Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 149
Filter
Add more filters

Publication year range
1.
Arch Microbiol ; 206(6): 261, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38753095

ABSTRACT

The search for affordable enzymes with exceptional characteristics is fundamental to overcoming industrial and environmental constraints. In this study, a recombinant GH10 xylanase (Xyn10-HB) from the extremely alkaliphilic bacterium Halalkalibacterium halodurans C-125 cultivated at pH 10 was cloned and expressed in E. coli BL21(DE3). Removal of the signal peptide improved the expression, and an overall activity of 8 U/mL was obtained in the cell-free supernatant. The molecular weight of purified Xyn10-HB was estimated to be 42.6 kDa by SDS-PAGE. The enzyme was active across a wide pH range (5-10) with optimal activity recorded at pH 8.5 and 60 °C. It also presented good stability with a half-life of 3 h under these conditions. Substrate specificity studies showed that Xyn10-HB is a cellulase-free enzyme that conventionally hydrolyse birchwood and oat spelts xylans (Apparent Km of 0.46 mg/mL and 0.54 mg/mL, respectively). HPLC analysis showed that both xylans hydrolysis produced xylooligosaccharides (XOS) with a degree of polymerization (DP) ranging from 2 to 9. The conversion yield was 77% after 24 h with xylobiose and xylotriose as the main end-reaction products. When assayed on alkali-extracted wheat straw heteroxylan, the Xyn10-HB produced active XOS with antioxidant activity determined by the DPPH radical scavenging method (IC50 of 0.54 mg/mL after 4 h). Owing to its various characteristics, Xyn10-HB xylanase is a promising candidate for multiple biotechnological applications.


Subject(s)
Endo-1,4-beta Xylanases , Recombinant Proteins , Xylans , Substrate Specificity , Hydrolysis , Xylans/metabolism , Endo-1,4-beta Xylanases/metabolism , Endo-1,4-beta Xylanases/genetics , Endo-1,4-beta Xylanases/chemistry , Recombinant Proteins/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Escherichia coli/genetics , Escherichia coli/metabolism , Hydrogen-Ion Concentration , Cloning, Molecular , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacterial Proteins/chemistry , Glucuronates/metabolism , Enzyme Stability , Kinetics , Molecular Weight , Oligosaccharides/metabolism , Disaccharides
2.
Psychopathology ; : 1, 2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38870915

ABSTRACT

INTRODUCTION: Pathological narcissism (PN) can be defined as the compromised and fluctuating ability to regulate self-esteem, the latter depending on external validation, admiration, or enhancement, all resulting in grandiose (e.g., self-enhancement, aggressiveness, manipulation) or vulnerable (e.g., depression, anxiety, self-criticism, avoidance) dysfunctional reactions when confronting with self-esteem threats. A link has been suggested between PN and emotion dysregulation (ED), but to date, no systematic review has been conducted. METHODS: We conducted a systematic review of the literature published until February 2024 studying the association between PN (with or without a diagnosis of narcissistic personality disorder) and ED, divided in two domains: emotion regulation difficulties and strategies. RESULTS: Twenty-two studies were included in our analysis. Altogether, the available data are insufficient to conclude on the link between grandiose narcissism and emotion regulation difficulties in non-clinical population (notably due to different patterns of associations depending on the scale used to assess narcissism). However, the small number of studies conducted in clinical population seems to indicate a possible absence of association between the two constructs. On the other side, there is considerable evidence for the existence of a positive association between vulnerable narcissism and emotion regulation difficulties, regardless of the scale used to assess narcissism and the type of population considered. Finally, regarding emotion regulation strategies, data are too scarce to draw any conclusion, even though there seems to be a trend toward positive association between narcissistic vulnerability and expressive suppression. CONCLUSION: ED seems to be highly associated with narcissistic vulnerability. Given that every patient suffering from PN may experience vulnerable states, we believe that ED should be considered as an important part of psychoeducation programs and psychotherapeutic treatments designed for this population.

