scholarly journals Preparation of Biodegradable Polyethylene Glycol Dimethacrylate Hydrogels via Thiol-ene Chemistry

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1339 ◽  
Author(s):  
Gavin Burke ◽  
Zhi Cao ◽  
Declan M. Devine ◽  
Ian Major
Keyword(s):  
Polyethylene Glycol ◽  
Monomer Concentration ◽  
Mechanical Analysis ◽  
Glycol Dimethacrylate ◽  
Unconfined Compression ◽  
Scanning Calorimetry ◽  
Drug Delivery Vehicles ◽  
Degradation Rates ◽  
Delivery Vehicles ◽  
Cell Carriers

Through the control of the molecular weight, water content and monomer concentration, polyethylene glycol dimethacrylate (PEGDMA) based hydrogels have been adapted for numerous applications, including as structural scaffolds, drug delivery vehicles and cell carriers. However, due to the low biodegradability rates, the use of PEGDMA in tissue engineering has been limited. Thiol-based monomers have been shown to improve the degradation rates of several PEG-based hydrogels, though their impact on several material properties has not been as well defined. In this work, several mercaptopropianoates, as well as mercaptoacetates, were mixed with PEGDMA and copolymerized. Following an initial polymerization check, it was determined that mercaptoacetate-based thiol monomers did not polymerize in the presence of PEGDMA, whereas mercaptopropionates were more successful. The wettability, and the compressive and tensile strength, in addition to the thermal properties, were determined for successfully copolymerized samples via a combination of differential scanning calorimetry, dynamic mechanical analysis, unconfined compression, and goniometry. Further study determined that dipentaerythritol hexa(3–mercaptopropionate) (DiPETMP) successfully enhanced the biodegradability of PEGDMA.

scholarly journals High-Resolution Imaging of Polyethylene Glycol Coated Dendrimers via Combined Atomic Force and Scanning Tunneling Microscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Shawn Riechers ◽  
Qian Zhong ◽  
Nai-Ning Yin ◽  
Arpad Karsai ◽  
Sandro R. P. da Rocha ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Polyethylene Glycol ◽  
High Resolution ◽  
Scanning Tunneling Microscopy ◽  
Scanning Tunneling ◽  
Great Promise ◽  
Tunneling Microscopy ◽  
Drug Delivery Vehicles ◽  
Atomic Force ◽  
Delivery Vehicles

Dendrimers have shown great promise as drug delivery vehicles in recent years because they can be synthesized with designed size and functionalities for optimal transportation, targeting, and biocompatibility. One of the most well-known termini used for biocompatibility is polyethylene glycol (PEG), whose performance is affected by its actual conformation. However, the conformation of individual PEG bound to soft materials such as dendrimers has not been directly observed. Using atomic force microscopy (AFM) and scanning tunneling microscopy (STM), this work characterizes the structure adopted by PEGylated dendrimers with the highest resolution reported to date. AFM imaging enables visualization of the individual dendrimers, as well as the differentiation and characterization of the dendrimer core and PEG shell. STM provides direct imaging of the PEG extensions with high-resolution. Collectively, this investigation provides important insight into the structure of coated dendrimers, which is crucial for the design and development of better drug delivery vehicles.

scholarly journals Air-Spun Silk-Based Micro-/Nanofibers and Thin Films for Drug Delivery

2021 ◽  
Vol 22 (17) ◽  
pp. 9588
Author(s):  
Christopher R. Gough ◽  
Xiao Hu
Keyword(s):  
Drug Delivery ◽  
Protein Structure ◽  
High Efficiency ◽  
Volume Ratio ◽  
High Porosity ◽  
Scanning Calorimetry ◽  
Fiber Network ◽  
Drug Delivery Vehicles ◽  
Delivery Vehicles ◽  
Silk Films

Micro-/nanofibers have shown high promise as drug delivery vehicles due to their high porosity and surface-area-to-volume ratio. The current study utilizes air-spraying, a novel fiber fabrication technique, to create silk micro-/nanofibers without the need for a high voltage power source. Air-spraying was used to create silk fibrous mats embedded with several model drugs with high efficiency. In order to compare the effect of biomaterial geometry on the release of the model drugs, silk films were also created and characterized. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and a drug release study were performed on both fiber and film samples to study how the model drugs interact with the protein structure. FTIR analysis showed that while drugs could interact with the protein structure of porous silk fibers, they could not interact with the flat geometry of silk films. As a result, fibers could protect select model drugs from thermal degradation and slow their release from the fiber network with more control than the silk films. A trend was also revealed where hydrophobic drugs were better protected and had a slower release than hydrophilic drugs. The results suggest that the physical and chemical properties of drugs and protein-based biomaterials are important for creating drug delivery vehicles with tailored release profiles and that fibers provide better tunability than films do.

Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

Nanoscale ◽  
2016 ◽  
Vol 8 (31) ◽  
pp. 14821-14835 ◽  
Author(s):  
Zhiqiang Shen ◽  
David T. Loe ◽  
Joseph K. Awino ◽  
Martin Kröger ◽  
Jessica L. Rouge ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Polyethylene Glycol ◽  
Self Assembly ◽  
Drug Delivery Vehicles ◽  
Delivery Vehicles

scholarly journals The Effect of Mold Conditions on Heat Resistance of Injection-Molded Stereocomplex Polylactide-b-polyethylene Glycol-b-Polylactide Bioplastic

2021 ◽  
Vol 58 (3) ◽  
pp. 11-22
Author(s):  
Yodthong Baimark ◽  
Wuttipong Rungseesantivanon ◽  
Natcha Prakymoramas
Keyword(s):  
Polyethylene Glycol ◽  
Heat Resistance ◽  
Softening Temperature ◽  
Mold Temperature ◽  
Mechanical Analysis ◽  
Cooling Time ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Injection Molded ◽  
Good Heat

The effect of mold conditions was investigated in terms of mold temperature (30oC and 90oC) and cooling time (30 s and 60 s) on the heat resistance of injection-molded bars for stereocomplex polylactide-b-polyethylene glycol-b-polylactide (scPLA-PEG-PLA). Comparative study was performed for poly(L-lactide) (PLLA) and PLLA-b-PEG-b-PLLA (PLLA-PEG-PLLA). scPLA-PEG-PLA was 90/10 (w/w) PLLA-PEG-PLLA/poly(D-lactide) blend. scPLA-PEG-PLA exhibited the easiest crystallization upon cooling scan as shown by differential scanning calorimetry (DSC). Higher mold-temperature and longer cooling-time induced higher degree of crystallinity as assessed by X-ray diffractometry (XRD) except for PLLA bars. The heat resistance of both PLLA-PEG-PLLA and scPLA-PEG-PLA bars was improved with increased mold-temperature and cooling-time as shown by dynamic mechanical analysis (DMA), vicat softening temperature (VST) and heat distortion-resistance tests except for PLLA bars. In conclusion, the heat resistance of injection-molded bars prepared at 90˚C mold temperature was in the order scPLA-PEG-PLA ] PLLA-PEG-PLLA ] PLLA. The results suggested that flexible PLLA-PEG-PLLA and scPLA-PEG-PLA with high degrees of crystallinity were successfully obtained by injection molding for use as good heat-resistant bioplastic products.

Light-cured dental composites characterization by Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 428-429
Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Service Performance ◽  
Dental Composite ◽  
Dental Composites ◽  
Neat Resin ◽  
Scanning Calorimetry ◽  
Research Meeting ◽  
Formulation Variables

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.

Nanoscale Functional Biomaterials for Cancer Theranostics

2018 ◽  
Vol 25 (25) ◽  
pp. 2987-3000 ◽  
Author(s):  
Linying Liu ◽  
Xiaoshuang Li ◽  
Lei Chen ◽  
Xin Zhang
Keyword(s):  
Brain Cancer ◽  
Molecular Level ◽  
Functional Materials ◽  
Therapeutic Agents ◽  
Lower Side ◽  
Drug Delivery Vehicles ◽  
Functional Nanoparticles ◽  
Delivery Vehicles ◽  
Functional Biomaterials ◽  
Cancer Theranostics

Nanomedicine is widely developed in recent years. In nanomedicine system, nanoscale and nanostructured functional materials are used to manipulate the human biology systems at the molecular level for cancer imaging and therapy. New nanostructure based functional materials consist of nanoscale liposomes, spheres, micelles, capsules, emulsion, suspension and phamacosomes. Several functional nanoparticles such as lipidbased and polymer-based materials are demonstrated to be drug delivery vehicles and imaging agents. These materials are biodegradable, biocompatible and have better biodistribution, lower side effect and lower toxicity. In addition, hybrids with these materials coating provide uniquely electrical, optical and magnetic properties. This review discusses the research on the applications of functional materials, especially nanoparticles as imaging contrast agents, cancer therapeutic agents and multi-functional agents and this review focused on the theranostic integration treatments on liver cancer and brain cancer.

