The role of multi-walled carbon nanotubes in enhancing the hydrolysis and thermal stability of PLA.

Polylactic acid (PLA) is a bioresorbable and biodegradable polymer extensively used in various biomedical and engineering applications. In this study, we investigated the mass loss and thermal properties of PLA-multi-walled carbon nanotube (MWCNT) composites under simulated physiological conditions. The composites were prepared by melting PLA with 0.1, 0.5, 1.0, and 5.0 wt% MWCNTs using an ultrasonic agitator, and FTIR analysis confirmed composite formation. Subsequently, the composites were subjected to hydrolysis under simulated physiological conditions (pH 7.4 and 37 °C) for up to 60 days. The results revealed that the mass loss of the composites decreased with increasing MWCNT content, suggesting that the presence of MWCNTs decelerated the hydrolysis process. On day 58, the mass loss of pure PLA was 12.5%, decreasing to 8.34% with 0.1% MWCNT, 5.94% with 0.5% MWCNT, 4.59% with 1% MWCNT, and 3.54% with 5.0% MWCNT. This study offers valuable insights into the behavior of PLA-MWCNT composites under physiologically simulated conditions, facilitating the development of new polymer composites with enhanced thermal stability and degradation resistance for biomedical applications.

Hemiplegia in acute ischemic stroke: A comprehensive review of case studies and the role of intravenous thrombolysis and mechanical thrombectomy.

Acute ischemic stroke is a significant health concern worldwide, often leading to long-term disability and decreased quality of life. Rapid and appropriate treatment is crucial for achieving optimal outcomes in these patients. Intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are two commonly used interventions for acute ischemic stroke, but their effectiveness in improving neurological symptoms and functional outcomes in patients with hemiplegia remains uncertain. The aim of this work was to evaluate the impact of IVT and MT within a 4.5-h time frame on patients with acute ischemic stroke and hemiplegia. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies that assessed the impact of IVT and MT within 4.5-h on hemiplegia in patients with an acute ischemic stroke were included. Data were extracted and analyzed to determine the overall effects of these interventions. Most included case reports indicate positive outcomes in terms of neurological symptom improvement and functional recovery in patients with hemiplegia after receiving IVT and MT within the specified time frame. However, the heterogeneity among the patients and the limited use of IVT due to contraindications posed challenges in determining the most effective treatment option. The findings from the included studies demonstrate that both interventions led to a decrease in National Institutes of Health Stroke Scale scores, indicating an improvement in neurological symptoms. The results highlight the beneficial effects of early thrombolytic interventions and MT on the neurological status and functional outcomes of patients with an acute ischemic stroke.

Nanoparticle-Mediated Delivery of Flavonoids: Impact on Proinflammatory Cytokine Production: A Systematic Review.

Flavonoids are a diverse group of plant-derived compounds that have been shown to have various health benefits, including anti-inflammatory effects. However, their use in the treatment of inflammatory diseases has been limited due to their low bioavailability. The nanoparticle-mediated delivery of flavonoids has been proposed as a potential solution to this issue, as it allows the sustained release of the flavonoids over time. There are several different nanoparticle systems that have been developed for flavonoid delivery, including polymeric nanoparticles, liposomes, and inorganic nanoparticles. This systematic review aims to evaluate the impact of nanoparticle-mediated delivery of flavonoids on pro-inflammatory cytokine production in various diseases. We analyzed the performance of flavonoid-encapsulated nanoparticles in regulating cytokine production in different in vitro and in vivo studies. To this end, we followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to conduct a comprehensive search of the literature and to assess the quality of the included studies. The results showed that flavonoid-encapsulated nanoparticles significantly downregulated pro-inflammatory cytokines, such as TNF-α, IL-1ß, IL-6, and IL-18. In some cases, this effect was significantly greater than that observed with non-encapsulated flavonoids These findings suggest that nanoparticle-mediated delivery of flavonoids may have potential as a therapeutic approach for the treatment of inflammatory diseases.

