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Materials (Basel, Switzerland) Jul 2023This study demonstrates the successful synthesis of Ni/YO nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray...
This study demonstrates the successful synthesis of Ni/YO nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray pyrolysis technique. They were collected in a water suspension with polyvinylpyrrolidone (PVP) as the stabiliser. The presence of the YO core and Ni shell was confirmed with transmission electron microscopy (TEM) and with electron diffraction. The TEM observations revealed the formation of round particles with an average diameter of 466 nm, while the lattice parameter on the Ni particle's surface was measured to be 0.343 nm. The Ni/YO nanocomposite particle suspensions were lyophilized, to obtain a dried material that was suitable for embedding into a polylactic acid (PLA) matrix. The resulting PLA/Ni/YO composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/YO showed a slight average decrease (8.55%) in flexural strength and a small decrease from 3.7 to 3.3% strain at the break, when compared to the base PLA. These findings demonstrate the potential for utilising Ni/YO nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields.
PubMed: 37512436
DOI: 10.3390/ma16145162 -
In Vitro Cellular & Developmental... Aug 2023Human vascular smooth muscle cells (SMCs) are adherent cells, and they cannot survive without scaffolds in suspension culture. Here, we aimed to establish a suspension...
Human vascular smooth muscle cells (SMCs) are adherent cells, and they cannot survive without scaffolds in suspension culture. Here, we aimed to establish a suspension culture of SMCs using the functional biopolymer FP003 and to investigate the proliferation status of the cells. When SMCs were suspension cultured with FP003, their proliferation was inhibited with a viability of 75% until day 15. When SMCs were re-plated on plastic plates after suspension culture with FP003 for 48 h, the SMCs proliferated as in a normal plate culture. The SMCs cultured in suspension with FP003 showed a relatively low phosphorylation of retinoblastoma protein, low expression of cyclin D1, high proportion of G0/G1 phase cells, low proportion of S phase cells, and no obvious signs of apoptosis, indicating that this culture system inhibited progression from the G1 to S phase. This growth arrest was a reversible property that showed no significant changes in the expressions of the marker proteins α-smooth muscle actin and smooth muscle myosin heavy chain. These results suggest that human SMCs can be stably cultured in suspension with FP003 without losing their characteristics when they are cultured on plastic plates again.
Topics: Humans; Animals; Cells, Cultured; Muscle, Smooth, Vascular; Proteins; Biopolymers; Myocytes, Smooth Muscle
PubMed: 37507645
DOI: 10.1007/s11626-023-00788-w -
Scandinavian Journal of Trauma,... Dec 2023Suspension syndrome describes a multifactorial cardio-circulatory collapse during passive hanging on a rope or in a harness system in a vertical or near-vertical... (Review)
Review
BACKGROUND
Suspension syndrome describes a multifactorial cardio-circulatory collapse during passive hanging on a rope or in a harness system in a vertical or near-vertical position. The pathophysiology is still debated controversially.
AIMS
The International Commission for Mountain Emergency Medicine (ICAR MedCom) performed a scoping review to identify all articles with original epidemiological and medical data to understand the pathophysiology of suspension syndrome and develop updated recommendations for the definition, prevention, and management of suspension syndrome.
METHODS
A literature search was performed in PubMed, Embase, Web of Science and the Cochrane library. The bibliographies of the eligible articles for this review were additionally screened.
RESULTS
The online literature search yielded 210 articles, scanning of the references yielded another 30 articles. Finally, 23 articles were included into this work.
CONCLUSIONS
Suspension Syndrome is a rare entity. A neurocardiogenic reflex may lead to bradycardia, arterial hypotension, loss of consciousness and cardiac arrest. Concomitant causes, such as pain from being suspended, traumatic injuries and accidental hypothermia may contribute to the development of the Suspension Syndrome. Preventive factors include using a well-fitting sit harness, which does not cause discomfort while being suspended, and activating the muscle pump of the legs. Expediting help to extricate the suspended person is key. In a peri-arrest situation, the person should be positioned supine and standard advanced life support should be initiated immediately. Reversible causes of cardiac arrest caused or aggravated by suspension syndrome, e.g., hyperkalaemia, pulmonary embolism, hypoxia, and hypothermia, should be considered. In the hospital, blood and further exams should assess organ injuries caused by suspension syndrome.
