Poly(hydroxyalkanoates): Biorefinery polymers with a whole range of applications. The work of Robert H. Marchessault

2008 ◽  
Vol 86 (6) ◽  
pp. 628-640 ◽  
Author(s):  
William J Orts ◽  
Geoffrey A.R. Nobes ◽  
Jumpei Kawada ◽  
Sophie Nguyen ◽  
Ga-er Yu ◽  
...  

This review describes the characterization and application of poly(hydroxyalkanoates), PHAs, a remarkable family of natural polyesters with a wide array of useful properties and potential applications. It places specific emphasis on the work of Robert H. Marchessault and his many colleagues outlining how Marchessault’s body of work both shaped the field and complemented the work of his contemporaries. Particular attention will focus on the “rediscovery” of poly(β-hydroxybutyrate), PHB, the first PHA to be discovered, from the late 1950s onward, highlighting some of the historical aspects of PHA’s path toward commercial applications. It will also cover why this class of materials is so unique, including PHA structure–properties relationships, its unique crystalline behaviour, in vivo – in vitro synthesis and degradation, and PHA-graft-copolymers.Key words: poly(hydroxyalkanoate), PHA, poly(β-hydroxybutyrate), PHB, biopolymers, bacterial polyester, random copolymers, polymer single crystals, graft copolymers.

2021 ◽  
Vol 22 (15) ◽  
pp. 8106
Author(s):  
Tianming Song ◽  
Yawei Qu ◽  
Zhe Ren ◽  
Shuang Yu ◽  
Mingjian Sun ◽  
...  

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.


2020 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
João P. Cotovio ◽  
Tiago G. Fernandes

Liver disease is one of the leading causes of death worldwide, leading to the death of approximately 2 million people per year. Current therapies include orthotopic liver transplantation, however, donor organ shortage remains a great challenge. In addition, the development of novel therapeutics has been limited due to the lack of in vitro models that mimic in vivo liver physiology. Accordingly, hepatic cell lineages derived from human pluripotent stem cells (hPSCs) represent a promising cell source for liver cell therapy, disease modelling, and drug discovery. Moreover, the development of new culture systems bringing together the multiple liver-specific hepatic cell types triggered the development of hPSC-derived liver organoids. Therefore, these human liver-based platforms hold great potential for clinical applications. In this review, the production of the different hepatic cell lineages from hPSCs, including hepatocytes, as well as the emerging strategies to generate hPSC-derived liver organoids will be assessed, while current biomedical applications will be highlighted.


Parasitology ◽  
2006 ◽  
Vol 133 (3) ◽  
pp. 261-278 ◽  
Author(s):  
A. HEMPHILL ◽  
N. VONLAUFEN ◽  
A. NAGULESWARAN

Neospora caninumis an apicomplexan parasite that is closely related toToxoplasma gondii, the causative agent of toxoplasmosis in humans and domestic animals. However, in contrast toT. gondii, N. caninumrepresents a major cause of abortion in cattle, pointing towards distinct differences in the biology of these two species. There are 3 distinct key features that represent potential targets for prevention of infection or intervention against disease caused byN. caninum. Firstly, tachyzoites are capable of infecting a large variety of host cellsin vitroandin vivo. Secondly, the parasite exploits its ability to respond to alterations in living conditions by converting into another stage (tachyzoite-to-bradyzoite orvice versa). Thirdly, by analogy withT. gondii, this parasite has evolved mechanisms that modulate its host cells according to its own requirements, and these must, especially in the case of the bradyzoite stage, involve mechanisms that ensure long-term survival of not only the parasite but also of the host cell. In order to elucidate the molecular and cellular bases of these important features ofN. caninum, cell culture-based approaches and laboratory animal models are being exploited. In this review, we will summarize the current achievements related to host cell and parasite cell biology, and will discuss potential applications for prevention of infection and/or disease by reviewing corresponding work performed in murine laboratory infection models and in cattle.


2021 ◽  
Vol 22 (17) ◽  
pp. 9508
Author(s):  
Nhung Thi Phuong Nong ◽  
Jue-Liang Hsu

Diabetes, a glucose metabolic disorder, is considered one of the biggest challenges associated with a complex complication of health crises in the modern lifestyle. Inhibition or reduction of the dipeptidyl peptidase IV (DPP-IV), alpha-glucosidase, and protein-tyrosine phosphatase 1B (PTP-1B) enzyme activities or expressions are notably considered as the promising therapeutic strategies for the management of type 2 diabetes (T2D). Various food protein-derived antidiabetic bioactive peptides have been isolated and verified. This review provides an overview of the DPP-IV, PTP-1B, and α-glucosidase inhibitors, and updates on the methods for the discovery of DPP-IV inhibitory peptides released from food-protein hydrolysate. The finding of novel bioactive peptides involves studies about the strategy of separation fractionation, the identification of peptide sequences, and the evaluation of peptide characteristics in vitro, in silico, in situ, and in vivo. The potential of bioactive peptides suggests useful applications in the prevention and management of diabetes. Furthermore, evidence of clinical studies is necessary for the validation of these peptides’ efficiencies before commercial applications.