Effect of Physiological Fluid on the Photothermal Properties of Gold Nanostructured.

Colloidal gold particles have been extensively studied for their potential in hyperthermia treatment due to their ability to become excited in the presence of an external laser. However, their light-to-heat efficiency is affected by the physiologic environment. In this study, we aimed to evaluate the ability of gold sphere, rod, and star-shaped colloids to elevate the temperature of blood plasma and breast cancer-simulated fluid under laser stimulation. Additionally, the dependence of optical properties and colloid stability of gold nanostructures with physiological medium, particle shape, and coating was determined. The light-to-heat efficiency of the gold particle is shape-dependent. The light-to-heat conversion efficiency of a star-shaped colloid is 36% higher than that of sphere-shaped colloids. However, the raised temperature of the surrounding medium is the lowest in the star-shaped colloid. When gold nanostructures are exited with a laser stimulation in a physiological fluid, the ions/cations attach to the surface of the gold particles, resulting in colloidal instability, which limits electron oscillation and diminishes the energy generated by the plasmonic excitation. Fluorescein (Fl) and polyethylene glycol (PEG) attached to gold spheres enhances their colloidal stability and light-to-heat efficiency; post-treatment, they remand their optical properties.

Gold Nanoparticles as Drug Carriers: The Role of Silica and PEG as Surface Coatings in Optimizing Drug Loading.

The use of gold nanoparticles as drug delivery systems has received increasing attention due to their unique properties, such as their high stability and biocompatibility. However, gold nanoparticles have a high affinity for proteins, which can result in their rapid clearance from the body and limited drug loading capabilities. To address these limitations, we coated the gold nanoparticles with silica and PEG, which are known to improve the stability of nanoparticles. The synthesis of the nanoparticles was carried out using a reduction method. The nanoparticles' size, morphology, and drug loading capacity were also studied. The SEM images showed a spherical and homogeneous morphology; they also showed that the coatings increased the average size of the nanoparticles. The results of this study provide insight into the potential of gold nanoparticles coated with silica and PEG as drug delivery systems. We used ibuprofen as a model drug and found that the highest drug load occurred in PEG-coated nanoparticles and then in silica-coated nanoparticles, while the uncoated nanoparticles had a lower drug loading capacity. The coatings were found to significantly improve the stability and drug load properties of the nanoparticles, making them promising candidates for further development as targeted and controlled release drug delivery systems.

Lipid nanoparticles for gene therapy in ocular diseases.

OBJECTIVES: Lipid nanoparticles, as a nucleic acid delivery system, have been used as an alternative to treat ocular diseases, since they can cross the ocular barrier and efficiently transfecting nucleic acids to various cells of the eye. The size influences the transfection of genes, biological distribution, diffusion, and cellular uptake. It is therefore important to establish a relationship between size, formulation, and encapsulation percentage. EVIDENCE ACQUISITION: In this review, we used a search strategy to compare studies of nanomedicine systems aimed at eye diseases where the size of the nanoparticles and the efficiency of encapsulation of genetic material are reported based on the criteria of Preferred Reporting Items for Systematic Reviews (PRISMA ScR 2020 guidelines). RESULTS: Out of the initial 5932, 169 studies met the inclusion criteria and were included to form the basis of the analysis. Nanoparticles reported are composed mainly of PEG-modified lipids, cholesterol, and cationic lipids, that in combination with messenger or interference RNA, allow the formulation of a nanoparticle with an encapsulation efficiency greater than 95%. The diseases treated mainly focus on conditions related to the retina and cornea. Certain characteristics of nanoparticles increase encapsulation efficiency, such as the size of the nanoparticle and the charge of the outer layer of the nanoparticle. CONCLUSION: It is still unknown what characteristics lipid nanoparticles should have to successfully treat human eye illnesses. The in vitro and in vivo investigations covered in this review, however, present encouraging results. To improve encapsulation effectiveness and disease gene silencing, nanoparticle formulation is essential. The most stable nanoparticles are those made mostly of cationic lipids, PEG lipids, and cholesterol, which also effectively encapsulate RNA. The encapsulation efficiency is not only influenced by size, but also by other factors such as methods of preparation.