Topics: Humans; Iron-Dextran Complex; Mountaineering; Heart Arrest; Hypothermia; Emergency Medicine
PubMed: 38071341
DOI: 10.1186/s13049-023-01164-z -
Scientific Reports Dec 2023The Patient Preference Survey aims to understand unmet needs related to riluzole management in people with Amyotrophic Lateral Sclerosis (ALS) and to identify which...
The Patient Preference Survey aims to understand unmet needs related to riluzole management in people with Amyotrophic Lateral Sclerosis (ALS) and to identify which characteristics of a new formulation could better match their preferences. The survey involved 117 people with ALS (PALS) treated with riluzole in four European countries. The dysphagic PALS were least satisfied with the riluzole tablet and oral suspension and with ease in self-administration; up to 68% of respondents postponed or missed the treatment due to swallowing difficulties and need of caregiver assistance. Overall, 51% of tablet and 53% of oral suspension users regularly crushed or mixed riluzole with beverages, respectively; PALS who always manipulated riluzole showed low satisfaction with the formulation and considered the risk of choking and pneumonia the most worrisome event. The survey evaluated the driving factors in choosing/switching the therapy: 67% of PALS declared a low risk of choking. The research finally evaluated which attributes of a new formulation would be preferred: the most relevant were ease of use (4.3/5), convenient/portable packaging (4.0/5) and oral-dissolving properties without tongue motility (3.9/5). The Patient Preference Survey suggests that patients have several unmet needs and preferences that could be addressed by a different formulation, e.g. using oral film technologies.
Topics: Humans; Riluzole; Amyotrophic Lateral Sclerosis; Suspensions; Europe; Airway Obstruction; Tablets; Neuroprotective Agents
PubMed: 38110502
DOI: 10.1038/s41598-023-49424-3 -
International Journal of Pharmaceutics May 2024Oral suspension is the most preferred dosage form for the paediatric population because of the difficulties related to solid medications, such as the swallowing... (Review)
Review
Oral suspension is the most preferred dosage form for the paediatric population because of the difficulties related to solid medications, such as the swallowing limitations, bitter taste, and poor oral bioavailability, which can cause serious impairment to attain a successful treatment. Given the importance of successful therapies, there is a need for safe and effective commercially-available paediatric oral suspension and their characterization. For the latter, it is important to identify safe excipients and preservatives. The paediatric group is a diverse category which includes infants and teenagers, with major pharmacokinetics and pharmacodynamics differences, mainly because of physiological and behavioral variations. Therefore, finding a single formulation for paediatric population remains a challenge, as well asthe formulation of stable-in-time suspension. In addition, drug's dissolving characteristic and permeation, are the main determinants for oral absorption, which are closely related to drug release kinetics from the pharmaceutical form. In this context, drug release profile is an important and limiting step in oral bioavailability, particularly for BCS class II drugs; thus, it is possible to increase bioavailability and minimize adverse effects by changing the release rate of such drugs. This review covers all the aspects for paediatric oral suspension development, and analyses the considerations for excipients selection as a crucial task for effectively choosing a safe and effective pharmaceutical form and correctly dosing paediatric patients.
Topics: Humans; Suspensions; Administration, Oral; Child; Excipients; Biological Availability; Drug Compounding; Adolescent; Drug Liberation; Chemistry, Pharmaceutical; Infant; Pharmaceutical Preparations
PubMed: 38688428
DOI: 10.1016/j.ijpharm.2024.124169 -
International Journal of Nanomedicine 2024Nanosuspensions have garnered recent attention as a promising strategy for mitigating the bioavailability challenges of hydrophobic drugs, particularly those... (Review)
Review
Nanosuspensions have garnered recent attention as a promising strategy for mitigating the bioavailability challenges of hydrophobic drugs, particularly those characterized by poor solubility in both aqueous and organic environments. Addressing solubility issues associated with poorly water-soluble drugs has largely resolved the need to enhance drug absorption and bioavailability. As mucosal formulations and topical administration progress in the future, nanosuspension drug delivery, straightforward formulation techniques, and versatile applications will continue to be subjects of interest. Nanosuspensions have undergone extensive scrutiny in preparation for topical applications, encompassing ocular, pulmonary, and dermal usage. Among the numerous methods aimed at improving cutaneous application, nanocrystals represent a relatively recent yet profoundly intriguing approach. Despite the increasing availability of various nanosuspension products, primarily designed for oral administration, only a limited number of studies have explored skin permeability and drug accumulation in the context of nanosuspensions. Nevertheless, the scant published research unequivocally underscores the potential of this approach for enhancing cutaneous bioavailability, particularly for active ingredients with low to medium solubility. Nanocrystals exhibit increased skin adhesiveness in addition to heightened saturation solubility and dissolution rate, thereby augmenting cutaneous distribution. The article provides a comprehensive overview of nanosuspensions for topical application. The methodology employed is robust, with a well-defined experimental design; however, the limited sample size raises concerns about the generalizability of the findings. While the results demonstrate promising outcomes in terms of enhanced drug delivery, the discussion falls short of addressing certain limitations. Additionally, the references largely focus on recent studies, but a more diverse inclusion of historical perspectives could offer a more holistic view of the subject.
