Nanotechnology, Science and Applications最新文献

Introduction: The aim of this interdisciplinary study was to answer the question of whether active antioxidants as graphene oxide (GO), sodium ascorbate, and L-ascorbic acid modify at a molecular and supramolecular level the tissue of pathological amnion and the necrotic eschar degraded in thermal burn. We propose new solutions of modifiers based on GO that will become innovative ingredients to be used in transplants (amnion) and enhance regeneration of epidermis degraded in thermal burn.

Methods: A Nicolet 6700 spectrophotometer with Omnic software and the EasiDiff diffusion accessory were used in FTIR spectroscopic analysis. A Nicolet Magna-IR 860 spectrometer with an FT Raman accessory was used to record the Raman spectra of the samples. The surface of the samples was examined using a Phenom ProX scanning electron microscope with an energy-dispersive X-ray spectroscopy detector to diagnose and illustrate morphological effects on skin and amnion samples. SAXS measurements were carried out with a compact Kratky camera equipped with the SWAXS optical system.

Results: Characterisation of amide I-III regions, important for molecular structure, on both FTIR and FTR spectra revealed distinct shifts, testifying to organization of protein structure after GO modification. A wide lipid band associated with ester-group vibrations in phospholipids of cell membranes and vibrations of the carbonyl group of GO in the 1,790-1,720 cm^-1 band were observed in the spectra of thermally degraded and GO-modified epidermis and pathological amnion. SAXS studies revealed that GO caused a significant change in the structure of the burnt skin, but its influence on the structure of the amnion was weak.

Conclusion: Modification of burn-damaged epidermis and pathological amnion by means of GO results in stabilization and regeneration of tissue at the level of molecular (FTIR, FTR) and supramolecular (SAXS) interactions.

Graphene and graphene oxide have become the base of many advanced biosensors due to their exceptional characteristics. However, lack of some properties, such as inertness of graphene in organic solutions and non-electrical conductivity of graphene oxide, are their drawbacks in sensing applications. To compensate for these shortcomings, various methods of modifications have been developed to provide the appropriate properties required for biosensing. Efficient modification of graphene and graphene oxide facilitates the interaction of biomolecules with their surface, and the ultimate bioconjugate can be employed as the main sensing part of the biosensors. Graphene nanomaterials as transducers increase the signal response in various sensing applications. Their large surface area and perfect biocompatibility with lots of biomolecules provide the prerequisite of a stable biosensor, which is the immobilization of bioreceptor on transducer. Biosensor development has paramount importance in the field of environmental monitoring, security, defense, food safety standards, clinical sector, marine sector, biomedicine, and drug discovery. Biosensor applications are also prevalent in the plant biology sector to find the missing links required in the metabolic process. In this review, the importance of oxygen functional groups in functionalizing the graphene and graphene oxide and different types of functionalization will be explained. Moreover, immobilization of biomolecules (such as protein, peptide, DNA, aptamer) on graphene and graphene oxide and at the end, the application of these biomaterials in biosensors with different transducing mechanisms will be discussed.

The use of medicinal plants in green synthesis of metal nanoparticles is increasing day by day. A simple search for the keywords "green synthesis" and "nanoparticles" yields more than 33,000 articles in Scopus. As of August 10, 2021, more than 4000 articles have been published in 2021 alone. Besides demonstrating the ease and environmental-friendly route of synthesizing nanomaterials, many studies report the superior pharmacological properties of green synthesized nanoparticles compared to those synthesized by other methods. This is probably due to the fact that bioactive molecules are entrapped on the surface of these nanoparticles. On the other hand, recent studies have confirmed the nano-dimension and biocompatibility of metal ash (Bhasma) preparations, which are commonly macerated with biological products and administered for the treatment of various diseases in Indian medicine since ancient times. This perspective article argues for the prospective medical application of green nanoparticles in the light of Bhasma.

Biofilms are bacterial communities that live in association with biotic or abiotic surfaces and enclosed in an extracellular polymeric substance. Their formation on both biotic and abiotic surfaces, including human tissue and medical device surfaces, pose a major threat causing chronic infections. In addition, current antibiotics and antiseptic agents have shown limited ability to completely remove biofilms. In this review, the authors provide an overview on the formation of bacterial biofilms and its characteristics, burden and evolution with phages. Moreover, the most recent possible use of phages and phage-derived enzymes to combat bacteria in biofilm structures is elucidated. From the emerging results, it can be concluded that despite successful use of phages and phage-derived products in destroying biofilms, they are mostly not adequate to eradicate all bacterial cells. Nevertheless, a combined therapy with the use of phages and/or phage-derived products with other antimicrobial agents including antibiotics, nanoparticles, and antimicrobial peptides may be effective approaches to remove biofilms from medical device surfaces and to treat their associated infections in humans.

Purpose: Surgical resection of hepatocellular carcinoma can be associated with recurrence resulting from the degeneration of residual volume of the liver. The objective was to assess the possibility of using a biocompatible nanofilm, made of a colloid of diamond nanoparticles (nfND), to fill the side after tumour resection and optimize its contact with proliferating liver cells, minimizing their cancerous transformation.

Methods: HepG2 and C3A liver cancer cells and HS-5 non-cancer cells were used. An aqueous colloid of diamond nanoparticles, which covered the cell culture plate, was used to create the nanofilm. The roughness of the resulting nanofilm was measured by atomic force microscopy. Mitochondrial activity and cell proliferation were measured by XTT and BrdU assays. Cell morphology and a scratch test were used to evaluate the invasiveness of cells. Flow cytometry determined the number of cells within the cell cycle. Protein expression in was measured by mass spectrometry.

