scholarly journals Persistent Prolate Polymersomes for Enhanced Co-Delivery of Hydrophilic and Hydrophobic Drugs

2019 ◽  
Author(s):  
Nicholas L’Amoreaux ◽  
Aon Ali ◽  
Shoaib Iqbal ◽  
Jessica Larsen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Nile Red ◽  
Poly Lactic Acid ◽  
Neural Cells ◽  
Hydrophilic Drugs ◽  
Spherical Structures ◽  
Fluorescein Dyes ◽  
Scanning Electron

AbstractSelf-assembled polymersomes encapsulate, protect, and deliver hydrophobic and hydrophilic drugs. Though spherical polymersomes are effective, early studies suggest that non-spherical structures may enhance specificity of delivery and uptake due to similarity to endogenous uptake targets. Here we describe a method to obtain persistent non-spherical shapes, prolates, via osmotic pressure and the effect of prolates on uptake behavior. Polyethylene glycol-b-poly(lactic acid) polymersomes change in diameter from 175 ± 5nm to 200 ± 5nm and increase in polydispersity from 0.06 ± 0.02 to 0.122 ± 0.01 nm after addition of 50 mM salt. Transmission and scanning electron microscopy confirm changes from spheres to prolates. Prolate-like polymersomes maintain their shape in 50 mM NaCl for seven days. Nile Red and bovine serum albumin(BSA)-Fluorescein dyes are taken up in greater amounts by SH-SY5Y neural cells when encapsulated in polymersomes. Prolate polymersomes may be taken up more efficiently in neural cells than spherical polymersomes.

Computational modeling of degradation process on the mechanical performance of Poly-lactic acid /Magnesium composite

2020 ◽  
pp. 146442072094825
Author(s):  
Armin Shahmohmmadi ◽  
Mostafa Baghani ◽  
Masoud Shariat Panahi ◽  
Kui Wang ◽  
Ehsan Hasanpur ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Cellular Automata ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Cellular Automata Model ◽  
Microscopy Images ◽  
Scanning Electron

In this study, the corrosion behavior of biodegradable composites is modeled. These composites are made of Poly-Lactic acid and Magnesium with different volume fractions. The scanning electron microscopy images of these composites were taken, and statistical reconstruction of the composite based on scanning electron microscopy images was done by the phase recovery algorithm, the three-dimensional structure of this composite was extracted with this reconstruction, then a three-dimensional cellular automata model was developed to predict the corrosion of this composite. Results of experiments for the composite with 10% of Magnesium volume fraction were used to calibrate the parameters of the cellular automata model, and with these parameters, the results for the composite with 5% of Magnesium volume fraction was obtained, and with comparing these data with the results of the experiment, our model was validated. In the end, we estimated the mechanical properties of these composites and analyzed the results.

scholarly journals Morphology, Structural, Thermal, and Tensile Properties of Bamboo Microcrystalline Cellulose/Poly(Lactic Acid)/Poly(Butylene Succinate) Composites

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 465
Author(s):  
Masrat Rasheed ◽  
Mohammad Jawaid ◽  
Bisma Parveez ◽  
Aamir Hussain Bhat ◽  
Salman Alamery
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Tensile Properties ◽  
Microcrystalline Cellulose ◽  
Poly Lactic Acid ◽  
Melt Mixing ◽  
Butylene Succinate ◽  
Uniform Dispersion ◽  
Scanning Electron

The present study aims to develop a biodegradable polymer blend that is environmentally friendly and has comparable tensile and thermal properties with synthetic plastics. In this work, microcrystalline cellulose (MCC) extracted from bamboo-chips-reinforced poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) blend composites were fabricated by melt-mixing at 180 °C and then hot pressing at 180 °C. PBS and MCC (0.5, 1, 1.5 wt%) were added to improve the brittle nature of PLA. Field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis (TGA), differential thermogravimetry (DTG), differential scanning calorimetry (DSC)), and universal testing machine were used to analyze morphology, crystallinity, physiochemical, thermal, and tensile properties, respectively. The thermal stability of the PLA-PBS blends enhanced on addition of MCC up to 1wt % due to their uniform dispersion in the polymer matrix. Tensile properties declined on addition of PBS and increased with MCC above (0.5 wt%) however except elongation at break increased on addition of PBS then decreased insignificantly on addition of MCC. Thus, PBS and MCC addition in PLA matrix decreases the brittleness, making it a potential contender that could be considered to replace plastics that are used for food packaging.

