Nanoscale poly(4-hydroxybutyrate)-mPEG carriers for anticancer drugs delivery.

Despite several advancements in chemotherapy, cancer is still the second most frequent cause of mortality worldwide. Drug delivery to solid tumors is one of the most challenging aspects in cancer therapy. In pharmaceutical industries biodegradable polymeric nanoparticles as drug carriers have attracted great research interest because of their biocompatibility, biodegradability and sustained release of drugs. In our study we prepared poly(4-hydroxybutyrate)-mPEG (P(4HB)-mPEG) nanocarriers for the delivery of cisplatin as anticancer drug to mouse hippocampal HT22 cells. P(4HB) is more suitable candidate to be utilized in pharmaceutical industries due to its wide medical applications. P(4HB) is a homopolymer of 4-hydroxybutyrate (4HB), and belongs to a diverse class of materials called polyhydroxyalkanoates (PHA) produced by microorganisms inside the cells as energy storage materials. P(4HB) has certain unique properties such as biocompatibility and rapid in vivo degradation, which differentiate it from others PHA based polymers. Novel amorphous amphiphilic block copolymer P(4HB)-mPEG nanocarriers were prepared and characterized. Flow cytometry, and confocal microscopy revealed a suppression effect by the cisplatin loaded nanocarriers on HT22 cell growth, and enhancement of apoptotic process of the cells compared to free drug treated cells. The amorphous polymeric nanocarriers could be effective vehicles for the sustained delivery of toxic anticancer drugs for the therapy of cancer.

Ecological risks of microplastics contamination with green solutions and future perspectives.

The rise of plasticulture as mulching material in farming systems has raised concerns about microplastics (MPs) in the agricultural landscape. MPs are emerging pollutants in croplands and water systems with significant ecological risks, particularly over the long term. In the soil systems, MPs polymer type, thinness, shape, and size induces numerous effects on soil aggregates, dissolved organic carbon (C), rapidly oxidized organic C, microbial biomass C, microbial biomass nitrogen (N), microbial immobilization, degradation of organic matter, N cycling, and production of greenhouse gas emissions (GHGs), thereby posing a significant risk of impairing soil physical and biochemical properties over time. Further, toxic chemicals released from polyethylene mulching (PMs) might indirectly harm plant growth by affecting soil wetting-drying cycles, releasing toxic substances that interact with soil matrix, and suppressing soil microbial activity. In the environment, accumulation of MPs poses a risk to human health by accelerating emissions of GHGs, e.g., methane and carbon dioxide, or directly releasing toxic substances such as phthalic acid esters (PAEs) into the soils. Also, larger sizes MPs can adhere to root surface and block stomata could significantly change the shape of root epidermal cells resulting in arrest plant growth and development by restricting water-nutrient uptake, and gene expression and altering the biodiversity of the soil pollutants. In this review, we systematically analyzed the potential risks of MPs to the soil-plant and human body, their occurrence, abundance, and migration in agroecosystems. Further, the impacts of MPs on soil microbial function, nutrient cycling, soil C, and GHGs are mechanistically reviewed, with emphasis on potential green solutions such as organic materials amendments along with future research directions for more eco-friendly and sustainable plastic management in agroecosystems.

Synthesis and characterization of PHV-block-mPEG diblock copolymer and its formation of amphiphilic nanoparticles for drug delivery.