2021 ◽  
Author(s):  
Rebecca L Pinals ◽  
Nicholas Ouassil ◽  
Jackson Travis Del Bonis-O'Donnell ◽  
Jeffrey W Wang ◽  
Markita P Landry

Engineered nanoparticles are advantageous for numerous biotechnology applications, including biomolecular sensing and delivery. However, testing the compatibility and function of nanotechnologies in biological systems requires a heuristic approach, where unpredictable biofouling often prevents effective implementation. Such biofouling is the result of spontaneous protein adsorption to the nanoparticle surface, forming the "protein corona" and altering the physicochemical properties, and thus intended function, of the nanotechnology. To better apply engineered nanoparticles in biological systems, herein, we develop a random forest classifier (RFC) trained with proteomic mass spectrometry data that identifies which proteins adsorb to nanoparticles. We model proteins that populate the corona of a single-walled carbon nanotube (SWCNT)-based optical nanosensor. We optimize the classifier and characterize the classifier performance against other models. To evaluate the predictive power of our model, we then apply the classifier to rapidly identify and experimentally validate proteins with high binding affinity to SWCNTs. Using protein properties based solely on amino acid sequence, we further determine protein features associated with increased likelihood of SWCNT binding: proteins with high content of solvent-exposed glycine residues and non-secondary structure-associated amino acids. Furthermore, proteins with high leucine residue content and beta-sheet-associated amino acids are less likely to form the SWCNT protein corona. The classifier presented herein provides an important tool to undertake the otherwise intractable problem of predicting protein-nanoparticle interactions, which is needed for more rapid and effective translation of nanobiotechnologies from in vitro synthesis to in vivo use.


Author(s):  
Marco Bonato ◽  
Francesca Corrà ◽  
Marta Bellio ◽  
Laura Guidolin ◽  
Laura Tallandini ◽  
...  

Due to their unique properties, perfluorinated substances (PFAS) are widely used in multiple industrial and commercial applications, but they are toxic for animals, humans included. This review presents some available data on the PFAS environmental distribution in the world, and in particular in Europe and in Veneto region of Italy, where it has become a serious problem for human health. The consumption of contaminated food and drinking water is considered one of the major source of exposure for humans. Worldwide epidemiological studies report the negative effects that PFAS have on human health, due to environmental pollution, including infertility, steroid hormone perturbation, thyroid, liver and kidney disorders and metabolic disfunctions. In vitro and in vivo researches correlated PFAS exposure to oxidative stress effects (in mammals as well as in other vertebrates of human interest), produced by a PFAS-induced increase of reactive oxygen species formation. The cellular antioxidant defense system is activated by PFAS, but it is only partially able to avoid the oxidative damage to biomolecules.


1964 ◽  
Vol 22 (1) ◽  
pp. 227-258 ◽  
Author(s):  
Burton Goldberg ◽  
Howard Green

In vitro synthesis of collagen by established mouse fibroblast lines has been examined by electron microscopy. During rapid growth (log phase), when collagen could not be detected in the cultures, the cells lacked a well developed granular ergastoplasm and Golgi system. Upon cessation of growth (stationary phase), collagen accumulated in the cultures and the cells demonstrated highly developed granular and smooth ergastoplasm. Collagen appeared to be synthesized in the rough-surfaced endoplasmic reticulum and to be transported as a soluble protein to the cell surface by vesicular elements of the agranular ergastoplasm. Fusion of the limiting membranes of these vesicles with the cell membrane permitted the discharge of the soluble collagen into the extracellular space, where fibrils of two diameter distributions formed. The secretion of collagen is concluded to be of the merocrine type. Alternative theories of collagen secretion are discussed and the data for established lines compared with the results of other in vitro and in vivo studies of collagen fibrillogenesis.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ziyu Ge ◽  
Luming Yang ◽  
Fang Xiao ◽  
Yani Wu ◽  
Tingting Yu ◽  
...  

Graphene family nanomaterials, with superior mechanical, chemical, and biological properties, have grabbed appreciable attention on the path of researches seeking new materials for future biomedical applications. Although potential applications of graphene had been highly reviewed in other fields of medicine, especially for their antibacterial properties and tissue regenerative capacities, in vivo and in vitro studies related to dentistry are very limited. Therefore, based on current knowledge and latest progress, this article aimed to present the recent achievements and provide a comprehensive literature review on potential applications of graphene that could be translated into clinical reality in dentistry.


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