3.
Int J Mol Sci ; 25(5)2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38474003

ABSTRACT

MicroRNA (miRNA) modulation has been identified as a promising strategy for improving the response of human prostate cancer (PCa) to radiotherapy (RT). Studies have shown that mimics or inhibitors of miRNAs could modulate the sensitivity of PCa cells to RT. In addition, pegylated gold nanoparticles have been studied as a therapeutic approach to treat PCa cells and/or vehicles for carrying miRNAs to the inside of cells. Therefore, we evaluated the capacity of hypofractionated RT and pegylated gold nanorods (AuNPr-PEG) to modulate the miRNA signature on PCa cells. Thus, RT-qPCR was used to analyze miRNA-95, miRNA-106-5p, miRNA-145-5p, and miRNA-541-3p on three human metastatic prostate cell lines (PC3, DU145, and LNCaP) and one human prostate epithelial cell line (HprEpiC, a non-tumor cell line) with and without treatment. Our results showed that miRNA expression levels depend on cell type and the treatment combination applied using RT and AuNPr-PEG. In addition, cells pre-treated with AuNPr-PEG and submitted to 2.5 Gy per day for 3 days decreased the expression levels of miRNA-95, miRNA-106, miRNA-145, and miRNA-541-3p. In conclusion, PCa patients submitted to hypofractionated RT could receive personalized treatment based on their metastatic cellular miRNA signature, and AuNPr-PEG could be used to increase metastatic cell radiosensitivity.


Subject(s)
Metal Nanoparticles , MicroRNAs , Prostatic Neoplasms , Male , Humans , MicroRNAs/genetics , Gold/metabolism , Cell Line, Tumor , Prostatic Neoplasms/metabolism , Polyethylene Glycols/metabolism , Gene Expression Regulation, Neoplastic
4.
Int J Mol Sci ; 25(4)2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38396953

ABSTRACT

Biosynthetic gold nanoparticles (bAuNPs) present a promising avenue for enhancing bio-compatibility and offering an economically and environmentally responsible alternative to traditional production methods, achieved through a reduction in the use of hazardous chemicals. While the potential of bAuNPs as anticancer agents has been explored, there is a limited body of research focusing on the crucial physicochemical conditions influencing bAuNP production. In this study, we aim to identify the optimal growth phase of Pseudomonas aeruginosa cultures that maximizes the redox potential and coordinates the formation of bAuNPs with increased efficiency. The investigation employs 2,6-dichlorophenolindophenol (DCIP) as a redox indicator. Simultaneously, we explore the impact of temperature, pH, and incubation duration on the biosynthesis of bAuNPs, with a specific emphasis on their potential application as antitumor agents. Characterization of the resulting bAuNPs is conducted using ATR-FT-IR, TEM, and UV-Vis spectroscopy. To gain insights into the anticancer potential of bAuNPs, an experimental model is employed, utilizing both non-neoplastic (HPEpiC) and neoplastic (PC3) epithelial cell lines. Notably, P. aeruginosa cultures at 9 h/OD600 = 1, combined with biosynthesis at pH 9.0 for 24 h at 58 °C, produce bAuNPs that exhibit smaller, more spherical, and less aggregated characteristics. Crucially, these nanoparticles demonstrate negligible effects on HPEpiC cells while significantly impacting PC3 cells, resulting in reduced viability, migration, and lower IL-6 levels. This research lays the groundwork for the development of more specialized, economical, and ecologically friendly treatment modalities.


Subject(s)
Antineoplastic Agents , Metal Nanoparticles , Prostatic Neoplasms , Humans , Male , Anti-Bacterial Agents/chemistry , Gold/chemistry , Spectroscopy, Fourier Transform Infrared , Metal Nanoparticles/therapeutic use , Metal Nanoparticles/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Prostatic Neoplasms/drug therapy , Green Chemistry Technology/methods , Plant Extracts/chemistry
5.
J Chem Phys ; 158(17)2023 May 07.
Article in English | MEDLINE | ID: mdl-37125707

ABSTRACT

In recent years, metal-organic frameworks, in general, and zeolitic imidazolate frameworks, in special, had become popular due to their large surface area, pore homogeneity, and easy preparation and integration with plasmonic nanoparticles to produce optical sensors. Herein, we summarize the late advances in the use of these hybrid composites in the field of surface-enhanced Raman scattering and their future perspectives.