Despite the recent research interest in the field of nanoparticles delivery system, their structure modification and transport behavior of various hydrophobic drugs is poorly developed. In this article the synthesis of novel amphiphilic diblock copolymer poly([R]-3-hydroxyvalerate)-block-monomethoxy poly(ethylene glycol) (PHV-block-mPEG) was undertaken by modifying the structure of biodegradable and hydrophobic poly([R]-3-hydroxyvalerate) (PHV) with hydrophilic monomethoxy poly(ethylene glycol) (mPEG). The chemical combination of the two blocks was carried out in the melt using bis(2-ethylhexanoate) tin as transesterification catalyst. The synthesized product was characterized by gel permeation chromatography (GPC), 1H nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) analysis. The block copolymer self-assembled into amphiphilic nanoparticles with a core of hydrophobic PHV and a shell of hydrophilic mPEG in aqueous solution. Characterization of the nanoparticles showed the formation of discrete, spherically shaped nanoparticles with mean particle size of 200 +/- 1 nm and zeta potential of -14 +/- 1 mV. A hydrophobic drug thymoquinone was efficiently incorporated into the core hydrophobic domain of the nanoparticles and its release kinetics was studied in vitro. The amphiphilic PEGylated nanoparticles showed biocompatibility when checked in neuronal hippocampal cells of prenatal rat. Our results suggest that the amphiphilic nanoparticles with core-shell structures are potentially useful to develop novel drug carriers.

Detection, Treatment Planning, and Genetic Predisposition of Bruxism: A Systematic Mapping Process and Network Visualization Technique.

BACKGROUND: Lack of sleep generates many disorders and bruxism is one of them. It has affected almost 31% of the world population. AIM: The purpose of this paper is to determine the volume of the research conducted on bruxism and to create a database. We aimed to highlight critical issues for further research commitments and communications. This paper designs a comprehensive and very perception-based picture of bruxism disorder. METHODS: The research-based work uses three methods, including a systematic mapping process, network visualization, and literature review. Softwares, such as VOSviewer, MATLAB, and MEGA- X, have been utilized to analyze the work. We have researched deep insights of information to retrieve the present understanding of bruxism disorder from dental to psychological concepts, from engineering detection to clinical treatment, and from temporomandibular disorder to biological genes. RESULTS: We found 10 keywords and 77 items of bruxism in PubMed, Scopus, Google Scholar, and Web of Science databases based on previous publications. These keywords and items are helpful for all types of researchers, which include engineering, science, and medical background personals. 11 genes and 75 research articles with approximately 115,077 subjects, for the analysis of detection, treatment, child and adolescent bruxism, have been reviewed in the research work. CONCLUSION: It has been found that bruxism altogether has sleep, neurological, dental, and genetic disorder components and is a complex phenomenon. This study has also mentioned the future direction and gap in research conducted so far on bruxism and has also tried to provide goals for the upcoming research to be accomplished in a more significant and scientific manner.

Amorphous amphiphilic P(3HV-co-4HB)-b-mPEG block copolymer synthesized from bacterial copolyester via melt transesterification: nanoparticle preparation, cisplatin-loading for cancer therapy and in vitro evaluation.

Cisplatin is a chemotherapeutic agent used against a variety of tumors. We determined the efficacy and bioavailability of cisplatin in the form of cisplatin-loaded self-assembled amphiphilic copolymer nanoparticles (NPs). Non-crystallizing bacterial copolyester was employed as hydrophobic segment to increase drug loading efficiency. Novel amorphous amphiphilic block copolymer P(3HV-co-4HB)-b-mPEG was synthesized from bacterial copolyester poly(3-hydroxyvalerate-co-4-hydroxybutyrate) coupled via transesterification reaction using bis(2-ethylhexanoate) tin catalyst to monomethoxypoly(ethylene glycol). The product was characterized, and core-shell particles with nanometer size range were prepared by emulsification-solvent evaporation method. Transmission electron microscopy (TEM) examination revealed that the NPs took the shape of spheres with inner concealed core of hydrophobic P(3HV-co-4HB) polymer and the outer shell formed by hydrophilic mPEG segment. The in vitro release profile of cisplatin from the core hydrophobic domain showed a sustained release of the drug. TEM and confocal microscopy examination revealed clearly the internalization of cisplatin-loaded NPs into the tumor cells. MTT assay, flow cytometry, western blot and confocal microscopy revealed a suppression effect by the NPs on tumor cell growth, and enhancement of apoptotic process of the tumor cells compared to free drug treated cells. The amorphous polymeric NPs could be effective vehicles for the sustained delivery of toxic anticancer drugs.