Topics: Humans; Suspensions; Drug Delivery Systems; Biological Availability; Nanoparticles; Administration, Oral; Solubility; Particle Size
PubMed: 38293608
DOI: 10.2147/IJN.S447429 -
Carbohydrate Polymers Dec 2023To study the potential impacts of shear stress on cellulose nanocrystals (CNCs), a microcapillary rheometer was employed to repeatedly shear approximately 10 mL of...
To study the potential impacts of shear stress on cellulose nanocrystals (CNCs), a microcapillary rheometer was employed to repeatedly shear approximately 10 mL of 6 wt% aqueous CNC suspension at 25 °C and rates ranging from 1,000 s to 501,000 s. A 9 wt% CNC suspension was also tested at 316,000 s for comparison of concentration effects on the behavior of the suspensions. After monitoring viscosity for 25 steady shear measurements, the suspensions processed at 1,000 s decreased in viscosity by approximately 20 %. Higher shear rates produced smaller changes in viscosity, while increasing the concentration produced higher general viscosities. Atomic force microscopy (AFM) and X-ray diffraction (XRD) probed physical changes between the neat and sheared CNC samples. AFM images showed up to a 24 % reduction in length after shearing, but an insignificant reduction in cross-section. XRD showed a slight increase in the ratio of amorphous to crystalline fractions of the CNCs. Additionally, conductometric titration showed insignificant differences between neat and sheared samples. These findings suggest that viscosity changes in CNC suspensions during steady shear flow arise from physical fracturing of the CNCs perpendicular to their length, and not significantly from chemical degradation or reduction in residual amorphous content.
PubMed: 37739516
DOI: 10.1016/j.carbpol.2023.121252 -
Polymers Nov 2023In the present study, sage-coated zinc-doped hydroxyapatite was incorporated into a dextran matrix (7ZnHAp-SD), and its physico-chemical and antimicrobial activities...
In the present study, sage-coated zinc-doped hydroxyapatite was incorporated into a dextran matrix (7ZnHAp-SD), and its physico-chemical and antimicrobial activities were investigated. A 7ZnHAp-SD nanocomposite suspension was obtained using the co-precipitation method. The stability of the nanocomposite suspension was evaluated using ultrasound measurements. The stability parameter calculated relative to double-distilled water as a reference fluid highlights the very good stability of the 7ZnHAp-SD suspension. X-ray diffraction (XRD) experiments were performed to evaluate the characteristic diffraction peak of the hydroxyapatite phase. Valuable information regarding the morphology and chemical composition of 7ZnHAp-SD was obtained via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) studies. Fourier-transform infrared spectroscopy (FTIR) measurements were performed on the 7ZnHAp-SD suspensions in order to evaluate the functional groups present in the sample. Preliminary studies on the antimicrobial activity of 7ZnHAp-SD suspensions against the standard strains of 25923 ATCC, 29212 ATCC, 25922 ATCC, and 27853 ATCC were conducted. More than that, preliminary studies on the biocompatibility of 7ZnHAp-SD were conducted using human cervical adenocarcinoma (HeLa) cells, and their results emphasized that the 7ZnHAp-SD sample did not exhibit a toxic effect and did not induce any noticeable changes in the morphological characteristics of HeLa cells. These preliminary results showed that these nanoparticles could be possible candidates for biomedical/antimicrobial applications.