6.
Am J Primatol ; 85(1): e23453, 2023 01.
Article in English | MEDLINE | ID: mdl-36468411

ABSTRACT

In tropical forests, anthropogenic activities are major drivers of the destruction and degradation of natural habitats, causing severe biodiversity loss. African colobine monkeys (Colobinae) are mainly folivore and strictly arboreal primates that require large forests to subsist, being among the most vulnerable of all nonhuman primates. The Western red colobus Piliocolobus badius and the King colobus Colobus polykomos inhabit highly fragmented West African forests, including the Cantanhez Forests National Park (CFNP) in Guinea-Bissau. Both species are also found in the largest and best-preserved West African forest-the Taï National Park (TNP) in Ivory Coast. Colobine monkeys are hunted for bushmeat in both protected areas, but these exhibit contrasting levels of forest fragmentation, thus offering an excellent opportunity to investigate the importance of well-preserved forests for the maintenance of evolutionary potential in these arboreal primates. We estimated genetic diversity, population structure, and demographic history by using microsatellite loci and mitochondrial DNA. We then compared the genetic patterns of the colobines from TNP with the ones previously obtained for CFNP and found contrasting genetic patterns. Contrary to the colobines from CFNP that showed very low genetic diversity and a strong population decline, the populations in TNP still maintain high levels of genetic diversity and we found no clear signal of population decrease in Western red colobus and a limited decrease in King colobus. These results suggest larger and historically more stable populations in TNP compared to CFNP. We cannot exclude the possibility that the demographic effects resulting from the recent increase of bushmeat hunting are not yet detectable in TNP using genetic data. Nevertheless, the fact that the TNP colobus populations are highly genetically diverse and maintain large effective population sizes suggests that well-preserved forests are crucial for the maintenance of populations, species, and probably for the evolutionary potential in colobines.


Subject(s)
Colobinae , Colobus , Animals , Colobus/genetics , Colobinae/genetics , Forests , Biological Evolution , Trees
7.
J Med Internet Res ; 25: e47735, 2023 07 26.
Article in English | MEDLINE | ID: mdl-37494079

ABSTRACT

BACKGROUND: Digital clinical tools are a new technology that can be used in the screening or diagnosis of obstructive sleep apnea (OSA), notwithstanding the crucial role of polysomnography, the gold standard. OBJECTIVE: This study aimed to identify, gather, and analyze the most accurate digital tools and smartphone-based health platforms used for OSA screening or diagnosis in the adult population. METHODS: We performed a comprehensive literature search of PubMed, Scopus, and Web of Science databases for studies evaluating the validity of digital tools in OSA screening or diagnosis until November 2022. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for diagnostic test accuracy studies. The sensitivity, specificity, and area under the curve (AUC) were used as discrimination measures. RESULTS: We retrieved 1714 articles, 41 (2.39%) of which were included in the study. From these 41 articles, we found 7 (17%) smartphone-based tools, 10 (24%) wearables, 11 (27%) bed or mattress sensors, 5 (12%) nasal airflow devices, and 8 (20%) other sensors that did not fit the previous categories. Only 8 (20%) of the 41 studies performed external validation of the developed tool. Of these, the highest reported values for AUC, sensitivity, and specificity were 0.99, 96%, and 92%, respectively, for a clinical cutoff of apnea-hypopnea index (AHI)≥30. These values correspond to a noncontact audio recorder that records sleep sounds, which are then analyzed by a deep learning technique that automatically detects sleep apnea events, calculates the AHI, and identifies OSA. Looking at the studies that only internally validated their models, the work that reported the highest accuracy measures showed AUC, sensitivity, and specificity values of 1.00, 100%, and 96%, respectively, for a clinical cutoff AHI≥30. It uses the Sonomat-a foam mattress that, aside from recording breath sounds, has pressure sensors that generate voltage when deformed, thus detecting respiratory movements, and uses it to classify OSA events. CONCLUSIONS: These clinical tools presented promising results with high discrimination measures (best results reached AUC>0.99). However, there is still a need for quality studies comparing the developed tools with the gold standard and validating them in external populations and other environments before they can be used in clinical settings. TRIAL REGISTRATION: PROSPERO CRD42023387748; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=387748.


Subject(s)
Sleep Apnea Syndromes , Sleep Apnea, Obstructive , Adult , Humans , Surveys and Questionnaires , Sleep Apnea, Obstructive/diagnosis , Sleep , Polysomnography/methods
8.
Int J Mol Sci ; 24(22)2023 Nov 09.
Article in English | MEDLINE | ID: mdl-38003314