Results: The nfND created a surface with increased roughness and exposed oxygen groups compared with a standard plate. All cell lines were prone to settling on the nanofilm, but cancer cells formed more relaxed clusters. The surface compatibility was dependent on the cell type and decreased in the order C3A >HepG2 >HS-5. The invasion was reduced in cancer lines with the greatest effect on the C3A line, reducing proliferation and increasing the G2/M cell population. Among the proteins with altered expression, membrane and nuclear proteins dominated.

Conclusion: In vitro studies demonstrated the antiproliferative properties of nfND against C3A liver cancer cells. At the same time, the need to personalize potential therapy was indicated due to the differential protein synthetic responses in C3A vs HepG2 cells. We documented that nfND is a source of signals capable of normalizing the expression of many intracellular proteins involved in the transformation to non-cancerous cells.

[This retracts the article DOI: 10.2147/NSA.S266663.].

Controlled and contactless movements of magnetic nanoparticles are crucial for fundamental biotechnological and clinical research (eg, cell manipulation and sorting, hyperthermia, and magnetic drug targeting). However, the key technological question, how to generate suitable magnetic fields on various length scales (µm-m), is still unsolved. Here, we present a system of permanent magnets which allows for steering of iron oxide nanoparticles (SPIONs) on arbitrary trajectories observable by microscopy. The movement of the particles is simply controlled by an almost force-free rotation of cylindrical arrangements of permanent magnets. The same instrument can be used to move suspended cells loaded with SPIONs along with predetermined directions. Surprisingly, it also allows for controlled movements of intracellular compartments inside of individual cells. The exclusive use of permanent magnets simplifies scaled up versions for animals or even humans, which would open the door for remotely controlled in vivo guidance of nanoparticles or micro-robots.

Introduction: Functionalization of water-soluble chitosan (WSCS) nanocolloids with, gold nanoparticles (AuNPs), and LyslLys3 (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-bombesin 1-14 (DOTA-BBN) peptide affords an innovative pathway to produce prostate tumor cell-specific nanomedicine agents with potential applications in molecular imaging and therapy.

Methods: The preparation involves the production and full characterization of water-soluble chitosan (WSCS), via gamma (γ) rays (80 kGy) irradiation, followed by DOTA-BBN conjugation for subsequent use as an effective template toward the synthesis of tumor cell-specific AuNPs-WSCS-DOTA-BBN.

Results: The WSCS-DOTA-BBN polymeric nanoparticles (86 ± 2.03 nm) served multiple roles as reducing and stabilizing agents in the overall template synthesis of tumor cell-targeted AuNPs. The AuNPs capped with WSCS and WSCS-DOTA-BBN exhibited average Au-core diameter of 17 ± 8 nm and 20 ± 7 nm with hydrodynamic diameters of 56 ± 1 and 67± 2 nm, respectively. The AuNPs-WSCS-DOTA-BBN showed optimum in vitro stability in biologically relevant solutions. The targeted AuNPs showed selective affinity toward GRP receptors overexpressed in prostate cancer cells (PC-3 and LNCaP).

Discussion: The AuNPs-WSCS-DOTA-BBN displayed cytotoxicity effects against PC-3 and LNCaP cancer cells, with concomitant safety toward the HAECs normal cells. The AuNPs-WSCS-DOTA-BBN showed synergistic targeting toward tumor cells with selective cytotoxicity of AuNPs towards PC-3 and LNCaP cells. Our investigations provide compelling evidence that AuNPs functionalized with WSCS-DOTA-BBN is an innovative nanomedicine approach for use in molecular imaging and therapy of GRP receptor-positive tumors. The template synthesis of AuNPs-WSCS-DOTA-BBN serves as an excellent non-radioactive surrogate for the development of the corresponding ¹⁹⁸AuNPs theragnostic nanoradiopharmaceutical for use in cancer diagnosis and therapy.

Introduction: Oxidative tissue damage caused by reactive oxygen species results in a significant decrease in the total antioxidant capacity of the biological system. The aim of this interdisciplinary study was to answer the question of whether active antioxidants modify, at a molecular and supramolecular level, the tissue of pathological amnion and the necrotic eschar degraded in thermal burn.

Methods: A Nicolet 6700 Fourier-transform spectrophotometer with OMNIC software and the EasiDiff diffusion accessory were used in the FTIR spectroscopic analysis. A NICOLET MAGNA-IR 860 spectrometer with FT-Raman accessory was used to record the Raman spectra of the samples. The samples were exposed to bacteria capable of causing nosocomial infections, ie Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli and Pseudomonas aeruginosa. Whereas samples of hypotrophic amnion interacted with Staphylococcus aureus, Escherichia coli and Enterococcus faecalis. The obtained flame retardant effect of placentas was evaluated using the method of the limiting oxygen index (LOI).

Results: The infrared spectroscopy analysis proved that after modification of the amniotic samples in graphene oxide and ortho-silicic acid, the amide II band is split into two components. Incubation of samples in modifier solutions: graphene oxide, sodium ascorbate and L-ascorbic acid results in shifts and changes of intensity within the broadly understood lipid band 1743-1745-1747 cm^-1. The oxidising changes observed within the lipid and amide bands are affected by the incubation effect of graphene oxide as a modifier, possibly adsorbing on the surface of the amniotic membrane. On the basis of microbiological studies, pathogenic bacteria commonly causing amniotic infections and growing in burn wounds were found to have particularly good resistance to stabilized ortho-silicic acid (E. coli) and lactoferrin (S.aureus).

Conclusion: This thermogravimetric study found the highest stability of the analysed tissues (hypotrophic amnion and burnt epidermis) after modification with graphene oxide and sodium ascorbate.