Dendrimers: General Aspects, Applications and Structural Exploitations as Prodrug/Drug-delivery Vehicles in Current Medicine

2018 ◽  
Vol 18 (5) ◽  
pp. 439-457 ◽  
Author(s):  
Merina Mariyam ◽  
Kajal Ghosal ◽  
Sabu Thomas ◽  
Nandakumar Kalarikkal ◽  
Mahima S. Latha
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Vehicles ◽  
Delivery Vehicles ◽  
General Aspects

Novel Phospholipid-Based Labrasol Nanomicelles Loaded Flavonoids for Oral Delivery with Enhanced Penetration and Anti-Brain Tumor Efficiency

2020 ◽  
Vol 17 (3) ◽  
pp. 229-245
Author(s):  
Gang Wang ◽  
Junjie Wang ◽  
Rui Guan
Keyword(s):  
Drug Delivery ◽  
Brain Tumor ◽  
Oral Delivery ◽  
Safe Delivery ◽  
Drug Delivery Vehicles ◽  
Therapeutic Benefits ◽  
Delivery Vehicles ◽  
The Brain

Background: Owing to the rich anticancer properties of flavonoids, there is a need for their incorporation into drug delivery vehicles like nanomicelles for safe delivery of the drug into the brain tumor microenvironment. Objective: This study, therefore, aimed to prepare the phospholipid-based Labrasol/Pluronic F68 modified nano micelles loaded with flavonoids (Nano-flavonoids) for the delivery of the drug to the target brain tumor. Methods: Myricetin, quercetin and fisetin were selected as the initial drugs to evaluate the biodistribution and acute toxicity of the drug delivery vehicles in rats with implanted C6 glioma tumors after oral administration, while the uptake, retention, release in human intestinal Caco-2 cells and the effect on the brain endothelial barrier were investigated in Human Brain Microvascular Endothelial Cells (HBMECs). Results: The results demonstrated that nano-flavonoids loaded with myricetin showed more evenly distributed targeting tissues and enhanced anti-tumor efficiency in vivo without significant cytotoxicity to Caco-2 cells and alteration in the Trans Epithelial Electric Resistance (TEER). There was no pathological evidence of renal, hepatic or other organs dysfunction after the administration of nanoflavonoids, which showed no significant influence on cytotoxicity to Caco-2 cells. Conclusion: In conclusion, Labrasol/F68-NMs loaded with MYR and quercetin could enhance antiglioma effect in vitro and in vivo, which may be better tools for medical therapy, while the pharmacokinetics and pharmacodynamics of nano-flavonoids may ensure optimal therapeutic benefits.

Delivery Efficacy Differences of Intravenous and Intraperitoneal Injection of Exosomes: Perspectives from Tracking Dye Labeled and MiRNA Encapsulated Exosomes

2020 ◽  
Vol 17 (3) ◽  
pp. 186-194 ◽  
Author(s):  
Xueying Zhou ◽  
Zhelong Li ◽  
Wenqi Sun ◽  
Guodong Yang ◽  
Changyang Xing ◽  
...  
Keyword(s):  
Intraperitoneal Injection ◽  
Drug Delivery Vehicles ◽  
C Elegans ◽  
Administration Routes ◽  
In Vivo Distribution ◽  
Obesity Therapy ◽  
Delivery Vehicles ◽  
Visceral Adipose ◽  
Mirna Abundance

Background: Exosomes are cell-derived nanovesicles that play vital roles in intercellular communication. Recently, exosomes are recognized as promising drug delivery vehicles. Up till now, how the in vivo distribution of exosomes is affected by different administration routes has not been fully understood. Methods: In the present study, in vivo distribution of exosomes following intravenous and intraperitoneal injection approaches was systemically analyzed by tracking the fluorescence-labeled exosomes and qPCR analysis of C. elegans specific miRNA abundance delivered by exosomes in different organs. Results: The results showed that exosomes administered through tail vein were mostly taken up by the liver, spleen and lungs while exosomes injected intraperitoneally were more dispersedly distributed. Besides the liver, spleen, and lungs, intraperitoneal injection effectively delivered exosomes into the visceral adipose tissue, making it a promising strategy for obesity therapy. Moreover, the results from fluorescence tracking and qPCR were slightly different, which could be explained by systemic errors. Conclusion: Together, our study reveals that different administration routes cause a significant differential in vivo distribution of exosomes, suggesting that optimization of the delivery route is prerequisite to obtain rational delivery efficiency in detailed organs.

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