ABSTRACT

The increasing attention that carbon-based nanomaterials have attracted due to their distinctive properties makes them one of the most widely used nanomaterials for industrial purposes. However, their toxicity and environmental effects must be carefully studied, particularly regarding aquatic biota. The implications of these carbon-based nanomaterials on aquatic ecosystems, due to their potential entry or accidental release during manufacturing and treatment processes, need to be studied because their impacts upon living organisms are not fully understood. In this research work, the toxicity of oxidized multi-walled carbon nanotubes (Ox-MWCNTs) was measured using the freshwater bivalve (Corbicula fluminea) after exposure to different concentrations (0, 0.1, 0.2, and 0.5 mg·L-1 Ox-MWCNTs) for 14 days. The oxidized multi-walled carbon nanotubes were analyzed (pH, Raman microscopy, high-resolution electron microscopy, and dynamic light scattering), showing their properties and behavior (size, aggregation state, and structure) in water media. The antioxidant defenses in the organism's digestive gland and gills were evaluated through measuring oxidative stress enzymes (glutathione-S-transferase, catalase, and superoxide dismutase), lipid peroxidation, and total ubiquitin. The results showed a concentration-dependent response of antioxidant enzymes (CAT and GST) in both tissues (gills and digestive glands) for all exposure periods in bivalves exposed to the different concentrations of oxidized multi-walled carbon nanotubes. Lipid peroxidation (MDA content) showed a variable response with the increase in oxidized multi-walled carbon nanotubes in the gills after 7 and 14 exposure days. Overall, after 14 days, there was an increase in total Ub compared to controls. Overall, the oxidative stress observed after the exposure of Corbicula fluminea to oxidized multi-walled carbon nanotubes indicates that the discharge of these nanomaterials into aquatic ecosystems can affect the biota as well as potentially accumulate in the trophic chain, and may even put human health at risk if they ingest contaminated animals.


Subject(s)
Corbicula , Nanotubes, Carbon , Water Pollutants, Chemical , Animals , Humans , Corbicula/metabolism , Antioxidants/metabolism , Nanotubes, Carbon/toxicity , Ecosystem , Oxidative Stress , Glutathione Transferase/metabolism , Fresh Water , Water Pollutants, Chemical/toxicity , Water Pollutants, Chemical/analysis
9.
Int J Mol Sci ; 24(4)2023 Feb 18.
Article in English | MEDLINE | ID: mdl-36835538

ABSTRACT

More than 50% of all prostate cancer (PCa) patients are treated by radiotherapy (RT). Radioresistance and cancer recurrence are two consequences of the therapy and are related to dose heterogeneity and non-selectivity between normal and tumoral cells. Gold nanoparticles (AuNPs) could be used as potential radiosensitizers to overcome these therapeutic limitations of RT. This study assessed the biological interaction of different morphologies of AuNPs with ionizing radiation (IR) in PCa cells. To achieve that aim, three different amine-pegylated AuNPs were synthesized with distinct sizes and shapes (spherical, AuNPsp-PEG, star, AuNPst-PEG, and rods, AuNPr-PEG) and viability, injury and colony assays were used to analyze their biological effect on PCa cells (PC3, DU145, and LNCaP) when submitted to the accumulative fraction of RT. The combinatory effect of AuNPs with IR decreased cell viability and increased apoptosis compared to cells treated only with IR or untreated cells. Additionally, our results showed an increase in the sensitization enhancement ratio by cells treated with AuNPs and IR, and this effect is cell line dependent. Our findings support that the design of AuNPs modulated their cellular behavior and suggested that AuNPs could improve the RT efficacy in PCa cells.


Subject(s)
Metal Nanoparticles , Prostatic Neoplasms , Radiation-Sensitizing Agents , Male , Humans , Gold/pharmacology , Cell Line, Tumor , Neoplasm Recurrence, Local , Radiation-Sensitizing Agents/pharmacology
10.
Angew Chem Int Ed Engl ; 62(10): e202215427, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36479797

ABSTRACT

Bioorthogonal chemistry has inspired a new subarea of chemistry providing a powerful tool to perform novel biocompatible chemospecific reactions in living systems. Following the premise that they do not interfere with biological functions, bioorthogonal reactions are increasingly applied in biomedical research, particularly with respect to genetic encoding systems, fluorogenic reactions for bioimaging, and cancer therapy. This Minireview compiles recent advances in the use of heterogeneous catalysts for bioorthogonal reactions. The synthetic strategies of Pd-, Au-, and Cu-based materials, their applicability in the activation of caged fluorophores and prodrugs, and the possibilities of using external stimuli to release therapeutic substances at a specific location in a diseased tissue are discussed. Finally, we highlight frontiers in the field, identifying challenges, and propose directions for future development in this emerging field.


