modified emulsion-solvent evaporation method. CUR-PLGA-GEL was prepared by cold-dissolving method using poloxamer407 (P407) and poloxamer 188 (P188) as gel matrix. The level of CUR in gel was determined by HPLC, and the irritation of it to rabbit eyes was investigated (self-control of left and right eyes of 5 rabbits were taken, while the Draize test was used to evalvate the irritation). 10 New Zealand white rabbits were randomly divided into 2 groups, with 5 rabbits in each group. Left eyes were given CUR-PLGA-GEL and CUR suspension (containing CUR 8 mg), respectively. The concentrations of CUR in aqueous humor of rabbits were determined before medication and 1, 2, 4, 6, 8, 10, 12, 24 h after medication. The pharmacokinetic parameters were calculated by using DAS 2. 0 software. RESULTS: CUR-PLGA-GEL was successfully prepared and the total score of irritation was 0, which indicated irritative to rabbits. In aqueous humor of rabbits, cmax and AUC0-24 h of CUR-PLGA-GEL were 2. 48 and 2. 71 fold of CUR suspension. CONCLUSIONS: Prepared CUR-PLGA-GEL can be used for ophthalmic delivery and can improve the utilization of CUR in the eye.