PubMed: 38231963
DOI: 10.3390/polym15234484 -
Evaluation of Power Wheelchair Dynamic Suspensions for Tip Prevention in Non-ADA Compliant Surfaces.Archives of Physical Medicine and... Dec 2023To evaluate the driving performance and usability of a mobility enhancement robot (MEBot) wheelchair with 2 innovative dynamic suspensions compared with commercial...
OBJECTIVE
To evaluate the driving performance and usability of a mobility enhancement robot (MEBot) wheelchair with 2 innovative dynamic suspensions compared with commercial electric powered wheelchair (EPW) suspensions on non-American with Disabilities Act (ADA) compliant surfaces. The 2 dynamic suspensions used pneumatic actuators (PA) and electro-hydraulic with springs in series electrohydraulic and spring in series (EHAS).
DESIGN
Within-subjects cross-sectional study. Driving performance and usability were evaluated using quantitative measures and standardized tools, respectively.
SETTING
Laboratory settings that simulated common EPW outdoor driving tasks.
PARTICIPANTS
10 EPW users (5 women, 5 men) with an average age of 53.9±11.5 years and 21.2±16.3 years of EPW driving experience (N=10).
INTERVENTION
Not applicable.
MAIN OUTCOME MEASURE(S)
Seat angle peaks (stability), number of completed trials (effectiveness), Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), and systemic usability scale (SUS).
RESULTS
MEBot with dynamic suspensions demonstrated significantly better stability (all P<.001) than EPW passive suspensions on non-ADA-compliant surfaces by reducing seat angle changes (safety). Also, MEBot with EHAS suspension significantly completed more trials over potholes compared with MEBot with PA suspension (P<.001) and EPW suspensions (P<.001). MEBot with EHAS had significantly better scores in terms of ease of adjustment (P=.016), durability (P=.031), and usability (P=.032) compared with MEBot with PA suspension on all surfaces. Physical assistance was required to navigate over potholes using MEBot with PA suspension and EPW suspensions. Also, participants reported similar responses regarding ease of use and satisfaction toward MEBot with EHAS suspension and EPW suspensions.
CONCLUSIONS
MEBot with dynamic suspensions improve safety and stability when navigating non-ADA-compliant surfaces compared with commercial EPW passive suspensions. Findings indicate MEBot readiness for further evaluation in real-world environments.
Topics: Male; Humans; Female; Animals; Swine; Adult; Middle Aged; Aged; Cross-Sectional Studies; Equipment Design; Wheelchairs
PubMed: 37329969
DOI: 10.1016/j.apmr.2023.05.016 -
Advances in Therapy Aug 2023Fungal keratitis, an ocular fungal infection, is one of the leading causes of monocular blindness. Natamycin has long been considered the mainstay drug used for treating... (Review)
Review
Fungal keratitis, an ocular fungal infection, is one of the leading causes of monocular blindness. Natamycin has long been considered the mainstay drug used for treating fungal keratitis and is the only US Food and Drug Administration (USFDA)-approved drug, commercially available as a topical 5% w/v suspension. Furthermore, ocular fungal infection treatment takes a few weeks to months to recover, and the available marketed antifungal suspensions are associated with poor residence time, limited bioavailability (< 5%) and high dosing frequency as well as minor irritation and discomfort. Despite these challenges, natamycin is still the preferred drug choice for treating fungal keratitis, as it has fewer side effects and less ocular toxicity and is more effective against Fusarium species than other antifungal agents. Several novel therapeutic approaches for the topical delivery of natamycin have been reported to overcome the challenges posed by the conventional dosage forms and to improve ocular bioavailability for the efficient management of fungal keratitis. Current progress in the delivery systems uses approaches aimed at improving the corneal residence time, bioavailability and antifungal potency, thereby reducing the dose and dosing frequency of natamycin. In this review, we discuss the various strategies explored to overcome the challenges present in ocular drug delivery of natamycin and improve its bioavailability for ocular therapeutics.
Topics: Humans; Natamycin; Antifungal Agents; Keratitis; Eye Infections, Fungal; Cornea
PubMed: 37289410
DOI: 10.1007/s12325-023-02541-x