Subject(s)
Nanostructures , Prodrugs , Fluorescent Dyes/chemistry , Catalysis
11.
Angew Chem Int Ed Engl ; 62(26): e202305299, 2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37186430

ABSTRACT

Hybrid composites between nanoparticles and metal organic frameworks (MOFs) have been described as optimal materials for a wide range of applications in optical sensing, drug delivery, pollutant removal or catalysis. These materials are usually core-shell single- or multi-nanoparticles, restricting the inorganic surface available for reaction. Here, we develop a method for the preparation of yolk-shells consisting in a plasmonic gold nanostar coated with MOF. This configuration shows more colloidal stability, can sieve different molecules based on their size or charge, seems to show some interesting synergy with gold for their application in photocatalysis and present strong optical activity to be used as SERS sensors.


Subject(s)
Metal-Organic Frameworks , Nanoparticles , Gold , Drug Delivery Systems , Catalysis
12.
J Am Chem Soc ; 144(4): 1663-1671, 2022 02 02.
Article in English | MEDLINE | ID: mdl-35073069

ABSTRACT

Mastering the manipulation of chirality at the nanoscale has long been a priority for chemists, physicists, and materials scientists, given its importance in the biochemical processes of the natural world and in the development of novel technologies. In this vein, the formation of novel metamaterials and sensing platforms resulting from the synergic combination of chirality and plasmonics has opened new avenues in nano-optics. Recently, the implementation of chiral plasmonic nanostructures in photocatalysis has been proposed theoretically as a means to drive polarization-dependent photochemistry. In the present work, we demonstrate that the use of inorganic nanometric chiral templates for the controlled assembly of Au and TiO2 nanoparticles leads to the formation of plasmon-based photocatalysts with polarization-dependent reactivity. The formation of plasmonic assemblies with chiroptical activities induces the asymmetric formation of hot electrons and holes generated via electromagnetic excitation, opening the door to novel photocatalytic and optoelectronic features. More precisely, we demonstrate that the reaction yield can be improved when the helicity of the circularly polarized light used to activate the plasmonic component matches the handedness of the chiral substrate. Our approach may enable new applications in the fields of chirality and photocatalysis, particularly toward plasmon-induced chiral photochemistry.

13.
Soft Matter ; 18(44): 8384-8397, 2022 Nov 16.
Article in English | MEDLINE | ID: mdl-36193825

ABSTRACT

Supramolecular short peptide-based gels are promising materials for the controlled release of drugs (e.g. chemotherapeutic drugs) owing to the biocompatibility and similarity to cell matrix. However, the drug encapsulation and control over its release, mainly the hydrophilic drugs, can be a cumbersome task. This can be overcome through encapsulation/compartmentalization of drugs in liposomes, which can also enable spatiotemporal control and enhanced drug release through a trigger, such as photothermia. Having this in mind, we explored the assembly of silica-coated gold nanoparticles and liposomes (storage units) with dehydropeptide-based hydrogels as a proof-of-concept to afford peptide-based NIR light-responsive lipogels. Several liposomes compositions were assessed that displayed influence on the final assembly properties by combining with silica-coated gold nanorods (∼106 nm). Gold nanospheres (∼11 nm) were used to study the preparation method, which revealed the importance of initially combine liposomes with nanoparticles and then the gelator solution to achieve a closer proximity of the nanoparticles to the liposomes. The control over a hydrophilic model drug, 5(6)-carboxyfluorescein, was only achieved by its encapsulation in liposomes, in which the presence of silica-coated nanorods further enabled the use of photothermia to induce the liposomes phase transition and stimulate the drug release. Further, both composites, the liposomes and silica-coated gold nanorods, induced a lower elastic modulus, but also provided an enhanced gelation kinetics. Hereby, this work advances fabrication strategies for the development of short peptide-based hydrogels towards on-demand, sustained and controlled release of hydrophilic drugs through photothermia under NIR light irradiation.