Study on the Properties of Poly(Lactic Acid)/Grafted Starch Composites

2011 ◽  
Vol 345 ◽  
pp. 70-74
Author(s):  
Shan Hu ◽  
Hu Liang Gao ◽  
Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Corn Starch ◽  
Starch Content ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Blending Method ◽  
Degradation Properties ◽  
Scanning Electron

The grafted starch was prepared from corn starch and maleic anhydride. Fourier transform infrared spectroscopy (FTIR) was used to characterize the product. The Poly(lactic acid) (PLA)/grafted starch composites were prepared by means of a melt blending method. The effect of grafted starch content on the properties of the composites was investigated. The morphology of the composites was observed by scanning electron microscopy (SEM). Thermal degradation properties were studied by thermogravimetry (TG). The results indicated that the toughness could be improved obviously by adding suitable content of grafted starch. When 35 wt% grafted starch was added into PLA, the tensile strength decreased to 26.6 MPa from 51.7 MPa for pure PLA, elongation increased from 12.0% to 20.3%, flexural strength decreased from 99.0 MPa to 50.2 MPa, impact strength increased from 4.20 kJ/m2 to 6.28 kJ/m2.

Effect of Catfish Bone Hydrolysate Addition to Milk in Yogurt Manufacturing

2011 ◽  
Vol 236-238 ◽  
pp. 2852-2855
Author(s):  
Xiao Qing Ren ◽  
Li Zhen Ma ◽  
Ju Chu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fermentation Time ◽  
Texture Attributes ◽  
Scanning Electron

The effects of milk supplementation with catfish bone hydrolysate (CBH) at levels of 0, 0.05, 0.15, and 0.5 % on the pH, lactic acid bacteria count (LABC), fermentation time, texture attributes and microstructure of yogurt were investigated. The addition of CBH stimulated acidification and reduced fermentation time (P < 0.05). In comparison with the control yogurt, CBH caused a decrease in product firmness, consistency, cohesiveness and index of viscosity/consistency. The additon of 0.5% CBH produced a higher decrease (P < 0.05). Scanning electron microscopy showed that CBH caused changes in microstructure of yogurt that had a coarser, less cross-linked microstructure than control yogurt.

scholarly journals Investigation of slow release of urea from biodegradable single- and double-layered hollow nanofibre yarns

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Leila Javazmi ◽  
Tobias Low ◽  
Gavin Ash ◽  
Anthony Young
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lactic Acid ◽  
Slow Release ◽  
Delivery Systems ◽  
Lower Amount ◽  
P Value ◽  
Urea Release ◽  
Novel Delivery Systems ◽  
Scanning Electron

AbstractUrea is the most common form of nitrogenous fertiliser. Recently, research has focused on the development of delivery systems to prolong fertiliser release and prevent fertiliser loss through leaching and volatilization. This study investigates and compares single- and double-layered hollow nanofibrous yarns as novel delivery systems to encapsulate and release urea. Single-layered hollow poly l-lactic acid (PLLA) nanofibre yarns loaded with urea fertiliser were fabricated using a customized electrospinning. Double-layered hollow nanofibre yarns were produced by electrospinning polyhydroxybutyrate (PHB) nanofibres as an outer layer, with urea-impregnated PLLA nanofibres as the inner layer. Scanning electron microscopy (SEM) with an energy-dispersive spectroscopy (EDS) was used to characterize the morphology of hollow electrospun nanofibre yarns. A total nitrogen instrument (TNM-1) was used to study the urea release from single- and double-layered hollow nanofibres yarn in water. A Carbon:Nitrogen (CN) elemental analyser determined encapsulated nitrogen in PLLA nanofibres samples. Results indicated that urea-impregnated double-layered hollow nanofibre yarns significantly started nitrogen releasing at much lower amount during first 12 h compared to single-layered hollow nanofibre yarns (P value = 0.000). In conclusion, double-layered hollow nanofibre yarn has potential as an effective alternative to current methods for the slow release of fertilisers and other plant-required chemicals.