A Review on the Efficacy and Safety of Nab-Paclitaxel with Gemcitabine in Combination with Other Therapeutic Agents as New Treatment Strategies in Pancreatic Cancer.

Pancreatic cancer has one of the highest mortality rates among cancers, and a combination of nab-paclitaxel with gemcitabine remains the cornerstone of first-line therapy. However, major advances are required to achieve improvements in patient outcomes. For this reason, several research groups have proposed supplementing treatment with other therapeutic agents. Ongoing studies are being conducted to find the optimal treatment in a first-line setting. In this work, we used a search strategy to compare studies on the efficacy and safety of nab-paclitaxel with gemcitabine in combination with other therapeutic agents based on the criteria of the Preferred Reporting Items for Systematic Reviews. We found seven studies in different clinical phases that met the inclusion criteria. The seven therapeutic agents were ibrutinib, necuparanib, tarextumab, apatorsen, cisplatin, enzalutamide, and momelotinib. Although these therapeutic agents have different mechanisms of action, and molecular biology studies are still needed, the present review was aimed to answer the following question: which formulations of the nab-paclitaxel/gemcitabine regimen in combination with other therapeutic agents are safest for patients with previously untreated metastatic pancreas ductal adenocarcinoma? The triple regimen is emerging as the first-line option for patients with pancreatic cancer, albeit with some limitations. Thus, further studies of this regimen are recommended.

Target Nanoparticles against Pancreatic Cancer: Fewer Side Effects in Therapy.

Pancreatic cancer is the most common lethal tumor in America. This lethality is related to limited treatment options. Conventional treatments involve the non-specific use of chemotherapeutical agents such as 5-FU, capecitabine, gemcitabine, paclitaxel, cisplatin, oxaliplatin, or irinotecan, which produce several side effects. This review focuses on the use of targeted nanoparticles, such as metallic nanoparticles, polymeric nanoparticles, liposomes, micelles, and carbon nanotubes as an alternative to standard treatment for pancreatic cancer. The principal objective of nanoparticles is reduction of the side effects that conventional treatments produce, mostly because of their non-specificity. Several molecular markers of pancreatic cancer cells have been studied to target nanoparticles and improve current treatment. Therefore, properly functionalized nanoparticles with specific aptamers or antibodies can be used to recognize pancreatic cancer cells. Once cancer is recognized, these nanoparticles can attack the tumor by drug delivery, gene therapy, or hyperthermia.

A Full Set of In Vitro Assays in Chitosan/Tween 80 Microspheres Loaded with Magnetite Nanoparticles.

Microspheres have been proposed for different medical applications, such as the delivery of therapeutic proteins. The first step, before evaluating the functionality of a protein delivery system, is to evaluate their biological safety. In this work, we developed chitosan/Tween 80 microspheres loaded with magnetite nanoparticles and evaluated cell damage. The formation and physical-chemical properties of the microspheres were determined by FT-IR, Raman, thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and SEM. Cell damage was evaluated by a full set of in vitro assays using a non-cancerous cell line, human erythrocytes, and human lymphocytes. At the same time, to know if these microspheres can load proteins over their surface, bovine serum albumin (BSA) immobilization was measured. Results showed 7 nm magnetite nanoparticles loaded into chitosan/Tween 80 microspheres with average sizes of 1.431 µm. At concentrations from 1 to 100 µg/mL, there was no evidence of changes in mitochondrial metabolism, cell morphology, membrane rupture, cell cycle, nor sister chromatid exchange formation. For each microgram of microspheres 1.8 µg of BSA was immobilized. The result provides the fundamental understanding of the in vitro biological behavior, and safety, of developed microspheres. Additionally, this set of assays can be helpful for researchers to evaluate different nano and microparticles.