Subject(s)
Liposomes , Metal Nanoparticles , Drug Liberation , Gold , Drug Delivery Systems/methods , Delayed-Action Preparations , Hydrogels , Silicon Dioxide , Peptides
14.
Nano Lett ; 21(17): 7298-7308, 2021 09 08.
Article in English | MEDLINE | ID: mdl-34428053

ABSTRACT

Chiral plasmonic nanostructures exhibit anomalously strong chiroptical signals and offer the possibility to realize asymmetric photophysical and photochemical processes controlled by circularly polarized light. Here, we use a chiral DNA-assembled nanorod pair as a model system for chiral plasmonic photomelting. We show that both the enantiomeric excess and consequent circular dichroism can be controlled with chiral light. The nonlinear chiroptical response of our plasmonic system results from the chiral photothermal effect leading to selective melting of the DNA linker strands. Our study describes both the single-complex and collective heating regimes, which should be treated with different models. The chiral asymmetry factors of the calculated photothermal and photomelting effects exceed the values typical for the chiral molecular photochemistry at least 10-fold. Our proposed mechanism can be used to develop chiral photoresponsive systems controllable with circularly polarized light.


Subject(s)
Nanoparticles , Nanostructures , Nanotubes , Circular Dichroism , DNA
15.
Nano Lett ; 21(24): 10315-10324, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34860527

ABSTRACT

Plasmonic nanocrystals and their assemblies are excellent tools to create functional systems, including systems with strong chiral optical responses. Here we study the possibility of growing chiral plasmonic nanocrystals from strictly nonchiral seeds of different types by using circularly polarized light as the chirality-inducing mechanism. We present a novel theoretical methodology that simulates realistic nonlinear and inhomogeneous photogrowth processes in plasmonic nanocrystals, mediated by the excitation of hot carriers that can drive surface chemistry. We show the strongly anisotropic and chiral growth of oriented nanocrystals with lowered symmetry, with the striking feature that such chiral growth can appear even for nanocrystals with subwavelength sizes. Furthermore, we show that the chiral growth of nanocrystals in solution is fundamentally challenging. This work explores new ways of growing monolithic chiral plasmonic nanostructures and can be useful for the development of plasmonic photocatalysis and fabrication technologies.


Subject(s)
Nanoparticles , Nanostructures , Circular Dichroism , Nanostructures/chemistry
16.
Int J Mol Sci ; 24(1)2022 Dec 22.
Article in English | MEDLINE | ID: mdl-36613630

ABSTRACT

Self-assembled peptide-based gels provide several advantages for technological applications. Recently, the co-assembly of gelators has been a strategy to modulate and tune gel properties and even implement stimuli-responsiveness. However, it still comprises limitations regarding the required library of compounds and outcoming properties. Hence, efforts have been made to combine peptide-based gels and (in)organic composites (e.g., magnetic nanoparticles, metal nanoparticles, liposomes, graphene, silica, clay, titanium dioxide, cadmium sulfide) to endow stimuli-responsive materials and achieve suitable properties in several fields ranging from optoelectronics to biomedical. Herein, we discuss the recent developments with composite peptide-based gels including the fabrication, tunability of gels' properties, and challenges on (bio)technological applications.


Subject(s)
Hydrogels , Stimuli Responsive Polymers , Peptides , Liposomes
17.
Int J Mol Sci ; 23(22)2022 Nov 16.
Article in English | MEDLINE | ID: mdl-36430620

ABSTRACT

Superparamagnetic nanoparticles are of high interest for therapeutic applications. In this work, nanoparticles of calcium-doped manganese ferrites (CaxMn1-xFe2O4) functionalized with citrate were synthesized through thermally assisted oxidative precipitation in aqueous media. The method provided well dispersed aqueous suspensions of nanoparticles through a one-pot synthesis, in which the temperature and Ca/Mn ratio were found to influence the particles microstructure and morphology. Consequently, changes were obtained in the optical and magnetic properties that were studied through UV-Vis absorption and SQUID, respectively. XRD and Raman spectroscopy studies were carried out to assess the microstructural changes associated with stoichiometry of the particles, and the stability in physiological pH was studied through DLS. The nanoparticles displayed high values of magnetization and heating efficiency for several alternating magnetic field conditions, compatible with biological applications. Hereby, the employed method provides a promising strategy for the development of particles with adequate properties for magnetic hyperthermia applications, such as drug delivery and cancer therapy.