Crystallization, Morphology and Mechanical Properties of PLA/PBAT/CaCO3 Composites

2012 ◽  
Vol 602-604 ◽  
pp. 768-771 ◽  
Author(s):  
Nan Shi ◽  
Jun Cai ◽  
Qiang Dou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Crystallization Behavior ◽  
Mechanical Test ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Crystallization Morphology ◽  
Morphology And Mechanical Properties ◽  
Scanning Electron

The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).

Effect of electrospinning parameters on production of polyvinyl alcohol/polylactic acid nanofiber using a mutual solvent

2021 ◽  
pp. 096739112110271
Author(s):  
Reyhaneh Fatahian ◽  
Mohammad Mirjalili ◽  
Ramin Khajavi ◽  
Mohammad Karim Rahimi ◽  
Navid Nasirizadeh
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Contact Angle ◽  
Water Absorption ◽  
Average Diameter ◽  
Poly Lactic Acid ◽  
Poly Vinyl Alcohol ◽  
Mean Diameter ◽  
Scanning Electron

Differences in the properties of poly(vinyl alcohol) (PVA) and poly (lactic acid) (PLA) polymers have attracted much attention today. In this research, the aim is to produce PVA/PLA nanofibers with hydrophilicity and good mechanical properties using a mutual solvent. In this regard, the ability to produce PVA/PLA nanofibers using a mutual solvent was evaluated. The effect of electrospinning parameters on the morphology of nanofibers, hydrophilicity of nanofibers produced by measuring water absorption and contact angle as well as mechanical properties of nanofibers were considered. The results obtained from scanning electron microscopy analyses of the structure of these fibers showed that PVA had the highest viscosity of 5.64 Pa.s and the highest diameter of 260 nm, which decreased the thickness of the nanofibers with increasing PLA. And pure PLA had the lowest mean diameter of 76 nm. In the consideration of the mechanical properties of the prepared nanofibers, it was found that the combination of PLA and PVA nanofibers will lead to overlap the properties of each other and the creation of desirable mechanical properties. Moreover, in the investigation of water absorption and contact angle, it was concluded that the PVA/PLA was fully absorbed in less than 200 seconds and the samples have a contact angle of less than 52°. Finally, it was found that the average diameter of the produced nanofibers was decreased by increasing the voltage and the needle tip to collector distance by considering the PVA/PLA samples with a ratio of 50:50.

Manufacture of a Homogenous Nano-Diamond/Poly (Lactic Acid) Bio-Engineered Composite

2008 ◽  
Vol 47-50 ◽  
pp. 1221-1224 ◽  
Author(s):  
Yong Qing Zhao ◽  
Kin Tak Lau ◽  
Hu Lin Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Melting Compound ◽  
Transmission Electron ◽  
Bridge Structures ◽  
First Time ◽  
Scanning Electron

A novel nanocomposite based on nanodiamond (ND) powder and Poly (lactic acid) (PLA) for potential bio-engineered applications was fabricated for the first time by using melting compound methods. Its structure and mechanical properties were investigated by using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and tensile property test. The results showed that as compared with pure PLA, ND/PLA nanocomposites possessed higher modulus, higher strength and comparable elongation at break, in other words, the mechanical properties of PLA were significantly improved by incorporating ND powder into it. This is presumably due to homogeneous dispersion of ND cluster, good interfacial bonding and unique ND bridge structures in the ND/PLA nanocomposites.

Hydrolysis of green nanocomposites of poly(lactic acid) (PLA), chitosan (CS) and polyethylene glycol (PEG) in acid solution

2016 ◽  
Vol 5 (5) ◽  
Author(s):  
Nguyen Thi Thu Trang ◽  
Nguyen Thuy Chinh ◽  
Nguyen Vu Giang ◽  
Dinh Thi Mai Thanh ◽  
Tran Dai Lam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Acid Solution ◽  
Solution Method ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Before And After ◽  
Hydrolysis Of ◽  
Scanning Electron

AbstractGreen nanocomposites based on poly(lactic acid), chitosan, and polyethylene glycol (PLA/CS/PEG) were prepared by the solution method. The content of PEG was 2–10 wt.% compared with the weight of PLA. The characterization and morphology of the nanocomposites before and after hydrolysis in acid solution were determined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and scanning electron microscopy (SEM). The hydrolysis of PLA/CS/PEG nanocomposites in acid solution for different times was also investigated. The shift of C=O, CH

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