Magnetite Nanoparticles Coated with PEG 3350-Tween 80: In Vitro Characterization Using Primary Cell Cultures.

Some medical applications of magnetic nanoparticles require direct contact with healthy tissues and blood. If nanoparticles are not designed properly, they can cause several problems, such as cytotoxicity or hemolysis. A strategy for improvement the biological proprieties of magnetic nanoparticles is their functionalization with biocompatible polymers and nonionic surfactants. In this study we compared bare magnetite nanoparticles against magnetite nanoparticles coated with a combination of polyethylene glycol 3350 (PEG 3350) and polysorbate 80 (Tween 80). Physical characteristics of nanoparticles were evaluated. A primary culture of sheep adipose mesenchymal stem cells was developed to measure nanoparticle cytotoxicity. A sample of erythrocytes from a healthy donor was used for the hemolysis assay. Results showed the successful obtention of magnetite nanoparticles coated with PEG 3350-Tween 80, with a spherical shape, average size of 119.2 nm and a zeta potential of +5.61 mV. Interaction with mesenchymal stem cells showed a non-cytotoxic propriety at doses lower than 1000 µg/mL. Interaction with erythrocytes showed a non-hemolytic propriety at doses lower than 100 µg/mL. In vitro information obtained from this work concludes that the use of magnetite nanoparticles coated with PEG 3350-Tween 80 is safe for a biological system at low doses.

Synthesis of Controlled-Size Silica Nanoparticles from Sodium Metasilicate and the Effect of the Addition of PEG in the Size Distribution.

Silica nanoparticles are widely studied in emerging areas of nanomedicine because they are biocompatible, and their surface can be modified to provide functionalization. The size is intrinsically related to the performance of the silica nanoparticles; therefore, it is important to have control over the size. However, the silica nanoparticles obtained from sodium metasilicate are less studied than those obtained from tetraethyl orthosilicate. Moreover, the methods of surface modification involve several steps after the synthesis. In this work, the effect of different concentrations of sodium metasilicate on the size of silica nanoparticles was studied. In the same way, we studied the synthesis of organically modified silica nanoparticles in a one-step method, using poly(ethylene glycol). The nanoparticles were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. It was found that the size distribution of the silica nanoparticles could be modified by changing the initial concentration of sodium metasilicate. The one-step surface-modification method caused a significant decrease in size distribution.

Nanoparticles for death­induced gene therapy in cancer (Review).

Due to the high toxicity and side effects of the use of traditional chemotherapy in cancer, scientists are working on the development of alternative therapeutic technologies. An example of this is the use of death­induced gene therapy. This therapy consists of the killing of tumor cells via transfection with plasmid DNA (pDNA) that contains a gene which produces a protein that results in the apoptosis of cancerous cells. The cell death is caused by the direct activation of apoptosis (apoptosis­induced gene therapy) or by the protein toxic effects (toxin­induced gene therapy). The introduction of pDNA into the tumor cells has been a challenge for the development of this therapy. The most recent implementation of gene vectors is the use of polymeric or inorganic nanoparticles, which have biological and physicochemical properties (shape, size, surface charge, water interaction and biodegradation rate) that allow them to carry the pDNA into the tumor cell. Furthermore, nanoparticles may be functionalized with specific molecules for the recognition of molecular markers on the surface of tumor cells. The binding between the nanoparticle and the tumor cell induces specific endocytosis, avoiding toxicity in healthy cells. Currently, there are no clinical protocols approved for the use of nanoparticles in death­induced gene therapy. There are still various challenges in the design of the perfect transfection vector, however nanoparticles have been demonstrated to be a suitable candidate. This review describes the role of nanoparticles used for pDNA transfection and key aspects for their use in death­induced gene therapy.