Subject(s)
Hyperthermia, Induced , Nanoparticles , Manganese , Calcium , Hyperthermia, Induced/methods , Nanoparticles/chemistry , Calcium, Dietary , Magnetic Fields , Oxidative Stress
18.
J Gene Med ; 23(7): e3342, 2021 07.
Article in English | MEDLINE | ID: mdl-33870576

ABSTRACT

BACKGROUND: Mesenchymal stromal cells (MSC) have been exploited for the treatment of ischemic diseases given their angiogenic potential. Despite bone marrow (BM) being the most studied tissue source, cells with similar intrinsic properties can be isolated from adipose tissue (AT) and umbilical cord matrix (UCM). The present study aims to compare the angiogenic potential of MSC obtained from BM, AT and UCM that were genetically modified with vascular endothelial growth factor (VEGF)-encoding minicircle (MC) vectors. The overexpression of VEGF combined with the intrinsic properties of MSC could represent a promising strategy towards angiogenic therapies. METHODS: We established a microporation-based protocol to transfect human MSC using VEGF-encoding MC (MC-VEGF). VEGF production levels were measured by an enzyme-linked immunosorbent assay and a quantitative polymerase chain reaction. The in vitro angiogenic potential of transfected cells was quantified using cell tube formation and migration functional studies. RESULTS: MSC isolated from BM, AT or UCM showed similar levels of VEGF secretion after transfection with MC-VEGF. Those values were significantly higher when compared to non-transfected cells, indicating an effective enhancement of VEGF production. Transfected cells displayed higher in vitro angiogenic potential than non-transfected controls, as demonstrated by functional in vitro assays. No significant differences were observed among cells from different sources. CONCLUSIONS: Minicircles can be successfully used to transiently overexpress VEGF in human MSC, regardless of the cell tissue source, representing an important advantage in a clinical context (i.e., angiogenic therapy) because a standard protocol might be applied to MSC of different tissue sources, which can be differentially selected according to the application (e.g., autologous versus allogeneic settings).


Subject(s)
Mesenchymal Stem Cells/metabolism , Vascular Endothelial Growth Factors/metabolism , Adipose Tissue/metabolism , Bone Marrow/metabolism , Cell Differentiation , Cell Movement , Cell Proliferation , Cells, Cultured , Gene Expression , Humans , Neovascularization, Physiologic , Transfection/methods , Umbilical Cord/metabolism
19.
Anal Biochem ; 628: 114285, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34118213

ABSTRACT

Minicircles (MCs) are DNA molecules that are produced in Escherichia coli by replicating a parental plasmid (PP) and inducing its site-specific intramolecular recombination into miniplasmid (MP; containing the prokaryotic backbone) and MC molecules (comprised by the eukaryotic cassette). The determination of the recombination efficiency and the monitoring of PP, MC and MP species during processing and in the final product are critical aspects of MC manufacturing. This work describes a real-time PCR method for the specific identification of PP, MP or MC that uses sets of primers specific for each species. The method was evaluated using artificial mixtures of (i) PP and MP, (ii) PP and MC and (iii) MP and MC that were probed for all three DNA molecules. The ratio of molecules of each DNA species in these mixtures were determined with differences lower than 10% relatively to the expected ratio of the species in 90% of the mixtures. Next, the recombination efficiency was successfully estimated by analysing pre-purified DNA samples obtained from cell cultures. A standard deviation < 2% was obtained between replicas and results closely correlated with those obtained by densitometry analysis of agarose gels. Further optimization is required to determine recombination efficiency directly from whole cells.


Subject(s)
DNA, Bacterial/genetics , Real-Time Polymerase Chain Reaction , Escherichia coli/genetics , Recombination, Genetic/genetics
20.
Nano Lett ; 20(10): 7068-7076, 2020 10 14.
Article in English | MEDLINE | ID: mdl-32991175

ABSTRACT

Major current challenges in nano-biotechnology and nano-biomedicine include the implementation of predesigned chemical reactions in biological environments. In this context, heterogeneous catalysis is emerging as a promising approach to extend the richness of organic chemistry onto the complex environments inherent to living systems. Herein we report the design and synthesis of hybrid heterogeneous catalysts capable of being remotely activated by near-infrared (NIR) light for the performance of selective photocatalytic chemical transformations in biological media. This strategy is based on the synergistic integration of Au and TiO2 nanoparticles within mesoporous hollow silica capsules, thus permitting an efficient hot-electron injection from the metal to the semiconductor within the interior of the capsule that leads to a confined production of reactive oxygen species. These hybrid materials can also work as smart NIR-responsive nanoreactors inside living mammalian cells, a cutting-edge advance toward the development of photoresponsive theranostic platforms.


Subject(s)
Nanoparticles , Animals , Catalysis , Nanotechnology , Semiconductors , Silicon Dioxide
SELECTION OF CITATIONS
SEARCH DETAIL